Just get the cometic .043" head gasket and be done with it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DRAGLS &raquo;</TD></TR><TR><TD CLASS="quote">Just get the cometic .043" head gasket and be done with it.</TD></TR></TABLE>

i still wouldnt have the clearance that i would like... and i would have even lower compression... like 8.2:1


i have three PR3 heads in the garage, one is a 93 with a couple scratched caps, that one measures at ~.045 MORE clearance over a P72, and i have 99 PR3 that im 90% sure was virgin that measured at a little better than .050"... plus the .026" of the headgasket that is PLENTY of clearance. if the piston hits the head, it wont be attached to the rod anymore the other one is on my car, was gonna sell the motor as a swap when this motor goes in, but...**** it. boost is more important

now its time to move onto the rest of my gathering of parts and crankcase ventilation...

 

My typical comfort zone is .030" piston to head.Pistons have some rock over at tdc.More piston to wall clearance of turbo engines makes this even more important.On engines that have been run hard with less than .030" sometimes will show contact with the head.If you piston is .010-.015" above the deck than the .043" cometic gasket will do the job.Another option with a flat top piston is the have the top of the piston machined for a zero deck.Most any performance machine shop can do this.

 

The stock head gasket is .030". Is that enough if the piston at TDC is even with the deck?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">The stock head gasket is .030". Is that enough if the piston at TDC is even with the deck?</TD></TR></TABLE>

no... the pistons stick up like .018".... and from the information i have found the stock headgasket has a crushed thickness of .026"...

***UPDATE***

im gonna run a ****** PR3 head i guess...that way i have shitloads of clearance... just gonna take it off my other motor and put my P72 head on it or just sell it and my Victor X and buy a new one for a PR3...

 

Cometic .043

 

Just do the calculations. I bleive on a boosted engine, you should have something around .040 piston to head clearance. Your already out of the block by .018 ...so get a Cometic gasket that is about .060 thick and you'll be fine. There is nothing wrong with Cometic headgaskets. I would keep away from stacking gaskets though and I wouldn't feel safe with a .043 gasket either because that would only leave you with .025 piston to head clearance...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PHDZINE &raquo;</TD></TR><TR><TD CLASS="quote">Just do the calculations. I bleive on a boosted engine, you should have something around .040 piston to head clearance. Your already out of the block by .018 ...so get a Cometic gasket that is about .060 thick and you'll be fine. There is nothing wrong with Cometic headgaskets. I would keep away from stacking gaskets though. Keep the GSR head...</TD></TR></TABLE>

you guys are failing to see the fact that my compression dips to 8.0:1 if i do that... nothing sounds more pimp to me that a ****** B16A @ 8:1 with a 60-1 T4...

EDIT:
&lt;~~post 1595 77.4 FTW

 

If you F*#Ken listen and stop being a SMART ***...you should go back and read your own post.
You said "so i guess my question is how much clearance is needed/safe? is this of a real concern?"
I told you that you need roughly about .040 piston to head clearance...and you start talking **** like you know everything.
Obviously a stock head gasket smashed down gives you .026...with your pistons sticking out of the the block .018...thats only leaves you with .008. Your idea with using a B16a is still shitty because you still don't have the clearance for a high boost/rev engine.
You shouldn't of been a cheap *** and got used pistons in the first place.

 

Are you sure your compression would be that low with the thicker headgasket? I would think it would be much higher seeing as how you have a piston that raises from the block and your adding about .40 to the top of it with a thicker gasket?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turbohf &raquo;</TD></TR><TR><TD CLASS="quote">

you guys are failing to see the fact that my compression dips to 8.0:1 if i do that... nothing sounds more pimp to me that a ****** B16A @ 8:1 with a 60-1 T4...

EDIT:
&lt;~~post 1595 77.4 FTW</TD></TR></TABLE>

The gasket thickness does not matter in compression ratio calculation,it's the squish (piston to head clearance).You are just punching in numbers without knowing what they mean.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PHDZINE &raquo;</TD></TR><TR><TD CLASS="quote">If you F*#Ken listen and stop being a SMART ***...you should go back and read your own post.
You said "so i guess my question is how much clearance is needed/safe? is this of a real concern?"
I told you that you need roughly about .040 piston to head clearance...and you start talking **** like you know everything.
Obviously a stock head gasket smashed down gives you .026...with your pistons sticking out of the the block .018...thats only leaves you with .008. Your idea with using a B16a is still shitty because you still don't have the clearance for a high boost/rev engine.
You shouldn't of been a cheap *** and got used pistons in the first place.</TD></TR></TABLE>



<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NJIN BUILDR &raquo;</TD></TR><TR><TD CLASS="quote">

The gasket thickness does not matter in compression ratio calculation,it's the squish (piston to head clearance).You are just punching in numbers without knowing what they mean.</TD></TR></TABLE>
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SuperTeg95 &raquo;</TD></TR><TR><TD CLASS="quote">Are you sure your compression would be that low with the thicker headgasket? I would think it would be much higher seeing as how you have a piston that raises from the block and your adding about .40 to the top of it with a thicker gasket?</TD></TR></TABLE>

http://www.zealautowerks.com/index.html &lt;~ i was using this calculator, and your right i dont know what the **** they mean...


THANKS FOR ALL YOUR HELP AND INCITE GUYS! MUCH APPRECIATED

 

With a correct piston to head clearance (it doesn't matter how you get there) and assuming the head hasn't been milled and estimating a -1.7cc piston volume,you will be at 8.9:1 (using the calculator).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NJIN BUILDR &raquo;</TD></TR><TR><TD CLASS="quote">With a correct piston to head clearance (it doesn't matter how you get there) and assuming the head hasn't been milled and estimating a -1.7cc piston volume,you will be at 8.9:1 (using the calculator).</TD></TR></TABLE>

from the information i have come up with i *think* they are a -4.5cc piston... thats what i have been basing my calculations off of... that is the closest thing to 9:1 that Endyn list on there site.

 

larry at endyne is usually pretty helpful for stuff like this. If you havn't tried to call him yet, then I would. He can help you with your CR and tell you what is necessary to complete your setup. In my past I have found it to be helpful asking him.

 

Ok, I didn't have time to read through everything because im at work, but the proper way to handle this situation (piston above deck) is to put the piston at TDC and find the center of the piston ON THE SIDE (above the wrist pin ends) to where when you rock the piston back in forth in the cylinder your gauge doesn’t move. Now that you have found the center of your piston measure how far that is above your deck it goes (do this to all 4 pistons on both sides and they should be the same, if not you'll have to use the largest measurement you get), take that measurement and add .04" - .045" and that's how big you need to order your head gasket. I have ran across this a few times, happens a lot when the block has been decked, but this is how you solve this problem and everything will be good. After you get your measurements, call cometic and have them make you a gasket or just order the one closest to what you need. And if you want to rev this motor like your saying then you need to get as close to .045" over your piston/deck measurement as you can.

Edit: Ok, i can see the correct procedure has already been given to you but you seem to be a stubborn *** thats worried about your compression. So i offer 2 pieces of advice... spend the money and get pistons with the c/r that you want (what you should of done in the first place), or........ think about your c/r in these terms the compression ratio of those pistons were determined with probably a .040 clearence, so what is the harm in using a thicker head gasket if you still have .040 clearence?

Or fine, run smaller clearences to increase your compression a half a nut hair, but i promise after a little heat and high revs you'll be wishing you had the .040 clearence.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turbodohcsi &raquo;</TD></TR><TR><TD CLASS="quote">Ok, I didn't have time to read through everything because im at work, but the proper way to handle this situation (piston above deck) is to put the piston at TDC and find the center of the piston ON THE SIDE (above the wrist pin ends) to where when you rock the piston back in forth in the cylinder your gauge doesn’t move. Now that you have found the center of your piston measure how far that is above your deck it goes (do this to all 4 pistons on both sides and they should be the same, if not you'll have to use the largest measurement you get), take that measurement and add .04" - .045" and that's how big you need to order your head gasket. I have ran across this a few times, happens a lot when the block has been decked, but this is how you solve this problem and everything will be good. After you get your measurements, call cometic and have them make you a gasket or just order the one closest to what you need. And if you want to rev this motor like your saying then you need to get as close to .045" over your piston/deck measurement as you can.

Edit: Ok, i can see the correct procedure has already been given to you but you seem to be a stubborn *** thats worried about your compression. So i offer 2 pieces of advice... spend the money and get pistons with the c/r that you want (what you should of done in the first place), or........ think about your c/r in these terms the compression ratio of those pistons were determined with probably a .040 clearence, so what is the harm in using a thicker head gasket if you still have .040 clearence?
Or fine, run smaller clearences to increase your compression a half a nut hair, but i promise after a little heat and high revs you'll be wishing you had the .040 clearence.</TD></TR></TABLE>

Thank you....I thought I wasn't explaining it right...

 

so my original question of:

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turbohf &raquo;</TD></TR><TR><TD CLASS="quote">so i guess my question is how much clearance is needed/safe? is this of a real concern?</TD></TR></TABLE>

has been answered. THANKS! hell even your criticizim is appreciated

am i stubborn? yeah... it is obvious that a B16A doesnt come with a P72 head, and that these pistons where designed ONLY to be used with a PR3 head. i had it in my mind that i was gonna use that P72 head. I SEE NOW THAT ITS JUST A SHITTY IDEA. i have decided now that i will be using the ITR/PR3 head off my other motor. works out better anyway cuz it doesnt need a trip to the machine shop to get raped like the P72 head. plus its got aftermarket springs and retainers in it already and cams.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">spend the money and get pistons with the c/r that you want (what you should of done in the first place),</TD></TR></TABLE>

thats the thing. i wanted Endyn RollerWave pistons at around 9:1 and these are the ones they offer so I GOT THEM, happened to find them used and saved myself ~300bucks.

 

i hear you man. i built my 1st engine by myself (with the help of h-t) but because there was so much invested in it, i needed to hear things from like 5 different people before i could accept that it would work/was true.

and by the time you hear it from 5 people, the original one (or 2) who told you gets pretty pissed off.

i wouldn't have done it any differently though.....lol