427 coming along

[tpepmeie]

Thanks to the guys at AES, my shortblock is now done. They did a good job, and were pretty patient with me during a few delays. Getting closer... dyno by spring!:pray

another thread on the parts that went into it...
http://www.zr1netregistry.com/forum/showthread.php?t=7400

http://www.photohost.org/gallery/data/500/2374IMG_1719-med.JPG

http://www.photohost.org/gallery/data/500/2374IMG_1812-med.JPG

http://www.photohost.org/gallery/data/500/2374IMG_1829-med.JPG

http://www.photohost.org/gallery/data/500/2374IMG_1824-med.JPG

http://www.photohost.org/gallery/data/500/2374IMG_1813-med.JPG

Todd

[tomtom72]

:jawdrop: those are some purdy valve relief's ya got there mister! :worship:



I'll bet you will be :dancing soon!


:cheers:

[Jagdpanzer]

Todd,
Your short block looks fantastic. I stopped by RFD yesterday afternoon and Curtis had your heads boxed up and ready to ship. Best of luck with the rest of the build and keep us updated.

Phil

[HAWAIIZR-1]

WOW!:cheers:

[Pete]

Nice :thumbsup:

The do it yourselfers,for price of a 368 you can have a 402, :).

Anybody remember the days of waiting 3-4 years for a 415 :dontknow:

Pete

[mgbrv8]

Those are some good looking liners. Very nice work Sir.

Dave

[Polo-1]

NOW THAT'S SOME LT5 PORN:worship:

[LT-5 Music]

Looks great!

Subscribed.:thumbsup:

[RHanselman]

Wish I could see the pic's. The UAE is blocking your picture website.

Cheers,
Ron Hanselman

[LT-5 Music]

Looks great. :thumbsup:

What kind of power have the 427's been making?

[phrogs]

oh please tell me how!



Nice :thumbsup:

The do it yourselfers,for price of a 368 you can have a 402, :).

Anybody remember the days of waiting 3-4 years for a 415 :dontknow:

Pete

[Pete]

oh please tell me how!



Offset grind stock crank to 3.75 stroke with 4.125 bore

Johnny,you got me.
I always exaggerate my inches.heheheh
Your right it makes 401ci.
Hey, if you have over 400 inches you won't miss 1 inch.:)

I would be very satisfied with one less inch and i'd look like this-->:-D

Pete

[tpepmeie]

Todd,
Your short block looks fantastic. I stopped by RFD yesterday afternoon and Curtis had your heads boxed up and ready to ship. Best of luck with the rest of the build and keep us updated.

Phil

Cylinder heads are done. Here are a couple of pics. :-D:-D:-D:-D

http://www.photohost.org/gallery/data/500/2374IMG_1849-med.JPG

http://www.photohost.org/gallery/data/500/2374IMG_1859-med.JPG

[XfireZ51]

Very nice, Todd. And the legendary 427CID. Be very interesting to put a
DOHC 427 v the LS-7.

[HIZNHRZ]

That is one terrific looking set of heads!

[Polo-1]

Cylinder heads are done. Here are a couple of pics. :-D:-D:-D:-D


http://www.photohost.org/gallery/data/500/2374IMG_1859-med.JPG

WOW that's a lot of chamber change. Trying for a hemi dome:icon_scra

[tpepmeie]

WOW that's a lot of chamber change. Trying for a hemi dome:icon_scra

Just something different :wink:. Actually opening the chamber up like that helps airflow a bit, and let me run a smaller dish volume in the piston. I needed that, because of the very short piston height I am running w/ the 6 in. rods.

It is also not unlike what Lotus did with the next-gen LT5 which Graham showed at BG 08. See newsletter issue 15. Also this design is similar to any Cosworth or other 4-valve race chamber.

Todd

[XfireZ51]

Todd,

Does compression ratio change much?

[tpepmeie]

Todd,

Does compression ratio change much?

The chamber is still only 49cc. Compression is around 12:1.

[Bob G]

Looks Really Good Have You Decided on camshafts? Did the head guy offer any suggestions on lift & duration?
Bob G
427 LT5

[tpepmeie]

Looks Really Good Have You Decided on camshafts? Did the head guy offer any suggestions on lift & duration?
Bob G
427 LT5

Cams are being designed as we speak. Should know specs in a couple weeks.

[flyin ryan]

Just something different :wink:. Actually opening the chamber up like that helps airflow a bit, and let me run a smaller dish volume in the piston. I needed that, because of the very short piston height I am running w/ the 6 in. rods.

It is also not unlike what Lotus did with the next-gen LT5 which Graham showed at BG 08. See newsletter issue 15. Also this design is similar to any Cosworth or other 4-valve race chamber.

ToddWhen I first saw this a couple days ago that's the first thing I noticed Curtis did was open up the curtain area around each Valve, most guys don't think so, but even if you did lose some C/R (which you aren't in this case) it is still be a good trade to help 'Mixture' enter the chamber.

What's your Compression Height going to be? Smallest I've ever run was 1.0"

[Locobob]

Looks like you're doing a first class build :thumbsup: I've got to stop looking at the head porting pics, getting the urge to mess with mine some more.

[tomtom72]

Please forgive my lack of knowledge demonstrated by the questions that I am about to ask!:o


The reshaping of the combustion chamber like what Todd has, is that a good idea to do to a stock displacement motor? I have read that our bore spacing is not optimal ( I don't understand why, but I accept it as a fact ) and that is one thing that gets solved with bigger liners?

Sorry, another Q, if not a stock displacement motor, then what would be a good displacement to go to?

I read the posts about how expensive it is to rebuild an LT5 to stock displacement/configuration. It obviously seems that if you need to rebuild your LT5 it is more cost effective to go up in cubes. Is it because the bigger liners and pistons and rods and the machining ( off-set grinding ) of the crank ( what is that btw? ) almost equal the amount of money spent trying to get "stock" parts? I'm sure that it's the stock cost vs the new power from the expensive bigger stuff, the balance tips to the bigger stuff because of the power added, right?

:o sorry for all the questions!
:cheers:
grasshopper

[Polo-1]

Please forgive my lack of knowledge demonstrated by the questions that I am about to ask!:o


I read the posts about how expensive it is to rebuild an LT5 to stock displacement/configuration. It obviously seems that if you need to rebuild your LT5 it is more cost effective to go up in cubes. Is it because the bigger liners and pistons and rods and the machining ( off-set grinding ) of the crank ( what is that btw? ) almost equal the amount of money spent trying to get "stock" parts? I'm sure that it's the stock cost vs the new power from the expensive bigger stuff, the balance tips to the bigger stuff because of the power added, right?

:o sorry for all the questions!
:cheers:
grasshopper

Never be sorry for asking a question :wave:

I think with all the "take out " parts people have, to rebuild a stock 350 would not be that much. I have seen and have myself liners,pistons,rods,rings,pins.. Whole drop in's for under $1000. Yes these are used, but if the rings have good tension and good gap.. under 10k miles whats not to reuse. So, you have all 8 holes for under 1K. My 402's JE pistons were $2200 or $2400 just piston's and rings. Then liners,rods,machine "bore & hone".

[tpepmeie]

Finally got the injector housings back. A little welding was needed :redface:. You'll see "hole" with an arrow on one of the pics. All in all, a first class job. I have not seen another example of a housing which loses less than 10 cfm at high lift. Perhaps they're out there, though.

Interesting, the area is not huge on these things. We're less than 36mm at the runner entry.

http://www.photohost.org/gallery/data/500/2374IMG_2004-med.JPG

http://www.photohost.org/gallery/data/500/2374IMG_2008-med.JPG

http://www.photohost.org/gallery/data/500/2374IMG_2007-med.JPG

Todd

[XfireZ51]

Very nice, Todd =D>.

[Polo-1]

You maybe farther along then me, but I know I have something you don't:p

http://i7.photobucket.com/albums/y292/kpie/2010-01-03034a.jpg

Housings look good Todd

[flyin ryan]

I have not seen another example of a housing which loses less than 10 cfm at high lift.

Interesting, the area is not huge on these things. We're less than 36mm at the runner entry.

I'm not at all surprised one bit....I'll bet anybody they'll work 'Really' good too............................................... .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .....Anybody?

Looks good Todd, glad your happy, you had a 'Good' guy doing them.

[scholtmj]

Interesting, the area is not huge on these things. We're less than 36mm at the runner entry.

Todd

Could you explain a little more on why you went with "smaller" runners? I thought siamesed IHs were the thing to do on big cube motors. Thanks!

[tpepmeie]

You maybe farther along then me, but I know I have something you don't:p

Kevin, obviously there has been a mistake... that should have shipped to Indiana. Please forward it at your earliest convenience.:razz::thumbsup:

[tpepmeie]

Could you explain a little more on why you went with "smaller" runners? I thought siamesed IHs were the thing to do on big cube motors. Thanks!

Well, I left the runner size up to the professional doing the work. As long as we got adequate/big airflow through the port and not too small as to cause choke, then the smaller runner will increase charge velocity. WIth this size, the nominal calculated velocity through the runner would be around 100 m/s (329 ft/sec). Not excessive by any means. The cams are being designed with these port areas in mind to take advantage of that velocity at IVC.

The inlet tract is not uniform in area throughout. There are different shaped areas to control the airspeed and help it turn the convoluted bends our manifolds make.

Probably everyone has their own theory on airspeed/port area for these motors. I trust the guy who did the work in this case. The dyno and track will be the judge. :thumbsup: Can always go bigger later.

Todd

[Paul Workman]

Could you explain a little more on why you went with "smaller" runners? I thought siamesed IHs were the thing to do on big cube motors. Thanks!

I believe :dontknow: he's referring to the "neck" at the runner/valve bowl area (adjacent to the valve guide (here on one of my work in progress heads)???.

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/12-27-09005Large.jpg

One wants :rolleyes: to avoid cutting the short radius which means more cutting on the long radius side of the curve...AND there is just so much metal there between the bore and the water jacket. As Marc explained to me; "85% of your liability lies in that last 15% of the metal removed (there)." Getting all the way to 36mm at the "neck" can be done, as many have gone there before. However, all technical advantages aside, getting there is not w/o some risk.

As for the "siamesing" the runners, that is often what is done to the plenum and to (at least) the inlet side of the IHs; sometimes more - depending on the guru doing the porting.;) The runners splay as they approach the valves, and there is water jacket between the runners in the heads, so siamese necessarily has to end there, if not (waaaaay) before.

Note to self: Next time pull the guides instead of trying to work around them. It would save hours of time, and the finished product looks mo bettah to the eye, if nothing else;)...

P.

[Paul Workman]

...( off-set grinding ) of the crank ( what is that btw? )
grasshopper

Off-set grinding to lengthen the stroke...voila! (with some obvious liabilities beyond a certain point...:rolleyes:)

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/Offsetgrinding.jpg

This here mekanikal chit is almost as much fun as e-letroniks!!:mrgreen:

P.

[tpepmeie]

I believe he's referring to the "neck" at the runner/valve bowl area (adjacent to the valve guide (here on one of my work in progress heads).

No, Paul, my post a couple above was talking about the injector housing size. At the entry to the housing where it meets the plenum, my runners are well under 36mm. The port in the cylinder head is another topic altogether.

At issue is the fact that one wants to avoid cutting the short radius which means more cutting on the long radius side of the curve...AND there is just so much metal there between the bore and the water jacket.

Hmmm. I can assure you that hours were spent on the short side radius on my heads. In fact, the "long side" of the turn does not need much material removed at all. The majority of the flow loss occurs on the short side. Shape is everything there.

As Marc explained to me; "85% of your liability lies in that last 15% of the metal removed (there)." Getting all the way to 36mm at the "neck" can be done, as many have gone there before. However, all technical advantages aside, getting there is not w/o some risk. I don't know what exactly the impetus for their choosing the neck diameter they did, but there is a practical reason for sub 36mm...is my point.
P.

I won't go into all the details of my ports, but the minimum cross sectional area on a good 4-valve head is not at the seat, but further up the port before the turn. In fact, it is not unusual to have a minimum cross-sectional area equivalvent to 80-85% of the valve diameter. Work that out for a 39 or 40mm intake valve, and it is nowhere near 36mm. Our castings are already larger than necessary in that key area, as well as the bowl below the valve. At least according to my guy.

That's not to say the port is small the whole length. The fact is it has to be larger in some areas simply to get the right shape to help the air turn without losing flow.

We'll have to see how it runs. The fact that he got great flow through the heads and housings without going huge or siamesing the housings is remarkable. Not saying it is the only way to do it, but it is a different concept. :cheers:

Flyin Ryan, back me up here. :wink:

Todd

[jonszr1]

gosh i would love to hear what ryan has to say on this subject . he has so much knowledge in this area . ryan have you ever thought of doing porting to a set of housings heads and plenums to see what you could get out of them . if you would like to play with a full set up i have an extra seup that i would be happy to donate to the cause :thumbsup:

[Polo-1]

You fancy high tech guys, and your cross sectional area, short side radius, short side radius................

BIG HOLE......... BIG POWER.............:jawdrop:

http://i7.photobucket.com/albums/y292/kpie/KP2.jpg

[tpepmeie]

To each his own. Those look nice too.

PS. still havent got the throttle body yet, is it on the way? :)

[Polo-1]

in the mail next week:wink:

[flyin ryan]

No, Paul, my post a couple above was talking about the injector housing size. At the entry to the housing where it meets the plenum, my runners are well under 36mm. The port in the cylinder head is another topic altogether.



Hmmm. I can assure you that hours were spent on the short side radius on my heads. In fact, the "long side" of the turn does not need much material removed at all. The majority of the flow loss occurs on the short side. Shape is everything there.



I won't go into all the details of my ports, but the minimum cross sectional area on a good 4-valve head is not at the seat, but further up the port before the turn. In fact, it is not unusual to have a minimum cross-sectional area equivalvent to 80-85% of the valve diameter. Work that out for a 39 or 40mm intake valve, and it is nowhere near 36mm. Our castings are already larger than necessary in that key area, as well as the bowl below the valve. At least according to my guy.

That's not to say the port is small the whole length. The fact is it has to be larger in some areas simply to get the right shape to help the air turn without losing flow.

We'll have to see how it runs. The fact that he got great flow through the heads and housings without going huge or siamesing the housings is remarkable. Not saying it is the only way to do it, but it is a different concept. :cheers:

Flyin Ryan, back me up here. :wink:

ToddDon't need to, Your doing great, Todd..'Really'! Your 'Guy', wink, wink, has taught you well on his methods...not that you didn't know anything before...not saying that :o. Understand...& I've said this on here before, I don't come on here to talk about engines, I come on here to 'Not' talk about them. For engine stuff, I hang out at Speed Talk & YellowBullet. I will say...how do I do this with-out pissing people off....? What I've found on here is a bit of an 'Old boys club' when it come to engine building & more specifically porting. Not enough of an open mind to what is being done today outside of the ZR-1/LT-5 bubble. Make it big, make it big, make it big...Seems like everyone is fixated on the 36mm thing:dontknow:. No thought given to taper & air speed, just focus on 36mm..., don't get it. It's all about air-speed & more importantly 'Mixture' speed. Tumble, turbulance, swirl, mixture motion, node waves, sound waves & velocity. A smart person once said the 5 most important things when it comes to port work is Velocity, velocity, velocity, velocity & velocity...so ya', it's important. Make the area bigger, the air speed slows down, not speed up! Making it 'Bigger' can flow a little more air, generally but not as a rule, but won't do anything to make air speed up. When I port, I want to keep the port as small as possible & move/flow the most air. Have to keep the airflow coefficients in check, can't just make them bigger & call it done! Work out the area people...these things are damn big out of the box! Not saying they are perfect. I'm into shapes, not size. The only time size becomes an issue is when your approaching an area where it becomes a choke, guys on here are making area's way to big that are already a good size. I'm not doing a very good job of not pissing people off, I can tell that already :redface:. Todd's program is current, that is the way heads are currently done by top teams, Nascar, NHRA, F-1 etc., trust me. Your stuff, Todd, sounds almost exactly the same as the way I did my heads last spring, Jeffvette knows the power it made but I think he's the only one. Siameseing...I don't even want to get into that, I'll for sure turn eveyone into haters against me, LOL. Didn't want to jump in here before but since I was called out, that's my 2 cents. You know what Todd, I'm not even excited to see how your deal/heads etc. turn-out,...I 'Know' it's going to be good, I have absolutly no doubt...as long as the cams are made proper, nothing crazy big etc. you'll be a happy person ;).

[jonszr1]

ryan thanx for sharing ,i am learning alot on this thread , its amazing how things have changed since the old days .i like the aproach that todd is taking and can hardly wait to see how she comes out , now if one could only get women to think about shape instead of size . jk:mrgreen:

[flyin ryan]

Your welcome. I'm sure your one of the few who will appreciate my point of veiw, the others will throw stones....I can feel it already, LOL. Don't know what it is, but when it comes to porting & cams, seems everyone want's to gravitate to bigger is better...well it's not :cool:. LT-5's can be great engines, don't need to get carried away. Lotus had some sharp people back then who were way, WAY ahead of the curve in terms of engine development. Here's a quick one...When I'm dynoing something & the customer is on site, We throw a spacer at it & it picks up, customer is like give it another...& another....& another....keeps picking up. Truth is, generally, it will pick up until the carb tickles the ceiling of the dyno cell!! But on the track, it won't run (accelerate) hard at all. The dyno will lie to you if you let it...every time! When the rubber hits the road...that's real world. Jeff along with some others were bugging me for the longest time about my 90's dyno...Well truth is, I don't like talking about dyno numbers at all cause' every single one (Dyno) in the world is not the same. That's a fact! Dyno numbers being thrown out are only good for picking up chick's in the bar, aside from that they don't mean much to anybody but the person him/her self. I wanted to run my 90 at the track to back up my dyno numbers but never had the chance so to me everything is still up in the air. My 90 dynoed higher here than my 93 did in Portland Aug.2008 at the PNW gathering, so that a good start, but doesn't mean much to me till I run down the track :dontknow:. I don't hear anybody on here talking about average or minimum cross sectional area...& that's damn important! How many F.P.S. (Feet per Second) are you running over the short turn....? Damn important. Sorry Todd, not trying to steal your great thread. You've got an awesome platform, gonna stand everybody on their ear's :thumbsup:.

[Polo-1]

Damn Canadians...........








When are you coming back:hello:

[Jeffvette]

Jeff along with some others were bugging me for the longest time about my 90's dyno...

Well you shouldn't dangle them out there. I think you just like to tease us.

=D>

[flyin ryan]

Well you shouldn't dangle them out there. I think you just like to tease us.

=D>When I E-mailed you the result's I didn't say...'Just keep it to yourself only'...whatever buddy. I never got an indication from you if it was good or not :dontknow:. Feels good/great in the car but that means squat :cool:. Things bone stock...Exh., Manifolds etc., except I ported the stuff & timed the cams (they were out in left field) did a PROM but had to have Marc H. modify the timing tables cause 'My guy' didn't lay it up as I asked/told him to. Got the impression from You & Dwight E., in Portland my 93 was pretty decent for stock & this thing on the dyno here was a hair better so I dunno...wanna run it down the track & see what that says :razz:. We'll see.

[flyin ryan]

Damn Canadians...........








When are you coming back:hello:Didn't think you wanted me back ?...LOL!

[Pete]

Here is my thoughts on this.

If you think old school pushrod motor with single big ports then yes worry about velocity LT5 has 2 small ports i don't think you can port them big enough to slow down velocity.

Pete

Ryan what the heck did the dyno show?
I'll tell you what your MPH should be :)

[tomtom72]

I would like to say a big thank you to all of you guys that know all this stuff about engine building and air flow for sharing your knowledge.

You guys, Todd, Pete, Ryan, Jeff, Kevin, Bob, Paul, Lee, and a host of others that I can't remember.....thanks! :thumbsup:

To be clear. I'm speaking for myself. I'm not trying to imply that there are a lot of other members here that are as behind the learning curve as I. I don't want anyone to think I'm trying to be a wise guy.

I really do appreciate it when these kinds of conversations take place among all of you and I get to listen in on it!:happy1:

[LGAFF]

This is interesting and has prompted me to do some research. First, there is no doubt that increasing the size of ports increases power. If not Haibeck and others would not be in business. I know the cars I have ported have seen 25-30hp increases even without tuning. The GM Techs siamesed Snakeskinners intake and that car was pretty damn fast.

That said, I have been reading up on port size and velocity. Many high rev motorcyle engines see a HP increase be actually reducing port size to 65% of the valve diameter. I also have read that many DOHC cars had oversized port diameters in order to ensure better emissions(much like the 2ndry ports we have).

I guess there are two ways to get there 1)by increasing port diameter and volume 2)by increasing port velocity and ramming the air in....

This is the kind of stuff that keeps in interesting.

[Polo-1]

Ryan what the heck did the dyno show?
I'll tell you what your MPH should be :)

I heard it's over 370 rwhp on a 100% stock car. air filter to tail pipes-factory stock..
My 100% 92 car was 323rwhp then hit 397 after filter,chip,porting,headers,corsa no cats.

Over 370 on a stock quiet car would be a hell of alot of fun. SLEEPER.....

[Pete]

I heard it's over 370 rwhp on a 100% stock car. air filter to tail pipes-factory stock..
My 100% 92 car was 323rwhp then hit 397 after filter,chip,porting,headers,corsa no cats.

Over 370 on a stock quiet car would be a hell of alot of fun. SLEEPER.....


WOW,that's the strongest stocker i've seen yet.

Should run 117-+1

I should add from what i have seen from 370rwhp on DynoJet

Pete

[flyin ryan]

I heard it's over 370 rwhp on a 100% stock car. air filter to tail pipes-factory stock..
My 100% 92 car was 323rwhp then hit 397 after filter,chip,porting,headers,corsa no cats.

Over 370 on a stock quiet car would be a hell of alot of fun. SLEEPER.....Except I ported it a little, right? To be clear we're on the same page. But yes, stock manifolds, exhaust, cams, T/B etc. Would have liked to dyno before I took it apart in a perfect world but didn't work out. Not that big of a deal, I would assume It wouldn't be any better that your 92 Kevin. So basically porting, valve seals added to the Exh. side & timed the cams & one cam was pretty far out, I thought anyways. Should point out too, I just used stock Dia. gaskets for the Inj. housing's & plenum. By the time I opened things up to match those I was happy with the size. I was just playing around with my junk here, never set out for it to be a maximum effort deal or anything. Stealing Todd's thread again, sorry...:o

[flyin ryan]

Here is my thoughts on this.

If you think old school pushrod motor with single big ports then yes worry about velocity LT5 has 2 small ports i don't think you can port them big enough to slow down velocity.

Pete

Ryan what the heck did the dyno show?
I'll tell you what your MPH should be :)I guess here is where it falls...personally I don't think LT-5 ports are small :dontknow:. I was actually quite shocked first time I went in & worked out the area. Area is area, an engine doesn't know if it has one port or ten, It's just drawing. I could look up some numbers of say small block Chev. C.S.A.'s compared to LT-5 just to see, can't remember off top of my head. Working on Hemi junk today :o, LOL. You've got your opinion Pete, That's cool, I respect that/you :hello:.

I can figure out MPH, that's not a problem. Just not a the top of my list. Not a big deal to me. I'll maybe take it to the track this year, we'll see. Did my 90 just for fun, had a couple oil leaks to fix, Cooler lines & Breaher Box plus I wanted to add valve seal's to the Exh. so while I was in there...:rolleyes:.

[Paul Workman]

I guess here is where it falls...personally I don't think LT-5 ports are small :dontknow:. I was actually quite shocked first time I went in & worked out the area. Area is area, an engine doesn't know if it has one port or ten, It's just drawing. I could look up some numbers of say small block Chev. C.S.A.'s compared to LT-5 just to see, can't remember off top of my head. Working on Hemi junk today :o, LOL. You've got your opinion Pete, That's cool, I respect that/you :hello:.

I can figure out MPH, that's not a problem. Just not a the top of my list. Not a big deal to me. I'll maybe take it to the track this year, we'll see. Did my 90 just for fun, had a couple oil leaks to fix, Cooler lines & Breaher Box plus I wanted to add valve seal's to the Exh. so while I was in there...:rolleyes:.

To paraphrase Struter Martin (the warden in Cool Hand Luke): "What we have heah...is failure to demonstrate!"

In one corner we have a group that has demonstrated some pretty substantial numbers, both on dynos and the track using ports at or above the vaunted "36mm", and in the other corner a professional builder that says smaller is better. What we need is a volunteer mule car, someone that would agree to bolting on plenums and IHs from each approach and see what what happens. We could be talking dyno comparisons (the same dyno/same day) and track times too. I have a plenum and IHs out of the car at the moment - with "good ol boy" ports. someone wanna put together some not so big ports e.g., well under 36mm and see what is what????

Any takers? I would be very interested to see a direct same-day same-car comparision. What U think? (and again...apologies to the OP for railroading his post.)

P.

[flyin ryan]

Todd would be the obvious choice if he's willing, don't need to do the work, it's already done :dontknow:. If you can't find a similar car (cubes) just work the math backwards. Good idea Paul, in theory, not sure it'll be that easy to pull off though, unfortunatly. The guys on here that are interested should search out 'Inertial Supercharging'...not sure what is out there but I'm thinking quite a bit...

[jonszr1]

there is a 2 day test and tune @ famoso the 3 rd weekend in feb . on my 90 are the siamesed injector housings and dividerless plenum . my 92 has the callaway ported inj housings and plenum which are on the smaller side .stk gaskets plenum and injector housings work on the callaway, i could try the 2 different setups on the callaway and see , but to be fair i would think the callaway setup would have to be sent to ryan for him to look over and adjust . pete know how the callaway porting looks ,maybe he can chime in . i would be more than happy to be the test mule. i could get my buddy jeremy to video the whole deal .

[flyin ryan]

For the record, it's not 'A engine builder...(Me)', obviously Todd's guy has parallel thinking as myself, especially considering his cubes. Funny, the world I live in 'Big' is in the minority...:)

[flyin ryan]

there is a 2 day test and tune @ famoso the 3 rd weekend in feb . on my 90 are the siamesed injector housings and dividerless plenum . my 92 has the callaway ported inj housings and plenum which are on the smaller side .stk gaskets plenum and injector housings work on the callaway, i could try the 2 different setups on the callaway and see , but to be fair i would think the callaway setup would have to be sent to ryan for him to look over and adjust . pete know how the callaway porting looks ,maybe he can chime in . i would be more than happy to be the test mule. i could get my buddy jeremy to video the whole deal .Be hard to make it happen, but something like this would be cool to do at BG :sign13:

[LGAFF]

I think Ryan is talking about this............:mrgreen:

http://www.tornadoair.com/buy1/

[Pete]

More thoughts.
Ryan i'm not saying bigger is better or more power.
I have tested big siemesed plenum with big siemesed IH's on my 350 and dyno tested with no gains, yes there is a point where too big you don't gain anything.

I will also add cam timing is worth power

Now on big inch motors it might be a different story.
Here is what i have tested.
Tested the Hogan's intake on the 421ci it gained 10-12rwhp over the stock ported intake.
Made a believer out of me on LPE's droped & siemised plenum & IH's he had sad it was worth 15 chp.
Of course peak power was a couple hundred RPM higher this might be the effect of the shorter & straight runners also the Hogan's intake box/plenum is bigger then stock plenum.

Man did we ever screw Todd,sorry Todd:)
Maybe start a new thread.

If we can get a couple of sponsers for gaskets,car,dyno time/expense we can do the testing that Paul mentioned.

I'm also interested to see what the magic porting # would be.

Pete

[tpepmeie]

Man did we ever screw Todd,sorry Todd:)
Maybe start a new thread.

If we can get a couple of sponsers for gaskets,car,dyno time/expense we can do the testing that Paul mentioned.

I'm also interested to see what the magic porting # would be.

Pete

Man you guys can screw up a good thread! Appreciate all the comments, although I didn't mean to start a "mine is bigger than yours" argument. I think a lot of the trend toward big holes is to get the flow #'s up. As long as the required airflow can be achieved, smaller is thought to be better. If anybody is really interested, search SpeedTalk for "discharge coefficient".

Ryan is right...SpeedTalk forums rock. I've learned a ton from those guys.

I am making a polyurethane port mold of my heads & housings today, just to get a better idea of the shape and area throughout. The inside mic shows a min cross sectional area not much bigger than the stock casting.

This A-B test you guys are talking about would have to include swapping both heads and housings and plenum. It all needs to work together. Huge port heads on small port housings would not be a fair comparison, and vice versa. I would offer my stuff for such a test, but it would be tough to just bolt on to someone else's motor. Valve stem heights are different, lifters are different, cams, and so on. Can't discount the need to tailor the cam profile to the port velocity either. That was a primary input into the lobe profile (ie, flow at different lifts, and port velocity).

Good stuff guys. :cheers:

Todd

[Demps]

Man, you guys are awesome! I would be dangerous with time and money.

One thing I desired (when I wussed out and paid someone else for the mod) was area under the [power] curve. My 415 made more power down low (with LPE B cams-->smaller exhaust) than dyno's I've seen with Stg III cams. My car is not the most powerful and I have not had a chance to track it yet but it pulls very well. I did not go with bigger valves for $ vs gained when it came down to that vs eating.


Scales are different on the two graphs but...
My car:

http://i148.photobucket.com/albums/s27/demps_photos/Teds415.jpg


Cam'd 415 Marc did (from his site):

http://www.zr1specialist.com/HAT%20Web/products/415%20chart.jpg

I'm not a dyno bench racer by any means...just proud to have what I have and learn more from the smart folks.

[flyin ryan]

Can't discount the need to tailor the cam profile to the port velocity either. Absolutly Todd, that is key.

[scholtmj]

I think those two dyno charts makes a good point about what you want the motor for. As Demps said, he wanted more power under the curve or what I assume is a very streetable power band. The second motor made much less hp at 3500rpm and didn't make the big number till much higher in the rpm range; maybe it's used as a race motor and sees high rpms quite often.

I asked Marc H about a 385 with stage 3 cams and this was his response:
"I dyno'ed a 385 with SGC Stage III cams that a customer brought in. I was able to tune it to 503 whp. That's 593 crankshaft hp. Torque at 3500 rpm was 325 at the wheels. The engine was way over cammed. The idle was very rough. 3500 rpm is an important speed if the car is driven on the street. Compared to my 385 package with stock cams the engine had -65 torque at the crankshaft. I don't think that the torque loss is worth getting the additional 28 chp.
The most cam that I would recommend is Stage II intakes and stock exhaust cams."

Back to topic.....tpepmeie, are you going to reveal your cam specs? :happy1:

[flyin ryan]

This A-B test you guys are talking about would have to include swapping both heads and housings and plenum. It all needs to work together. Huge port heads on small port housings would not be a fair comparison, and vice versa. My exact feelings as well, only way to do it. Everything 'Starts' at the valve seat.

[flyin ryan]

I think those two dyno charts makes a good point about what you want the motor for. As Demps said, he wanted more power under the curve or what I assume is a very streetable power band. The second motor made much less hp at 3500rpm and didn't make the big number till much higher in the rpm range; maybe it's used as a race motor and sees high rpms quite often.

I asked Marc H about a 385 with stage 3 cams and this was his response:
"I dyno'ed a 385 with SGC Stage III cams that a customer brought in. I was able to tune it to 503 whp. That's 593 crankshaft hp. Torque at 3500 rpm was 325 at the wheels. The engine was way over cammed. The idle was very rough. 3500 rpm is an important speed if the car is driven on the street. Compared to my 385 package with stock cams the engine had -65 torque at the crankshaft. I don't think that the torque loss is worth getting the additional 28 chp.
The most cam that I would recommend is Stage II intakes and stock exhaust cams."

Excellent post :thumbsup:

[jonszr1]

i understand the need for a complete setup ie heads inj housings and plenum. i was just offering to see what different porting on inj housings and plenum on a basicly stk motor . what i have decided inon doing is 2 different tests. 1 testing the stainless works headers and corsa exhaust that is currently on the 92 .then changing it out for the jeal headers and dr gas spin tech set up that is on the 90. then changing out the ported stuff off my 90 onto my 92 . famoso has 2 ,2 day sessions consecutive . weekends . wekend one will be the exhaust and weekend 2 will be the injector housings and plenum . am going to bill bs. next week to have a new clutch setup put in as i hope to make 10-15 runs each weekend .so for the hijack . i really like the thought of the smaller contured ports to make power .

[XfireZ51]

...Can't discount the need to tailor the cam profile to the port velocity either. That was a primary input into the lobe profile (ie, flow at different lifts, and port velocity).

Good stuff guys. :cheers:

Todd

My turn to screw up Todd's thread. Very true tho Todd. At the time I was deciding on a cam profile for my 84 after installing TFS 23D heads, I read several articles by David Vizard. He very much is of the opinion that optimizing cam timing events and profile are a function of the port flow. More specifically, he focuses on port flow at low lift (< .200") which is where overlap takes place. By deciding where you want power peak, itself a function of runner length and induction system flow capacity(ie I shot for about 5000rpm on a ported/modded Xfire manifold), this defines the optimum LSA for the desired rpm range.
He also recommends that minimum valve lift be 25% of valve diameter. This produces an unobstructed "window" for the airflow past the valve head. His article(s) that I read were directed to 2 valve Chevy heads.

[Pete]

Oh boy now we went to cams.
Did some testing there also.


Well here are some findings on 421ci with SGC Stage II's these are Intakes .237 .440 Exhaust .237 .440.

We changed the exhaust cam with a .224 .425 car picked up 10-20+ thru the curve with gains at peak.

I never said bigger is better.
I never tested a 34mm or 35mm ports maybe they will make same HP as 36mm somebody do it and let me know.
I have tried bigger 38mm fully siemesed plenum/IH's with no gains this was on my 350.
I really think big inch motors would benefit from big siemesed & dropped plenum /IH's

On the above Dyno sheets it's not like the 415 making 350rwtq at low rpm is going to drive like a slug down the street.

Pete

[XfireZ51]

Oh boy now we went to cams.
Did some testing there also.


Well here are some findings on 421ci with SGC Stage II's these are Intakes .237 .440 Exhaust .237 .440.

We changed the exhaust cam with a .224 .425 car picked up 10-20+ thru the curve with gains at peak.

I never said bigger is better.
I never tested a 34mm or 35mm ports maybe they will make same HP as 36mm somebody do it and let me know.
I have tried bigger 38mm fully siemesed plenum/IH's with no gains this was on my 350.
I really think big inch motors would benefit from big siemesed & dropped plenum /IH's

On the above Dyno sheets it's not like the 415 making 350rwtq at low rpm is going to drive like a slug down the street.

Pete

Pete,

I think my point and I believe Todd's point is how interrelated port flow and cam timing events are. In the effort to optimize/maximize the results,
(and this isn't new stuff) the cam needs to take maximum advantage of the airflow made available through the induction system and the heads.
Too many times people choose the cam first without much regard to the cylinder head design and flow characteristics.

[Pete]

Pete,
my point and I believe Todd's point is how interrelated port flow and cam timing events are. In the effort to optimize/maximize the results,
(and this isn't new stuff) the cam needs to take maximum advantage of the airflow made available through the induction system and the heads.
Too many times people choose the cam first without much regard to the cylinder head design and flow characteristics.



Dom, don't get me wrong i think most understand it's the whole combo to a good power plant.

I would like to find the best cam and head combo but with the LT5 it gets a bit expensive to try different cam and head/intake combos.
This is why we make do with what we have.

I have tried a couple of different cam spec combos on my Z and i think i have found what seems to be the best,i'm sure there could be a better combo, but man does it get expensive after a while.

For what it's worth getting 550-600RWHP N/A on pump gas,very docile
handles great and a top speed of 200+ is not too shabby for a 415-441ci.
I know that other engines can accoplish the same and cheaper,what i'm trying to say is with the amount of research and parts available for the LT5 we are doing pretty darn good.

Maybe if i win lotto i can try some more combo's:)
Pete

[Demps]

Pete, I chose the cams I have on your advice.

I wish I were experienced enough to comment on y'all's specifics. I do have a car torn apart putting on coilovers though.
Ted

[Pete]

Pete, I chose the cams I have on your advice.

I wish I were experienced enough to comment on y'all's specifics. I do have a car torn apart putting on coilovers though.
Ted


Ted, hope your happy with your set up.:thumbsup:

Todd, has done alot of homework he made sure he dot his i's crossed his t's and it will show.

Pete

[XfireZ51]

Dom, don't get me wrong i think most understand it's the whole combo to a good power plant.

I would like to find the best cam and head combo but with the LT5 it gets a bit expensive to try different cam and head/intake combos.
This is why we make do with what we have.

I have tried a couple of different cam spec combos on my Z and i think i have found what seems to be the best,i'm sure there could be a better combo, but man does it get expensive after a while.

For what it's worth getting 550-600RWHP N/A on pump gas,very docile
handles great and a top speed of 200+ is not too shabby for a 415-441ci.
I know that other engines can accoplish the same and cheaper,what i'm trying to say is with the amount of research and parts available for the LT5 we are doing pretty darn good.

Maybe if i win lotto i can try some more combo's:)
Pete

Pete,

The Vizard article was about exactly the issue that you raise. You can try many camshafts with a given set of heads to try an find the best combination, but as you state, that's a very expensive proposition even if you're doing a vanilla SBC. When I did my 84, I used a company in New Mexico called Motors and Machine which was highlighted in the Vizard article. They had a software package based on Vizard's specifications for cam selection. It was $40 to have them calc a cam based on airflow measurements for the cylinder heads you had chosen. Besides that they wanted to know the operating range of the motor and where you were interested in having peak power occur along with calc'd CR.
They sent me a spec for a cam fitting those requirements. Be interesting to see what the calc'd cam spec would be for the LT-5 with "X" airflow numbers.

[Polo-1]

I think the little 402 will fire up before the 427:p

http://i7.photobucket.com/albums/y292/kpie/IMG_0548.jpg

[Jagdpanzer]

Looking good Kevin!
Like the head studs and coated pistons
How long before it's alive?

[Dynomite]

I think the little 402 will fire up before the 427:p

http://i7.photobucket.com/albums/y292/kpie/IMG_0548.jpg

That is a beauty :thumbsup:

Where do you get those head studs?
I am assuming ARP automotive?

[Polo-1]

Liners and Studs from Ron Woods.

[Dynomite]

Liners and Studs from Ron Woods.

Is there a web site? ;)

I can tell I am going to have to get one Z to drive and one Z to modify :mrgreen:

[Jeffvette]

Is there a web site? ;)

I can tell I am going to have to get one Z to drive and one Z to modify :mrgreen:


I've got a spare motor we can build if you want. :cheers:

[Paul Workman]

[QUOTE=Dynomite;83400My problem is I get as BIG a BANG modifying them as I do driving them :mrgreen:[/QUOTE]

It is a sickness, :rolleyes: and there is no cure - only temporary relief when it goes a little faster. Then you get accustomed to that level, or someone in a hopped up Mooostang waxes ya. :jawdrop: Then it starts all over again...But! You're in great company!;)

P.

[tpepmeie]

I think the little 402 will fire up before the 427:p



Hey, get that "little" motor outta my thread. :sleepy1:

Waiting cams. Started messing around with the ATI damper today. Didn't get it installed, f'ed up the crank key though. Rest of the bottom end is all done. BG is coming too fast to have it all done by then. :cheers:

Todd

[Jagdpanzer]

Is there a web site? ;)

http://www.zr1products.com/