first off its a B16A with Endyn Rollerwave pistons and a P72 head... oh and i will also be reving the **** out of it...

i am assembling this bottom end and i noticed that intake and exhaust sides of the pistons are sitting above the deck?!?!?

this every much bothers me seeings how im using a P72 head and it has a flat surface with the deck.

now from the information i have found the headgasket has a compressed thickness of .026 and the measurements from my crude harborfrieght digital calipers it looks like the piston pops up about .018...

so i guess my question is how much clearance is needed/safe? is this of a real concern?


please give me some inside...im freaking out over here...

 

makes me feel so much better knowing i got the answers i needed...wait.....

 

bump, someone help him out

 

Some pic would be nice.

 

 

 

Correct me if I'm wrong, but I believe that endyn makes them that way on purpose for better quench and slightly higher compression for more power.

 

this is easy to do get your self some play doh or some clay. now flaten a ball pf clay on the top of one pistion about a 1/8 think. not put a head gasket on and then the head on and tighten it down like you would for final asambly. make shure you have the pistion with clay on it up and the top! after then head is tight rock the crank a littler bit( dont roll the motor compleatly over) just rock it foward and back a bit, now take off the head and look. you will see very well if there will be any issues!

 

what compression are the pistons?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by goldhatch94 &raquo;</TD></TR><TR><TD CLASS="quote">this is easy to do get your self some play doh or some clay. now flaten a ball pf clay on the top of one pistion about a 1/8 think. not put a head gasket on and then the head on and tighten it down like you would for final asambly. make shure you have the pistion with clay on it up and the top! after then head is tight rock the crank a littler bit( dont roll the motor compleatly over) just rock it foward and back a bit, now take off the head and look. you will see very well if there will be any issues! </TD></TR></TABLE>

without a headgasket? the GSR head is FLAT with the deck on the intake and exhaust sides of the head...


i didnt buy the pistons new... he told me 9:1... but it looks to be more close to 8.8:1 with a P72 head...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by goldhatch94 &raquo;</TD></TR><TR><TD CLASS="quote">not put a head gasket on and then the head on and tighten it down like you would for final asambly. make shure you have the pistion with clay on it up and the top! after then head is tight rock the crank a littler bit( dont roll the motor compleatly over) just rock it foward and back a bit, now take off the head and look. you will see very well if there will be any issues! </TD></TR></TABLE>

He said he has a GSR head, meaning the quench pads are flat, meaning zero clearance. He'd get that .018" gap over the whole deck if he used no HG. For some reason I can't remember the recommended minimum for clearance. You definately will want some, as a high-revving motor needs some protection from slight rod stretch (heat and inertia). I've always hated doing heat expansion calculations.

 

yeah... the heat expansion and rod stretch is what scares me. i bought the Pauters over everything else for the 100% intention on reving the **** out of this motor. the motor they came from was reved to 11k rpms and made over 650whp... i would like to come close i have every intention on having a powerband between 5-9.5k

 

My pistons sit .016 out of my deck, I am using 9:1 Wiseco's. My head has had .020 taken off it and I use a Cometic .065 Gasket to be safe. If you are worried about P/V contact just clay the motor like mentioned above. I however did not do that and I am somewhat paraniod to touch the cam gears. I have revved this motor to 9500rpm w/o any problems so I am just gonna go buy the seat of my pants and say screw it.

 

I AM NOT WORRIED ABOUT PISTONS TO VALVE CLEARANCE... (at work, caps ownage lol)

its the PISTON to HEAD SURFACE that concerns me.

 

see the flat surface of the combustion chamber? and the piston sits out the deck in the same areas...

 

Motor was probly setup to use a b16a head wich has a round chamber

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C1CYA &raquo;</TD></TR><TR><TD CLASS="quote">Motor was probly setup to use a b16a head wich has a round chamber</TD></TR></TABLE>

that is my best guess at this point... if i dont get some solid info i will probably be calling Larry at Endyn on mon-tue for some deff anwsers...

the reason i dont want to use a PR3 head is that i bought a VictorX for a P72 head already... and my PR3 head has scratched up cam journals...

 

**UPDATE**

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TheOldOne &raquo;</TD></TR><TR><TD CLASS="quote">The quench distance, or piston to head clearance had been set at .032”, to effectively give us “zero” quench clearance at 9500 rpm, due to rod stretch. .032” caused the pistons to hammer the head pretty hard at 10,000+, ultimately work hardening the pistons.</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TheOldOne &raquo;</TD></TR><TR><TD CLASS="quote">I’m using a .036” Cometic head gasket to achieve a piston to head clearance of .038”</TD></TR></TABLE>

quoted from http://www.theoldone.com/articles/badtothebone/


well ****...... im gonna buy another ****** headgasket and stackem... **** that only gives me ~.034-.036"....this is ****** gay...

 

I would recommend you go with a thick Cometic head gasket rather than stacking head gaskets.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">I would recommend you go with a thick Cometic head gasket rather than stacking head gaskets.</TD></TR></TABLE>

actually i think im gonna just get a PR3 head. i have one lined up... but the HUGE issue with that is that i have given all my PR3 compatible intake manifolds away, and i have spend real money on a VictorX for my P72 head that is now worthless if i go with a PR3 head...


anyone want to trade a P72 VicX for a PR3? mine is BNIB... just been sitting on my kitchen counter for the last year...

 

p72 gsr? i will take it if it will work on a b16 head. i do have a stock b16 intake i will let go

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by goldhatch94 &raquo;</TD></TR><TR><TD CLASS="quote">p72 gsr? i will take it if it will work on a b16 head. i do have a stock b16 intake i will let go</TD></TR></TABLE>

what makes no since.... re-read what i wrote...

 

honestly i doubt you will have much of a problem trading your mani for a b16 head manifold, but you might want to start by posting it in the classifieds


the for sale, the forced induction and your regional, if nothing less you can sell it and buy a b16 one

 

i think its going to be alot easier to just get a properly sized gasket, rather than try to swap heads, sell an intake manifold, buy a new head, buy a new intake manifold... and then in the end... i doubt you are going to get the needed clearance by swaping the heads out.....

the thick cometic gasket is going to be the way out.

 

You need to buy a dial indicator and get the true number that your working with..You typically want to run about .015 clearance p&gt;h. You have two options here unless you plan to swap the pistons out. One, you can run a thick head gasket and take a chance of blowing gaskets all the time. Two, you can have the machine shop machine the quench pad areas on the chambers so you can run a .030-.040 head gasket.