Rebuilding my Type R

Nick_C78

New Member
Stock ring gaps is ideal for cast pistons and NA.

These are mine:
Top Ring Gap: .016
2nd ring Gap: .020

But that is with a .003 piston to wall clearance. Also I have forged pistons and the motor is turning really high RPM.

The style of pistons doesn't matter too much, but your RPM range does. Heavily.
 


CKnight90

New Member
I'm going to have to check the wall to piston clearance. Can you explain why that's a big part of ring gaping? I thought ring gaping had to do with just the cylinder wall size? I mean from what I read and how everyone shows/does the gaping of the rings, has to do with the cyl wall. Yes I guess you can call them replicas of the B18c5 pistons. RS Machine Pistons. Before it was bored It was at 81.0mm, with B18c ITR pistons. Rev was set to 9k. Other mod is Jun 3 cams. Ran really good with no issues unless reved high and burned oil. Was bored to 81.5 due to cyl 3 issues. Crank is fine. bottom end of block is fine. B18c5 Type R rods are fine.
 
Last edited:

Nick_C78

New Member
I'm going to have to check the wall to piston clearance. Can you explain why that's a big part of ring gaping? I thought ring gaping had to do with just the cylinder wall size? I mean from what I read and how everyone shows/does the gaping of the rings, has to do with the cyl wall. Yes I guess you can call them replicas of the B18c5 pistons. RS Machine Pistons. Before it was bored It was at 81.0mm, with B18c ITR pistons. Rev was set to 9k. Other mod is Jun 3 cams. Ran really good with no issues unless reved high and burned oil. Was bored to 81.5 due to cyl 3 issues. Crank is fine. bottom end of block is fine. B18c5 Type R rods are fine.
It is by cylinder size. Cylinder size is based on piston size + piston to wall clearance desired. Piston to wall clearance is based on piston type, rpm, turbo/NA, etc. It all goes hand in hand.

Just set it to stock specs. Lol
 

Samurai_Blue

Yolo Whippin'
stick to the basics. set it to OEM spec. If youre unsure have a reputable builder build the motor.
 


Muckman

Not a M0derator
Are you rebuilding an engine without the service manual?
Set the ring gaps per the service manual.
You have not built the engine outside of the stock specs so rest easy that you can safely use stock specs.

Does totally rebuilt head include new valve guides and cut valve seats?
 

CKnight90

New Member
It is by cylinder size. Cylinder size is based on piston size + piston to wall clearance desired. Piston to wall clearance is based on piston type, rpm, turbo/NA, etc. It all goes hand in hand.

Just set it to stock specs. Lol
Got it.

stick to the basics. set it to OEM spec. If youre unsure have a reputable builder build the motor.
Ok got it. Tomorrow I'm going to a known local person who's built many Honda engines. Turbo & NA.

Are you rebuilding an engine without the service manual?
Set the ring gaps per the service manual.
You have not built the engine outside of the stock specs so rest easy that you can safely use stock specs.

Does totally rebuilt head include new valve guides and cut valve seats?
Yes I am. I'm going by what everyone is posting & other sites I found. I was told to find the online manual for the GSR build? I can't locate it. I've had a lot of guidence in other forums and google searching though. Stock specs got it x3! Yes. Everything on the head was replaced. EVERYTHING from guides, seals, vavles, cut valve seats, dual vavles, retainers, ect...!

Again thanks for the replies. Helps a lot when people post and remind me of stuff and add more what is needed. What's a good Wall to piston clearance? Does that also base on how thick the ring is from piston seats to cyl wall?
 

Muckman

Not a M0derator
For the service manual Register on http://www.hondahookup.com and go to the downloads tab.

There is also a guide by Jeff Evans called the definitive build guide that will help you.

Cast pistons dont expand as much as forged pistons do as they are different alloy. This means you can go tighter probably .0020 ~ .0025" p2w. Forged starts at .0030 and up.

Good job on the head. Very thorough.
 

Muckman

Not a M0derator
That shows what I know. I've never built an engine using cast pistons. That seems ridiculously tight.
 

Nick_C78

New Member
Oh it gets tighter. Honda OEM specs are .0004" - .0016", with a service limit of .002". RS Machine recommends .00125 to .0015. I recommend .0015". I have ran .002" with RS Machine cast pistons and it burned some oil.

He should call RS Machine and ask them what specs they recommend. I am willing to bet they say exactly what I did (.00125-.0015), since it is what they told me.
 

CKnight90

New Member
Took it to a local builder. He gave me this paper with them measurements. Also I do remember STD stamped on my old bearings(wish I would of saved them). I'm assuming they are ACL? As for piston to wall clearance. I did not get unfortunately. BUT i will next time I see him when I have my bearings & he's going to do my rings. He did all this for me on his spare time so no cost :) . Just a fellow enthusiast helping another :D

What Bearings do you suggest? I'm trying to put this block back together to OEM standards, or as close as I can. Go with ACL again? OR OEM? If possible please direct me to the ones for ACL and OEM with a link or detailed description? I will be driving this car around own here and there once in a while. I may take it to a strip just to have fun once in a while. I will be doing some pulls on the highway here and there.




Thanks again guys! I really appriciate your responses & this learning experience!
 
Last edited:

Nick_C78

New Member
Gotta plug in different bearings and calculate what the clearances will be and pick which ones fit your clearance goal. ACL are the same as oem green. Also, if you had ACL std before and they cleared then why not use the same...really depends how they wore.
 
Top