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birkey 11-10-2012 08:41 PM

283 .125 over
 
Anybody have experience doing this? What years are capable of handling it.

techinspector1 11-10-2012 09:10 PM

Quote:

Originally Posted by birkey (Post 1609749)
Anybody have experience doing this? What years are capable of handling it.

Only one way to be sure. Sonic check the walls. If they would be minimum 0.135" all around after boring and honing, go for it.

vinniekq2 11-10-2012 09:22 PM

yes,a 301 was popular back in the 60s before GM made them.Its cool to say you made one.

cobalt327 11-11-2012 12:31 AM

Quote:

Originally Posted by birkey (Post 1609749)
Anybody have experience doing this? What years are capable of handling it.

We used to do a lot of these before and right after the 327 came out, the failure rate was less often caused by the wall thickness being too thin after boring than it was by inclusions and sand pockets that ruined the bores.

Your best bet is blocks from 1958-'62, 1959-'62 being preferred because they use the 2-piece rubber rear main seal instead of the rope seal used in 1958.

FWIW there is a 283 block that some sources say was used for both the 283 and the 327. It is c/n 3789817, according to my notes. This is later block (used through '67), so because of that I do not have firsthand info on whether it would be a good candidate or not, or if it's even true in the first place. But it's something you can research if you'd care too.

Good luck.

BOBCRMAN@aol.com 11-11-2012 07:36 AM

Cobalt327 is right. I have bored dozens of 283 blocks to 4".
Air bubbles and slag inclusions are the biggest problem. Usually apearing in the cylinder about mid way down and as life/luck would have it, usually on one of the last cylinders being bored..

The "preferred" blocks are relieved at bottom of the cylinders and look more like a 327 block. Actually a 327 crank fits and counterweights clear. The 817 block was the best. But almost all of these blocks are over 50 years old and I would have them sonic checked, especially between the bores, just for safety.

Back in the day, 301-302 inch were very popular. The TRW forged pistons "escaped" from the Flint engine plant by the hundreds and were cheap on the market.

CNC BLOCKS NE 11-11-2012 08:22 AM

To go .125 over the block should be sonic tested a short block showed up at my shop a couple of years ago sonic tested it and on cylinder was .088 on the thrust. Was then sold on EBAY by the customer.

I have always gone by Bill Jenkins on cylinder wall thickness which .160

birkey 11-11-2012 09:46 AM

so i bought this motor for $25 and was going to scrap everything but the block. is anything worth keeping? how much hp and rpm will the stock crank handle? 375-400hp? 6500 rpm? are the heads worth more than scrap value. not a chevy guy so i'm really lost on quality of stock parts.

vinniekq2 11-11-2012 09:58 AM

283 60 over can easily make 400 hp with stock crank.283 heads dont make any power,give them to a guy that wants an old period correct head. 7,000 rpm is also acceptable

cobalt327 11-11-2012 10:00 AM

Quote:

Originally Posted by birkey (Post 1609877)
so i bought this motor for $25 and was going to scrap everything but the block. is anything worth keeping? how much hp and rpm will the stock crank handle? 375-400hp? 6500 rpm? are the heads worth more than scrap value. not a chevy guy so i'm really lost on quality of stock parts.

I'd hang on to the bottom end if for no other reason than if I tossed it, the next week someone would be around looking for it! lol

But unless you have a storage problem, I'd say to at least keep the crank and rods. Unless the heads are Power Pacs, they probably aren't worth much to anyone. Unhardened exhaust seats and a whole lotta water under the bridge since they were new; at the least they'd need to be inspected before considering using them again.

As far as power to bottom end durability goes, getting too much power out of a 283 for the crank and rods isn't too likely naturally aspirated. I have seen stock 3" stroke bottom ends take 7000 rpm abuse all day ever day w/o issue. I suppose you could build some sort of top end fire breather that could tax it, but anything driven on the street isn't gonna hurt it.

Thread on the PP heads and some estimates on power: http://www.hotrodders.com/forum/powe...eads-3692.html

1Gary 11-11-2012 10:22 AM

This a small journal 283??. I think they where back then.I forget the yr change on that. Back in the day we used to destroke a 327 with 283 cranks.We had one that we ran D/MP that with as Isky solid roller,TRW forged pistons,M/T aluminum rods and Mondello double hump ported heads,we buzzed to the moon.If you wanted to destroke a 327 someday,it might be worth keeping the bottom end.
Some of the nostalgia drag guys might want that.

cobalt327 11-11-2012 10:27 AM

Quote:

Originally Posted by 1Gary (Post 1609893)
This a small journal 283??. I think they where back then.I forget the yr change on that. Back in the day we used to destroke a 327 with 283 cranks.We had one that we ran D/MP that with as Isky solid roller,TRW forged pistons,M/T aluminum rods and Mondello double hump ported heads,we buzzed to the moon.If you wanted to destroke a 327 someday,it might be worth keeping the bottom end.
Some of the nostalgia drag guys might want that.

There was never a factory 283 that was anything but SJ crank/rods.

vinniekq2 11-11-2012 10:35 AM

1968 the 327 was either small journal steel or large journal cast.

cobalt327 11-11-2012 10:38 AM

Quote:

Originally Posted by vinniekq2 (Post 1609905)
1968 the 327 was either small journal steel or large journal cast.

It sure was. That was the year things changed over. Like the LWP front accessory dress for cars.

birkey 11-11-2012 10:42 AM

the guy i got it from had the crankshaft laying on its side for sometime, can i check the warp with a dial indicator and the crank laying in block.

vinniekq2 11-11-2012 10:57 AM

I dont see why not? crank straightening used to be an art


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