360 blocks

Posted By: DusterKid

360 blocks - 01/23/09 11:32 AM

Do 360 motors have a weak point around main cap 4? I have 2 blocks that with a new crank, cap 4 marks up the bearing. The one motor was supposively just line bored by a machinst, the other hasn't been to a machine shop yet. I know the one that hasn't been touch, could need lined bored, but the other one that was line bored I don't know if it wasn't done properly or is there something with a 360 block that will "fail" and allow this to happen?

Posted By: MR_P_BODY

Re: 360 blocks - 01/23/09 02:09 PM

Quote:

Do 360 motors have a weak point around main cap 4? I have 2 blocks that with a new crank, cap 4 marks up the bearing. The one motor was supposively just line bored by a machinst, the other hasn't been to a machine shop yet. I know the one that hasn't been touch, could need lined bored, but the other one that was line bored I don't know if it wasn't done properly or is there something with a 360 block that will "fail" and allow this to happen?

I've never heard of any thing. There are plenty of
360 out there being raced. The only thing is that
the #2 and #4 cam bearings draw off oil for the valve
train

Posted By: Rapid340

Re: 360 blocks - 01/23/09 03:29 PM

Check the runout on the crank.

Posted By: Moparnut426

Re: 360 blocks - 01/23/09 03:33 PM

I do know from experiance that you should do your homework when chosing a shop to line bore/hone. I have had it screwed up before, and it can be messed up pretty easily. The 360 I had line honed was so peak and valley it was crazy how far off each main was from the other. I couldnt turn the crank over with no pistons in the block. Not even with a breaker bar.

some shops are great with certain things, but struggle with others I have found.

Posted By: MR_P_BODY

Re: 360 blocks - 01/23/09 03:44 PM

Quote:

Do 360 motors have a weak point around main cap 4? I have 2 blocks that with a new crank, cap 4 marks up the bearing. The one motor was supposively just line bored by a machinst, the other hasn't been to a machine shop yet. I know the one that hasn't been touch, could need lined bored, but the other one that was line bored I don't know if it wasn't done properly or is there something with a 360 block that will "fail" and allow this to happen?

The one thing that seems to be common between the
2 engines is the crank... it could be tweeked, have
it checked. Like was said above have a good shop
do the line bore... thats why I use Best Machine,
its great that they are local to me

Posted By: DusterKid

Re: 360 blocks - 01/23/09 05:25 PM

Its not the crank, we've actually tried 2 cranks, one that we had turnt that is 10/10 and a brand new one that is standard. We measured the cranks and both are dead on for specs. The machinst that did the line bore we have had do our cranks before without an issue, but apparently he doesn't either have the proper equipment or the knowledge to properly line bore. He measure the block and said it was .003 out before line boring, but when we got the block back it still does the same thing as before. Hoping its just a bad line bore job and take the block to another shop and have it done and not go back to that guy anymore.

Posted By: MR_P_BODY

Re: 360 blocks - 01/23/09 05:35 PM

Quote:

Its not the crank, we've actually tried 2 cranks, one that we had turnt that is 10/10 and a brand new one that is standard. We measured the cranks and both are dead on for specs. The machinst that did the line bore we have had do our cranks before without an issue, but apparently he doesn't either have the proper equipment or the knowledge to properly line bore. He measure the block and said it was .003 out before line boring, but when we got the block back it still does the same thing as before. Hoping its just a bad line bore job and take the block to another shop and have it done and not go back to that guy anymore.

I dont know if this happened to you or not but the
machine shop I dealt with years ago, I had them line
bore the cam tunnel and the mains, well the cam tunnel
was done and they forgot to do the mains but charged
me for both. By the time I assm. the engine and
checked it the guy had moved out alot farther so I
ended up going to Best Machine with it and havent
gone any where since. What I'm trying to say is MAYBE
they forgot to line bore it(specially that much off)

Posted By: Moparnut426

Re: 360 blocks - 01/23/09 06:15 PM

Well, mine was off more than that, mine was .004 on the thrust, and .003 on the rear, the front was ok and the 3rd was a bit out. The shop said my crank was bad, it wasnt, i accually took up a set of guages and showed him personally, and even then he argued. then I talked to a guy who used to work with that shop and they had an old machine in which the stones would accually get cocked in the tooling crooked and cause all kinds of problems. Lucky for me it didnt ruin my capl or block.

Kasey

Posted By: ccarson

Re: 360 blocks - 01/23/09 11:48 PM

You need to find a good Machine Shop and
stay with them, I use Best Machine also, all the best parts in the world wont matter, have to make sure everything likes each other or you will soon have junk.