Hey guys, as some of you know I am building a new twin-turbo blow through SBC 383 for my little 280z. It will see around 12 psi on pump gas, maybe a tad bit more on C-16 race gas at the track.

I have my 350 4 bolt block at the machine shop right now being hot tanked, mag'd, bored and honed (w/deck plate), decked, ARP main studs installed w/line hone, etc.

Today I dropped in to see about a set of heads for another motor and the machinist asked if this motor (refering to the block being machined) was the one I planned of twin-turbo'ing. I confirmed that it is the one and he asked if I wanted head studs installed too.

To be honest, I hadn't planned on it, but since this is my first forced induction I wanted to know what you guys thought. I was already planning on running Cometic head gaskets instead on O-ringing.

So, ARP head bolts OR ARP Head Studs??

Thanks guys!!

in my engines i stud everything possible, mains, oil pump,heads,distributor hold down, carb,even headers if you can. the reason being that most hi po engines get torn into often and a stud doesn't pull threads out, and when a bolt pulls all the threads out of your rear main cap and you have to find another cap and have the engine alignhoned and all new gaskets and bearing and rings in a perfectly good engine you will see what i mean. plus the clamping force is better with studs. i would say head studs are a must for yours.

I run ARP head, oil pump, and main studs on my N/A race motor. Would recommend head studs on a duo turbo application! Whats your compression?

Originally posted by blazerbob:
I run ARP head, oil pump, and main studs on my N/A race motor. Would recommend head studs on a duo turbo application! Whats your compression? Haven't gotten that far yet. Hopefully in the 7.0-7.5-8.0 range. Ideal would be 7.5:1.

When we machine blocks we always ask if they are using head bolts or studs and we ask what gasket they are using so we can duplicate what they are using as it makes a differance when plate honing.

Head studs it is!! Summit #ARP-134-4001

Thanks guys!!

i ran over 18 lbs of boost thru my 383(with 9.5 comp), and i was running standard felpro gaskets and arp head bolts-when i pulled it down over the winter, the heads had sealed perfectly, but i did have heads receiver grooved and used the special felpro gaskets just in case-i would have used studs, but was worried about water leaking thru the threads-i might but them in my new project if i find a good sealer i think would work
more important than anything is good, FLAT surface on deck and head-good luck

As already said, having a flat and true surface is very important. On a big block with regular Fel-Pro head gaskets with the pre-flattened copper ring (non-receiver groove) I ran regular head bolts on an engine that ran just past 17 psi. Remember that on a supercharged engine that "boost psi" is just a measure of backed up flow in the intake manifold - it is not a measure of the actual airflow or cylinder pressure during compression.

Thomas

Hey just to let you know. I put head studs on BBC.I had a hell of a time to remove heads,after 3 years on engine.I could lift the engine with all the stud bolts off head and engine hoist just on one cyclinder head still did not come off or even budge. Had to pry up and push back down, and I used arp thread sealer even under the washers.The bolts will almost weld them selves to heads.Moral of story not to burst your bubble but to save you the trouble of the fight youll have to remove heads, unless you take engine apart once a year not to mention the fact you cant remove heads in the car,if you had to.Yes studs are better than bolts,only for frequent rebuilds. Good luck

You might want to talk to those Buick guys. They've got that street turbo stuff down.

My brother had a ten second car and the other 11. He sold the faster car. Never figured that one out.

He uses head bolts but does O-Ring. His new engine is 700+ hp though. Not sure how that one's being built since its under build now. I can find out his engine builders name and number and get that to you. Don't know him and I hear he's hard to get but that's one perspective.