Advice regarding engine re-rebuild

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rocketship4

Guest
G'day guys,

Long time reader, late member here.

Just wanted some experienced opinions on my situation.

I had my motor rebuilt a while back with all standard parts including Nissan .2mm oversize pistons.

I have looked after this motor, however I now find myself with a GT3037 turbo and wanting around 350-400hp atw.

I will be purchasing over the next couple of months engine management, injectors, cams, valve springs, head gasket etc.. However, should I trust the std pistons and rods? or would it be mandatory to get some rods and pistons and send the block off to be machined again?

Thanks for any thoughts/advice on the matter.

Geoff.
 

Rishi

Still waiting on some shims!
Pistons will need replacing.. Basically the cast pistons cant disipate the heat as quick as the forged items.. Even with the right cooling they will be on the raged edge as they won't like those kind of cylinder pressures..

Rods are good! Just use some ARP Rod Bolts!
 
R

rocketship4

Guest
Thanks for your reply :)

I think I'll look into getting some 86.2mm forged pistons made up then rather than buying 86.5 or 87mm and getting all that machining done again :?

Cheers,

Geoff.
 

GINGA

Active Member
The great thing about the R pistons being fairly weak is you can afford to risk trying to run big hp on them as when they do fail, its only normally the ringland that breaks and you loose compression but very little other damage is caused, so you could fit your big turbo, injectors, ecu etc and run them on your engine and see how it goes, if the pistons do fail, so what, then fit the forged pistons, cams, headgasket etc you were going to do anway but if they don't then you've just saved yourself a packet.
 
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rocketship4

Guest
Thanks mate,

I'm going back to Japan early January 2008, so the Cams, Injectors etc I will purchase over there. If I can get a good brand (JUN/TOMEI) rods for a good price, I'd say that would be another thing... just incase the std rods were to let go.

Geoff.
 
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Odin

Guest
I ran 400 bhp on my standard engine for 2 years before the ring lands let go, And as Paul said it didn't do any other damage.

You just need better Cooling, I'd fit a new cooper rad from absolute radiator.com, And a 16-19 row oil Cooler and that should help it last.

The standard rod will be fine mine where, But I'd fit some arp rod bolts if it where me,
The 3037 is a good choice but the 3071 seem's to work very well and is cheaper.



Rob
 

GINGA

Active Member
Although the 3071 is a great turbo it will be no good for the power he's looking for, the 3037 or a 3076 (I believe there pretty much the same turbo?) should provide the 350atw he's looking for at around 1.5bar boost which the std pistons might be able to handle and the 400atw with 2bar when/if he decided to fit the forged pistons etc. The 3071 would need at least 2bar to make 350atw and be at its max capacity, plus the std pistons are very unlikely to take that sort of pressure.
I wouldn't even bother with the arp rod bolts as you'll probably do more damage trying to fit them in situ than if you just left alone, as there a barstard to fit, plus I've never heard of a rod bolt or rod failing?
If it was me and I knew that I already had a very good std engine, I'd leave the engine totally std inc the cams and headgasket and just fit the turbo, ecu, injectors, fuel pump, intercooler, oil cooler and run it at 1.5bar then see how it gets on.
 
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Odin

Guest
GINGA said:
Although the 3071 is a great turbo it will be no good for the power he's looking for, the 3037 or a 3076 (I believe there pretty much the same turbo?) should provide the 350atw he's looking for at around 1.5bar boost which the std pistons might be able to handle and the 400atw with 2bar when/if he decided to fit the forged pistons etc. The 3071 would need at least 2bar to make 350atw and be at its max capacity, plus the std pistons are very unlikely to take that sort of pressure.

:doh: I didn't notice the ATW's bit :oops: .




Rob
 
O

Odin

Guest
Keira said:
yep, which isn't 400bhp :lol:

Was actually 399.7 bhp I'll have you know ;-) , Which is near enough for the purpose of answering this fellow's question :lol: :lol: :lol: :lol: .




Rob
 

Dooie Pop Pop

New Member
Odin said:
Was actually 399.7 bhp I'll have you know ;-) , Which is near enough for the purpose of answering this fellow's question :lol: :lol: :lol: :lol: .




Rob
i thought yours only blew up because you were running more boost than it was mapped for:?
 
O

Odin

Guest
Dooie Pop Pop said:
i thought yours only blew up because you were running more boost than it was mapped for:?

Nope, Was on the rollers getting mapped when it broke ;-) .




Rob
 
R

rocketship4

Guest
Hey guys,

Just to update.

I have decided what to buy etc, unless you experienced campainers can talk me out of it :)

I have already bought the 3037s (52/73) and want the car for occasional street/drag strip duties. Not as much track work. 8000rpm readline.

Todo/get:
Keep standard rods, just get ARP/JUN Bolts
Custom Forge Pistons to suit my fresh 86.2mm bore
Cometic 1.2mm Head Gasket (Min was taken off the deck and head when re-built)
Tomei Rocker Stoppers - Part no. 13220R300 (i hope)
JUN Cam Kit (272 OR 264)? Im thinking the 272's? Please let me know if 264's would be better!
JUN Adj. Pulleys
Sard 700cc Injectors
ARP or JUN Head and Main Bolts

Main Questions!

Do I keep the std rods? or id be better off forking out the extra $$ for JUN/Tomei Rods?

Which Cam? 264's or 272's for my application?

Thanks a great deal for any of your advice!

Geoff
 
P

pulsarboby

Guest
you will be better to keep standard rods but uprate the bolts to arp studs.
imo you will be better to go for 272 cams, will give you loads more torque, but to get the full benefit of the cams, you will need the head ported and gasflowed.
with piper 272's you can retain the original valve springs too.

i wouldnt even waste my money on the head studs either, a new set of oe bolts is more than good enough for that kind of power your running;-)

put the money you save on rods and head studs towards the head porting!
 
R

rocketship4

Guest
Thanks Pulsarboby,

Im going to Japan and JUN prices are not too bad, so I'll most prolly go with them.
I will look into the head work though!

So thats one vote for std rods and 272's :)

Cheers,

Geoff
 
R

rocketship4

Guest
Hey Guys,

Update for you all,

I now have Jun 272's (the 2R kit with sprockets).
Sard 700cc Injectors
ARP Head Bolts
Autronic SM4
Used Japanese unknown tuned length manifold
Greddy M-Spec Cooler and custom pipework.

Still need to buy a Head Gasket, won't be going with Cometic after reading some of the info on here.

After getting a few quotes for another rebuild, pistons, rods, head service/re-shim etc, I am thinking of bolting it all up and running her as is... Infact, not thinking, I'm pretty sure of it. :der:

New plan is to aim for 300-350BHP, and to do one of the following -

Standard rods and pistons (as is), HKS/Tomei Head Gasket, ARP Head and Conrod bolts, Jun 272 Cams etc and a damn good SAFE tune.

or

Standard rods and pistons, and a tune that will make the most out of its current build.

Personally, I am leaning toward the first option but would like to hear what you guys think!

Thanks once again,

Geoff.
 
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