Jump to content
SAU Community

Recommended Posts

hey, im about to set my ring gap on my rb25 and would like some opinions from you guys. im using cp's with 40 thou over pistons. cp reccommend bore x 0.0065/0.007 for top ring, bore x 0.007/0.008 for 2nd and min. of 0.015 for oil.

my bore is 3.425'' so top works out at 0.023, 2nd at 0.0274.

is this suitable or is should i be running something smaller. thanks.

Link to comment
https://www.sau.com.au/forums/topic/239144-cp-ring-gap/
Share on other sites

umm, id take 5 thou of that. for both. there gaps are a little big for a street motor.. somwhere around 15 and 18 is fine.

correct...the ring gaps quoted by Elite are excessive to say the least.

i wont quote what ring gaps i use but some where around or near to whats quoted above

Link to comment
https://www.sau.com.au/forums/topic/239144-cp-ring-gap/#findComment-4179720
Share on other sites

correct...the ring gaps quoted by Elite are excessive to say the least.

i wont quote what ring gaps i use but some where around or near to whats quoted above

Great! so now you know more than the piston manufacturer. Congratulations.

I just hope this guy has the good sense to not listen to your comment and instead listen to the people who make the piston and rings.

But hey, I could be wrong. While you're at it, give him your rule of thumb on piston to bore clearances. We wouldn't want him making the mistake of using the piston manufacturers specs on that one.

Link to comment
https://www.sau.com.au/forums/topic/239144-cp-ring-gap/#findComment-4180288
Share on other sites

Run them where you/he likes...its your/his engine

ask my customers have they ever had a problem with an excessive breathing rattly engine when using CP pistons.

my piston to bore clearances are none of your business...i don't want to give you any more free advice. :banana:

Yeah nice.

But when he cranks the boost up and binds the ring ends because you told him to run 17thou, how are you going to explain that to this guy. If you don't follow the instructions made by the manufacturer then you are asking for problems. Or do you just choose the information you adhere to or not? I don't really care what piston to bore clearance you run and I certainly don't need your advice. I just think you need to think about the consequences of giving advice like that in a place like this.

Link to comment
https://www.sau.com.au/forums/topic/239144-cp-ring-gap/#findComment-4180313
Share on other sites

Great! so now you know more than the piston manufacturer. Congratulations.

I just hope this guy has the good sense to not listen to your comment and instead listen to the people who make the piston and rings.

But hey, I could be wrong. While you're at it, give him your rule of thumb on piston to bore clearances. We wouldn't want him making the mistake of using the piston manufacturers specs on that one.

Run them where you/he likes...its your/his engine

ask my customers have they ever had a problem with an excessive breathing rattly engines when using CP pistons.

my piston to bore clearances are none of your business...i don't want to give you any more free advice. :banana:

Edited by DiRTgarage
Link to comment
https://www.sau.com.au/forums/topic/239144-cp-ring-gap/#findComment-4180305
Share on other sites

....and I wouldn't call 28thou excessive in a 3.425 inch bore. People cringed when engine builders started running closer to 3thou BE clearances but it was all for a reason. Ring technology these days is that far advanced from the 90's. You don't need to run tighter end gaps to keep it sealed.

Link to comment
https://www.sau.com.au/forums/topic/239144-cp-ring-gap/#findComment-4180324
Share on other sites

After seeing how well my engine stood up to the work i put it through before the clutch explosion, I am not arguing with 3lit3 32. I dragged it, raced it, and generally did all you can do in a high performance car. On teardown the piston.s rings. and bore.s were still like new. He built it and is building the replacement and i wouldnt have it any other way.

Link to comment
https://www.sau.com.au/forums/topic/239144-cp-ring-gap/#findComment-4180325
Share on other sites

ive already done them to elites spec. and yeah its also what cp reccommend so cant be too wrong. just wanted to double check. last thing i want is the rings binding. and yeah it is turbo (garrett t04z), planning on running high boost. street car but will be seeing the track a fair bit! thanks again.

Link to comment
https://www.sau.com.au/forums/topic/239144-cp-ring-gap/#findComment-4180842
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • There's plenty of OEM steering arms that are bolted on. Not in the same fashion/orientation as that one, to be sure, but still. Examples of what I'm thinking of would use holes like the ones that have the downward facing studs on the GTR uprights (down the bottom end, under the driveshaft opening, near the lower balljoint) and bolt a steering arm on using only 2 bolts that would be somewhat similarly in shear as these you're complainig about. I reckon old Holdens did that, and I've never seen a broken one of those.
    • Let's be honest, most of the people designing parts like the above, aren't engineers. Sometimes they come from disciplines that gives them more qualitative feel for design than quantitive, however, plenty of them have just picked up a license to Fusion and started making things. And that's the honest part about the majority of these guys making parts like that, they don't have huge R&D teams and heaps of time or experience working out the numbers on it. Shit, most smaller teams that do have real engineers still roll with "yeah, it should be okay, and does the job, let's make them and just see"...   The smaller guys like KiwiCNC, aren't the likes of Bosch etc with proper engineering procedures, and oversights, and sign off. As such, it's why they can produce a product to market a lot quicker, but it always comes back to, question it all.   I'm still not a fan of that bolt on piece. Why not just machine it all in one go? With the right design it's possible. The only reason I can see is if they want different heights/length for the tie rod to bolt to. And if they have the cncs themselves,they can easily offer that exact feature, and just machine it all in one go. 
    • The roof is wrapped
    • This is how I last did this when I had a master cylinder fail and introduce air. Bleed before first stage, go oh shit through first stage, bleed at end of first stage, go oh shit through second stage, bleed at end of second stage, go oh shit through third stage, bleed at end of third stage, go oh shit through fourth stage, bleed at lunch, go oh shit through fifth stage, bleed at end of fifth stage, go oh shit through sixth stage....you get the idea. It did come good in the end. My Topdon scan tool can bleed the HY51 and V37, but it doesn't have a consult connector and I don't have an R34 to check that on. I think finding a tool in an Australian workshop other than Nissan that can bleed an R34 will be like rocking horse poo. No way will a generic ODB tool do it.
    • Hmm. Perhaps not the same engineers. The OE Nissan engineers did not forsee a future with spacers pushing the tie rod force application further away from the steering arm and creating that torque. The failures are happening since the advent of those things, and some 30 years after they designed the uprights. So latent casting deficiencies, 30+ yrs of wear and tear, + unexpected usage could quite easily = unforeseen failure. Meanwhile, the engineers who are designing the billet CNC or fabricated uprights are also designing, for the same parts makers, the correction tie rod ends. And they are designing and building these with motorsport (or, at the very least, the meth addled antics of drifters) in mind. So I would hope (in fact, I would expect) that their design work included the offset of that steering force. Doesn't mean that it is not totally valid to ask the question of them, before committing $$.
×
×
  • Create New...