CJ3b....That is what the vin tag says.

[jonah]

Thanks! Just got back from the first road test. Nice, definite improvement in power. Had a little run on when I came in. I think I might have a little too much timing advance. Of course the timing light I bought today doesn't work...

Ok, just got a working timing light...40 degrees total advance, oops. I guess the moral is, don't let the photographer tune the motor by "ear".

Now it is at 16 initial, 23 total - no more run on.

[RAT]

Thanks! Just got back from the first road test. Nice, definite improvement in power. Had a little run on when I came in. I think I might have a little too much timing advance. Of course the timing light I bought today doesn't work...

Ok, just got a working timing light...40 degrees total advance, oops. I guess the moral is, don't let the photographer tune the motor by "ear".

Now it is at 16 initial, 23 total - no more run on.

So now a set of wheelie bars is in order to keep the front end down...
Looks good Jonah

[6spdYJ]

Photographer my foot! You're a Jeep builder who happens to know how to take good pictures. More fabrication envy. Looks great.

[jonah]

Well, I gambled on a used engine and I lost. Just got back to the shop and found a puddle under the jeep - antifreeze. Tracked it down to the worst case scenario. Coming from under the paint on the side of the block, chipped the paint off to find a crack with coolant seeping through, damn it. It was running good too.

I don't know what to do now...

[RAT]

Well, I gambled on a used engine and I lost. Just got back to the shop and found a puddle under the jeep - antifreeze. Tracked it down to the worst case scenario. Coming from under the paint on the side of the block, chipped the paint off to find a crack with coolant seeping through, damn it. It was running good too.

I don't know what to do now...

First off I'd be pissed! Is it by a freeze plug?
How big is the crack? If it isn't too long it can be fixed. i've done this before.

[jonah]

yeah, I am pissed. But at least I didn't pay much for it.

It is right above the freeze plug (about .75 inches up from the top of the plug), about 1.5 inches long.

Waddaya think?

[red baron 13]

Jonah, that blows. When I see stuff like that; I leave. Then, I come back to shop to re-inspect -- thinking I was dreaming. However, it never ends up to be a dream...ugh!! Good luck!

[jonah]

Yeah, when I saw the puddle my heart sank. When I saw the general area it was coming from I was hoping that it was just a freeze plug, then the hammer dropped.

I am reading up on stitching cracks, maybe I can make it work.

[aw12345]

Well here is a solution transfer all the running parts to the other block and call it good. Rigdge ream the old block a quick date with a flexhone some rings and call it good.
Or carefully try to weld it. Boat engines and cracks in the block are very common.

[jonah]

I was thinking the same thing, so I pulled the heads off the other one. There is a pretty good groove. I would say at least a .010 lip. What is the max for reaming, honing and ringing?

What is it about boat motors that make them crack? Is it the introduction of cool water from the sea/lake for cooling? I guess I learned my lesson about boat motors....probably.

Anyway, I have been looking at www.locknstitch.com. It looks like they have repaired much worse than mine. I had never heard of this before.

[RAT]

I was thinking the same thing, so I pulled the heads off the other one. There is a pretty good groove. I would say at least a .010 lip. What is the max for reaming, honing and ringing?

What is it about boat motors that make them crack? Is it the introduction of cool water from the sea/lake for cooling? I guess I learned my lesson about boat motors....probably.

Anyway, I have been looking at www.locknstitch.com. It looks like they have repaired much worse than mine. I had never heard of this before.

I have used something similar. It does work. I've welded a whole chunk of block back in that was popped out from freezing (yes the freeze plugs blew and it still cracked). Need some high phospherous wire, or try the locknstitch. You have to drill holes at both ends of the crack to prevent it from migrating. That part is very important. If you don't drill it in the right places it will continue to crack. Preheating is good but you have to heat as much of the block as possible and that isn't so easy. But like I said it works and more improtant it lasts.

[jonah]

Are you saying the welding lasts or the lockstitch works and lasts? Or either one? I think I will try the lockstitch first since pre and post heating the block would be tough. If the metal is too thin to stitch, I might look into using the old block. The cylinders didn't look too bad other than being worn down.

[inVERt'D]

Jonah, I think the chances of not bunging that thing up more by welding it are pretty dicey--especially if you're not going to tear it down and pre- and post-heat it.

Do you still have an oxy-acetylene setup? I would suggest you try a cast iron brazing alloy like this one.

http://www.aluminumrepair.com/hts528.asp

I've used their aluminum product (HTS-2000), and it's impressive. I'm intending to use their cast iron product (HTS-528) to braze a new upper starter bolt ear onto a my "new" truck's engine block. There are similar products, but this one specs out as probably the strongest (102,000 psi tensile str) and most heat-resistant (1400*F melting point).

[aw12345]

The reason boat motors crack is that it's hard to get all the water out and not easy to fill then with a antifreeze solution, really doesn;t take much of a frost to crack a engine block. an 0.010 ridge you can run if you get the ridge out. You could even mike the pistons and stick the biggest one in that hole as long as you orientate the rods correctly. Doesn't hurt to try and weld or use these stitch locks to try and fix the other engine block, of it fails patch up the other one. Either way you have enough parts to make a decent running engine.

[jonah]

Thanks for all of the input guys.

David, those rods look interesting. They seem like they could do the trick. But I think I will try to stitch lock it first.

If it fails I will do like Art is suggesting and mix and match parts to get one good one. If I go that way and use the crank and cam from the boat motor, do I need to get new main and cam bearings? Use the bearings from the boat motor or original motor? Or just measure and use the closest ones?