93 black t/a

Ok so i just talked to my machine shop, and i told them i was switching to studded 2 bolt mains and i asked if i would need to have the mains aligned bored? They said i didn't didn't need to if i was using the stock caps, which i am. Is this correct??

Stroked96Bowtie

I would get a second opinion if you arent sure. I cant answer but just my .02

97 6SPEED Z

WOW, maybe you found a truly honest machine shop.

Call ARP and see what they say about changing from bolts to studs while using your original main caps.

Granite00

Studs shouldn't change the alingment of the caps. They screw into the same holes as the bolts. The only reason you would need to have in align bored/honed is to correct an out of alignment issue.

wrd1972

When you switch from bolts to studs, you should have the block line bored. The torqueing characteristics regarding the threads between studs and bolts is different and minor misalignment of the caps may occur at high RPM. My engine builder told me this. He has done Hemi prototype work for Dodge plus has built motors for Tony Stuart. I trust his judgement.

WS6T3RROR

Yeah, have it aligned. The deformations caused by studs are different than bolts at full tq, also the factory machine work in this area is sometimes not all that great. It is never a bad idea to make sure that everything is true and straight regaurdless.

Sometimes the answer you get from a shop hinges on if they do that particular job or farm it out also.

Joe B

Mic your mains with the factory bolts......Then add the studs, mic the mains again, and you'll know "for certain" whether or not anything changed to any measurable degree with the addition of the studs.........whether things change enough (or at all for that matter) depends on that particular engines architecture bolt/stud/ clamping force, ect..ect.......... It's "super common" for nothing at all to change to any measurable degree with just the addition of main studs while "still" using the same factory caps in the same factory holes (seen it dozens of times for a proven fact with the best Mics money could buy).......in fact, many of the best engine builders I know try to avoid an align bore or hone (unless needed for the addition of aftermarket main caps & additional bolts of-course) for the fact that much of the time they end up more out of whack than they ever were from the factory, necessitating the need to jockey around main engine bearing sizes like a Vegas blackjack dealer.......many guys forget that 99% of the engine building shops throughout the country (the affordable ones anyway) don't have a super accurate way to align bore and/or hone main's (watch it done sometime)....unless your having your work done at Hendrick Motorsports...............so like I said in the beginning, check them to be sure.............good luck..........Joe

WS6T3RROR

What does a bore gauge have to do with how much a series of 5 holes are in line? It creates a different axial load in the main webbing not so much the cap, sometimes enough to yield a thinner web a small ammount or one with a casting imperfection. Cast iron has very different curves for compression and tensile loads.

We're not talking a huge shift, but when you have .0025-.003" of clearance if you're off .0015" out of plane then that kinda makes for a problem.

93 black t/a

Well i think i'm going to call ARP, and see what they say. I've talked to a few other ppl and most of them seem to agree to that i dont need to have it align bored but it would be a good idea to at least have it honed.

97 6SPEED Z

I think calling ARP is an excellent idea. Do let us know what they say about this.

In one of his many books on re-building SBC motors .... David Viszard(sp?) had a very practical test for the need for align boring/honing main caps on a "seasoned" block rebuild. Basically he said .... "after boring and decking the block, assemble just the crank into the block with the main caps, bearings and fastners you're going to use, (with liberal amounts of 30 weight oil on the bearings, of course), torque the caps to spec, and .... if you can rotate the crank freely by hand ..... you DON"T need to have it align bored/honed". His explanation was that the crank and block "twist" sooooo much at load and RPM that align boring/honing was WAAAAAY overrated. This always made pretty good sense to me.