main studs

[scottk]

Im replacing main bearings !can I replace the bolts with studs with out any problems or should i use factory bolts?

 

[noahzark]

yes you can...noah.

 

[Dominic]

If you replace the bolts with studs you MUST have the block align honed. Or you can try it and let us know how long it takes you to spin the mains out of it! I have seen people do it before and had no problems untill they tore them down and saw the wear, but they didint make any power and they have this thing called "dumb luck" on their side.

Every time you replace a bolt or stud on a bearing journal (rod or main) you must have them re sized or checked. Ask a machinist or engine builder, they will agree, and if they don't stay away from them.

 

[Blown&Injected]

DO NOT DO THAT!!!!

Must machine caps for studs - cannot just replace bolts for studs!!!

 

[S10xGN]

I beg to differ. My block was spec'ed for studs but machined with bolts, which I then promptly replaced with studs. I was concerned and personally checked all clearances. Then checked for binding and proper rotation every time I stepped up the torque during assembly. Never had a problem and that was 4 years ago. Just be sure to check everything! Of course, if you do have a problem, then consider align honing or staying with bolts.

 

[scottk]

thanks for the replys! the motor is not going back together any time soon to many other problems

 

[Blown&Injected]

I beg to differ. My block was spec'ed for studs but machined with bolts, which I then promptly replaced with studs. I was concerned and personally checked all clearances. Then checked for binding and proper rotation every time I stepped up the torque during assembly. Never had a problem and that was 4 years ago. Just be sure to check everything! Of course, if you do have a problem, then consider align honing or staying with bolts.

Wow, I would not believe that all 4 caps would make it back to where they need to be.

I must admit that I have done some things that one "should not do" without problems - although never the bolt to main stud thing

 

[S10xGN]

Wow, I would not believe that all 4 caps would make it back to where they need to be.

I must admit that I have done some things that one "should not do" without problems - although never the bolt to main stud thing

I'm having a hard time seeing how they wouldn't! The caps do NOT register on the fasteners in no way, shape, or form. The caps have a machined step in the block that locates them. Again, the fastener(s) have nothing to do with locating the caps, only holding them down. Studs will provide a more even clamping force because you're only clamping, not screwing and clamping.

You'll know right off if your bolt-stud swap won't work just by noting any substantial increase in rotational drag after each torque increment when torquing the fasteners. Although I've never seen it or heard of anyone who has...

 

[Blown&Injected]

I'm having a hard time seeing how they wouldn't! The caps do NOT register on the fasteners in no way, shape, or form. The caps have a machined step in the block that locates them. Again, the fastener(s) have nothing to do with locating the caps, only holding them down. Studs will provide a more even clamping force because you're only clamping, not screwing and clamping.

You'll know right off if your bolt-stud swap won't work just by noting any substantial increase in rotational drag after each torque increment when torquing the fasteners. Although I've never seen it or heard of anyone who has...

Agree except to the extent that main studs hold/locate/grab the cap tighter and firmer than a bolt. The mains are critical enough that the caps should even be torqued to the same torque that is used when machining and that does not seem to be as big a leap as switching from bolts to studs considering there are differences between torque wrenches.

 

[yullose]

Often times the recommended torque is much higher on studs than it is on bolts. The add'l clamping force from the higher torque will distort the caps differently.

This is the whole reason for honing cylinders with a "torque plate". It simulates a cylinder head being bolted on the block because the cylinder walls will distort differently when the heads are torqued on. The main caps and connecting rods are no different.

 

[87TIGN]

I dont understand why you have to have your block machined for main studs. I am probebly missing something. If someone could explain this I would appreciate it cause I am doing my motor right now and its at the mchne shop so I may have to have them prepare this for me. I know they make ARP head bolts and ARP rod bolts which I want to use but I cant find ARP main bolts. Do they make these? If I switch to ARP bolts I dont need machine work to accomodate that do I?

 

[Dewey]

You do NOT need to align hone the block when changing to studs. These aren't connecting rod bolts which locate the end cap properly. If you're torquing the studs so tight you're distorting the caps enough to cause bearing issues then an align hone is not going to save you. I have studs in my otherwise stock block. I didn't bore or hone the mains and it spins as free as it ever did. The only issue I had is that I had to grind down one of the rear main cap studs so my oil pan would seat properly. No biggie.

 

[BlackBandit]

You do NOT need to align hone the block when changing to studs.

Agreed. Also, summit sells ARP main studs for our cars. Mine were $51.00.

 

[87TIGN]

So how do I choose main studs? Some people say there is a set for stock caps and a set for othercaps. How do I know which one to use? How do you install main studs? How do you get them tight cause there is no head to tighten with?

 

[BlackBandit]

As far as what ones, I don't know. I guess it depends on what you have. I know they make a set for windage trays and for engines w/o. I've never used the billet caps so I don't know about any height difference. As far as installing the studs themselves the new ARP's come with an allen head. The studs themselves go in pretty much finger tight (5 lb-ft) though so the allen head helps more for removal. They should also come with instructions. It's pretty straight forward. You're just turning a nut instead of a bolt. The torque cycling sucks the first time you install, but IMO it's worth it. HTH james