Head and Main Bolts

[John(XJ)Jeep]

Hey guys, I'm in the process of building my stroker and I've been searching around for a set of head bolts and main bolts for a while now. I run into a lot of threads about people suggesting to change the head bolts but not giving a place to buy from.

I went to most of the parts stores around town looking for sets but the only place I found could only combine kits to make a set of head not main bolts or studs I should say cause I'm looking for studs rather than bolts really. I'm not really willing to spend hundreds to make one set from ARP and have a box full of leftover bolts I can't use not mention it would cost me $500 bucks from the dealer just for head bolts, I didn't even bother asking how much for the mains.

I was wondering if anyone here knows a place where to get a complete head and main set for the Renix 4.0L

I was also wondering if it would be ok to get bolts say from fastenal or similar place maybe made from SPS or equivalent would be strong enough?

 

[Robs92XJ]

headbolts.com has head bolts for most years of 4.0/4.2, for about $45. There were some slight differences in the set I bought for my '92, compared to what came off - the studded bolts that go on the driver's side of the head did not have flanges on the bottom, and the head side on those was 11/16" instead of 5/8" (the passenger side bolts were still 5/8", looked like a regular grade 8 flange-head 1/2"-13 bolt, so I had to swap sockets constantly while torquing the head bolts down).

But they worked, and seem to be the standard place to get the head bolts for a 4.0L.

Not sure about main bolts. Headbolts.com may even have those.

 

[Talyn]

Most parts stores can get head bolts for the 4.0L. Rockauto, Advance, Autozone, etc. As for studs, they aren't necessary and if you stud the mains you will need to have the bore honed as well as lose the ability to put on the stock main girdle.

 

[magimerlin]

They newer bolts are the same as the Renix with the exception of the newer ones have the alignment stud on top of a couple of the bolts for the valve cover gasket. And yes I know this for a FACT as I am running them now on my 89 and on a couple other Renix motors that I have done the head gaskets on now. The lengths are the same. I matched them up with the Renix befor I used them.

 

[John(XJ)Jeep]

Thanx guys, for the mains I'd rather at least getting new bolts for them. I thought that the bolts for the mains that use the girdle were different than the ones without.

Although I'd still rather have studs for the head though so I wouldn't have to buy hardware all the time, not to mention uneven clamp loads and warping, distortion ect. High compression, high RPM is my real reason for concern.

Too bad our aftermarket is not like the 350 like it should be, questions like this wouldn't exist. It just annoys the hell out of me that "ARP!!!" doesn't make a specific kit for our engines, theres only 2 million of them out there. :flamemad:

 

[Talyn]

Thanx guys, for the mains I'd rather at least getting new bolts for them. I thought that the bolts for the mains that use the girdle were different than the ones without.

They are. The bolts for the mains have studs on them with the girdle.

Although I'd still rather have studs for the head though so I wouldn't have to buy hardware all the time, not to mention uneven clamp loads and warping, distortion ect.

There is no real problem with the stock bolts. There are plenty of bolts based on the head size. With studs you can't remove the head while the engine is in the XJ.

High compression, high RPM is my real reason for concern.

What are you planning?

 

[John(XJ)Jeep]

You can remove the studs from the block they are only in there at 15-20 lbs/ft come out the same as bolts as long there not too long.

4.7 at 9.8-10-1 CR most of the HP comes at around 3.5 to 4KRPM up to about 5.5K, more of a top end motor.

All the work is done already, hardware is the only thing holding me back right now. I think I might might have to suck it up and get the the "TWO" different kits to make one BS to get this done....

Any suggestion where to get bolt/stud mains for the girdle without being raped? I'm a check ARP again to see if they have main hardware for that size.

 

[Talyn]

That isn't high compression. Stock head bolts will be fine.

For stock main bolts the only place is the dealer or maybe used. Hesco sells a main stud kit, but you can't use the main girdle with them.

 

[John(XJ)Jeep]

Well in any case, I left a email with ARP just now and we'll see what they say. It just sucks cause I'm stuck and the old bolts are in no condition to go back in.

 

[Talyn]

If the machine work is done you should not use main studs.

 

[John(XJ)Jeep]

Don't worry about it's ok, I'm a find and use the main girdle anyway. It'll be fine. Thanks anyway.

Found out today that ARP 112-4001 stud kit for the 258 1/2-13 will be compatible with Renix blocks I assume that are all 1/2-13 holes. I went to the salvage yard today to verify this theory. I kick myself for not thinking this before simply because I couldn't get 7/16 out of my head for the 258. Which is still true actually but the kit is 1/2 size for that Part#. Came out of a 79' but not sure if buddy actually knew the year he wrote on the cab. No biggie.

 

[Talyn]

After you open up the holes for the main girdle to use the studs there won't be enough meat left on the girdle to make it useful.

 

[John(XJ)Jeep]

I didn't bother using studs for the mains because that very thought. When I went to pull a girdle out I could see that there much meat on the ends not to mention meat left on the threads either. I just got regular main bolts for it. So I decided against that. I was happy that I only needed 1/8 washers for the girdle though.