Labor Day Putting down your wrenches or time for
MORE wrenching? 
Plenty of places to share. | | Click on image for the lowdown. 
====
| | | Forums66 Topics128,005 Posts1,055,261 Members48,418 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Sep 2010 Posts: 49 Wrench Fetcher | | Wrench Fetcher Joined: Sep 2010 Posts: 49 | Will boring out the engine (235) to .060 weaken the engine or cause it to run hot. | | | | | Joined: Nov 2005 Posts: 6,100 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 6,100 | Hy larryelvick, according to the parts book GM only offered pistons as large as .040" oversize. That being said in my experience .060" is the usual large size limit to reboring most engines. The newer engines with their thin wall castings cannot be bored even to .060" I have safely bored 265 V8 and 283 V8 blocks to .125", the last 261 rebuild I did for a customer was a 1955 - 62 block which was succesfully bored to .080" with no operating problems whatsoever. There is a new tool in the machine shops arsenal, sonic testing to check the thickness of the cylinder walls, hope that helps. | | | | | Joined: Dec 2003 Posts: 2,733 Shop Shark | | Shop Shark Joined: Dec 2003 Posts: 2,733 | A good many 235's were reported to have been bored .125 but I cannot confirm it. That being said I wouldn't hesitate to bore one .060 to .080. I did bore mine .060 in fact and it runs cool as a cucumber. | | | | | Joined: Sep 2010 Posts: 49 Wrench Fetcher | | Wrench Fetcher Joined: Sep 2010 Posts: 49 | Thanks for the info guys.
Larry | | | | | Joined: Jan 2005 Posts: 310 Shop Shark | | Shop Shark Joined: Jan 2005 Posts: 310 | Everything I've read over the years states that a 235 block can handle boring to .090 with absolutely no problem. Above that, I don't know...
-Tim
'51 Chevy 3104 w/'56 235, 848 Head, HEI Dizzy, Corvette Cam, Split Manifold and Dual Carter YF's
| | | | | Joined: Dec 2009 Posts: 194 Shop Shark | | Shop Shark Joined: Dec 2009 Posts: 194 | I bored my 54 Chevy 235 block .060 and no problems. Still running after 11 years. Good luck. | | | | | Joined: Sep 2011 Posts: 1,451 'Bolter | | 'Bolter Joined: Sep 2011 Posts: 1,451 | Same here, '60 235 bored .060" many years & many miles ago, no issues.
BC
1960 Chevy C10 driver 261 T5 4.10 dana 44 power loc
1949 GMC 250 project in waiting
1960 C60 pasture art
Retired GM dealer tech. 1980 - 2022
| | | | | Joined: Feb 2001 Posts: 1,094 'Bolter | | 'Bolter Joined: Feb 2001 Posts: 1,094 | 59 261 bored .060, been running almost 10 years. It runs 180 al day long, in traffic may get to 190, has never overheated.
Tommy
59 apache 1/2t
261 short stepside
| | | | | Joined: Aug 2011 Posts: 835 Shop Shark | | Shop Shark Joined: Aug 2011 Posts: 835 | 1953 Powerglide 235 bored .60 over 26 years ago. No problems.
kurt | | | | | Joined: Feb 2004 Posts: 29,742 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,742 | The "sonic test" device from 60 years ago was an 8-ounce ball peen hammer. A good machinist could find thin spots and sand pockets by tapping inside a cylinder and listening for different sounds of the hammer strike. I've seen my father offset-bore a flathead Ford engine to move the center cylinders away from each other to avoid the built-in thin spot around the exhaust ports, and go .250" oversize on some of the race engines he built. He had to grind the small end of the connecting rods to let the pistons center up in the cylinders on the four middle ones. Of course, these were very short life engines, particularly when they ran on alcohol and hydrogen peroxide at 11:1 compression.
Jerry
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
| | |
|
|
