ARP head stud swap question.

If capable, can you swap out head bolts with ARP studs without performing a head gasket? On the 22re that's not possible due to design, but I'm wondering if it could be done in my 1uzfe, if/when I decide to boost it.

Possibly. The trick would be to keep the compressive load on the gasket throughout the process. If you untorque and replace one bolt at a time, the gasket would remain compressed without relieving it. The gasket wouldn't know what happened. I would rather do it properly, remove the heads, clean surfaces, and new gaskets.

Something else to think about with boosting 1UZ's. The overhead oil drain is a shared passage with crankcase ventilation. PCV is on the valve covers. If the engine is aging and has high blow-by, that problem will compounded under boost. The crankcase air wants to go up, but the overhead oil wants to go down into the sump. The heads will pool with oil and starve the pump, and there goes your bearings. I think this is what was happening to the Wreck Racing 1UZ V8 Miata after it was supercharged. We went through probably 5 stock junkyard long blocks in 2 years, only driving at GRM Challenge, autocrosses, UTCC that one time, and testing, at under 10 psi of boost. I would recommend a re-ring/hone or some kind of vent system for the block to allow oil to drain back properly. There is something funky with that engine's crankcase ventilation system.

http://www.lextreme.com/pcv-fi.html

Seems like head gaskets for the 1UZ are $35-50 each. I'd much rather pony up the money and do new gaskets vs having to pull the heads shortly after the install if something were to go wrong. It seems like cheap insurance to me.

That being said, if they were fairly new, you got far enough into the job to remove them, and they looked ok in a thorough inspection, you might get away with it. It would be one of those things that you wouldn't know until you got it apart though.

In reply to maschinenbau:

Thanks for that! I did not know!

STM317 wrote: Seems like head gaskets for the 1UZ are $35-50 each. I'd much rather pony up the money and do new gaskets vs having to pull the heads shortly after the install if something were to go wrong. It seems like cheap insurance to me. That being said, if they were fairly new, you got far enough into the job to remove them, and they looked ok in a thorough inspection, you might get away with it. It would be one of those things that you wouldn't know until you got it apart though.

I would tend to agree, plus you are adding boost. New head gaskets are cheap insurance.

12v cummins guys do the '1 head stud at a time' trick all the time when they start to push big boost and they dont have any problems doing so.

personally i think as long as i knew the existing head gaskets were good and i didnt have to remove anything else (like cams) to do it i would just do the head studs, but if it is getting close to needing a timing belt or you do have to remove the cams then i would go ahead and do it all while you are in there.