Block,piston nothc CCs
- Thread starter Skip FIx
- Start date
I've seen the Edelbrock head chamber listed as having 7 cc's.
It'll be interesting to see what you get.
I'm sure you've got this part covered but here's a link to a compression ratio calculator... http://www.wallaceracing.com/cr_test2.php
It'll be interesting to see what you get.
I'm sure you've got this part covered but here's a link to a compression ratio calculator... http://www.wallaceracing.com/cr_test2.php
M
monk
Guest
I'll have to check and see what our Eddy's
cc'd at.
cc'd at.
Gerry, how come you are in G/stock? What are the requirements? What class would I run in @ 12.20?
Ray,
The best way to answer your question is to say that my car meets the
requirements for NHRA/IHRA stock eliminator. Class is determined by
lbs. per factored horsepower which is listed in the "Stock Car Classification
Guide". You can view this at NHRA.com. For my car the original factor
for the 360 hp is 10.10 which is E-Stock. However, several years ago
IHRA refactored the 1961 360 hp to 325hp. To recalculate the class,
use the original 10.10 factor multiplied by the original 360 hp=3636 lbs.
Divide the 3636lbs. by the refactored 325 hp=11.19. 11.19 is the
weight break for G-Stock (11.00-11.49) Using the lower number, 11.00,
multiplied by 325 hp=3575 lbs + 170 driver weight=3745 min. car weight
when I go on the scales.
To run in Stock Eliminator, car and engine combination must have been
available from the factory, and the engine/chassis must comply with the
various rules for Stock Eliminator.
I hope this answers your question.
Gerry
The best way to answer your question is to say that my car meets the
requirements for NHRA/IHRA stock eliminator. Class is determined by
lbs. per factored horsepower which is listed in the "Stock Car Classification
Guide". You can view this at NHRA.com. For my car the original factor
for the 360 hp is 10.10 which is E-Stock. However, several years ago
IHRA refactored the 1961 360 hp to 325hp. To recalculate the class,
use the original 10.10 factor multiplied by the original 360 hp=3636 lbs.
Divide the 3636lbs. by the refactored 325 hp=11.19. 11.19 is the
weight break for G-Stock (11.00-11.49) Using the lower number, 11.00,
multiplied by 325 hp=3575 lbs + 170 driver weight=3745 min. car weight
when I go on the scales.
To run in Stock Eliminator, car and engine combination must have been
available from the factory, and the engine/chassis must comply with the
various rules for Stock Eliminator.
I hope this answers your question.
Gerry
Ray, you may have to add a little bit to that driver weight formula....to make your calculations correct..........
uh oh! :eek: We're not going down the "Jenny Craig" road again are we?
There you go !!!! 
bangbang
............ YEEE HAA !!
Dave
bangbang............ YEEE HAA !!Dave
Skip FIx
Well Known Member
Well more fitting this weekend. Using a 251/251 @ 0.050 .3883 lobe lift solid roller with Comp lifters.LS 112 IC108. Looks like with the 1.7 Comp SS rockers the intake pushrod will be 9.250 and the exhaust 8.850. If I could use a 1.8 would use a 8.750 BUT there is an issue with V-P on the intake side.
At TDC with an old composition Victor head gasket that is aroud 0.040 there is .0.273 available on the intake and 0.359 on the exhaust even with no exhaust notch in the piston. The deck is 0.009 out so when I get the 0.051 head gaskets in there will be a little more to add in.
On the exhaust side with the lash in there there is over .220 clearance. Bad news on the intake side even with the lash there is only 0.084 from about 5 to 15 degrees ATDC with the 1.7s. Not even that much with the 1.8s so won't be trying them.
At TDC with an old composition Victor head gasket that is aroud 0.040 there is .0.273 available on the intake and 0.359 on the exhaust even with no exhaust notch in the piston. The deck is 0.009 out so when I get the 0.051 head gaskets in there will be a little more to add in.
On the exhaust side with the lash in there there is over .220 clearance. Bad news on the intake side even with the lash there is only 0.084 from about 5 to 15 degrees ATDC with the 1.7s. Not even that much with the 1.8s so won't be trying them.
Skip, With the 112 lsa installed at 108, you should be happy with .084 on the intake vpc. With the springs you are using , yoou will have no problems. I have run .070 with no issues and know many others that squeeze tighter than that. Sounds like you are getting closer and closer. Good luck
Skip FIx
Well Known Member
Yes the exhaust pushrods are longer, miss typed.
Ronnie I ran one of my Pontiacs alot tighter when we kept going bigger on the cam in that motor, just figured with this moderate cam and custom pistons we'd have a little extra room to go to a bigger cam if I wanted in the future. Although the smaller the notch the less CR lost.
Ronnie I ran one of my Pontiacs alot tighter when we kept going bigger on the cam in that motor, just figured with this moderate cam and custom pistons we'd have a little extra room to go to a bigger cam if I wanted in the future. Although the smaller the notch the less CR lost.
Didn't know this!! That is one thing I hate about the new LS1 style engines. I guess it was a non-issue with the flat tappets.
From looking at the numbers, I need about 52 cc's (ballpark) to get in the 13.5:1 range with Edelbrock heads, Fel Pro .040" thick gaskets (used 4.380" for gasket bore diameter.....anyone know the actual size?) and a 4.350" bore x 4.000" stroke @ zero deck.
How does one go about ordering custom pistons to achieve that chamber size?
It's not as simple as saying "A 54cc dome on my L88/ZL1 style pistons to get 13.5:1 with 113cc chambers in the heads in my 433."
I am totally lost on how to get what I want here......do I just tell them what the target compression is and HOPE for the best?
I don't even see how I can know what size the valve relief I'll need to cut into the cylinder will be before I get the pistons and do a mock-up.......so how would I have that figure to give the piston manufacturer? Guess?? From looking at a few pictures I'd guess 4 cc's maybe? (Not the factory notch, but a new notch for .730" lift in a passenger block.)
Skip, if you can find your spec sheet - what was the "effective dome volume" of your pistons? How about dome height and Compression distance or compression height? Thanks in advance, Jason
Merry Christmas
Merry Christmas
Thank You!!