Installing head studs without removing head?

1337computing

New member
Is this possible? I bought my car with the head gasket already done and would like to install headstuds. Before I pull the valve cover and take a look thought I would ask first.
 

fussellbug

New member
Whether you can swap the bolts for studs without lifting the head doesn't really matter. As soon as you relieve the torque on the head, you should replace the gasket. And no, you can't replace the bolts with studs one at a time either, because the torque across the head needs to be applied evenly in the correct pattern to ensure a proper seal and prevent unnecessary stresses on the engine. Just set aside some extra time and pull the head so you don't risk leaks or damage.
 

MWP

New member
I don't quite agree with the others.

Even if the odds are only 50/50 that it'll work ok... its worth a try anyway.
If you blow a HG shortly after, then its no great loss time wise. Where if it does work ok, you've saved yourself a heap of time and $$s.
 

underscore

Well-known member
Why are you changing the studs if the gasket was already done? I can't think of a reason to replace the studs but not need to change the gasket.
 

alltracman78

Active member
Sounds like he wants to replace the head bolts with studs, not replace studs.

I would think you could do it if you could do 1 at a time. Even pressure is a lot more important while the engine is running than when it's just sitting there, as long as you're not going too crazy.
Just like if you had installed them with the wrong torque, you can go back and retorque them. Even if you had to loosen and tighten them, you do 1 at a time.
 

1337computing

New member
Head gasket was already done but factory bolts were used not studs. I would like to install studs with out pulling the head for obvious reasons, I might give it a try and will post back after completion. Thanks for everyone's input.
 

88st165

New member
What's wrong with the factory bolts? Just curious since I was planning on buying new Toyota head bolts relatively soon.
 

underscore

Well-known member
For those of us who aren't finding the reasons so obvious, why would you do this? I thought the only benefit was that ARP studs are reusable and OEM bolts are not.
 

___Scott___

Active member
I think you can better understand by thinking of them not as bolts but as springs. Springs stretch under tensile force. For a fixed amount of force, a spring with a low spring rate will stretch more than a spring with a high spring rate. The OEM bolts have a low spring rate compared to ARP studs.

ARP studs will do a better job of maintaining the clamping force you expect vs the OEM bolts which can stretch under adverse conditions like detonation and allow for the head gasket to fail.

Whether that's good or bad depends on your point of view. Stretchy head bolts and a failed head gasket is a cheaper and easier fix than say cracked pistons. So you can think of those OEM bolts and a gasket failure as a "fuse" that protects other parts of the engine. Sort of the way a crappy clutch in a Subaru protects the "glass" transmission.
 

Hic

Member
You can do it 1 by one. Did this 100 tines on mitsubishi evo for rally, never had a problem. Cold engine and that is it. Start from the middle (bolt 1)
 

1337computing

New member
Hic":3txcq5jk said:
You can do it 1 by one. Did this 100 tines on mitsubishi evo for rally, never had a problem. Cold engine and that is it. Start from the middle (bolt 1)

Experience is the best, once completed most likely in spring I will post with results, thanks again.
 
Top