Some "Dynomite" Heads!

[Locobob]

Just getting started on Dynomite's head porting so I thought I'd share as I go along. Some interesting measurements from the stock (untouched) heads:

Combustion Chambers came in around 41cc with not much deviation, this was using my own method and a spark plug in the hole.

Intake runner dimensions:
Diameter at IH gasket surface: Primary 32.3mm, Secondary 36.4mm
Diameter, narrowest point of runner: Primary 32mm, Secondary 32mm (just upstream of valve guide)
Runner width at valve guide: Primary 33mm, Secondary 33mm
Valve seat diameter: Primary 34.7mm, Secondary 34.7mm

Exhaust port dimensions:
Valve seat diameter: 32mm
Width across valve guide: 34.8mm
Runner narrowest point: 31.5mm (where ports merge into one)
Header gasket surface: 51.8mm long, 35.6 tall

[Locobob]

Some close ups of the chambers:

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/PC140002.jpg

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/PC140004.jpg

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/PC140029.jpg

The worst areas are hard to see, sharp edges and poor transitions an inch or so above the valve seats.

[Locobob]

Looking down the intake runners:
It would appear from the measurements I made that the two runners are mirror image castings with only the machining done to the top of the secondary port differentiating them.

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/PC140020.jpg

Exhaust ports:

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/PC140025.jpg

Here is the template I made off the bottom of the injector housings which I had enlarged only slightly. You can see just how skewed the port alignment is from the factory. It is noticeably worse on the primary runners, secondaries are closer probably due to the machine work done on these.

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/PC140030.jpg

And marked on the head without the template

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/PC140033.jpg

[mgbrv8]

Excellent work Sir, keep the pictures coming.

[Polo-1]

are those the fire sale heads:wave:

[Kevin]

glad to see your heads getting some love

[tomtom72]

( insert wolf whistle here ) It's nice to see your car getting some head work dunn =D>

:cheers:
Tom

[A26B]

:cheers:Great pictures Bob. When I first started making gaskets, I used LT5 engine drawings & made them to that spec. Scared the bejesus out of me when I check fit to early style engine parts.

Looking forward to seeing the entire series, all the way to the finish line.:fahne:

[FU]

:cheers:Great pictures Bob..

Looking forward to seeing the entire series, all the way to the finish line.:fahne:

:thumbsup: Agreed

[GOLDCYLON]

No (that is a long story)....by the way..the fire sale heads are very nice

:cheers:

we need to chat about those heads cliff ;)

[Locobob]

Some "boring" video footage.... get it.. boring haha... okay sorry I'm not that funny.

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/th_PC210001.jpg (http://s418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/?action=view&current=PC210001.mp4)

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/th_PC210002.jpg (http://s418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/?action=view&current=PC210002.mp4)

[carter200]

Some "boring" video footage.... get it.. boring haha... okay sorry I'm not that funny.

You got that right :sign10:

[Locobob]

You got that right :sign10:

The "boring" or the "not funny"??? Dont hurt my feelings now Carter :mrgreen:

[carter200]

The "boring" or the "not funny"??? Dont hurt my feelings now Carter :mrgreen:

It's all good. Just giving you a little pre Christmas "goose" :dancing

[RICKYRJ1]

Thanks for the starting info! Dynomite is getting good head :mrgreen:. Locobob gave me a great education in porting & cleared up a lot of misinformation that I had., Dyno will be more than happy with the work. Keep this thread updated with you progress. :cheers:

[GOLDCYLON]

I have to keep those Fire Sale Heads untill I get the 650 hp ZR1 going :D

Then you have to talk with Robert as I left those Very Nice Fire Sale Heads in his garage ;)

If that does not work out....I am going with this 405 hp :sign10:

http://i287.photobucket.com/albums/ll142/dynomite007/ZR1/95RFront.jpg

Im paying down the Bottom half was home to get the set back together ;)

[GOLDCYLON]

You got that right :sign10:


Well im confused I though this was machinst porn :icon_scra

[Locobob]

Got a little more time in on the heads. Currently I am still working on enlarging the primary intake ports and also matching them to the injector housings.

Here we have the bottom of the injector housing with the balsa wood template in place. I like to use this small dremel sander to trace around the ports - it is easy to control and allows me to precisely control any angle so as to get a proper representation of the top of the port.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/PC270001.jpg

Same template only now applied to the head. I use this fine marker to trace the pattern onto the mating surface of the head.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/PC270002.jpg

Same head now with the balsa template removed, you can see the red marker designating the area to be worked in order to match up the head ports with the injector housing ports.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/PC270004.jpg

Generally I repeat this process 3 or 4 times until I am at the size I want and have a good match. A bit overkill... yeah probably but it helps to keep and eye on your work as you go - otherwise you can end up with mistakes that are hard to correct. Primary ports in these photos are 35mm at the mating surface and will end up being about 36mm when I am finished.

[LGAFF]

Thing of beauty! Thanks for sharing, once I get the motor out of the 90, going to port the heads....first venture with head porting.

[Locobob]

Thing of beauty! Thanks for sharing, once I get the motor out of the 90, going to port the heads....first venture with head porting.

This is my first start to finish head porting venture also Lee. It is nice having the set I reworked handy for reference.

[Paul Workman]

If y'all are interested...I'll be happy to share w/ you where the "quicksand" is and how you might avoid having to pay big bucks to a welder when you have an "oops" moment...

Course, going it alone has it's own mystery and the excitement of "discovery" awaits; something to be said for that, I recon! Well...just a thought

P.

[Locobob]

If y'all are interested...I'll be happy to share w/ you where the "quicksand" is and how you might avoid having to pay big bucks to a welder when you have an "oops" moment...

Course, going it alone has it's own mystery and the excitement of "discovery" awaits; something to be said for that, I recon! Well...just a thought

P.

Do you have a diagram or something Paul, that would certainly be helpful to see. :cheers:

[LGAFF]

if I recall Jerry has some heads that are scrap.....do what Mercury MArine did, section the heads to find the weak spots.....would be cool for an article for HOB or video clip.

Just a thought

[A26B]

I'm gonna cut those heads up in single cylinder chunks, with the cam cover installed, have 'em signed by Bob Hall, Pete P., and some other famous members and sell 'em for about a zillion bucks each so I can retire.

Seriously, it takes quite a few sections to see everything that is of concern for full boogie head porting.

[Paul Workman]

Sectioning the LT5 heads...Sounds like a winter project coming on!

I have a friend of mine that sends stuff out to a head repair outfit - that often sections heads (not LT5 heads) to make repairs. I'll see about sectioning mine and keep y'all posted. Also, I might need to borrow a stock (un-touched) head to take some measurements from, and or maybe make a reference casting from. (I'll attempt to locate the approximate location of oil and water, relative to the stock ID. The actual dimensions of say my ports are the "intellectual property" of Pete, Bob G's and Marc Hs. I'll just say they are big, and as Marc H said once, "80% of the risk (of perforating the runner) is in the last 20% of the cutting.

In the mean time, I'll get some measurements and do a diagram and post it, for anyone interested.

P.

[Pete]

I'm gonna cut those heads up in single cylinder chunks, with the cam cover installed, have 'em signed by Bob Hall, Pete P., and some other famous members and sell 'em for about a zillion bucks each so I can retire.

Seriously, it takes quite a few sections to see everything that is of concern for full boogie head porting.


Thanks for the compliment Jerry,i'll start cutting my heads to sell for zillions :)

LocoBob i see your having some fun,very nice work :thumbsup:

There will be some fast Z's at BG next year (5 months):-D

Pete

[Locobob]

Thanks for the compliment Jerry,i'll start cutting my heads to sell for zillions :)

LocoBob i see your having some fun,very nice work :thumbsup:

There will be some fast Z's at BG next year (5 months):-D

Pete

Thanks Pete, wish I could do BG this year but its not in the cards, be fun to see what you FBI boys have been busy cooking up.

[Locobob]

Doing a little clean up in the bowl area with a sanding drum.

Here you can still see some of the casting imperfections.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P1050001.jpg

The unworked (grey area) to the side of the valve guide sticks out a good bit and forces an abrupt change in air direction just before the throat. I will be taking a good bit of this off and doing a lot of blending here. It is more pronounced on the primary side do to the angle of the port where as the secondary has a straighter shot "as cast".
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P1050007.jpg

Another angle on this
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P1050004.jpg

Looking down the primary you can see the "J" shape of the port near the bottom.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P1050011.jpg

[tomtom72]

:o
okay, dumb Q's from the penut gallery.

The Bowl is the area ( space ) starting the back side of the valve seat and going back up the head port(?) toward the I/H port(?)? The guide sticks into the bowl and into the air flow causing not good things?

To "blend a Bowl" is to get rid of the rough casting finish, fix the protruding part of the guide, and some how 'straighten out' the air flow path from the I/H to the back side of the valve?

I'm sorry to ask so many Q's. Thanks Bob.

:mrgreen:
grasshopper

[Locobob]

:o
okay, dumb Q's from the penut gallery.

The Bowl is the area ( space ) starting the back side of the valve seat and going back up the head port(?) toward the I/H port(?)? The guide sticks into the bowl and into the air flow causing not good things?

To "blend a Bowl" is to get rid of the rough casting finish, fix the protruding part of the guide, and some how 'straighten out' the air flow path from the I/H to the back side of the valve?

I'm sorry to ask so many Q's. Thanks Bob.

:mrgreen:
grasshopper

The bowl is basically the area above the valve seat extending upstream to about where the valve guide boss is.
Not much you can do about the valve guide, you can trim it up a little and maybe contour it some. A few have cut it short but frankly I'm not sure that is a good idea, could lead to durability issues.
The valve guide boss can be reduced in size and blended - by blending I mean smoothed and shaped.
Straightening airflow is a key goal in most cases, it is not really possible in the bowl however. The air has to turn at the valve so basically you want to bias the port so that the air can make a gentle turn toward the center of the combustion chamber.

[tomtom72]

Thank you Bob. I have just always wanted to know what all the terminology meant. I'm not going to become a cutter & a polisher any time in the future. It's just nice to be able to follow all the conversations that all you guys have and have a clue what you guys are talking about.
:handshak:

[Paul Workman]

Uh...Say there, Bob! Bout time for some eye candy and an update on dem heads progress, yes?

P.

[Locobob]

Yep time for an update

Here we have both primary and secondary intake ports opened up to approx 35mm down as far as the valve guide boss. Primary is close to 36mm at the top and secondary still around the factory 36.5mm at the top. Note the ring left by the factory machining process around the secondary port just below the butterfly location. It was machined by the factory to about 36.5mm down to this ring after which they did a quick machine blend reducing the port to about 32mm in just a half inch or so.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P1160001.jpg

Secondary port with telescoping gauge set at 35mm in three locations, still a fairly large change with the port now at 35mm. Obviously the butterfly assembly takes up some of the extra volume at the top of the port.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P1160008.jpg

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P1160003.jpg

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P1160004.jpg

[Locobob]

Been fine tuning the intake runners and matching to the injector housings.

I've been using a template to align the ports, now it's time to bolt the parts together and fine tune the match.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P2040001.jpg

This is a 3/4in tall sanding sleeve mounted on a 1/2in tall rubber drum - allows a little flex to get into the curve areas at an angle.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P2040004.jpg

Drum sander on a long mandrel, bend-o-light through the injector boss for lighting.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P2040008.jpg

After working the port around the mating surface with the drum I switch to a flap wheel to finish it off.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P2040012.jpg

[Locobob]

Looking down the primary port, can you find the gasket surface between the two parts? :mrgreen:
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P2040017.jpg

And the secondary port. You can see the mating surface line on these, someone went a little overboard on the factory match and I didn't want to get crazy enlarging them to get rid of the tiny lip they created.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P2040016.jpg

Looking up the primary from the combustion chamber side.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P2040022.jpg

And same view for the secondary port.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P2040023.jpg

[Aurora40]

Looks good!

[FU]

:worship: Again , very nice work Rob !
Now some may understand the time and effort that need's to be put into porting the top end of an LT5.

[tomtom72]

:worship: Again , very nice work Rob !
Now some may understand the time and effort that need's to be put into porting the top end of an LT5.

"Amen" to that thought Frank!

Bob, I kind of thought I had an idea about just how much fine detail work was involved, but now I really have a better grasp of the work involved. Thanks for the time it takes to share this with us! :handshak:

[Paul Workman]

Looking down the primary port, can you find the gasket surface between the two parts? :mrgreen:
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P2040017.jpg



Smmmmooooooth! Yeah, it is amazing just how abrupt many of the joint and especially the so-called "taper" below the secondary throttle plate is as the system comes from the factory. I recon that is why these motors respond so very well to a little TLC in the runners.

Beautiful work, Bob.

P.

[sammy]

all i can say is that this is the best work i have ever seen on a set of heads the atten to detail second to none .thankyou for sharing , this stuff is art .

[Locobob]

Thanks for the encouragement everyone :cheers:
Quality of work is what I really strive for in doing this, takes forever but I think its worth the extra effort.

[Locobob]

Almost done with the intake side of the heads. At this point I am mainly working the area around the valve boss and guide in an effort to provide a smooth channel for the air around these obstructions.

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P2140001.jpg

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P2140002.jpg

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P2140005.jpg

[Locobob]

Switching gears to the exhaust side, the stock valve guide bosses are huge and don't blend well into the overall port - much like the primary bosses on early style injector housings. The casting compensates for this somewhat by extra port width in this general area.

Here we have: left side boss with just a little bit of blending around the perimeter, right side boss with some rough cut size reduction.

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P2240004.jpg

Some more rough cut reduction and blending

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P2240006.jpg

A little closer shot of the same

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P2240007.jpg

View from header side. Interestingly I have found that "as cast" one exhaust runner tends to be slightly larger than the other - near where they come together.

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P2240008.jpg

[Pete]

Rob,very nice :thumbsup:


Pete

[Locobob]

Rob,very nice :thumbsup:


Pete

It's getting there. Maybe if I take my sweet *** time you can talk Cliff into doing some cams :mrgreen:

[Pete]

It's getting there. Maybe if I take my sweet *** time you can talk Cliff into doing some cams :mrgreen:

$750 adds another 20-25 hp :)
I have a set done on the shelf no waiting,i would need his stock intake cores.

Pete

[RICKYRJ1]

Nice Job Rob, nice to see the work of a true craftsman who cares about the final results of his hard labor :saluting:

[1990 quasar blue]

$750 adds another 20-25 hp :)
I have a set done on the shelf no waiting,i would need his stock intake cores.

Pete

Wow. Someone would have to be crazy to go through all the time and expense of head porting and leave at least 20 more horses on the table for 750.00. Sorry to get off topic Rob phenomenal work as always. A surgeon with a grinder.

[Pete]

Pete......do you have a thread somewhere describing what you do to cams ;)
Why only the stock intake cores?

Can I use my original lifters?

Robert........how are we going to attribute HP gain to porting if I use Pete's cams :D

Well i figure you want just Intakes.
If you want exhaust cams i would also need your stock ex.cam cores.
Specs:
Intake
.236 .425
Exhaust
.220 .425

What do you mean by what i do to them? of course i don't have the machinery to regrind cams i send them out.

Pete

[Pete]

The exhaust cams are worth about 5 hp.
With intakes alone you will see 15-20 add exhaust will 25.


Pete

[XfireZ51]

The exhaust cams are worth about 5 hp.
With intakes alone you will see 15-20 add exhaust will 25.


Pete

Pete,

So intakes alone add 20+, if including exhaust cams then it's a total of 25, correct?

[Pete]

Pete,

So intakes alone add 20+, if including exhaust cams then it's a total of 25, correct?


Just intakes 15-20,i saw these #'s with my set up.

Pete

[Locobob]

Decided to take a few hours and finish up the port work on the intake so I can send it off to powder. I went a little bigger than usual on this intake since the ported heads will be able to take advantage of some extra flow. Here are a few pics:

Airhorn
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3050004.jpg

Plenum
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3050010.jpg

Injector housings
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3050018.jpg

Secondary runner
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3050015.jpg

Primary runner
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3050016.jpg

[sammy]

i will say it again ,one can really tell you care alot how the finished product comes out ,just an awsome job

[A26B]

Robert, that is one beautiful job......and I ain't just sayn' that either, I darn sure mean it. Just excellent, truly excellent.

[tomtom72]

=D>

Bob, man that package is a work of art!

:cheers:

[RICKYRJ1]

=D>

Bob, man that package is a work of art!

:cheers:

I agree Great job! :saluting:

[Jagdpanzer]

Excellent craftmanship Bob!
How do you go about achieveing the surface finish of the ports and flanges shown in the photos?

[Locobob]

Excellent craftmanship Bob!
How do you go about achieveing the surface finish of the ports and flanges shown in the photos?

Here are some of the flap wheels I use for the final finish - they are all 60 grit. The big one is 1.5in and requires some trimming before it fits in the port, usually I work it on the air horn or inside the plenum to get it down to size.
I get most of my stuff from Precision Abrasives.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3110001.jpg

Oops! Guess I will need a new one of these.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3110003.jpg

[LGAFF]

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3110001.jpg

Oops! Guess I will need a new one of these.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3110003.jpg[/QUOTE]



I will give away my one and only secret porting tip....I don't trim the 1.5". I spray it in alittle WD40 put it in the opening of the port and spin it up slowly, and you end up with perfectly round ports.(At the gasket surface)

PS: Cams should be complete next week sometime

[Locobob]

If I use an electric sometimes I can pull that off if the port size is close - not so much with the air powered die grinder.

Looking forward to hearing the latest on the cam experiments :cheers:

[Locobob]

Exhaust ports are getting pretty close to done now.
Here we have a template I made off of my own Stainless Works headers. My purpose in doing this is not to precisely port match but rather to give me a general guide for where to remove material. The header flange ports should be bigger than the head exhaust ports in order to discourage reversion. Most of the ports show a larger discrepancy in height as opposed to width - the one pictured is actually more of an exception as it shows a good deal of room in width. I have added very little width to the head port outlet, instead focusing on adding height. Stock height is 1.4in and the one pictured is currently at 1.47in, probably going to call it good at 1.5in. I am also removing more material from the roof rather than the floor as it presents a straighter flow path - heads in photo are upside-down so roof is at the bottom.

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3180002.jpg

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3180004.jpg

[LGAFF]

I bet that was some exhausting work!

[Locobob]

More "Exhausting" work!
Here the ports are almost done - presently finished with 60grit

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3240002.jpg

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3240003.jpg

Some of my tool selection for blending around the valve bosses, these are all 1/8in bits:
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3240004.jpg

[RHanselman]

Man, wish I could see the work! the internet sucks here in Afghanistan... No pic's will come through!

[Locobob]

Man, wish I could see the work! the internet sucks here in Afghanistan... No pic's will come through!

Hi Ron, good to hear from you - thought you were done traveling?

[Locobob]

Working on the chambers:

Rough cut - blending out the quench areas a bit.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3270001.jpg

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3270003.jpg

Decided to make a template out of plexi to try and keep things consistent from cylinder to cylinder. Using the head bolt holes for alignment worked fine on the head I made the template off of - on the other head the holes were slightly off making this a bit more challenging.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3270007.jpg

A chamber after some sanding around the edges.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3270009.jpg

[Polo-1]

Look at you..... The Big Guy on the LT5.

Looking good Rob

What's your thinking on the laying out the clover leaf. I like the idea of unshrouding the valves. This picked up some cfm on mine.

[carter200]

Unshrouding is always a good thing....Opps, I did NOT put my hand up :o

[Locobob]

Look at you..... The Big Guy on the LT5.

Looking good Rob

What's your thinking on the laying out the clover leaf. I like the idea of unshrouding the valves. This picked up some cfm on mine.

I'm taking kind of a middle of the road approach. Blending back the quench area enough to unshroud the valves some but not taking it out too far. I noticed most of the newer four valve designs have more of a round chamber with a taper - Todd did something like this on his 427 build. I'm not exactly an F1 mechanical engineer though so I'm staying with the tried and true. I'm basically copying what I've seen on LPE chambers here.

[Polo-1]

my chamber and valves stock.

round out the "flats" at the four valves edge ( for a 4" bore) and pick up 13 cfm.

I just think you might be doing more work for VERY small gain on the "left/right" clover.

I know I told what to do to pick up 7-10 HP on the exhaust side. I did not see it done in the pictures.... 1/8 wide flat spot.

Todd's stuff is out there (and it worked for him). Keep your build to tried and true. Much easier and cheaper, and you wont need a heavy mill or special pistons to get back compression.

[RHanselman]

Hi Ron, good to hear from you - thought you were done traveling?

I wish... I'm retired but still a gluten for punishment...

You should bring some of your fine work down to LV in Sep. I'm going to host another event...

[Paul Workman]

Working on the chambers:


http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3270001.jpg

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3270003.jpg


http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3270007.jpg


http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P3270009.jpg

So, tell us, Bob.... Are you actually porting heads, or painting the Sistine Chapel?:sign10: JK, bro!;)

P.

[XfireZ51]

Bob,

You going to unshroud the valves?

[Locobob]

my chamber and valves stock.

round out the "flats" at the four valves edge ( for a 4" bore) and pick up 13 cfm.

I just think you might be doing more work for VERY small gain on the "left/right" clover.

I know I told what to do to pick up 7-10 HP on the exhaust side. I did not see it done in the pictures.... 1/8 wide flat spot.

Todd's stuff is out there (and it worked for him). Keep your build to tried and true. Much easier and cheaper, and you wont need a heavy mill or special pistons to get back compression.

Hey Kev, I do plan on rounding out the flats (unshrouding the outer edges of the valves), that is why I was asking about the liner thickness. I can see the gasket rings on the heads so I figured if I knew the liner thickness I could use the rings as a reference point.
I did consider doing Gregs exhaust mod, talked to him about it a while back... but decided against it for a combination of reasons. Main reason was I simply could not come up with a way of doing it with the equipment that I have to work with, I really think a mill is needed to pull this off. I also have some concerns over proximity to coolant and air flow reattachment. I understand the theory behind the idea and Greg indicated some positive test results but I'd really like more detail on the testing and to see more proof of the concept before jumping on board - then I might be tempted to talk with some of my machine shop buddys about how to execute. I'm going to generally stick with the LPE influence on this - only with a bit more intake volume and a bunch of my (anal) attention to detail.

[Locobob]

Bob,

You going to unshroud the valves?

Yes :cheers:

[Locobob]

I wish... I'm retired but still a gluten for punishment...

You should bring some of your fine work down to LV in Sep. I'm going to host another event...

I'd really love to do the Vegas thing again, realistically though I doubt I will be able to swing it this year.

[Locobob]

So, tell us, Bob.... Are you actually porting heads, or painting the Sistine Chapel?:sign10: JK, bro!;)

P.

I am using the pink pen just for you Paul, I know it's your favorite color :mrgreen:

[Polo-1]

I'm out of stock on standard & LA sleeves. I do have a RW HD liner on the bench. If you need to use one for inking.

The exhaust deal was told to me ( they had the motor on the dyno, pull the ex manifolds off, flattened the edge and pulled 7-10 more hp ) this was done on more than one motor to verify.

Just FYI :handshak:

[XfireZ51]

Polo,

Please describe the GVD exhaust mod further. I just put on a set if GVD heads and noted a mod on the exhaust port/header interface.

[Polo-1]

if you look in the port of GVD vs Rob's you will see it.

It's the old knife edge or flat edge debate.

[XfireZ51]

Yes, I noticed that in my heads. Port divider has a flat edge to it.

[Locobob]

After tiptoeing around the valve seats working the chambers I finally got smart and had my local machine shop cut me some junk valves to use for protecting the seats. I think they came from a Toyota or something but anyhow I had them cut so that they fit almost perfectly flush with the chamber roof. Wish I had done this earlier - makes the job so much easier.
Here are some pics of the chamber work coming along.

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P4010004.jpg

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P4010003.jpg

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P4010002.jpg

[Polo-1]

you might be on to something Rob " under sized valves " :D

[Locobob]

Almost done, just some fine tuning to do.

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P4060003.jpg

[Polo-1]

a little more polish and they will be ready to hang on the wall:D

They look really nice Rob.

[tomtom72]

I have to stop looking at your work Bob or I will start to hate my stock ZR-1.....which I used to be extremely happy with I might add!:)


Man that is just some fine head work! I have head envy!:sign10:

[FU]

Stock is boring Tom. Take a ride to Chicago :cheers:

[Locobob]

Stock is boring Tom. Take a ride to Chicago :cheers:

:iamwithst

Headers, exhaust and porting really wake up the motor and let the 32 valve design shine.

[Locobob]

CC ing again. I did this before starting just to establish a baseline but now the focus is on chamber to chamber consistency. Anyhow the my results after working the chambers came in at a smallest of 41.5cc and a largest of 42.5cc. I do each chamber twice as an error check, if I see any substantial difference then I do it over until I get a consistent result. My method has proven to be accurate and repeatable, I figure my margin of error is probably under .5cc. The largest volume was the chamber I used to make my template - which I expected as it shows the difference between the template and the marker trace on the others. The next step is to remove some more material to bring all the chambers up to the volume of the largest.

Here we have a chamber filled with water and a bit of food coloring. The plate over the top is 1/2in plexi with some Vaseline around the edges and valves for sealant.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P4090002.jpg

How much difference is 1cc? About 2.4%
Here is 1cc poured into the corner of a chamber - probably looks like more than it is since the head is tilted. Anyhow when I'm done they will all be at 42.5cc and then the heads will be surfaced to achieve the desired compression ratio.
http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P4090003.jpg

[Locobob]

Well I just couldn't leave it alone. Found this glass burette kit complete with stand and teflon stopcock for $60 shipped and just had to have it. It has a 50cc capacity with .1cc markings which greatly increases the accuracy of my measurements. I remeasured using the burette and was pleasantly surprised by how accurate my previous measurements were using the syringe method - all chambers were within about .25cc of my prior measurements. As it stands now I have 1 chamber at 42.5cc, 4 at 42.4cc, 1 at 42.3cc, 1 at 42cc and 1 at 41.8cc. I'm happy with the 5 chambers that are within a .1cc so I just have 3 that require some minor material removal. I am still using water at this time, if I can verify that my set-up is alcohol compatible then I will probably give that a try next since it's supposed to be a better measuring liquid. One thing I learned right away is that cleanliness is critical to using a burette, it doesn't take much debris to create a clog and it's a real bitch to get it out.

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P4210005.jpg

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P4210002.jpg

P.S. This anal retentive madness is all your fault Cliff since you won't be picking up your stuff for a little while yet :D

[LGAFF]

If you have an IH ported, can you CC that to compare to my siamese job?

[Locobob]

Of you have an IH ported, can you CC that to compare to my siamese job?

Sure, did you want to see my 368 "B" port partial siamese or a conventional 2 port 36mm? What did you use to seal the injector hole?

[LGAFF]

I sealed with an injector, would be neat to see both, but I was thinking of the 36mm port. Mine ended up about 235CC

[LGAFF]

Siamese: 235-240cc
Stock: 180-185cc

[Polo-1]

Hey Rob

I know these have crazy hours in them. Have you come up with a price for porting the heads yet?

[Polo-1]

I thought test set was free:p

[Locobob]

Hey Rob

I know these have crazy hours in them. Have you come up with a price for porting the heads yet?

Dr. Evil says:
One Miiiillion Dollars..... Muuuuhaahaa Muuuuhaahaahaa

[Locobob]

Made a little trip out to the powdercoaters yesterday....

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P4220004.jpg

[tomtom72]

I have LT5 parts envy! :mrgreen:


Boy oh boy that stuff looks sweet! Congrats Cliff that stuff is going to be sweet on your motor!


The Maestro has dunn it again! Very very very nice work Rob!

[GOLDCYLON]

Dr. Evil says:
One Miiiillion Dollars..... Muuuuhaahaa Muuuuhaahaahaa

Hmmm and One Miiiiiilion Horse Power ;)

[GOLDCYLON]

Made a little trip out to the powdercoaters yesterday....

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P4220004.jpg


LT5 porn I love it :dancing

[Locobob]

Siamese: 235-240cc
Stock: 180-185cc

Lee

Full 36mm Injector housings are about 215cc

My partial siamese came in around 220cc

The 220cc partial siamese IH's along with my B port plenum raised hp to 480rwhp but lost some low/mid range torque on my 368. Your full siamese at 235 is really wide open in comparison - probably more appropriate for a stroker I would think. It'll be interesting to see how your project turns out.

[rhipsher]

Bob! I have a question. Are the head ports pretty much striaght down perpendicular to the face of the head. Because unlike the plenum and the injector housings which are curved." Those head ports look straight. Its got me thinking and stroking my chin. I'm thinking of a way to port the heads on the CNC mill with as little hand work as possible. Figuring out the bore taper angle from top to bottom isnt a big deal. I'm thinking a lolipop shaped 1" dia endmill. Writing a program that spiral feeds down the bore as close to the bottom as I can get. Then finish the rest by hand. You want to talk about fast. Accurate and with any finish you could desire. This would be it. But you can also scrapp them real fast. Id rather try it on a set of trashed ones first to be sure. And next would be mine. But the bores look pretty symetrical. But since you, Paul and Pete have already been there and done that you can tell me if my assumptions are correct. Because I have incredible capabilities to make it happen. Top notch software and top of the line CNC equipment.
I'm not looking to take anybodies bread and butter away from them. I would just do it to my own ZR-1 thats all.

[Locobob]

The majority of the head intake port is relatively straight. You could pretty easily do the area above the valve guide with a CNC program. Once you get close to the valve guide you need to transition into more of an oval shape (width wise) for better airflow and to avoid expensive problems. The exhaust side would likely be a bit more challenging to program. I think Pete has done the CNC route - might ask him about it.

[Locobob]

The heads are now at the machine shop - pressure tested good, seats and valves cut, decking to bring chambers down to 39cc. I managed to space off getting new valve seals but Jerry's Gaskets fixed me right up, amazing quick and efficient service - Thanks Jerry, you are terrific!

[4DSZR1]

Sounds like you're getting close to putting the engine back in....cool :-D

[Paul Workman]

Sounds super especially the pressure testing :dancing



Sounds good so far! I recon Bob already knows this, but just a thought:

Marc told me he recommends throwing in a pellet of that powdered walnut stop leak (available from a GM dealer) into the coolant, "for peace of mind". A vacuum test is needed to verify no oil seepage near the spring seat. If there is, Locktite 620 applied while the runner is under vacuum will draw the goop into the leak(s) seal any minor seepages. Or, Bob G has a line on some aluminum based sealer that has been used by some racers. (Maybe Bob or Pete can reveal their "better mousetrap", namely the maker and part number of the aluminum material he used to cure an oil seeper.)

Then the nail biting begins until you have several heat/pressure cycles behind you. Marc says if it doesn't spring a leak after about 500 miles, then your probably "good to go".

Just hope Bob ain't charging ya by the hour!! :mrgreen:

:cheers:

P.

[-=Jeff=-]

I did not think marc did anything for the L98 as far as PROM/Chip recalibration's were concerned

[Paul Workman]

I would hesitate using stop leak or aluminum based sealer if there are leak potentials. I will just pull the heads at that point. The trick is to determine if there are leaks with either water in oil, water in exhaust, oil in water or oil in exhaust. I am using Randy's ARP studs vice head bolts so I can pull the heads as many times as required. Something about torquing Head bolts into aluminum several times that is an issue which using ARP studs eliminates :cheers:

I am picking the heads and other top end up in a drive by vice having them shipped UPS which should save some money for that hourly charge :D

Paul....as I recall...you have heads ported also....how did you check for leaks of any kind (confirming you had no leaks) and did that potential really concern you? ;)

I am assuming you used new head bolts vice ARP studs?

Marc will have two EPROMs coming his way for recalibration (one 90' L98 and one 91' ZR1).

Maybe two 91' ZR1 chips...one for 87 octane and one for 91 octane :p

Testing was done before installing the heads!! NO way would I be interested in installing LT5 heads (whole engine has to come out) before attaining some confidence thru preliminary testing.

Understand this from a neophite under direction of FBI gurus (an expert I ain't and don't pretend to be!):

Coolant leak: I pressure tested the water jacket using Pete's homemade steel plate jig and RTV to block off the combustion ports and testing by spraying some detergent down the holes and looking for bubbles/foaming while applying 30# air pressure (thru a standard air hose nipple mounted port on the jig).

Oil leak: Sealing the runner at the combustion chamber and applying vacuum thru the valve guide, a piece of plexi sealed with an O ring over the runner allows one to observe the runner for bubbles/foam the same way - using soapy water to observe bubbles in the runner AND monitoring the vacuum gauge on the "Mitivak" - the "acid test", so to speak.

Yes, the head bolts were re-used. Pete has reused head bolts many times without any problems. (The bolts in the 90 are massive SOBs - weighing something like 24# for the bolts alone!)

FWIW,

P

[Locobob]

Here are the heads assembled and ready to go.

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P5260003.jpg

Machine shop decked them to get the chambers down to 39cc. I cc'd a couple of chambers after the fact to compare. My numbers came in just slightly higher but still less than 40cc - must be some difference in technique.

[Paul Workman]

Here are the heads assembled and ready to go.

http://i418.photobucket.com/albums/pp270/locobob68/Cliff-headporting/P5260003.jpg

Machine shop decked them to get the chambers down to 39cc. I cc'd a couple of chambers after the fact to compare. My numbers came in just slightly higher but still less than 40cc - must be some difference in technique.

Shweeeet! Don't know 'bout U Bob, but I'm looking forward to the dyno #s!:cheers:

P.

[Locobob]

Nice collage Cliff, didn't know you were so artistic lol

I'm thinking it should be in the 430rwhp ballpark. It's mostly proven technique - with a little extra degree of precision.

I also checked the valve stem length using my pipe method which allows comparison to stock values. The machine shop trimmed them up some but they are slightly taller than stock by about .010 - .015in. This should be fine and get soaked up by the hydraulic lifters from what I understand.