Hey guys, I got a 360 motor that I was going to be dropping in my 72 Duster 4 speed that was only 10,000 on a rebuild. The good news was it looked real fresh, has .030 over low comp 4 valve relief speed pro hyper pistons and absolutely no ride in the cyliners. The bad news is that it got a little water in 2 cylinders from not having the intake on it and those 2 got a little rust, so theres a little pitting in them. I was thinking about just honing the cylinders and slapping it back together and running it for now but now I'm thinking about taking it to the machine shop and see what they think.

If its not acceptable, I'm going to see if a .060 overbore will get it all cleaned up. The question is how safe is a .060 over 360 for a street car? ITs a 73 motor which I hear were cast using the same 340 mold and can be bored quite a bit. Also how about a .060 bore for a 408 build with a 4" crank( of corse it wouldnt be a 408 then) is that pushing it with a stroker crank?

Was looking for a cheap motor to drop in till I can build a bigger one down the line in a few years so I can concentrate on getting the body and paint done, but if I have to re bore, I'll just try to build a decent motor now.



Butch

Without sonic-testing the cylinder walls, it's a guess.
Even "thick castings" can be compromised by core shift.

Any idea what sonic testing usualy costs? Ballpark?

Why not just go .040 over and not worry about cylinder wall thickness. That's what my 408 (410) stroker is. I've been racing it for 2 seasons and driving it on the street with no problems. KB has a couple of piston choices for that bore.

I dont think .040 will do it, these are the pits!!!

If that is the bottom of the cylinder and out of the ring travel, don't see where it would be a ptoblem.Probably be OK at .040.

It probably doesn't need to be bored. Run it like it is, I 'll bet ya it'll be fine.

I've ran clys that were worse than that with no problems.

Post more pictures if you can.

I think you would be suprised what even a .030 over will remove, I bet most or all that would be gone, even if you went .030 the rings would slide right over something like that, heck they would probably be fine as is.

.030 will remove .015 from each side and those are probably no more than .005 deep any how.

hmm, I'm in exactly the same boat

Just got a mag 360, 500 miles on a 30 over rebuild, and water in the cylinders. I just put wheel bearing grease over the cylinder walls to prevent any additional pitting. I don't think mine is quite that bad, but I haven't cleaned it up real well yet.

I'll be watching this thread.

Thanks for the input guys, those pits are at the top of the cylinder. My step father said the same thing about it probably being fine to run it as it is, especially seeing as the other cylinders look so good and the rest of the components look perfect, including the bearings.

I'll put up a couple more pictures, see what you guys think. I'd love to be able to put it all back together and run it, I doubt I'll even put 5000 miles on this motor before its pulled in favor of a bigger motor or the cars sold for a new project the way I go.


Butch

another

and another

And heres the second cylinder that got water...

No biggie, run it. It ain't no pro stock motor. Like I said, I've ran worse. Don't waste the block by boring again.

I'd be willing to bet you can get them cleaned up going to .040 over which is std bore for a 340 (4.04). I would go that route becasue that sort of rust if I knew it was there would always bug me. I would also have it sonic tested. It costs between $75-$200 depending on the equipment, the guy, and your part of the country.

my engine for my 70 challenger an E58 police car engine sat uncovered in a junk yard. had to hammer out the pistons. Then had it bored .060 , that was over 12 years ago, no problems

I went .040 with a stroker kit, and got 410 cid..

Hey guys, Thanks, Thats what I'm gonna do. I'll take it down to get rehoned, and slap it back together and run it. I'd rather wait till I have enough $ to build a nice motor, the right way in the future. I'm going to cc the heads and see what my compression is and deciede between a Hughes Whiplash cam with low compression, or mill the heads a little and go with a solid cam likeMP 528 or Comps XE274 Solid(always wanted to run a solid cam, )

Glad to hear some of you have been in the same boat!!!

Butch

comp XE262 is a very nice cam with low comp in a 360.

pulls very hard from ~1500-1800 up to 5500 RPM, with great midrange.