427 coming along

[tpepmeie]

Originally Posted by Bob G

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]

Originally Posted by tpepmeie

Just something different . 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

When 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 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!


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?

sorry for all the questions!

grasshopper

[Polo-1]

Originally Posted by tomtom72

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


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?

sorry for all the questions!

grasshopper

Never be sorry for asking a question

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 . 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.







Todd

[XfireZ51]

Very nice, Todd =D>.

[Polo-1]

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



Housings look good Todd

[flyin ryan]

Originally Posted by tpepmeie

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]

Originally Posted by tpepmeie

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!