Lunati cam and Pro Comp head discussion

[nlauffer]

I am having trouble finding out what cc the pistons are.  The machinist says they are just stock dish and he can't remember exactly what that is.  I have looked and looked.  The closest I have found is a set of Speed Pro (which I don't think these are) that is 10cc. 

Can anyone tell me just by looking at the pic above.  I am figuring 12cc.

[nlauffer]

I have used about every number combination that people say "should be" stock.  I come up with a final CR of 9.14 to 9.44, except if it is the worst of the choices at 18cc dished pistons and a 67cc head putting it at 8.9.  None of these numbers sound bad at all to me, they are definitely better than what I have.  Until I find out more about the heads I am just guessing. 

Still haven't decided to pull the trigger on a camshaft yet.

[nlauffer]

I spent some time on the phone with Eric from EQ today.  It took him quite awhile to decide my heads were a 2005 model which they did not list as a possibility.  He did not show the part # RH350Z.  The "Z" was the kicker.  Turns out after much searching that the only combination not listed in the catalog and the most likely answer is they are the 64cc, heart shaped chamber with 180cc intake runner.  I was hoping for this.

[454Man]

A 180 runner is perfect for the street! Awesome head! Go Get you a tq cam somewhere in the 220 or close to range. Those 1.6 rockers will increase duration a tiny but to possibly give you a pinch of a lope.

What's under the hood??? If you have to ask maybe we shouldn't race...

[rich weyand]

That's close to the Vortec heads, which have 64cc combustion chambers and 170cc intake runners.  With flat-top pistons, you should get a static compression ratio of about 10:1.  With stock dished pistons, it will be around 9:1.

What kind of pistons do you have?

[nlauffer]

There is a picture of them in a previous post. They are dished at possibly 12cc but the machinist couldn't remember for sure.

I finally got Camquest 6 downloaded. I like it. I will be using the XE262H. Part number 12-238-2.

Probably stick with 1.5 roller tip rockers.


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[rich weyand]

Dished at 12 cc should give you about a 9:1 compression ratio, which is fine.  No problem with pump gas, though you may need premium.

Looks like about 350 hp @5000 and 420 ftlb @4000.  Not shabby at all.

[nlauffer]

Here are the flow results for the heads.

Intake    Lift    CFM    Exhaust    Lift    CFM
    0.1   65.4                   0.1   55.3
    0.2   130               0.2   106.6
    0.3   177.9       0.3   133.2
    0.4   212.8       0.4   156.6
    0.5   234.9       0.5   174.5
    0.6   242.3       0.6   182.8
    0.7   244.3       0.7   188.3




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[nlauffer]

Well it took some time, but Comp finally got back to me and let me know the best cam choice is the 12-238-2.

I take it as a good sign this is the same on I want so ill go ahead and purchase the full kit


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[rich weyand]

Gonna be awesome.

[454Man]

Get that cam! :-) it will have a good lope to it...will sound and perform great with your setup.

What's under the hood??? If you have to ask maybe we shouldn't race...

[dsgb610]

Hey I have RHS heads and I love them. I went with a vortec manifold and perimeter boltvalve covers. RHS only makes aluminum heads now  but the heads we have are awesome for the price and flow better than vortecs. My compression ratio is a little higher and i went with a Comp 280h camshaft.

[nlauffer]

I'm still trying to decide whether to use center bolt or perimeter bolt valve covers.  I like the black Proform center bolt ones.

[rich weyand]

I think center-bolt ones are easier to seal up. 

[454Man]

X2 center bolt will seal better and wool have less chance of future leak.

What's under the hood??? If you have to ask maybe we shouldn't race...