Opinions on bottom end rebuild

Z

zer099

Member
So I was thinking of having the bottom end rebuilt while I'm out on my next contract and I was wondering what you guys thought. Nothing amazing crazy planned, but it still merits me asking on opinion:

CP 87mm 8.5:1 pistons, rings, and that jazz (Or maybe JE? Opinions?)
ARP rod bolts
Cosworth HG (not sure on the thickness yet)
Porting of the oil ways and making sure everything is nice and clean
Balancing the crank
New OEM bearings all around
New Water & Oil pump (maybe VE, people are half and half swearing up and down it's either bigger/better or not)
New pullies all around

I have future plans of fluffing up the head later, but on thing at a time for now. My end goal is for 500whp when wanted/needed. She sits around the very low 300s for now, and when I slap on a GT30R I'm sure I can get 500 if I tune right (after the head work to of course), I just want to make sure the bottom end is strong, not over the top, but above all things not too week.
 
GTIR-LOZ

GTIR-LOZ

New Member
hi, if you are going for that power i would recomend getting new liners i.e darton or similar as at 550 bhp the standard block is supposed to start twisting
 
PaulB

PaulB

Member
My two penneth for you......

CP 87mm 8.5:1 pistons, rings. JE, Arias etc, all US gear and decent. Jap gear like HKS, tomei is of higher spec.

ARP rod bolts will get these with the uprated rods you will require to get 500+whp
Cosworth HG go for a 1.2mm HKS gasket to keep the same C.R
Porting of the oil ways and making sure everything is nice and clean bit OTT i think
Balancing the crank and flywheel
New OEM bearings all around
New Water & Oil pump (maybe VE, people are half and half swearing up and down it's either bigger/better or not) just get brand new SR20 pump
New pullies all around

I have future plans of fluffing up the head later, but on thing at a time for now. My end goal is for 500whp when wanted/needed. She sits around the very low 300s for now, and when I slap on a GT30R I'm sure I can get 500 if I tune right (after the head work to of course) Id say something bigger than a GT30 to get 500+whp, I just want to make sure the bottom end is strong, not over the top, but above all things not too week.
 
M

mascot

Guest
god dont some pepole talk shite on this forum

what makes you come to the conclusion hks , tomei are better than the rest ffs most are made in the same bloody factory with the same matireals just stamp the hks on and double the price

and as for 1.2mm head gasket it depends what you have skimed of the block and head mate when they machine them for you










 
PaulB

PaulB

Member
Well the HKS stuff is said to be better quality, however im using Arias and Im happy.

The reason I said to be bigger than a GT30 was because he was referring to wheel horsepower.


P.S note the title of this thread......... OPINIONS :roll:
 
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G

gunmetalgtir

New Member
mascot said:
god dont some pepole talk shite on this forum

what makes you come to the conclusion hks , tomei are better than the rest ffs most are made in the same bloody factory with the same matireals just stamp the hks on and double the price

and as for 1.2mm head gasket it depends what you have skimed of the block and head mate when they machine them for you












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What crawled up your a55 and died? :lol: You seem quite annoyed by Rishi's statement!

Is it your time of the month? :lol:

I'm sure Rishi has got good reasons for saying this and will no doubt elaborate on it. ;)
 
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M

mascot

Guest
gunmetalgtir said:
What crawled up your a55 and died? :lol: You seem quite annoyed by Rishi's statement!

Is it your time of the month? :lol:

I'm sure Rishi has got good reasons for saying this and will no doubt elaborate on it. ;)
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wasnt disputeing the fact what rishi said he was basicly saying the same thing i think that theres no diffrence apart from price well thats what am asuming he was meaning anyway

and yea to be fair that time of month and on rag and all that like lmao :lol:

like chinese wispers so and so is better thats way forums work dont always belive everything u read i no i dont :lol:
 
Z

zer099

Member
Thanks so far for everything guys. Yes, I did ask for opinions so thank you very much for them.

I'm going for the GT30 because it is the smallest for my goal. Though 500whp would be nice, 480 or in that range would make me happy. I would like 500 to be a peak, not the everyday power level.

People are saying new rods all the way, and I thought the stock ones might take it, but I think I was reading in my sleep when I thought I read that they could, so I was thinking of going with maybe Eagle rods. I can still use the stock 19mm bearings with them, correct?

Also, for the HG and CR, I was thinking of going whatever keeps me at stock as well (after teh machine work). I just didn't know if I should go for something a little lower or higher and whated to hear what you all thought.

And lastly, thank you for pointing out the balancing of the crank & flywheel. Another guy pointed that at as well. Good to cover all teh bases. He also mentioned lightening them, but the fact that I might get more vibrations came up. What are your thoughts on that?

Thanks again guys for all your thoughts on this!
 
Z

zer099

Member
Odin said:
The Eagle rods use a 17mm bearing as far as I know, I wouldn't use anything other than rods that are designed to use the correct 19mm bearing.

Their are a few options as far as I know, I'm using Par rods myself.

Rob
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Didn't know. So, what are my options? I want to stick with the 19mm. So Par is good? Any others?
 
red reading

red reading

Active Member
wossner also make pistons and rod's ,the eagle rod's fitted to gtir303 engine were 19mm,as for rob's comment on using 17v19mm i have to agree as you would be spreading the load better on the crank using 19mm ,2mm does'nt sound alot but point loading wise it's a huge amount
 
Z

zer099

Member
I know where to get Pautner rods, but what about PAR and Wossner? I was reading up on PAR and really liking what I read. Pautner is nice, but really pricie.
 
J

jpward

Guest
GTIR-LOZ said:
think pauter do some but i may be wrong, i believe pauter also have the best reputation
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I ve always been told Carrillo are the daddies as most big racing bikes have them fitted but they are expensive!


I believe what Rishi was commenting on was the fact the differences in pistons tends to only realy be the metalergy of them as in the % of various metals to make up the final alloy.

The “4032” performance piston (like HKS) alloy has an approximate silicon content of 11%. This means that it expands from heat less than a piston with no silicon, but since its eutectic level of silicon is fully alloyed on a molecular level, this alloy is less brittle and more flexible than a stock hypereutectic “smog” piston. These pistons can survive mild detonation with less damage than stock pistons.

The “2618” performance piston alloy has less than 2% silicon and could be described as hypo (under) eutectic. This alloy is capable of experiencing the most detonation and abuse while suffering the least amount of damage. Pistons made of this alloy are also typically made thicker and heavier because of their most common applications. Because of the higher than normal temperatures these pistons experience in their usual application and also the low-silicon content allowing the maximum possible aluminium heat-expansion, these pistons have their cylinders bored to a very loose cold-fit. This leads to a condition known as “piston slap” which is when the piston rocks in the cylinder and it causes an audible tapping noise that continues until the engine has warmed to operational temperatures. These engines should not be revved when cold, or excessive scuffing can occur

;-)


Plenty people use JE's Weisco Arias without issue!
 
PaulB

PaulB

Member
yup, im using Arias and eagle rods. Had the little grove machined on the rods to take the 19mm bearing. I think this setup should take 550bhp+. I know the eagle stroker kit on the EVO is proven at 600bhp.
 
Rishi

Rishi

Still waiting on some shims!
Basically what i was meaning was that you cannot simply say that the Jap stuff is the best.. Its a bad arguement.. If it was the best then the Indy Cars, F1, Nascar, Top Fuel Drag Cars would all be using them. But they don't! They use JE, CP, Mahle, Cosworth, etc..

Remember that the JAP brands are mostly made by other companies to the Jap Brands specs. ie. JUN Pistons are actually Cosworth! Even US companies are the same, AMS Pistons are i think ROSS Pistons!..

As for which type of piston to go for, as JPWard says i wrote a little thing about it all here: http://www.gtiroc.com/forums/showthread.php?t=48031

Worth a read!
 
Z

zer099

Member
I read that actully. It was very informative. It was funny because I was reading a book on turbo builds and got to that part of the book right after I read that post so it stuck in my mind.

I contacted Eagel and they told me that there rods are made for the normal spec SRs and that if I use them to just use the 17mm bearings. I would like to find rods that are good, but not over the top pricie. I konw they are some good rods that can handle 500whp out there made for the 54c block. Like I said, I liked what I read about PAR, but cant find for the life of me who sells them.
 
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