HybridKOOP

I know this issue will probably stir some **** up, but I'm posting it up anyway. I'm about to put my motor together, and good friends of mine have given me a warning about PTW clearances in my motor.

Fact: Laskey AND CP both suggest to run the pre-built in clearance with CP pistons which is .0032 on my 83MM pistons, all the way up to 800HP.

Fact: I have been warned by people who have ran these exact pistons, to run a much looser clearance. Someone just ran the .0032, made huge power, and immediately found a ton of metal in the oil prompting an immediate rebuild (he is going .005 now).

I trust Laskey, I trust CP, but I also trust my competent motor-building friends who suggest almost double with CP does. Who has first-hand experiences with different clearances? And I totally understand if you don't want to mention exact clearances for your own personal reasons.

- Louis

DaveF

we have always run piston to wall @ 4.5 thou or more. my old Ge block piston/wall was 5.5 thou


it will sound like a diesal but a little heat will take care of that

tony1

A wise man once said, run them too tight and everybody knows it, run them too loose and nobody knows it...

HybridKOOP

Except for the clankclankclank at idle when cold

Oh well, off to the machine shop. I wonder if an aggressive hone will remove .0013 worth of material? Or will I need a full blown bore...

.CUBISH.

4.5-5 here i never run my turbo motors under 4

HybridKOOP

Rumor has it that Steph Eggums motor is at .014

BlackT5

My Volvo is running 9 thou with Ross pistons. I only drove it one year during the winter, now i garage it and drive the crx. Wasn't too bad at idle, but if you drove it when it wasn't warmed up... yea

RTW DC2R

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">A wise man once said, run them too tight and everybody knows it, run them too loose and nobody knows it...</TD></TR></TABLE>

ummm so what does this mean? lol

fjt

Not exactly experience on CP pistons but i have seen tons of setups running on d series between .006 and up to .008 P2W clearance with success..no loss of Compression and NO blow by.

One of these setups, with the biggest P2W clearance of .008 is making 442whp on a mustang dyno (estimated 465whp on a dyno jet) all this with a stock head.

So im saying you can safely run bigger clearance and be fine with it.

HybridKOOP

87.5MM in a B-Series? Good lord.

I'd say run .006 from what I've been reading.

Boostfed

.005" with Wiseco 84mm Custom pistons.

I had some Arias 83mm pistons machine shop bored it to .0035" and #1 and #3 scuffed the cylinder walls bad, I have been told it was probably a combination of not enough piston to wall clearance and too much timing on that motor

I have been told also by a very good engine builder they do 1 thousands for every 100hp

HybridKOOP

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boostfed.com &raquo;</TD></TR><TR><TD CLASS="quote">.005" with Wiseco 84mm Custom pistons.

I had some Arias 83mm pistons machine shop bored it to .0035" and #1 and #3 scuffed the cylinder walls bad, I have been told it was probably a combination of not enough piston to wall clearance and too much timing on that motor

I have been told also by a very good engine builder they do 1 thousands for every 100hp </TD></TR></TABLE>

I wouldn't completely agree with the last comment. I know of 300WHP Honda N/A cars that run in the neighborhood of .008, sometimes more... almost triple the logic your engine builder uses.

Boostfed

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

I wouldn't completely agree with the last comment. I know of 300WHP Honda N/A cars that run in the neighborhood of .008, sometimes more... almost triple the logic your engine builder uses.</TD></TR></TABLE>

The two people who gave me those fugures did not build my engine. They have built some of the fastest Turbo and All Motor cars out there though.

When I asked about clearances we were talking about TURBO motors also, I didn't ask them anything about an NA set up. We also were talking about HIGH HORSEPOWER motors 500whp and up , they just said general rule of thumb 1 thousand per 100hp. Everyone can do as they like and everyone will have different opinions BUT that is what you asked for is experiences and opinions so that is what was posted.


Edit:Also my last motor with the Arias with .0035" clearance that is what Arias recommended even though I stated may be up to 800whp, the machinists did it at that THOUGH he was skepticle still. Again #1 and #3 scuffed the cylinder walls bad

BlueSi2k

If I had to do it again I would have definitely gone looser in my last motor. In my first motor I used stock bore endyns which netted between .006-.007 after the hone. I beat the crap outta that motor and it lasted 60k miles. The skirts on the pistons eventually cracked from too much side loading. My second motor I went 20 over and had the clearances at .003. Running the same setup it lasted only 3k miles. Cracked #3 wall. It looked like the pistons expanded too much from the heat. Probably could have been saved with a less aggressive tune but id rather have that extra margin of safety.

sleepencivic

0Golden Eagle

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HybridKOOP &raquo;</TD></TR><TR><TD CLASS="quote">Rumor has it that Steph Eggums motor is at .014 </TD></TR></TABLE> not true.

for big boost motors we sagest .005 and up

Kelly.

48 thou on my d16 with wisecos
made 441/362

clearence suggested by my machinist, it was ~15 thou over what wiseco recommended if i remember right

Rocket

0.0015 clearance with 600whp. This is not for shelf stock.

TTT

While you are talking about P2W clearance.

What about talking about ring end gap too? Too tight a ring gap with lots of heat will cause wall scuffing too.

HybridKOOP

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TTT &raquo;</TD></TR><TR><TD CLASS="quote">While you are talking about P2W clearance.

What about talking about ring end gap too? Too tight a ring gap with lots of heat will cause wall scuffing too.</TD></TR></TABLE>

I think a common relationship between more size and ring gap can be established on a ratio basis. Thoughts?

SovXietday

Vitara user here.

.005 P2W clearance, I actually like the deisel sound to it.

.0045 1st ring gap, .005 2nd gap, I don't have any blow by and it seems to be working just fine. I hope to make 400+whp with time.

The Hastings rings didn't need to be filed down, that's just what they came out to be when I put them in. No issues yet, motor runs strong as hell.

litovi3tboi503

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HybridKOOP &raquo;</TD></TR><TR><TD CLASS="quote">87.5MM in a B-Series? Good lord.

I'd say run .006 from what I've been reading.</TD></TR></TABLE>

haha he said H man..

Blind-Fashion

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr Wonderfull &raquo;</TD></TR><TR><TD CLASS="quote">hey tony... I talked to you about my built h a while ago with the endyns that **** the bed... Im going CP at 87.5 mm bore. what kind of clearances would YOU reccomend if anything other than CPS recomendations. Ive been known to flog the **** out of my car. "low" boost is about 500whp... High should be around 600. I DO NOT want to have to rebuild this ****** again... Just want some input as to your reccomendatiopns. Not daily driven, but driven quite a bit. Run on the track once in a whaile, but beat at the street races often.

Thanls.</TD></TR></TABLE>

BULLSHIT!!

its your daily driver and you beat the **** out of it! its your only car *** nog!!

Blind-Fashion

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr Wonderfull &raquo;</TD></TR><TR><TD CLASS="quote">and you are the bullshit police??? HAHAHA thats funny. It wont be daily driven anymore... Oh ya and if you read the whole post, I mnetioned I beat the **** out of it. Bro...... </TD></TR></TABLE>


You know me ;-)

Blind-Fashion

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr Wonderfull &raquo;</TD></TR><TR><TD CLASS="quote">and you are the bullshit police??? HAHAHA thats funny. It wont be daily driven anymore... Oh ya and if you read the whole post, I mnetioned I beat the **** out of it. Bro...... </TD></TR></TABLE>

Lol... BUT you said its not a dail.. it sure n hell is if it has a motor in it!

PS Hows the bus treating you? still riding in the back?