RB30 engine conversion (lots of pics) - Page 23 - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

R.I.P.S NZ · 27th March 2007, 10:03 AM

Quote:

Originally Posted by R32 Combat

There does seem to be an engineering issue with some RB30's running massive piston/bore clearance. Oil comsumption is crap and they are noisy. Mine has 0.006" some have even more. I think the guy's in Oz/Nz like this. Personally, I think it's sh1t. I'm runing 0.003" in the wisecos. The ACL's were causing the engine to use 1L of oil every 700miles.

ACL pistons or 0.006 clearance is not the reason you used 1 liter of oil every 700 miles, you obviously had other issues to cause that.

In the past we have done some RB30's with Ross or Venolia pistons with 0.006-0.007 clearance (recommended by manufacturer) and although a bit noisey when cold they have run fine, made real good power and there has been no issue with oil consumption or DET.

We now use a different piston that runs 0.0035, its quieter obviously but other than that there is very little difference.

Rob

tyndago · 27th March 2007, 04:27 PM

Just looking at this thread after a few months. #5 and #6 are the lean holes. Adding some clearance to the lean holes, *might* cause a little more oil in them than normal. The oil lowers the effective octane of the fuel. So you have the lean holes, more oil than normal. Good recipe for destruction.

We just finished a GT-R here in the US.2.6 liter (86mmx73.7) Dynapack numbers-rear wheel drive, 653 whp on 91 octane (PON) , 777.5 whp on C16. Laggy 2835's, top mounts. Its on an AEM with stock ignition. Good cold plugs($30 US)each.

Picasa Web Albums - Sean - Desktop Photos

andy42uk · 27th March 2007, 09:23 PM

I KNOW this is different, but relevant I hope.
I have just had my RB25DET block bored to suit 87mm Wiseco pistons, 3 thou was the suggested clearance, when I put the block in I was advised by the machinist that slightly under will be fine, he highly rated wiseco's since they were brought out around 2000, He did my last re-bore about 16 months ago, (different car and engine) it was good.....I crashed it!
I'll let you know, I pick it up tomorrow and by Sunday I'll have the lot done and be driving...
Regards,
Andy.

R32 Combat · 1st April 2007, 05:54 PM

Well, after a short delay, it's in and running again. The usual water bleed issue, but nothing major. Now to put a few miles on the old girl before the Marham bash..

And Dave, where are those brakes????

Madden · 1st April 2007, 06:18 PM

Well done mate.

Start driving the thing then and get some miles on it

R32 Combat · 1st April 2007, 06:20 PM

Yeh, I might cruise over to check out your gaff in the week. I hope my car doesn't wee it's pants... You having any joy there??

Madden · 1st April 2007, 09:53 PM

Yea gonna get a new pump tomorrow and sorted an replacement dump valve as well. Yea its weird mate im not losing water all the time. I left yours got home parked up no leak. I went to tescos and it pissed its self again. Also im not having to top it up either. Went to put some water in it today and it wouldnt take any what so ever. Very Strange.

Yea man come over to my place and we could go on a drive to scotland together to run the bloody cars in .

Zoltarc · 2nd April 2007, 06:55 AM

Quote:

Originally Posted by R32 Combat

Crank position snesor setup mockup.

Is that a Honeywell GT1 hall effect sensor?

SR BEAST · 2nd April 2007, 12:04 PM

Very interesting thread there ... !

I've had almost the same situation as ur rb30..except mine is an rb26 with cp/eagle rods

Clearance was supposed to be 0.0035 for the cp's, but ended up with 0.008 or bigger :s

I bought some JEs 87mm now, and I'll run 0.003 or 3.5 thou and hope the rings don't move like they did on the cps for some weird reason ..

WIT BLITZ · 2nd April 2007, 08:20 PM

I am learning some check that alot about skylines(yes I know this is a skyline forum)

and I know abit about cars and engines

awesome thread

R32 Combat · 2nd April 2007, 08:57 PM

After 100 miles, the engines performing well. Crank case blowby is non existent, which is about 1000000000000000 times better than the sh1tty ACL clearance.

Off for a run in on the rollers on Thursday and a road tune ready for Marham. It's getting a bit bloody tight now...

SR BEAST · 3rd April 2007, 04:47 PM

Quote:

Originally Posted by R32 Combat

After 100 miles, the engines performing well. Crank case blowby is non existent, which is about 1000000000000000 times better than the sh1tty ACL clearance.

Off for a run in on the rollers on Thursday and a road tune ready for Marham. It's getting a bit bloody tight now...

Did you have crankcase pressure before on the acl's ?

whats the previous clearance and the new clearance ?

R32 Combat · 3rd April 2007, 04:52 PM

Old PBC was 0.006", new is 0.003". Yes, the ACL's did chuff slightly all the time..

SR BEAST · 3rd April 2007, 05:14 PM

Quote:

Originally Posted by R32 Combat

Old PBC was 0.006", new is 0.003". Yes, the ACL's did chuff slightly all the time..

CP pistons recommend 0.0035
JE says 0.004

Should I follow the recommendations ? or should I go lower ?I had crankcase pressure on the CPs on my rb26

what ring end gaps have u filed them at ? top, 2nd and oil rings ?

R32 Combat · 3rd April 2007, 08:54 PM

Zoltarc, yes, the sensor is a GT1 from Honeywell

http://rswww.com/cgi-bin/bv/rswww/se...cape&Nr=avl:uk

My rings gaps were OK as supplied from Wiseco. 0.014" for the 2 comp rings. I forget what the oil control rings were.

2nd April 2007, 08:20 PM	#340 (permalink)
WIT BLITZ GTR Register Member Join Date: Apr 2007 Location: South Africa Posts: 666	Awesome Thread I am learning some check that alot about skylines(yes I know this is a skyline forum) and I know abit about cars and engines awesome thread

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27th March 2007, 04:27 PM	#332 (permalink)
tyndago GTR Register Member Join Date: Oct 2002 Location: LBC , CA Posts: 2,268	Just looking at this thread after a few months. #5 and #6 are the lean holes. Adding some clearance to the lean holes, might cause a little more oil in them than normal. The oil lowers the effective octane of the fuel. So you have the lean holes, more oil than normal. Good recipe for destruction. We just finished a GT-R here in the US.2.6 liter (86mmx73.7) Dynapack numbers-rear wheel drive, 653 whp on 91 octane (PON) , 777.5 whp on C16. Laggy 2835's, top mounts. Its on an AEM with stock ignition. Good cold plugs($30 US)each. Picasa Web Albums - Sean - Desktop Photos

27th March 2007, 09:23 PM	#333 (permalink)
andy42uk GTR Register Member Join Date: Sep 2005 Location: Oxford Posts: 860	I KNOW this is different, but relevant I hope. I have just had my RB25DET block bored to suit 87mm Wiseco pistons, 3 thou was the suggested clearance, when I put the block in I was advised by the machinist that slightly under will be fine, he highly rated wiseco's since they were brought out around 2000, He did my last re-bore about 16 months ago, (different car and engine) it was good.....I crashed it! I'll let you know, I pick it up tomorrow and by Sunday I'll have the lot done and be driving... Regards, Andy.

1st April 2007, 05:54 PM	#334 (permalink)
R32 Combat New Users Join Date: Jan 2004 Location: Berkshire Posts: 4,341	Well, after a short delay, it's in and running again. The usual water bleed issue, but nothing major. Now to put a few miles on the old girl before the Marham bash.. And Dave, where are those brakes????

1st April 2007, 06:18 PM	#335 (permalink)
Madden New Users Join Date: Nov 2004 Location: Berkshire Posts: 2,079	Well done mate. Start driving the thing then and get some miles on it

1st April 2007, 06:20 PM	#336 (permalink)
R32 Combat New Users Join Date: Jan 2004 Location: Berkshire Posts: 4,341	Yeh, I might cruise over to check out your gaff in the week. I hope my car doesn't wee it's pants... You having any joy there??

1st April 2007, 09:53 PM	#337 (permalink)
Madden New Users Join Date: Nov 2004 Location: Berkshire Posts: 2,079	Yea gonna get a new pump tomorrow and sorted an replacement dump valve as well. Yea its weird mate im not losing water all the time. I left yours got home parked up no leak. I went to tescos and it pissed its self again. Also im not having to top it up either. Went to put some water in it today and it wouldnt take any what so ever. Very Strange. Yea man come over to my place and we could go on a drive to scotland together to run the bloody cars in .

2nd April 2007, 12:04 PM	#339 (permalink)
SR BEAST GTR Register Member Join Date: Mar 2005 Posts: 258	Very interesting thread there ... ! I've had almost the same situation as ur rb30..except mine is an rb26 with cp/eagle rods Clearance was supposed to be 0.0035 for the cp's, but ended up with 0.008 or bigger :s I bought some JEs 87mm now, and I'll run 0.003 or 3.5 thou and hope the rings don't move like they did on the cps for some weird reason ..

2nd April 2007, 08:57 PM	#341 (permalink)
R32 Combat New Users Join Date: Jan 2004 Location: Berkshire Posts: 4,341	After 100 miles, the engines performing well. Crank case blowby is non existent, which is about 1000000000000000 times better than the sh1tty ACL clearance. Off for a run in on the rollers on Thursday and a road tune ready for Marham. It's getting a bit bloody tight now...

3rd April 2007, 04:52 PM	#343 (permalink)
R32 Combat New Users Join Date: Jan 2004 Location: Berkshire Posts: 4,341	Old PBC was 0.006", new is 0.003". Yes, the ACL's did chuff slightly all the time..

3rd April 2007, 08:54 PM	#345 (permalink)
R32 Combat New Users Join Date: Jan 2004 Location: Berkshire Posts: 4,341	Zoltarc, yes, the sensor is a GT1 from Honeywell http://rswww.com/cgi-bin/bv/rswww/se...cape&Nr=avl:uk My rings gaps were OK as supplied from Wiseco. 0.014" for the 2 comp rings. I forget what the oil control rings were.