Cracking Rb26 Blocks

[Roy]

I have been hearing about RB26 blocks slitting/cracking lately. It has now happened to 4 RB26s i know of, with them typically producing 320-360rwkws.

Is it a common problem? Is there anything that can be done to prevent it?

...i should add the examples i know of do track work, so it may not be the case on everyday cars that dont get put under constant loads/stress...

[GTRgeoff]

You should add examples.

I only know of a couple and they were pushing some big numbers.

Now find me an RB26 head with all your contacts. I don't want to have to fork for a whole engine to separate.

[R31Nismoid]

If your putting a 26 block into a RWD, dont worry

[GTRgeoff]

Not me. Hardly worth it when I have a 30 waiting for the donor.

[R31Nismoid]

oo... walk talking to Troy

[Leewah]

I've cracked 2 in my Skyline life time.

When we sent the 1st one to see if it could be repaired, we got a phone call within an hour saying there were 7 cracks on the deck alone. Not even worth doing an xray on it.

The second block had a hairline crack b/w 3 and 4 and the bores were no longer round

Both these blocks were used to make more than 600awkw though

[Leewah]

Give Nige a call at RacingLine. They might have one coz I took the block off a full engine

  GTRgeoff said:

YNow find me an RB26 head with all your contacts. I don't want to have to fork for a whole engine to separate.

[GTRgeoff]

Thanks Dave. I think he sold it just days before I decided to go ahead with the engine. He may still have a bare one but no good for me.

[benm]

I cracked the threads where all the bellhousing bolts screw in but that was caused by an exploding flywheel/bellhousing

[N I B]

Ive seen a few N1 blocks crack their bores and 2 standard blocks crack thru the bolt holes.

[predator]

Any idea whether these were the original factory engines or blocks on their 2nd or 3rd rebuild? could be a factor?

[dontfeelcold]

Is there a common cause for block cracking?

There is an article floating around (seen it on this forum), that covers the Gibson GTR over the period it ran in the Group A era. It mentioned something about block cracking being caused by harmonics and the fix was different engine mounts.

[R31Nismoid]

  dontfeelcold said:

Is there a common cause for block cracking?

without going too far into it.

RPM/launches/power are the factors

[Chris_R33GTSt]

  dontfeelcold said:

Is there a common cause for block cracking?

There is an article floating around (seen it on this forum), that covers the Gibson GTR over the period it ran in the Group A era. It mentioned something about block cracking being caused by harmonics and the fix was different engine mounts.

Very interesting indeed! I just tried a search and came up with nothing. Maybe I'm just shit at doing searches...

[Swiper the Fox]

ive cracked 1...around the oil feed near the centre of the block.....engine had 3 years of hard racing though

[N I B]

N1s were new the others were old engines.

[wrxhoon]

I have seen several cracked RB26 blocks ( all on GTRS though). Around the oil feed mostly , all had over 300awkw, all with aftermarket turbos, some 86mm bore , some oversize. At first they seem to just loose coolant but eventualy the crack goes throught to the bore . All the cracked blocks I have seen are the standard 5u blocks ..

[markimak]

N1 blocks wont crack so easially.

my mate just picked up his red N1 BNR32.. hes got a N1 block and N1 turbos.. very lucky man. anyone knw the old owner he lives in sydney.?

Edited January 25, 2007 by markimak