Porsche 944 turbo road to racecar.

[333pg333]

Unlikely...these are 9/16"s as it is! Big buggers. The problem is 30 year old Alu blocks. Going to have to strip the motor again and Time Cert them all.

[333pg333]

19mm stud holes bored by machinist. Paul hand tapped them yesterday. Picked up the custom Timeserts today. Fingers, toes, eyes...etc all crossed!!!

[Greg Rust]

that looks the business

[tim510]

19mm studs, jesus!

[333pg333]

9/16" headstuds pulling out of a 30 year old Alu block...doesn't leave many options! Reckon they'll be sweating bullets when they're torqing the head down today...

[da9jeff]

The increased surface area of the insert should make it much stronger, if it still pulls out you'd guess that the block has gone soft.

[333pg333]

Yes, that was the design brief when ordering them. Be curious what tq values other motors need to hold their heads down per psi? Ours starts lifting not much over 22psi...which just won't cut the Mustard this year. Be lucky to have much over 400whp with this backup motor. Looking at the winning GTR from last year that has double that on his 'low boost' setting doesn't give me much cause for optimism. Ah well, all about the journey they tell me....

[agentcrm]

Hmm, if you have a spare buggered block floating around section it and see if you can run deeper or all the way through the block.

[333pg333]

From memory, I think you can run all the way through on 8 out of 10 holes. Not sure the in's and out's of that concept though?

[333pg333]

Apparently all went perfectly! Phew.

[dougmo]

good news mate, what is the head torqued too on those studs? are they just run of the mill arp's? or L19 or better?

[agentcrm]

From memory, I think you can run all the way through on 8 out of 10 holes. Not sure the in's and out's of that concept though?

You wouldn't be able to strip the thread on the steal nut if you where through bolting.
Pulling threads is always going to be an issue when torquing the head studs and then the extra forces from the boost in an Ali block. Let a lone an old block.

Just looked up the 4g63 and it's Iron block so much harder to pull threads.

[333pg333]

good news mate, what is the head torqued too on those studs? are they just run of the mill arp's? or L19 or better?

Not 100% sure of the spec on these. They'd be deffo higher than run of mill though. They torqued it down to 100ft/lbs this time. Wanted to go higher but not worth the risk.

You wouldn't be able to strip the thread on the steal nut if you where through bolting.
Pulling threads is always going to be an issue when torquing the head studs and then the extra forces from the boost in an Ali block. Let a lone an old block.

Just looked up the 4g63 and it's Iron block so much harder to pull threads.

Essentially this isn't the right platform to try and get modern levels of hp out of. Wish it did have an Iron block...that would make life soooo much easier!

[gxxr]

924 looking appealing about now, lol!

Interesting historical perspective, ye olde BRM v16 running ungodly boost went from 1/2" to 5/8" studs in an effort to retain the heads, finally fixed with smaller tty 3/8" ones.

[Roy928tt]

Hang on ?

It was my understanding that the 944 engine was basically half a 928 engine, but the 928 has an open deck block, clearly your's doesn't, is that standard ? and while we are at it does the 944 usually run an alloy bore or are iron sleeves standard fitment.

Meanwhile I realised that you are running the single cam cylinder head, I would have thought by now you would have swapped to a 4 valve head, they are the same bolt pattern.