Sleeved & Bored Engines

[Pete Pritchett]

I,ve been looking to purchase an engine block for a 1965 327/350hp. I had agreed to buy a block that was supposed to be a standard bore. After it was cleaned it up. It was found to have a scratch in a bore. It was going to bored 30 over. Which I had agreed to accept. But it was determined that a couple of cylinders had some pitting and two cylinders were sleeved.
The question is on the service of the blocks. I had always thought a block with sleeves was a problem. The person selling it said was as good or better than an one without them. I am slso looking at a block that is 30 over now. So what is the prevailing opinion? And how much of an over bore should be considered as still a good purchase and what about sleeved cylinders?

[Chuck G.]

Re: Sleeved & Bored Engines

I'm no machinist or engine builder, but I have been told by several respected local individuals that the sleeves are actually of better quality than the block itself. The problem is the cost, about $80.00/cylinder around the Baltimore, MD area the last time I checked. I also have no problem with a 30 over engine. All 3 of my Corvettes are 30 over. No problems, no overheating, etc. Chuck

[Chuck G.]

Re: Sleeved & Bored Engines

I'm no machinist or engine builder, but I have been told by several respected local individuals that the sleeves are actually of better quality than the block itself. The problem is the cost, about $80.00/cylinder around the Baltimore, MD area the last time I checked. I also have no problem with a 30 over engine. All 3 of my Corvettes are 30 over. No problems, no overheating, etc. Chuck

[Joe L.]

Re: Sleeved & Bored Engines

Peter and Chuck-----

I agree. I don't have any problems with the concept of cylinder sleeves. I didn't used to like the idea, but I studied it quite a bit. Now, I'm fully of the opinion that sleeves are just fine. Without a doubt, the material is better than the substrate cast iron of the block. That's because the block is gray iron and the sleeves are usually ductile or nodular iron which are much superior forms of cast iron.

As Chuck mentioned, the real problem with sleeves is the cost. In most cases, the cost of sleeving a complete engine is far more than the block is worth. However, the "most cases" does not include rare and valuable blocks that have restoration significance for Corvette or other restorers. In those cases, sleeves are well worth the cost. For a "garden variety" block, though, if it requires more than 1 or 2 sleeves, it's usually considered scrap.

[Joe L.]

Re: Sleeved & Bored Engines

Peter and Chuck-----

I agree. I don't have any problems with the concept of cylinder sleeves. I didn't used to like the idea, but I studied it quite a bit. Now, I'm fully of the opinion that sleeves are just fine. Without a doubt, the material is better than the substrate cast iron of the block. That's because the block is gray iron and the sleeves are usually ductile or nodular iron which are much superior forms of cast iron.

As Chuck mentioned, the real problem with sleeves is the cost. In most cases, the cost of sleeving a complete engine is far more than the block is worth. However, the "most cases" does not include rare and valuable blocks that have restoration significance for Corvette or other restorers. In those cases, sleeves are well worth the cost. For a "garden variety" block, though, if it requires more than 1 or 2 sleeves, it's usually considered scrap.

[Zachary K.]

Re: Sleeved & Bored Engines

I purchased a complete engine that apparently had been left outside for some time years ago. The price was right for the complete unit. When I disassembled it I found one cylinder had water laying in it. Rain water had come in through the carb and down through the intake and past an intake valve that was open. After complete disassembly you could see where the water had frozen at one point and actually damaged the cylinder beyond anything I had ever seen before in all the years I've worked on engines. There was actually an area that looked as if it had pushed the cylinder wall out where the water was frozen but hadn't cracked the wall. At the time I had a friend that worked at a speed shop, and he suggested a sleve. I was very leary at the time but he guaranteed me the same thing, that a sleve was better than the original cylinder wall. I had the one done that was damaged and eventually put over 110,000 miles on the engine before selling the car. I even raced it for two summers. If the price is right for the block, feel comfortable with the sleved engine, and make sure a reputable machine shop does the work. If I remember correctly the price (70.00 per cyl) some 15 years ago doesn't make 80.00 seem too bad now. Good luck, Zach # 9838.

[Zachary K.]

Re: Sleeved & Bored Engines

I purchased a complete engine that apparently had been left outside for some time years ago. The price was right for the complete unit. When I disassembled it I found one cylinder had water laying in it. Rain water had come in through the carb and down through the intake and past an intake valve that was open. After complete disassembly you could see where the water had frozen at one point and actually damaged the cylinder beyond anything I had ever seen before in all the years I've worked on engines. There was actually an area that looked as if it had pushed the cylinder wall out where the water was frozen but hadn't cracked the wall. At the time I had a friend that worked at a speed shop, and he suggested a sleve. I was very leary at the time but he guaranteed me the same thing, that a sleve was better than the original cylinder wall. I had the one done that was damaged and eventually put over 110,000 miles on the engine before selling the car. I even raced it for two summers. If the price is right for the block, feel comfortable with the sleved engine, and make sure a reputable machine shop does the work. If I remember correctly the price (70.00 per cyl) some 15 years ago doesn't make 80.00 seem too bad now. Good luck, Zach # 9838.

[Jack H.]

Agree with Chuck/Joe....

But, the trick isn't in the sleeve, it's in the machinest's ability to properly bore the block (want a GREAT interference fit with no pockets for 'hot spots' to develop) and install the sleeve properly making sure it won't walk/slip and IS NOT skewed to the direction of piston travel.

Around this neck of the woods, we figure $100-120 per 'hole' for a sleeve job done by a pro machinest with solid reputation. By that I mean a guy who'll back the sleeve job for EXTREME stress/use like vintage wheel-to-wheel competition, the vintage Pike's Peak Hill Climb, or drag strip use. Any 'Bozo' machinest can pump sleeves into a block. But, those who've been around the block and know the ropes + pay-attention to detail charge a little more for their work and the delta cost is PEANUTS....

On, boring out the holes big time, well Duke said it best in a prior post. There's a reason for bore limits. You shave the thermal mass surrounding the water jacket, and at extreme bores (say, 105-over on SB blocks) you'll wind up with a power plant that runs 'hot'.... But, within reasonable limits (Chevy is KNOWN for their thick wall block designs) there's no problema and you postpone the day of reconning for the sleeve job.

Consider my '65 BB. It'd thrown a wrist pin and chewed the living daylights out of the #8 hole. That's why the original block hit the basement floor when my uncle owned the car--bore scars wouldn't 'make' even at 60-over which was the then current GM discard limit. The car spent the rest of it's pre-restoration life tooling down the road with a SB power plant under the hood....

BUT, the 396 was the precursor for 427 and there's so much extra 'meat' on the walls that you can go right on up to a 4.25-inch bore. Sooooo, we bored 'er out to 90-over and used 60-over 402 pistons (equivalent of a 413). She runs reliably and NOT hot.

Point is if you know what you're working with, what it's limits are, and have faith in your machinest you can make intelligent trade-off decisions. Sleeve technology, DONE RIGHT, is perfectly OK....

[Jack H.]

Agree with Chuck/Joe....

But, the trick isn't in the sleeve, it's in the machinest's ability to properly bore the block (want a GREAT interference fit with no pockets for 'hot spots' to develop) and install the sleeve properly making sure it won't walk/slip and IS NOT skewed to the direction of piston travel.

Around this neck of the woods, we figure $100-120 per 'hole' for a sleeve job done by a pro machinest with solid reputation. By that I mean a guy who'll back the sleeve job for EXTREME stress/use like vintage wheel-to-wheel competition, the vintage Pike's Peak Hill Climb, or drag strip use. Any 'Bozo' machinest can pump sleeves into a block. But, those who've been around the block and know the ropes + pay-attention to detail charge a little more for their work and the delta cost is PEANUTS....

On, boring out the holes big time, well Duke said it best in a prior post. There's a reason for bore limits. You shave the thermal mass surrounding the water jacket, and at extreme bores (say, 105-over on SB blocks) you'll wind up with a power plant that runs 'hot'.... But, within reasonable limits (Chevy is KNOWN for their thick wall block designs) there's no problema and you postpone the day of reconning for the sleeve job.

Consider my '65 BB. It'd thrown a wrist pin and chewed the living daylights out of the #8 hole. That's why the original block hit the basement floor when my uncle owned the car--bore scars wouldn't 'make' even at 60-over which was the then current GM discard limit. The car spent the rest of it's pre-restoration life tooling down the road with a SB power plant under the hood....

BUT, the 396 was the precursor for 427 and there's so much extra 'meat' on the walls that you can go right on up to a 4.25-inch bore. Sooooo, we bored 'er out to 90-over and used 60-over 402 pistons (equivalent of a 413). She runs reliably and NOT hot.

Point is if you know what you're working with, what it's limits are, and have faith in your machinest you can make intelligent trade-off decisions. Sleeve technology, DONE RIGHT, is perfectly OK....

[Pete Pritchett]

Re: Sleeved & Bored Engines

Thanks fellas, for all your input and answers. Thats what I needed to know. It certainly makes it easier and a lot less stressful to make a decision now.

[Pete Pritchett]

Re: Sleeved & Bored Engines

Thanks fellas, for all your input and answers. Thats what I needed to know. It certainly makes it easier and a lot less stressful to make a decision now.

[john lokay]

Re: Agree with Chuck/Joe....

Very interesting topic with some very good information posted. He's my situation: I own a 1967 327/300 black on red convertible that's been sitting in my garage for ten years. In 1992, the original engine was re-built and each cylinder was bored 80 over. I never liked the way engine ran, following the rebuild, and she did run hot. I am now thinking about getting the car back on the road, pulling the engine and having each cylinder sleeved to standard bore size. There are many engine rebuilders in the New York area, but as noted on the DB, you've got to find a knowledgeable professional to do the work. I would like some suggestions on some of the better engine re-builders in the country who could do this type of work. Given that's it's the orginal engine that came with the car I feel the capital investment is warranted. Thanks

[john lokay]

Re: Agree with Chuck/Joe....

Very interesting topic with some very good information posted. He's my situation: I own a 1967 327/300 black on red convertible that's been sitting in my garage for ten years. In 1992, the original engine was re-built and each cylinder was bored 80 over. I never liked the way engine ran, following the rebuild, and she did run hot. I am now thinking about getting the car back on the road, pulling the engine and having each cylinder sleeved to standard bore size. There are many engine rebuilders in the New York area, but as noted on the DB, you've got to find a knowledgeable professional to do the work. I would like some suggestions on some of the better engine re-builders in the country who could do this type of work. Given that's it's the orginal engine that came with the car I feel the capital investment is warranted. Thanks

[John Daly]

Re: Agree with Chuck/Joe....

John,
Talk with fellow Metro-LI chapter member Bill Mees at S&K Speed.
John

[John Daly]

Re: Agree with Chuck/Joe....

John,
Talk with fellow Metro-LI chapter member Bill Mees at S&K Speed.
John