JustAFooL

iTrader: (45)

Running a comp 224/230 and just got patriot stage 2's milled to 59. Is the compression going to be to high for pump gas? .051 gasket over .041?? Any suggestions will be great cause intake currently coming of car..

batboy

iTrader: (6)

LS1? Stock flattop pistons? If so, the CR will be about 11.3 to 11.4 with .051 gaskets. Hope you can get good 93 octane.

JustAFooL

iTrader: (45)

We do have93 here, but thats crazy high c r. Really didn't think it was going to be that high. Is that getting to the point that its going to effect the motor life and have to mess with the timing??

mark21742

You might want to pull a few degrees timing, but the thinner gasket will make the motor less prone to detonate even though the compression will be a hair higher....if the motor isn't together yet you could go ahead and cut small valve reliefs in the pistons or do some grinding/polishing in the chamber to add a few cc's

Check on one of the calculators like wallaceracingcalculators to see what your dynamic compression comes out to....you might also be able to retard your can a few degrees to get the intake valve to close a little later...that will drop your dynamic compression down too....for instance on my 408 I'm running full timing on 93/92 pump gas with 12.5:1 scr, but because of the size of my can motor only sees 8.22:1 dcr

You want an absolute max 9.0:1 dcr for 93 octane....and to be safe is shoot for just at or under 8.5:1dcr

anheuserbusch08

iTrader: (11)

that cam will work perfect for heads milled 59ccs! i ran a 232 236 610 608 112+4 with 59cc 243s and worked flawlwssly

JustAFooL

iTrader: (45)

I get lost on all the static and dynamic. This is my first build so I'm just wanting everything To go smooth as possible. I know pistons will have to be cut, thats fine though. Car is a garage queen but i Would still likethe motor to last a while. Scared now compression will be to high

JustAFooL

iTrader: (45)

What size gasket you run?? And what was cr like?? How much was cut?

batboy

iTrader: (6)

If you flycut valve reliefs into the pistons and use the stock GM MLS gasket, that should drop you down to about 11 CR which is just about right.

Sales1@Texas-speed

Either setup will work for you on pump gas with the proper tune. With the thinner gasket obviously raising compression a bit more over the standard .051 gasket.

JustAFooL

iTrader: (45)

What about detonation and all the other factors. Which anthem better route?

mark21742

You optimum quench is around .035" for best burn and less chance of detonation, do o personally would go with and have ran the .041" gasket

JustAFooL

iTrader: (45)

Talked to a guy at tsp earlier and he said go with factory gaskets. Still kinda worried date talking tongue about the heads cam combo being a good one though

Sales2@Texas-speed

iTrader: (5)

Good talking to you earlier! Like I said, I'd give up a bit of quench to bring that static number down a little with a relatively small cam and early intake valve events! If you cut the pistons, you'd solve the problems because the cuts will bring your compression down a bit too!

JustAFooL

iTrader: (45)

So cut pistons or thick gaskets, which one??

batboy

iTrader: (6)

GM MLS gaskets.

cool breeze

iTrader: (1)

@JustAFooL Hey bud, im pretty sure i bought these heads from you. Do you remmeber or have an old text message or pm?
If so they're still on my ls1 and have been running great but i want to go full effort camshaft.
Trying to see how big i can go if these are them...ms4 maybe?

Bob570

He hasn't been here in nearly 2 years, he's probably not going to respond.

That said, those are a set of ported 243 heads right? Texas Speed might be able to tell you if it will have acceptable PTV because all 243 heads milled down to 59cc will have similar PTV. However I'm guessing an MS4 will require flycutting a fair bit.