360 bore question

[Monaco Man 78]

can a 360 that is bored .030 over, be bored to .060 over without over heating problems or any thing of that sort. thanks guys

[dodger1]

I doubt it, unless you have the cyl. walls tested for thickness. Personally I wouldn't even consider anything over .030 - I'd rather find another stock-bore block if the .030 one was damaged.

[Dart 360]

It always pays to check wall thickness, however the early 360's (71 & 72) are reported to have used the 340 castings giving a thicker wall thickness.

[clarkj]

Can only speak from my own experience, but I ran a .060 over 360 in a lifted 4x4 truck and it didn't even begin to get hot. It was about 425 HP at the crank and 10.5 compression as well. I ran premium fuel and had an electric fan to help when I was messing around in town and whatnot, but I could go out and thrash that truck off road all day and then drive it home on the highway at 70...no heating issues whatsoever. I understand the cautious outlook, but there are all sorts of .040-.060 engines running around on dirt tracks, and if they aren't getting hot...

[DJM]

Originally Posted by clarkj

Can only speak from my own experience, but I ran a .060 over 360 in a lifted 4x4 truck and it didn't even begin to get hot. It was about 425 HP at the crank and 10.5 compression as well. I ran premium fuel and had an electric fan to help when I was messing around in town and whatnot, but I could go out and thrash that truck off road all day and then drive it home on the highway at 70...no heating issues whatsoever. I understand the cautious outlook, but there are all sorts of .040-.060 engines running around on dirt tracks, and if they aren't getting hot...

MAN, you said a mouthful and I fully agree with you so I won't repeat it.
PS: they sell .060 pistons so -- go figure.

[Monaco Man 78]

would it get better performance from 4.060 bore than a 4.030. i figure it would but never ran a 360 with that size of bore.

its always good to ask questions when in doubt, thanks for yalls input.

[DJM]

Really I would doubt that you will feeel or notice the difference. They guys that are doing it are trying to get every little thing out of the engines that they can or are running engines that would not clean at .030.
The best thing to do is to bore with as little as you can get by with so as to have some room down the road. Boring oversize is very cost inefficient by itself.

[Monaco Man 78]

im running stock compression heads valves, etc except cam carb and intake. basically high performance street engine.

[Monaco Man 78]

tough decision i have to make but, more than likely i would want to get another block but dunno yet.

[dodger1]

Originally Posted by DJM

Really I would doubt that you will feeel or notice the difference. They guys that are doing it are trying to get every little thing out of the engines that they can or are running engines that would not clean at .030.
The best thing to do is to bore with as little as you can get by with so as to have some room down the road. Boring oversize is very cost inefficient by itself.

I'll go with the above - I don't believe the 1-2% gain in displacement will be noticed in a mild to medium streetable engine. But it really depends on what you need to do with your existing engine. Is the bore damaged? Worn? Got any other damage?

[Monaco Man 78]

well all i know now is the cylinders are worn, also water has set in one part of the head causing rust, only in one part underneath the head. believe the passenger side head, we have an ice storm every year almost, when i got it from the salvage little after that.

[dodger1]

OK, you may have nothing worse than a blown head gasket, but you'll need to pull the heads at least, and do a careful inspection of the parts as they come off the engine. Could be a cracked head, or a cracked block as well. Before you do all that, try a cooling system pressure test and see if you can at least localise the coolant leak.

[Zach H]

The pitts may be worse in the cylinder wall than it looks. It may be cheaper to find a solid junk yard block than sleeving a cylinder. Just another thing to consider.

[Monaco Man 78]

pulled both heads already, need to test, it havent seen any cracks or anything, but i have to get it tested looks like water settled in the one of the passenger side cylinders. engine was settin for a while before i pulled it.

[JCFcuda]

Unless, the the block has serious core shift you should be ok. I have done 2 60 over's no heating issues.
A few years ago Heneley's performance, in Tenn, were sonic testing 318 and punching them out to 4.00.

Jim F

[fat 360]

early blocks up to 74 were thicker,the rest really should only goto '30,but sooo many have gone more without probs it's not funny,from the sound of it,your not gonna lean on this thing too hard(even with the 4'inch crank).
If it was me...I'd bore it only as much as it needs,and get pistons to suit,strong cylinder bores don't flex and create blow-by,and you'll get more power(and longer life outta the engine)that way.
Trust me tho,If you bored it '60,it ends up 371ci,and if you bore it '30,it ends up 365ci.....you will not feel 6ci at all,it is just not worth it to do it unless absolutely necessary!

[Monaco Man 78]

went and pulled a stock bore block 360 yesterday, gonna go with that

[DJM]

"early blocks up to 74 were thicker,the rest really should only goto '30,but sooo many have gone more without probs it's not funny,from the sound of it,your not gonna lean on this thing too hard(even with the 4'inch crank)."
Not nessessarly. That is what the books say, in the real world it does not nessessarly turn out that way and many of the later blocks have thicker walls than the early ones. It is the luck of the draw.

[Monaco Man 78]

well i have a 88 360 block. with matching non smog heads.

[DJM]

I will repeat myself from your other thread:
--------------------------------------------------------------------------------

You will find that virgin the 340/360 heads up to the closed chamber and magnum heads will CC on the average of 70-72 cc's. They will all with very little work flow the same. Even in stock form you will not notice any difference unless you are getting time slips and the difference will not be as much as you think.

[Monaco Man 78]

yeah i know thats what you said i was just saying, everythings good on my part, matching block heads, and main caps