Sonic Boom

iTrader: (11)

What kind of BHP is the max for Standard Headbolts?
What kind of BHP is the max for ARP Stud and Nuts?
Or is more a case of how much boost you run?
Cheers Rich

Paul_RS

iTrader: (4)

I know my friend was running 430bhp on standard bolts and gasket. To be honest i've heard horro stories about the stud and nut kit, personally i'll just be long studding.

cozmeister

iTrader: (1)

The horror stories from the stud and nut kits come from improper installations of them.

The head bolts are fine for big power - the Group A touring cars used them.

What are you aiming for?

Sonic Boom

iTrader: (11)

Going for 500+ the bottom end has already been built and fitted back into the car with a Cometic head gasket and standard bolts, the head needs to come off again to have some work done as at the moment it's standard with BD10's.
But I didn't really want to have the whole engine out again and stripped just to long stud it.
I was hoping ARP Stud and nuts with a WRC head gasket would be upto the job?
Cheers Rich

Sonic Boom

iTrader: (11)

Bump
Rich

cozmeister

iTrader: (1)

My humble opinion is that if Group A touring cars used head bolts, then they were good enough for me and my 'little' Cossie when I did my head gasket.

While ARP might work great for some people, they do need to be installed properly, I didn't fancy taking the chance with mine.

Paul_RS

iTrader: (4)

WRC cars used long studs and they had less power

Personally for over 500bhp i'd be long studding. I know gaskets have come on a long way since long studding was required, but you still get a better clamping force from a stud and a nut, than from a bolt.

J1mbo

iTrader: (1)

Karl

Both touring cars AND WRC cars ran std head bolts!

Bart

Karl, do you need them changed or retourqed after some time on big BHP engines?

LHD220Turbo

iTrader: (4)

yes its advisable to have them changed if your running sily boost/ horse power

IMO i would just have a 200 block long studded with a decent gasket - fit and forget

J1mbo

iTrader: (1)

touring cars may have but wrc cars did not,

they ran 6 long studs then they went to 10 studs

Paul_RS

iTrader: (4)

Thought so Jimbob, i've seen mountune advertise WRC long stud kits before.....

morto

just want to add into this thread about arp head studs, im doing a full rebuild on my evo 6 engine and was going to use arp, after talking to dave ears motorsport who has been ralling evo,s for many years, has also has told me some horror stories about the studs coming loose!! and he now doesn't use them instead he uses arp head bolts .. he did say tho that arp rod bolts are a must, but for me im going down the oem head bolt route as i think there strong enuff, with arp rod bolts

Cossie Phil

I also ran std headbolts with a YB0611 headgasket successfully for around 10 years with the engine seeing 30psi boost more often than not. The only thing that bought the engine down was some corrosion around the water jackets on the exhaust side of the head. The issue was that if the engine was turned off when warm the coolant could find its way back into no4 cyl if the rad cap wasnt released. Even in this state the car ran a 11.6@119mph just before the decision was made to rebuild the engine chasing more grunt.

In saying that I have decided to go the 200 block with 6 long studs route with the new engine just for good measure...if the turbo can deliver over 30psi the new engine will be seeing it.