Hi Hp Guys I Need Some Help.....

[zeekh2b]

Hi to everybodey in here ..

Im new in this forum and would like to introduce my self first befor talkin about the problum that Im facingwith my car, my name is yousif alzayani and from kingdom of bahrain. I owned a drag race nissan z32 with rb30/rb26 setup. the car produce 1200+whpand my personal best is 7.1sec@299km the run strong but recently im facing problums with the head studs the rb25 head studs couldnt hold the power that I got In my setup when I run the over 30psi the head is lifting, so I decided to move forward with rb26 head studs and I drilled the deck but couldnt solve the problum this time the block craked and I think its because of the drilling.anybody fcaced this problum guys im talking to the hi hp guys I need some help if anybady got it.

Here some pic of the car :

[Shoota_77]

Beautiful car and great setup!

That is one majorly busted engine! I'm not sure you could blame the enlarged bolt holes or not. The crack runs through one of the holes but whether it originated from the hole or just ran through the path of least resistance which is the hole. Very hard to say. The vast majority of RB's floating around are far less than 1200HP so there may not be a lot of relevant experience on whether they crack at that point regularly. I've only seem RB's crack in the middle of the block and underneath at the sump mounting face. Yours is certainly an impressive effort (but obviously not appreciated!).

Good luck with it. Some of the sand racer Patrol guys over there might be able to shed some light on it as they're running similar power to yours.

[Ben C34]

Cant help, but that car is awesome.

I hope you can get it sorted soon.

[GOD12A]

Hi ZEEKH2B,

I can't speak form experience, but is it possible to drill and tap the head studs further down into the block?

This would spread the load across more block area (with more material above the intersection of stud to block) and possibly reduce the flex in the block.

You would need to find/make longer studs, but since the block is the weakest point at the moment, not the studs, this may be worth investigating.

The guys at RIPS in New Zealand play with some big HP RB's, they may have come across this issue previously.

http://www.ripsracing.com/

Hope it helped.

Mark

[PN-Mad]

^^^

Thats what I was thinking, how much thread was in the block? More thread, better spread of pressure. It is possible to run 1/2 inch, as the group A cars did it.

[GOD12A]

Heya PN-MAD,

I was more thinking that if the same thread was moved further down in the block, it'd have more material above it to reduce flex.

If the thread was longer it'd spread the load over more area. So if the thread pulled through, I'd go for a longer thread for sure. What do you think? Just throwing around some ideas

I guess it's much of a muchness...

Furthermore, if the thread was moved/extended lower into the block it'd also have less stress on the thin cylinder/stud wall from combustion.

Mark

[33GTRV]

Thats almost identical to my block. It was caused by core shift. Also happened at 30+ psi. I am now sleeving a new block and half filling it.

[PN-Mad]

Heya PN-MAD,

I was more thinking that if the same thread was moved further down in the block, it'd have more material above it to reduce flex.

If the thread was longer it'd spread the load over more area. So if the thread pulled through, I'd go for a longer thread for sure. What do you think? Just throwing around some ideas

I guess it's much of a muchness...

Furthermore, if the thread was moved/extended lower into the block it'd also have less stress on the thin cylinder/stud wall from combustion.

Mark

I'm far from experienced, but I guess at a certain level it just becomes R&D. Unless you can get some info out of the big builders (RIPS Maatouks etc).

[KiwiRS4T]

That's a very impressive time and 2wd as well! I'm afraid I haven't come across that problem yet but as above Robbie from Rips will have all the answers.