ARP main studs

[Hnl_sr20]

Hey guys new to the forum. I’ve always been an enthusiasts of sr engines.
So I decided to build one of my own on my down time while looking for a shell. . So I’ve been searching and searching and can’t find a clear answer about arp main studs. I’ve just received my block from the machine shop and they machined it with the stock main bolts and I’m wondering if I can just install the arp mainbolts or would I have to get it machined with the arp main studs?


Thanks guys!

[Kingtal0n]

When going from bolts -> studs they need to be installed, torqued down, and the cylinder or mains (studded parts) need machining to re-create the round holes.

The head requires a deck plate studded down for this
In the mains of sr20 I've never tried studs but I assume its the same as other engines, align bore/hone with studs andno bearing, then install bearing and torque without crank to check with dial bore gauge and mic the crank, reorder correct bearing, repeat as necessary until all are round and proper clearance. then install crank

[speedfiend]

If you are installing arp main studs I would highly suggests having the mainline rehoned. Reason being is the arp studs will apply force on the mainline differently then the stock main bolts which can possibly change the size of the main bores as well as pull them out of line.
Cameron

[Hnl_sr20]

Thank you for your input you guys. Now it feels like I’m stuck in a rut. Just having it back from the mAcjkne shop then giving it back for the studs.
My horse power goal is between 350 to 450 would the bottom end stock bolts hold that much? If not the I guess I’ll drop the block off again.


Again thanks guys!

[smoked240]

I added arps to my Rb25 and didn't have a line hone done. Engines have been built for decades without being line honed and have no issues.

I believe it depends on what engine/ hp goals and what you're doing with the engine, also why was it rebuilt? Did it spin a main bearing? If so a mainline hone would be smart to do. RB engines have a giant one piece maincap gurdle. Now if it was like a Small block Chevy with individual main caps, a line hone wouldn't be a bad idea. I've built a few Chevy 350s without mainline honing and they're still going to this day.

I'm not telling you DONT main line hone your engine, I'm simply informing you of my experience with it.

If I was going to build my RB for 800-1000hp all day and gonna be slamming it off the revs then yes, a mainline hone would have been in the build.
Just my .02 cents.

[Hnl_sr20]

Originally Posted by smoked240

I added arps to my Rb25 and didn't have a line hone done. Engines have been built for decades without being line honed and have no issues.

I believe it depends on what engine/ hp goals and what you're doing with the engine, also why was it rebuilt? Did it spin a main bearing? If so a mainline hone would be smart to do. RB engines have a giant one piece maincap gurdle. Now if it was like a Small block Chevy with individual main caps, a line hone wouldn't be a bad idea. I've built a few Chevy 350s without mainline honing and they're still going to this day.

I'm not telling you DONT main line hone your engine, I'm simply informing you of my experience with it.

If I was going to build my RB for 800-1000hp all day and gonna be slamming it off the revs then yes, a mainline hone would have been in the build.
Just my .02 cents.

S13 blacktop. Had a Bent rod. So I tore it down sent it to the machine shop where they resurface and rehoned the cylinders. Also got my crank micro polished and my bearings mic to make sure it wasn’t fcked up from the bent rod.

My goals are anywhere to 350 to 400 would be great if stock bottom end bolts hold.

Thanks

[Kingtal0n]

big gap between 350 and 450. Then you said 350 to 400.

Stock engine I would trust all day at 320-350rwhp.
380+ recommend a forged piston.

'cookie cutter build' for stock motor is usually a 40lb/min turbo

[ericb382]

Run stock bolts. They won’t have a problem at that power level. If you do arp studs you will need a line hone. That's also an operation that a lot of machine shops don’t get right. So you’re opening a can of worms for no reason going with arp mains.

[Hnl_sr20]

Originally Posted by Kingtal0n

big gap between 350 and 450. Then you said 350 to 400.

Stock engine I would trust all day at 320-350rwhp.
380+ recommend a forged piston.

'cookie cutter build' for stock motor is usually a 40lb/min turbo

Sorry my fault. In the future I would love to see 450. Sorry for the confusion I meant 350 to 400 as of now. I ordered Manley rods and wiseco pistons. 9:1. But I’m just making sure that the stock main bolts can handle the power goal I’m looking for.

[Hnl_sr20]

Originally Posted by ericb382

Run stock bolts. They won’t have a problem at that power level. If you do arp studs you will need a line hone. That's also an operation that a lot of machine shops don’t get right. So you’re opening a can of worms for no reason going with arp mains.

What’s the most could those stock bolts hold up to? Couldn’t really find a good answer to it. Just a lot of ball parks

[LayNLow]

I had a similar issue. Built my motor with arp mains, and ended up not being able to turn the crank way before the specified toque value. Threw OEM bolts in it and it was as smooth as a babys butt. Some people have luck with it, others don't.