Arp Main studs or stock bolts with girdle ?

[ArcticCat843]

What should I do? What's stronger? I'm hoping to be pushing 300 horse and I might spray it a little in the future.

Also if the stock bolts with the girdle Is better then should I install the girdle as I Aline hone the mains or no?

[unlimitedrubicon]

From what I have read ARP bolts are too large to work with the girdle. I tried to get ARP to make studs for our engines, but they do not yet have double-ended studs in the differing sizes. They said this is an area they are looking into, but will start with their higher-volume engines. New factory studs should be fine and if you keep the girdle it will help increase overall bottom-end strength tying all of the mains together. While stud for stud the ARP wins hands down, but by adding the benefits and stability of the girdle you have a very strong bottom-end. The ideal solution though would be custom ARP studs with the girdle.

[ArcticCat843]

Yeah I realized I had to pick one or the other...that's what I'm asking? So your saying go with new factory
Bolts and run the girdle?

[unlimitedrubicon]

That's what I did.

[unlimitedrubicon]

To be more precise I sent diagrams and measurements to ARP to see about custom studs, then I went with new factory studs and a girdle after they said it was not an option. The additional strength of each main tied into the next is always a good thing.

[uscav_Scout]

You have seven mains for six pistons (This is part of the reason the jeep motor lasts so long, think V8 has five for 8). Go with the stock studs and the girdle. If everything is balanced the mains fasteners don't nearly get as much load as you would think (The engine is inherently balanced, all I-6s are, I could do the math to show you guys but I don't want to bust out the calculus). Make sure you use good rods that have been fluxed, and get the arp fasteners. If you really want to make sure your block is squared away get the mains line honed (All the same bearing size, and that they are exactly 90 degrees to deck surface).

[Sailboy42]

I'm assuming this is still an issue with buying ARP mains.

However if one uses the stock main bolts, are they long enough to still use washers to space the girdle?

[Russ Pottenger]

Stock Main bolts with a .120 ground flash washer.

If you decide to go with an aftermarket piston and rod assembly my steel rods are fully profiled with no balance pads making clearancing for the girdle a little bit easier.

[Bossman]

It has been a slightly contention issue in the small block Ford community that girdles are worthless. The 4.0L platform, from an "outside" view, isn't weak enough in any area of the shortblock that the girdle would add ANY value. Your caps are plenty strong, you don't turn enough rpm and HP to make them chatter or distort. I would highly doubt without a bunch of boost and rpm you would crack the block.

[bnelson]

Russ, what size exactly do those washers need to be? I got all the other stuff from you but forgot about the spacers for the girdle. When the machine shop gets the block and head done I'd hate to get stuck on a Sunday assembling the motor because I forgot a few washers

[Mike B]

Make sure you space it out enough, my buddy put washers in between his girdle and the bolts and thought he had enough and never checked. Long story short he spent a couple moths and a few tear downs to find a knock, only to realize the rods were hitting the girdle ever so slightly.

[Sailboy42]

Ouch

[Russ Pottenger]

Russ, what size exactly do those washers need to be? I got all the other stuff from you but forgot about the spacers for the girdle. When the machine shop gets the block and head done I'd hate to get stuck on a Sunday assembling the motor because I forgot a few washers

3/8 x .120 or .060 if you want to spend a little time grinding the underside of the girdle for the proper clearance.

I recommend going over to your drill bit index and grabbing a .060 drill and using it to verify you have the proper clearance.