Jeep Strokers

I think I figure out that I do have 0.020 over pistons. My machinist measured the old pistons and got 3.875, and so these are 3.895, that should confirm it right? Anyways, there was some confusion with the info the book was giving my machinist, and for a second he thought that I had the wrong pistons and didn't want to continue, but after doing more measuring he realized that we were good to go. What I don't get is that when I look up over sized pistons on lets say O'riely auto parts, they still have the bore size at 3.875 no matter what over bore size they list them at. So they can be .030 or .040 over sized but the bore size will still say 3.875.

You're good to go.

I'm just waiting on my stuff from the machine shop at this point, and I decided to order a re manufactured head from ebay because I couldn't find a 7120 head at the JYs. It was about $100 more than if I were to have found one at the JY, and gotten it worked on from the machine shop, plus it would save me time cause you never know what you're getting at the JY.

I was wondering about what damper to use though. Right now I have the Hesco damper/crank sensor kit on my 4.2, so I was wondering if I would be able to reuse that?

You can re-use the Hesco damper.

Can I reuse the rest of the pulleys, water pump, brackets, alternator and steering pump from my 4.2? It was converted to an mpi years ago so I have the wiring set up to take a modified 4.2 alternator so I don't get a code.

optmaxx wrote:Can I reuse the rest of the pulleys, water pump, brackets, alternator and steering pump from my 4.2? It was converted to an mpi years ago so I have the wiring set up to take a modified 4.2 alternator so I don't get a code.

I don't see any reason for not reusing those ancillaries but if the set up is for a serpentine belt, make sure that the water pump is a reverse rotation type i.e. counterclockwise with a smooth-edged pulley.

Well, I should be getting my engine pretty soon so I'm just trying to plan things out.

-What clearance will I need for the rod bearings with the ARP bolts torque spec?

-What brand assembly lube do you guys recommend?

-Will the Chiltons manual be enough for this rebuild?

-Installing the cam seems like a delicate procedure. Any tips on installing the cam without damaging the cam bearings? Does the cam use a different lube than the rest of the engine?

-I saw a DVD for sale on rebuilding a 4.0 on ebay, so I was wondering if maybe the dealer might have the samething?

I'm not worried about the top end of the block since I've replaced the head and exhaust manifold before, working on the bottom end will be new to me.

Handy if you don't have a hard copy here is a link for it.

http://oljeep.com/JeepEngines.pdf

/cheers
Brian

Thanks for that link. I was going through it and noticed that it said that some 4.0 cylinder bores might need to be notched at the bottom when installing a 4.2 crank? I looked that up and it seems that notching the bottom of the cylinder bore is done to compensate for the extra swing from stroking the engine? I noticed that no one has mentioned this in their builds, so it's probably not a problem, but I still would like to know what you guys think about that?

optmaxx wrote:Thanks for that link. I was going through it and noticed that it said that some 4.0 cylinder bores might need to be notched at the bottom when installing a 4.2 crank? I looked that up and it seems that notching the bottom of the cylinder bore is done to compensate for the extra swing from stroking the engine? I noticed that no one has mentioned this in their builds, so it's probably not a problem, but I still would like to know what you guys think about that?

I have had to clearance blocks for strokers in Chevy's and Fords. No big deal your just removing an obstruction and providing at least .075" clearance. Just don't leave any sharp thin edges that could break off under stress and ruin your day.

I have never heard that anything in the block needs extra clearance for the 258 crank.

SilverXJ wrote:I have never heard that anything in the block needs extra clearance for the 258 crank.

Certainly not for a standard stroke 258 crank but possibly for an offset-ground 258 crank with a longer stroke.

I finally got my stuff back from the machine shop with some set backs, they' don't seem to be a big deal though.

-The first set back is that they ground the crank 0.010 instead of the 0.020 he said he was going to do, and I ordered the rod and main bearings for 0.020. I reminded him that at first we were going to go with 0.010 but then decided to go with 0.020, he totally forgot. He did offer to grind it to .020, but said that it would probably be better to leave it at .010, so I'm just going to get new bearings.

-The second set back is that I noticed the wire locks aren't installed in my bulltear pistons. I know that the OEM rod pins are press fit, but these came with wire locks so they should be installed right? I'm just not sure if they should have done that? It shouldn't be hard to do if I need to do it right?

-I meant to ask earlier, and I probably didn't look hard enough, but I can't seem to find arrows or any markings on top of the piston that shows which direction they should face.

Here are some pics, I won't be able to start till next weekend. I bought the head from ebay.

Your machine shop sure does things funny.

We might order .010 bearings but then we cut the crank to match the desired bearing clearance.

If they pushed the pins on the rods you don`t need the locks. The locks are for full floating applications.

Again,
your machine shop sure does things funny.

I am not saying it`s wrong but there is a big difference between a engine rebuild machine shop vs. a performance machine shop.

optmaxx wrote:-The second set back is that I noticed the wire locks aren't installed in my bulltear pistons. I know that the OEM rod pins are press fit, but these came with wire locks so they should be installed right? I'm just not sure if they should have done that? It shouldn't be hard to do if I need to do it right?

No need for locks with press fit wrist pins. If the pin comes out you have bigger problems.

-I meant to ask earlier, and I probably didn't look hard enough, but I can't seem to find arrows or any markings on top of the piston that shows which direction they should face.

The quench pad goes on the manifold side of the block, opposite of the cam valley.