Rb30 Crank At Rb26 Block

[Supra2000]

Can I use RB30 Crank for RB26 block and using RB26 conrods? Or there is any why to use that RB30 Crank because my RB30 Block is damaged and it cannot be repaired.

[rev210]

no you can't.

[humz]

30 block are cheap as.

but i would like to know the ans to this question also

is it due to the longer stroke which can smash the piston into the valves???

and how high would the head need to be raised to prevent this?

the tomie rb30 uses the 26 block with 3.0L crank so why isnt this possible to do yourself???

Edited August 20, 2007 by humz

[Adriano]

There is a guy on here who has put an rb30 crank into an rb26 block, though he worked at an engine machine shop, and required custom pistons and conrods. Rb30 blocks are about $100 from any wrecker.

[The Mafia]

hhmmm, interesting. Keeping an eye on this thread.

[GTRsean]

You need different pistons with a shorter deck height.

[R31Nismoid]

hhmmm, interesting. Keeping an eye on this thread.

Have a look about 6 months ago.

Guy did it, wouldnt go into much detail so its safe to assume one of two things

1. He was talking shit

2. Is cost a lot of time, and money and probably isnt worth the effort

Plus, when a 26 crank works just fine, not sure why you would bother

[T04GTR]

lol

[Supra2000]

As you know I want to but RB30 Crank because it has longer Stroke is more than RB26 Stroke, I mean if I can use RB26 Conrods because it's short and I think it will give me more renovation.

Edited August 20, 2007 by Supra2000

[Dahtone Racing]

the block is 38mm too short to use the RB30 crank

stroke is too long

[Adriano]

the block is 38mm too short to use the RB30 crank

stroke is too long

Thats only if you use the rb30 conrods, it may be possible with the 26 rods, but you may need shorter ones again.

[N I B]

Rod stroke ratio would be shocking.OS use a spacer on the block with liners.

[Supra2000]

Is there any one try to use RB26 rod's on the RB30 Crank

Edited August 20, 2007 by Supra2000

[[200]]

big end bore diameter is different between rb30 and rb26 rods, so that means their cranks are different. so if someone tried using rb26 rods on an rb30 crank without getting the rods custom made then they are wasting their time and money.

[Supra2000]

Where can I get that crank rods which it's made for RB26 Block.

[Adriano]

I think the for sale section would be a good place to start, feel free to continue to ignore all the advice and waste your money

[[200]]

Yeah, you're looking at around $2500 to $3000 to have a set custom made.

Cheaper than buying a RB30 block hey...

[TTT]

it's definitely cheaper than buying 35 rb30 blocks.

[[200]]

lol

[Spoolup]

I think these forums need to be IQ means tested.

Lets look at the stroke of the following

rb26 86 x 73.7

rb30 86 x 85

Now thats the stroke - thats the distance the piston travels from the bottom of the bore to the top of the bore.

So the Rb30 travels 11.3mm overall more - divide that by 2, as half is at the bottom and the other half is at the top - so from basic maths the rb30 stroke is 5.65mm more than the rb26 at the bottom and at the top of the stroke.

So if you were to install a RB30 crank into a RB26 block, you would end up with a stroke that sticks the psiton 5.65mm higher than the RB26 crank - now this couldnt be good for your piston to head clearance.

So you would either have to use a custom piston or a custom conrod to make this work.

It would be a lot cheaper and easier to buy a RB30 4wd adaptor plate and bolt that in your GTR

As you know I want to but RB30 Crank because it has longer Stroke is more than RB26 Stroke, I mean if I can use RB26 Conrods because it's short and I think it will give me more renovation.