How many people on here have experience with these pistons?

They are going inside my rebuild.

Scott at nexus said hed rather fit pistons that he has tried and tested, he wouldnt like to fit them as he doesnt want to hurt his rep if they blow. Thats fair doos but im not looking for massive power gains just a set that can handle at least 17psi.

Im rebuilding the standard tubs myself and getting them balanced and having bigger injectors fitted at a later date.

I read recently max psi on oem tubs is around 16-17 am i wrong?

 

Also its debatable on which headgasket to use, oem or an uprated metal one, i heard uprated are more prone to failure, legrath you mentioned using a stock one.

I cant decide on these two options

help...

 

What are you lot using then?

I think that's "Cometic" ;)

really? every time ive heard them called Cosmetic - there's as many references to one as there are the other on Google lol.

really? every time ive heard them called Cosmetic - there's as many references to one as there are the other on Google lol.

 

That's because eveyone gets it wrong! Cometic it is ;)

Unless they've started selling bling chromed cosmetic ones LOL

That's because eveyone gets it wrong! Cometic it is ;)

Unless they've started selling bling chromed cosmetic ones LOL

 

bugger!!!!! thats my sig out the window then :headvswal

http://www.cometic.com/

But whats the advantages of a cometic gasket? does it just withstand heat better?

At what kinda power are they needed?

Ive read that they are prone to failure.

bugger!!!!! thats my sig out the window then :headvswal

 

lol put a cheap fix in! my rad was wrong too

I'm sure the stock gasket is fine unless you're wanting to alter the compression.

There's plenty of big power Z's around with stock gaskets and it's very rare they ever go.

I'd stick with tried and tested stock especially if you're not wanting to go to silly power outputs - what's the point?

I'm sure the stock gasket is fine unless you're wanting to alter the compression.

There's plenty of big power Z's around with stock gaskets and it's very rare they ever go.

I'd stick with tried and tested stock especially if you're not wanting to go to silly power outputs - what's the point?

 

Ok you have made me come to a decsion oem it s :)

Save me a few bob too.

I have Wesco pistons and they have done 7000 miles and no problems. The torque is a massive jump up from standard and My original engine was within compression spec. I did go up to 89mm though. I was only going to go 88mm, but Mitch only had 89mm in and i took the chance.

 

I also have Standard OEM head gaskets. I did a lot of research before I decided on the present build as I believed I'd had had a disaster with the previous engine build.Turned out to have been a disaster with the people that were suposed to install it, but thats another story. So as my intension was to run about 450/500ish RWHP I decided that OEM was good enough.

 

I also went for big GT2871RS turbos, but have no intention of ever using them to there full potential. However I built the rest of the engine to cope should I loose my mind again and go for a 300degree rail and 850injectors, but then I'd get some heavly worked heads and comtecs. Se rides link in sig.

I have Wesco pistons and they have done 7000 miles and no problems. The torque is a massive jump up from standard and My original engine was within compression spec. I did go up to 89mm though. I was only going to go 88mm, but Mitch only had 89mm in and i took the chance.

 

I also have Standard OEM head gaskets. I did a lot of research before I decided on the present build as I believed I'd had had a disaster with the previous engine build.Turned out to have been a disaster with the people that were suposed to install it, but thats another story. So as my intension was to run about 450/500ish RWHP I decided that OEM was good enough.

 

I also went for big GT2871RS turbos, but have no intention of ever using them to there full potential. However I built the rest of the engine to cope should I loose my mind again and go for a 300degree rail and 850injectors, but then I'd get some heavly worked heads and comtecs. Se rides link in sig.

 

Would there be alot of difference between the 87.5 and a 89mm?

How much power gain will i feel, seen as im running real low compression at the mo? You got any figures from stock to forged?

Would there be alot of difference between the 87.5 and a 89mm?

How much power gain will i feel, seen as im running real low compression at the mo? You got any figures from stock to forged?

 

I don't see there being a great deal of power difference. Just a but more torquey.

 

I took a chance because I've been told that I should have had the block tested before I went 2mm bigger bore as it can some times cause the block to crack if there are any casting flaws.

 

Touche wood quickly

I don't see there being a great deal of power difference. Just a but more torquey.

 

I took a chance because I've been told that I should have had the block tested before I went 2mm bigger bore as it can some times cause the block to crack if there are any casting flaws.

 

Touche wood quickly

 

Ok so i can either go for 87.5 or the 88 think il go slighty bigger with the 88, but does that mean il be paying extra for the rebore?

 

Another thing, now that your using a 89mm piston, what does your engine capacity stand at? i know standard is around 2960 i think.

Do you know?

I'm pretty sure a 0.5mm rebore will cost the same as a 1mm rebore. You really need a good engineer who will match each piston to a cylinder. I'd also advise getting the heads sorted ie lifters checked over and any that arn'y up to muster replaced. Valve stems and guideds checked, because freashing up your engine will magnify any weeknesses in the heads.

 

http://www.300zx.co.uk/forums/vbgarage.php?do=view&id=3122

 

As for displacement. the 89mm pistons make it almost 3.1

I'm pretty sure a 0.5mm rebore will cost the same as a 1mm rebore. You really need a good engineer who will match each piston to a cylinder. I'd also advise getting the heads sorted ie lifters checked over and any that arn'y up to muster replaced. Valve stems and guideds checked, because freashing up your engine will magnify any weeknesses in the heads.

 

http://www.300zx.co.uk/forums/vbgara...do=view&id=3122

 

 

As for displacement. the 89mm pistons make it almost 3.1

 

Thanks for the info mate, i still got a load of research to do.

87.5mm make it about 2990cc

so should i go for the 87 or the 88? i cant decide?

so as long as my head is in good shape 88 will be fine?

I have 88mm weisco pistons in mine.

 

Had to get the block bored but to be honest I was going to have to do that anyway as part of the turbine scratched the cylinder number 4 when I blew my turbo.

 

Mark when you say that you need a really good engineer to match each piston to the cylinders are you saying the each of the pistons are not going to be exactly the same even though they come from the exact same cast ?.

 

This worries me a little because I went to a well reccommended engineering shop that only deals with engine rebuilds from Race cars and they didn't mark the pistons to tell me what piston number each one is. If what you say is true, am I likely to experience problems with compression because I have no idea what piston should go in what cylinder ? :(

I have 88mm weisco pistons in mine.

 

Had to get the block bored but to be honest I was going to have to do that anyway as part of the turbine scratched the cylinder number 4 when I blew my turbo.

 

Mark when you say that you need a really good engineer to match each piston to the cylinders are you saying the each of the pistons are not going to be exactly the same even though they come from the exact same cast ?.

 

This worries me a little because I went to a well reccommended engineering shop that only deals with engine rebuilds from Race cars and they didn't mark the pistons to tell me what piston number each one is. If what you say is true, am I likely to experience problems with compression because I have no idea what piston should go in what cylinder ? :(

 

Am i not correct in saying the cylinders have to be rebored when fitting new pistons anyway?

I thought that was a normal procedure when fiiting new rings and pistons.

Surely the block wears as well as the rings etc, a rebore is done so that the new rings can wear together with the newly cut cyclinders? am i wrong?

Unless the cylinder wall was truly shagged, you'd normally just have the block honed (puts the hatch marks back into the cylinder walls) AFAIK, rather than bore it out.

How much does a rebore cost?

How much does a rebore cost?

 

Again it all depends on your engineer.

 

I supplied all the parts to Phil a C & S Wood and they did the works. Have a look at some of the engine build pics in my pages 5, 6 & 7 of my Photobucket. He had the block reboared and all flashing removed from water jackets, Stripped the heads and had them machined, Enameled the engine and rebuilt it all included in the £1500 price. With a load of extras I had him do. My total bill was still under £2000 and it only took two and a half weeks from delivering the car and parts to drivng it away.

 

Might be worth thinking about a trip up to Manchester.

Again it all depends on your engineer.

 

I supplied all the parts to Phil a C & S Wood and they did the works. Have a look at some of the engine build pics in my pages 5, 6 & 7 of my Photobucket. He had the block reboared and all flashing removed from water jackets, Stripped the heads and had them machined, Enameled the engine and rebuilt it all included in the £1500 price. With a load of extras I had him do. My total bill was still under £2000 and it only took two and a half weeks from delivering the car and parts to drivng it away.

 

Might be worth thinking about a trip up to Manchester.

 

£2000 you serious?

is that including labour and removing engine?

or Did you remove engine yourself?

£2000 you serious?

is that including labour and removing engine?

or Did you remove engine yourself?

 

That is all labour, paint and some materials.

 

I supplied the parts which in total with the Turbos was about £4.2K for engine and £2K for the clutch, prop, camber arms, oil coolers and diff.

right so u spent lots then. :)

was it worth it you recon?

right so u spent lots then. :)

was it worth it you recon?

 

Prior to this build I had spent £12K on a total disaster, but things like all the bushes having been done and HICAS removed stayed. So yes I think it was well worth it and well done, but my divorce may result in it parting company from me which will really hurt.

 

Since the rebuild it has has Mike Smith manifolds and some odds and sods done.