2001 GS-R: Engine rebuild, other refreshments

[aw614]

I will say, if you do 81.5, that Wiseco piston ring compressor was a dream to use when dropping in the pistons into my motor last spring especially compared to the cheap adjustable tool.

I went with Swapshop racing to get my JDM ITR 81.5mm pistons. No complaints, but the piston rings it came with did seem to measure out too wide, and it took buying a few different piston rings to get the gap I wanted.

[DC231]

I will say, if you do 81.5, that Wiseco piston ring compressor was a dream to use when dropping in the pistons into my motor last spring especially compared to the cheap adjustable tool.

I went with Swapshop racing to get my JDM ITR 81.5mm pistons. No complaints, but the piston rings it came with did seem to measure out too wide, and it took buying a few different piston rings to get the gap I wanted.

I've had this happen as well. Most of the time it's within spec. If you are going for the tighter side of clearance then this does happen frequently with the rings. You can get the total seal rings and adjust accordingly in this situation. I've only ever had 1 set of rings fail to seal so I don't believe ring brand is as important as the actual gaps and clearances to pistons along with quality machine work and assembly.

[Dave7CDMTYPER]

If you use OEM Honda pistons then you will have to use the adjustable type tapered ring compressor like this

https://www.summitracing.com/parts/sme-90a3100

Or the plier type like this

https://www.summitracing.com/parts/otc- ... GqEALw_wcB

It seems that the ARP and Wiseco tapered ring compressors only come in .5mm so they have 81 & 81.5 but not 81.25.

That being said I would go with the plier type adjustable set personally if you decide to go with OEM pistons.

I have never had this issue because I've always used Nippon or forged pistons the past 20 years.

Thank you sir. I just ordered a Toda 81.25 piston slider.

[Dave7CDMTYPER]

I will say, if you do 81.5, that Wiseco piston ring compressor was a dream to use when dropping in the pistons into my motor last spring especially compared to the cheap adjustable tool.

I went with Swapshop racing to get my JDM ITR 81.5mm pistons. No complaints, but the piston rings it came with did seem to measure out too wide, and it took buying a few different piston rings to get the gap I wanted.

Ok interesting, why did you choose 81.5 instead of 81.25? I'm going to get a set of the Nippon, because they are pretty inexpensive, will have on hand if I decide to use them. I ordered a Toda 81.25 slider tool, so that should do the trick.

[DC231]

If you use OEM Honda pistons then you will have to use the adjustable type tapered ring compressor like this

https://www.summitracing.com/parts/sme-90a3100

Or the plier type like this

https://www.summitracing.com/parts/otc- ... GqEALw_wcB

It seems that the ARP and Wiseco tapered ring compressors only come in .5mm so they have 81 & 81.5 but not 81.25.

That being said I would go with the plier type adjustable set personally if you decide to go with OEM pistons.

I have never had this issue because I've always used Nippon or forged pistons the past 20 years.

Thank you sir. I just ordered a Toda 81.25 piston slider.

Very nice! It does not surprise me that this is a tool you can get from Toda.

[aw614]

I will say, if you do 81.5, that Wiseco piston ring compressor was a dream to use when dropping in the pistons into my motor last spring especially compared to the cheap adjustable tool.

I went with Swapshop racing to get my JDM ITR 81.5mm pistons. No complaints, but the piston rings it came with did seem to measure out too wide, and it took buying a few different piston rings to get the gap I wanted.

Ok interesting, why did you choose 81.5 instead of 81.25? I'm going to get a set of the Nippon, because they are pretty inexpensive, will have on hand if I decide to use them. I ordered a Toda 81.25 slider tool, so that should do the trick.

Back in 2017, it was recommended when I went with the local machine shop and I just went with that.

But that was also my first time putting a short block together and a ton of mistakes were made . I think I would have still gone with 81.5 as there seems to be more options piston wise. Honestly, Im still shocked that motor lasted 20k miles as is with the amount of autocross and track days I did on it and how much it burned...

[JDMJNKY]

Tons of solid advice in here.


I hope this inspires you. I almost passed state ref on a VAFC tune. Made well over 200whp

https://youtu.be/RLz-4a6miG8

[Dave7CDMTYPER]

Back in 2017, it was recommended when I went with the local machine shop and I just went with that.

But that was also my first time putting a short block together and a ton of mistakes were made . I think I would have still gone with 81.5 as there seems to be more options piston wise. Honestly, Im still shocked that motor lasted 20k miles as is with the amount of autocross and track days I did on it and how much it burned...

This is my first time doing a short block too. If you want to share any wisdom you gained, by all means. Or assembly procedures/processes that you wished you would have learned. I am really trying to do this process in the right way, so that everything runs great when put back together. I am putting fair amount of time and money into the project, which is motivating me to do it correctly.

Tons of solid advice in here.


I hope this inspires you. I almost passed state ref on a VAFC tune. Made well over 200whp

https://youtu.be/RLz-4a6miG8

Almost passed eh? What did you end up doing to pass?

Yes inspiring video! That will most likely be very similar to my engine setup. 200whp would be super great. Is that your car? In the comments it says it is a gsr motor stock valvetrain with P30 pistons. That's impressive, and my engine is gonna be way cooler than that anyway.

That makes me wonder. That car was untuned on stock obd2 ecu. Impressive that it was running so well without a tune. Would that car pass smog in that condition? For my car, maybe I'd put in stock ecu to pass smog, then back to the tuned ecu after that.

[Dave7CDMTYPER]

Is there any reason I should get one of these intake manifolds? Although I think S2 has a bad reputation here because of the forum issues several years ago.

https://4pistonracing.com/collections/i ... tra-street

https://4pistonracing.com/collections/i ... kunk2ultra

[aw614]

Back in 2017, it was recommended when I went with the local machine shop and I just went with that.

But that was also my first time putting a short block together and a ton of mistakes were made . I think I would have still gone with 81.5 as there seems to be more options piston wise. Honestly, Im still shocked that motor lasted 20k miles as is with the amount of autocross and track days I did on it and how much it burned...

This is my first time doing a short block too. If you want to share any wisdom you gained, by all means. Or assembly procedures/processes that you wished you would have learned. I am really trying to do this process in the right way, so that everything runs great when put back together. I am putting fair amount of time and money into the project, which is motivating me to do it correctly.

On the first build, I should have trusted my gut over my friend's and gone with the tighter piston ring gap and follow the manual on piston ring orientation. After I redid things on the current engine, I don't have the smoke or the crazy consumption the previous setup had. I still consume some, but a whole 5 quart jug of oil will last me 2.5k to 3000 miles and not 1000 miles with a mix of autocross, an occasional track day and driving to and from events. And I don't have a dirty bumper full of oil. Now instead of oil that gets on my bumper, it's just dirt, (who knew, but the rear end gets as dirty as my GTI does with just dirt). Both motors made identical power, but one doesn't smoke Both made around 180 whp, which I am fine with.

Also expect the unexpected. I went through so many random issues during the first start up, oil leaks and coolant leaks. The rear main seal I used at the time leaked a bunch of oil and the trans had to be pulled out. Additionally, another oil leak was found due to forgetting the oil pump o-ring that I discovered months later, thinking it was the oil pan gasket...

With coolant, the water pipe wasn't in all the way so it weeped a bit and I had issues with the hose clamps I originally used (non-oem spring loaded clamps) and the water pipe was not seated all the way in on the water pump side. .

I suspect due to excessing idling during the first start trying to figure out why the coolant would keep dropping during the bleeding processto see it on the ground along with an oil leak. I probably did not get a good break in of the motor.

The second go around, worked with another friend on assembling the short block and head, and got it timed. he did most of that, but the other stuff that I was more comfortable with, I did, like the water pipe, cooling lines, oil pan gasket, etc. I really wish I had consulted with him on the assembly and build the first time, but he was going through personal things at the time like going back to grad school, etc.