Got 205psi compression...

[Snook]

Think I overdid it on compression ratio. Using iron MW 80cc heads and flat tops with valve relief slugs are down in the hole 0.001". Mostly street with some limited NSS in the future.

Chuck (snook)

 

[Bighouse]

I want to hear that one running

 

[33 IMP]

More head gasket, more camshaft.

 

[Snook]

I want to hear that one running

I'll see if I can get a decent sound clip. I think it sounds pretty good with those solid rollers rattling around in there.

Chuck (snook)

 

[RemCharger]

Think I overdid it on compression ratio.

Not at all!
Just don't try to run it on horsepiss. That would be silly.

 

[Snook]

More head gasket, more camshaft.

0.051" head gasket and a ISKY RR570T on a 108*LC:

• Roller
• Valve Lift Int/Ext. 0.570
• Valve Lash Hot Int/Ext. 0.028
• ADV Duration Int/Ext. 290
• 0.050 Duration Int/Ext. 250
• Lobe Center 108

Chuck (snook)

 

[33 IMP]

0.051" head gasket and a ISKY RR570T on a 108*LC:

• Roller
• Valve Lift Int/Ext. 0.570
• Valve Lash Hot Int/Ext. 0.028
• ADV Duration Int/Ext. 290
• 0.050 Duration Int/Ext. 250
• Lobe Center 108

Chuck (snook)

With that much cam and that thick a head gasket, how did you get that much compression with flat tops?? Stroker crank?

 

[beanhead]

All assuming your tester is in good order, first (and easiest) thing I'd try is tightening up the lash a little at a time and check it.
What centerline did the cam end up on? You could also back the cam up a few degrees (as long as you have adequate exhaust valve clearance).
Besides that, you're looking at opening it up for thicker gaskets as 33 said, or different pistons(ouch)!
Or find a good race gas supplier near you!

 

[Snook]

With that much cam and that thick a head gasket, how did you get that much compression with flat tops?? Stroker crank?

Nope, stock forged 440 crank.

Chuck (snook)

 

[Snook]

All assuming your tester is in good order, first (and easiest) thing I'd try is tightening up the lash a little at a time and check it.
What centerline did the cam end up on? You could also back the cam up a few degrees (as long as you have adequate exhaust valve clearance).
Besides that, you're looking at opening it up for thicker gaskets as 33 said, or different pistons(ouch)!
Or find a good race gas supplier near you!

Tester is in good shape, not a cheap one. Right now, I'm running a mix (1/3 100 aviation and 2/3 94); I'm in airboat country, not hard to find hi-test. Runs well on that. I'm building a new engine, will be ready later this year. I'll be using that cam again, it's a good one. Ended up at 105.5*

Chuck (snook)

 

[33 IMP]

That cam looks similar to the .557 purple shaft im using. Yours has slightly less duration at .050, slightly more lift. I like it.

 

[R413]

That fuel mix is borderline, you don’t want any detonation.

 

[33 IMP]

Agree with R413. I think I'd run 2 parts 100LL to 1 pump premium.
Of course it helps that the 100LL I get here is about the same price as cali pump 91......

 

[dvw]

My 580" at 15.1-1 barely cracks 200psi. Of course the cam is 285_292@ .050". Flat tops, 10ccvalve reliefs and .069" gaskets. 57cc chambers.
Doig

 

[Geoff 2]

Overly advanced cam will give high readings.

 

[Kern Dog]

0.051" head gasket and a ISKY RR570T on a 108*LC:

• Roller
• Valve Lift Int/Ext. 0.570
• Valve Lash Hot Int/Ext. 0.028
• ADV Duration Int/Ext. 290
• 0.050 Duration Int/Ext. 250
• Lobe Center 108

Chuck (snook)

I had a reading similar to that.
I logged onto several car forums and read all sorts of advice. I was pig headed and wasn't willing to pull the engine to swap in dished pistons so I took short cuts. Big cam. Thick head gaskets. Yeah, it worked but it runs better now with dished pistons and quench.

 

[BSB67]

I like it. I think you will too. You’ll just need to run good fuel. There are no adjustments you can make to get from 205 to the 165-ish you’ll need to run pump gas, IMO.

 

[451Mopar]

Bring it to Colorado, that will fix the problem

 

[BSB67]

Bring it to Colorado, that will fix the problem

Good point!

 

[MCODECUDA]

Think I overdid it on compression ratio. Using iron MW 80cc heads and flat tops with valve relief slugs are down in the hole 0.001". Mostly street with some limited NSS in the future.

Chuck (snook)

Almost 14:1. We built a stock class 355 Chevrolet with flat top pistons and angle milled fuelie heads. We ended up with 265psi compression (almost 15:1) and ran
Cam 2 racing gas. Luckily our sponsor covered our fuel bill.