360 help

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DusterOnaDime

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Hi all, I have a 73 360 engine my kids and I are assembling. I just got the block back from the machine shop. When we picked it up, I brought the crank in and he mic’d it to see if it was still in usable shape. He said it was but when we installed it tonight, we checked bearing clearance with plastigauge. After removing the caps to check, the bearings never contacted the plastigauge. I measured with a dial caliper (I know it’s not a micrometer) it measured 2.79550 so I’m guessing it has been ground. Question is, will any 360 crank work in my 73 LA motor, or does it have to be a certain year to fit.
 
The standard main journal diameter is 2.81". Either it's been turned, is a wore slam out standard, or you're misreading your caliper. If you're confident in your measurement, take it to a new machine shop. Sounds to me like your measurement is probably close if the plastigage is not compressed. Maybe the shop turned the crank? Maybe they gave you the wrong one?
 
want to say stock main journal should be 2.81

That would make yours .0145 under. Even with a .010 bearing that is a ton of clearance
 
If the stock main dia. is 2.81, you can have that crank ground to accommodate .020 under bearings. Any used crank that you find to replace it will probably be less than perfect.
 
How good was the shop? I've learned there are two types of shops, Farmer/reman grade and Performance grade. The first being loosy goosy, their stuff works for stock, low expectation builds.

Chances are your cranks was cored into a grinder and that is what the shop got back.
 
dano said:
How good was the shop? I've learned there are two types of shops, Farmer/reman grade and Performance grade. The first being loosy goosy, their stuff works for stock, low expectation builds.

Chances are your cranks was cored into a grinder and that is what the shop got back.
Click to expand...


There are MANY “performance” shops that aren’t qualified to butter toast at the local choke and puke.

There are some right in your backyard.
 
Yes, all 360 cranks will work in a 360 no matter the year. Assuming you have matched bearings to journal size. You don’t. Your standard size bearings are not going to work. You need to determine accurately what size the crank is (not a judgement) so you can determine what oversized bearing you need. If the crank is more than 10 under, then you have it turned to the next size you can get a bearing set for. Too bad you are so far away, I have a standard size crank I will never use.
 
Im starting to wonder, I pulled this 360 back in the 90’s for my duster. It took 30 years and my kids begging me to get it on the road. I bought the duster I was 15, and now am working on it when I can. The shop was recommended to me by a buddy. They fluxed, bored, cleaned, and installed all plugs for me. Total was $570. Oh and they installed cam bearings. Now I’m worried that the work I paid for might not be “up to par”. Like I originally posted, when I picked up the block, I brought my crank in and he mic’d it right there in front of me and compared numbers to numbers in his book. He said the journals were all within spec, and standard bearings would be fine.
 
A couple of things.......

Did he use the right comparative numbers in his book?
Is your plastigauge the right size for the clearance that you are trying to measure?
Maybe bring it back and have it re-mic'd......Or get your own accurate mic?
 
Are the bearings standard or undersized for a regrind?

Buy some second hand micrometers off of ebay so you can take some basic measurements.
 
Newbomb Turk said:
There are MANY “performance” shops that aren’t qualified to butter toast at the local choke and puke.

There are some right in your backyard.
Click to expand...
Yes, just like there are lots of "farmer" type shops that are qualified to work on the space shuttle. Ask me how I know! lol
 
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