I have 283 block that probably wont clean up at 60 over,My question is can this block be bored to a 4" bore and built as a standard 327 or 302? Thanks
this has been discussed before , and i have given my opinion ,which is sometimes different than others on here! it depends..with core shifting during the original casting process and 40+ years of rust , the only way to know for sure is to have the cylinder walls sonic tested. then there can be a deep rust pit that doesn't show up in testing. some years blocks are susposed to have thicker walls , but no one seams to agree on what years my opinion is boring a 283 to 4" is a **** shoot read what RACEFAB says in this thread: http://www.jalopyjournal.com/forum/showthread.php?t=62753
Been boring them since the mid sixties, MOST will go 4" but there is always the exception. Some, due to core shift, air bubbles in casting, sand pits, will not.. Sonic testing is the only SAFE way to go. Also be sure the cam bearing bore is well centered with the machined face.
Like said above .....YES & NO..... I have done it with no problems ........long before sonic testing was available.....and I had one crack a cylinder wall and get water......riding down the road with my mother in the car....... ( I was 17 and it was 40 years ago ). You know I was driving very safely and NOT turning the 301 up I would not invest the money.......it is mostly a ****shoot. SBC blocks are too inexpensive to come by.....unless you have a rare matching number situation or some other attachment to that block. I bored my last 283 ...just 60 thousands....I had a set of NOS sixty over Corvette FI pistons.... .
Are there such things as .080 over 283 pistons? Or is this a cu$tom pi$ton order? Reason i ask is that I already have a 283 that is .060 over and worn out. Just wondering if I can do a cheap rebuild on this engine or time to look for a less-used block?
This is the perfect block to try a 4" bore on. If I owned this I'd try the .120 over and see how it went. If it fails your not out to much. If I had a block that was std. or just .030 over I'd just clean it up with .030 over the existing bore.
Before factory 4" blocks were readily available (junkyard) it was common to go to 4" with 283 and I have personally used a 265 with .155 overbore.If sand holes or flaws are found in 1 cyl a sleeve will cure that with good reliability.I s****ped a 63 327 planned for a Corvette when 3 cyls showed a flaw, and we only wanted to bore .030 OS.I have done quite a lot of cylinder preparation over the last 45 years and I feel like the early sbc used a very "soft" (cheap) alloy compared to Buick,Chrysler "slant 6", and Cadillac, but later engines seem to have much better cylinder life.Early 327 and 307 the worst.A later 4 ncher should be a longer lived block and a better risk of soundness.
You are right, but this is a 66 block. Supposedly the later blocks are not as thick cylinder walls? Guess a sonic check is the way to tell for sure. I had always thought of getting a decent 327 small journal block and build my 4-inch bore engine from that.
I've got the same thing with a '57 block. If anyone needs another I'd be happy to let this one go for cheap.
Don't forget if you tap the block out too much you can run into the problem of having the engine run alot hotter........maybe too hot for basic street use............hope it works out.
In the 50's i ran a 283 bored to 4'' in a dragster. I don't know about longevity or running hot, but we went thru blocks at the rate of 2,or 3 a yr. I have a similiar eng now that is poured, to the top and won't run water in a fed. You can get too big on the bore and the wall won't be able to get rid of the heat,in a street application.
Like the man said if there is minimal core shift and not too much rust erosion (sonic testing will tell) bore to 4" throw in a set of 327 pistons and some cam and this little 301 will rev like hell. No bottom end torque, but we used to wind these motors to 7000 - 8000 RPM. Watch out though when the cylinder wall cut loose as they ****tered pretty quick.
302 pistons, yes. 327 pistons, no. The 1/8 inch difference in compression height won't do much for compression.
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