R33 Rb30 Conversion

[RBCalais]

Hey everyone, I have got a timing belt that was sold to me by a local performance shop. They did an R32 with a 30DET in it using an RB25 head and they told me they rang gates and organised a belt with them that works with the idler/tensioner the same as TWINVL was setup but its a shorter belt so it doesnt run so close. The belt I was given is 25mm wide, its a Gates Racing powergrip belt. It has T1592R on it and the numbers 102 through to 106 and 5-25.

Not sure if this information will help anyone in anyway, ive seen belts setup so many different ways its not funny, so what ever works go for it!

[Cubes]

How did twinvl do his.. I forget.

[Scooby]

Kaige posted:

TWIN VL... 'now using the same belt p/n T306 due to the gates not fitting properly so should be all fine!'

RB Calais posted:

...same as TWINVL was setup but its a shorter belt so it doesnt run so close...it's a Gates

So I'm assuming that TWINVL has used the 'close' set up. BUT he appears to have moved to using the T306 belt (his website still indicates that he used the Gates) presumably due to the perceived problem with the Gates tooth profile.

Edited January 9, 2007 by Scooby

[Cubes]

Scooby.. He's a dude on ct.com.

Just did a comp test. Motors done 50,000km's. 158psi exactly through out. I did 2 tests on each cylinder. The tests only varied 1psi. I took the highest reading.

So same as last time. Exactly the same across the board.

The motors running 0.0040" bore to piston clearance with a set of rb25 wiseco's.

[SirRacer]

the rb30e sump is slightly deeper than the rb20e sump. my engine went into a cefiro and we needed the space as the 30 sump would have hit the crossmember

my brother overfilled the engine and i can report than an rb30 can hold more than 10 litres :-)

hah yeap i was incredibly suprised when my 10 litre bucket didnt have enough space

what pistons does one reccomend if the acl ones arent suited?

[Cubes]

hah yeap i was incredibly suprised when my 10 litre bucket didnt have enough space

what pistons does one reccomend if the acl ones arent suited?

S3_girl (Darren) is running Precision Hyperutetic pistons in his 370rwkw odd rb30 with std rods.

[psi]

talking about pistons... I am quite sure that the dirty old VG30 has a slightly larger bore than the RB30. if i remember rightly, it is 0.5 mm. i'll check that..

Anyway, i havn't actually seen it for myself, but i've been led to beleive that they are a flat top style piston. I you bored the RB30 to suit it get you closer to the 9:1 comp ur after. most know that the VG also had a turbo version, so use that piston! wouldn't be the most ideal setup for making bulk power, but a good sound setup for a mild streeter..

Its worth the consideration and checking pins fit and deck height and all the usual stuff...

That help??

[Scooby]

Scooby.. He's a dude on ct.com.

Just did a comp test. Motors done 50,000km's. 158psi exactly through out. I did 2 tests on each cylinder. The tests only varied 1psi. I took the highest reading.

So same as last time. Exactly the same across the board.

The motors running 0.0040" bore to piston clearance with a set of rb25 wiseco's.

Hell thats good Cubes, well done. I still reckon your motor is one to aspire to. I went with RB25 Super Techs 8.98 according to software comp; .0025 coated and thats what they recommend.

Still want to get to the bottom of the timing belt issue. My preference is to run the 'close' set up using the same belt Kaige is using. The issue with the Gates belt profile has got me wary.

Edited January 9, 2007 by Scooby

[Bl4cK32]

Hell thats good Cubes, well done. I still reckon your motor is one to aspire to.

Well mine was built at the same time, side by side Cubes' motor, so does that mean mines special too?

[Cubes]

PSI,

I remember the pin size was different. Slightly larger. 22mm vs the RB30's 21mm. Nothing a set of forged rods can't sort though.

So they won't just bolt in with the std rods.

[Scooby]

Well mine was built at the same time, side by side Cubes' motor, so does that mean mines special too?

Special or 'Speshhhhiaaaallll'?

Absolutely if you're getting the same reliable solid performance out of yours.

Edited January 10, 2007 by Scooby

[SirRacer]

S3_girl (Darren) is running Precision Hyperutetic pistons in his 370rwkw odd rb30 with std rods.

is that the brand? im in nz so havent heard of them before

i was going to go with acl ones with the chromoly ring but you guys are doing very well at putting me off

[Cubes]

is that the brand? im in nz so havent heard of them before

i was going to go with acl ones with the chromoly ring but you guys are doing very well at putting me off

I assume so.. Precision is what I remember he said.

I can't find much on them via google.

[r33_racer]

Hey cubes....you ran 4thou piston to bore clearance in your motor, with wisecos and you said you get some piston slap when its cold. I ran acls in my personal road r33 when i rebuilt the rb25 not long ago, i ran 3 thou piston to bore clearance, which was 2 thou tighter then what acl specs stated. Even so i get absolutely no audible piston slap, not even straight up in the morning on cold start.

Out of curiosity what was your ring end gap clearance?

[Cubes]

I do get some slap but its not audible unless you pop your bonnet and really listen. Even then it only sounds like a little top end noise. So definitely not what I'd consider 'piston slap' but its definitely there for the tuned ear.

I have No idea what the ring end gap clearance is.

The bloke who built my motor said never to let it sit and idle on cold starts. Simply get in and drive it lightly to bring the engine temps up quickly. He also did something funky with the bore hone to reduce leak down and speed up run-in.

[r33_racer]

hmm i wonder if he washed the bore down with shellite and sprayed inox or wd40 to quicken up ring bed in. I know thats a common practice these days for some workshops to help speed up the run in. Normally you just wash down the bore with hot soapy water after honing and then coat with oil until its fully assembled and started up.

Would be interesting to know how many people/workshops actually use that method after boring and honing and if there has been any noticeable effects from it, good or bad.

[Adriano]

Precision engine parts are in silerwater, they are cheap, but probably no worse than standard in quality/strength.

[Cubes]

If precision hypereutectic are no stronger than factory pistons then there's no need to run forged pistons until you're over 400rwkw.

There's a few words over at calaisturbo on the precision pistons.

http://www.calaisturbo.com.au/showthread.php?t=28737 - Post 5

http://www.calaisturbo.com.au/showthread.php?t=66415 - Post 3

I noticed there's a few reports of failed hyp acl pistons over at ct.com.

[Scooby]

Hey cubes....you ran 4thou piston to bore clearance in your motor, with wisecos and you said you get some piston slap when its cold. I ran acls in my personal road r33 when i rebuilt the rb25 not long ago, i ran 3 thou piston to bore clearance, which was 2 thou tighter then what acl specs stated. Even so i get absolutely no audible piston slap, not even straight up in the morning on cold start.

Out of curiosity what was your ring end gap clearance?

4 thou seems standard for forgies, unless they're coated like Mahle or Super Tech which run around 2.5 thou recommended. Not withstanding that you ran the ACLs tighter, which could have helped address a tendency towards slap when cold, I know the ACLs have a different skirt design that combats slap.

Cheers

[rockabilly]

just to add guys my cp,s in the rb26 run .35mm clearance. they do slap a little when cold.but that at 4 degrees,,