This has probably been asked before, but I searched google and TGO and cannot seem to find the answer. If I want to use ARP main studs in place of the bolts in my 350, would it require machine work, even if I use the same caps? (the caps are new and don't need replacing). Thanks in advance.

 

No.

 

depends on who you ask. My machinist thought so. You'd need a line hone.
See what your machinist thinks (but I think I know the answer, $$$)

 

i'd say yes you need to align hone the main bores

 

I don't quite understand why I would need an align hone though. This is a new 4 bolt 350 from GM, caps installed. The caps are already machined for the block. I do understand that the studs apply pressures to the caps and not so much to the block threads as bolts do. Do the studs change the way the caps seat to the block enough to require machine work, even though they are already matched?

 

If you are merely removing the factory bolts to replace them with studs (using the same bearing caps), there should be no reason to hone the crank cradle. Main cap alignment is maintained by the webs in the case more than the bolt/stud locations.

 

It all depends on who you ask. Being that I have access to my engine builder that does the motor for my dragster, we always line hone the block when changing from bolts to studs.

I would be more worried about the new block. They are not seasoned when they are new. Some people call them "green" blocks. We always run the block through an over a few times to season the block before doing any machine work to it. You would be amazed how much things move around after a few cycles in the oven.

 

Are you also changing to splayed bolt caps in the process? That would be understandable, and would be a reason to align bore (instead of hone). The local NHRA/NASCAR engine builder says "No" unless something else is changed. I've never had reason to question the guy, except for the fact that he is partial to Mopar wedges and hemis.

 

BTW the block is 1-piece rear, 4 bolt 350 new

I was going to post a few more Q's about the new block, but I'll ask here since you bring it up. What would you recommend for the new block, as far as break-in goes? Obviously I need the machine shop to balance the rotating assembly (internally and without flexplate of course), it's receiving a hydraulic cam so no break-in issues there, but as far as the block itself is concerned what should I be concerned with? I don't see the need to hot tank it or bake it seeing it has the mains, freeze plugs and cam bearings installed and I don't want to pay to have these redone.

VADER: No it won't be splayed, it is already a 4-bolt main. I am only replacing the bolts with studs for added security, keeping the existing caps, so it seems I don't need to have it re-honed. Thanks for your reply.

 

VaderAre you also changing to splayed bolt caps in the process? That would be understandable, and would be a reason to align bore (instead of hone). The local NHRA/NASCAR engine builder says "No" unless something else is changed. I've never had reason to question the guy, except for the fact that he is partial to Mopar wedges and hemis.
Vader, if you change the caps you do need to line bore and then line hone for final fitment. I have never been a big fan of having to line bore a block for cap replacement. Usually the cap is not going to be the weakest link in the equasion. While it is nice to be able to say that yea I have splayed main caps for a street motor they are way overkill. When you line bore a block you move the crainshaft closer to the cam. This causes other issues like the timing chain being a bit too loose and sometime you have to get into timing chains that are undersize. If your using a belt drive that is adjustable then none of that really matters but the average guy building a motor will not know that the timing chain is too loose and will just run it with way more slop that it should really have.

PhatfiddlerBTW the block is 1-piece rear, 4 bolt 350 new

I was going to post a few more Q's about the new block, but I'll ask here since you bring it up. What would you recommend for the new block, as far as break-in goes? Obviously I need the machine shop to balance the rotating assembly (internally and without flexplate of course), it's receiving a hydraulic cam so no break-in issues there, but as far as the block itself is concerned what should I be concerned with? I don't see the need to hot tank it or bake it seeing it has the mains, freeze plugs and cam bearings installed and I don't want to pay to have these redone.

VADER: No it won't be splayed, it is already a 4-bolt main. I am only replacing the bolts with studs for added security, keeping the existing caps, so it seems I don't need to have it re-honed. Thanks for your reply.
The question becomes what are you going to be doing with the block? If it is just a mild street it should be more then good to run as you have it. One thing that I saw was you saying that it "receiving a hydraulic cam so no break in issues there"? Unless your talking about a hydraulic roller you do need to break in the cam.

 

Yes hydraulic roller

The motor is purely for street use, and will probably never see a track. The planned build thus far should place me around 400hp at the flywheel, with room to add nitrous/procharger later if i feel so compelled to do so. I am still in the "part gathering" phase of the build, so I have a ways to go. Just covering my bases right now so I don't have to redo it later