View Poll Results: Which Rebuild Would You Prefer?
Punch All Eight Holes 0.060 Over
10
29.41%
Keep All Seven Holes 0.030 Over with one Sleeve
24
70.59%
Voters: 34. You may not vote on this poll
Sleeve or Large Overbore
#21
Le Mans Master
Thread Starter
A new block isn't always the hot ticket. For some folks, seasoned blocks are more desirable than a new block anyway (excluding aftermarket blocks and so on). But it matters how much metal is left, I'm with you there. We'll have it sonic checked so I'll know in the end.
Last edited by davepl; 02-02-2018 at 12:03 PM.
#22
Safety Car
most people do not care if your motor is bored out.
almost all will think twice about the motor, ... when you state 1 cylinder is sleeved.
almost all will think twice about the motor, ... when you state 1 cylinder is sleeved.
Last edited by 69Vett; 02-02-2018 at 03:25 PM.
The following 2 users liked this post by 69Vett:
73racevette (02-02-2018),
Chicago Bob (02-22-2018)
#23
Burning Brakes
I had this issue with a 350 that was going into my ‘72 SS Nova. It was a ‘72 Corvette motor with the same specs as the original 350. I had two bad cylinders due to rust, just like you, but the rodent urine that caused mine ruined the 2 valves, valve seats and two cylinders. My machine shop guy had another 350 4 bolt block and we used that one, .30 over.
#24
Pro
I would have a hard time buying a car or an engine that had a sleeve in it if I knew it. No telling how the remainder of the block is in an unknown engine. As someone says, I would purchase a new GM block from summit and be done. Yes, it is likely a bit more, but it is a dramatically cleaner build.
#25
Race Director
If you plan to drive the car then I would replace the block.
If you plan to build it for sale and it truly is a one of a kind Pontiac/Corvette, then maybe do what you need to do to repair the block.
Another option may be to drop in a create motor and keep the complete original stored in case you do sell in the future and give it to the buyer with the choice to do what he would like with it.
If you plan to build it for sale and it truly is a one of a kind Pontiac/Corvette, then maybe do what you need to do to repair the block.
Another option may be to drop in a create motor and keep the complete original stored in case you do sell in the future and give it to the buyer with the choice to do what he would like with it.
#27
Pro
The block was trashed.
#28
Melting Slicks
Maybe not buy a block which had been sleeved without having it checked. If I had a block which needed a sleeve, had it magnafluxed, should be okay? Understand a future buyer may be skeptical. May need to supply some documentation from the machine shop...
Last edited by BBCorv70; 02-02-2018 at 05:34 PM.
#29
Drifting
Member Since: Aug 2015
Location: NSW, Australia
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C3 of Year Finalist (track prepared) 2019
Nothing wrong with a well done sleeve. I had all 8 cylinders sleeved in the 393 stroker Cleveland in my f250, the sleeves are tougher/wear better than the original block.
#30
Le Mans Master
Thread Starter
So the story gets stranger.
The rusty hole will need a sleeve, but the weird thing is, IT ALREADY HAD ONE. It appears the the block developed a small crack at some point and they put in a thin sleeve on this hole.
I can't tell if that was before or after they went 0.030 over, but maybe that sleeve is so thin BECAUSE it's been overbored already? It sure looks thin though.
Anyway, the plan is re-sleeve that one hole with a better sleeve, bore everything 0.040 over with torque plates, new pistons, balance, line hone.
Thanks for tall the input! 72% said Sleeve and that's the plan.
The rusty hole will need a sleeve, but the weird thing is, IT ALREADY HAD ONE. It appears the the block developed a small crack at some point and they put in a thin sleeve on this hole.
I can't tell if that was before or after they went 0.030 over, but maybe that sleeve is so thin BECAUSE it's been overbored already? It sure looks thin though.
Anyway, the plan is re-sleeve that one hole with a better sleeve, bore everything 0.040 over with torque plates, new pistons, balance, line hone.
Thanks for tall the input! 72% said Sleeve and that's the plan.
Last edited by davepl; 02-22-2018 at 02:41 PM.
#31
Sleeve it. I've never heard of one failing.
Plus - years back a friend had a bad *** 68 Camaro. Had a screaming 302 built by a high end local race shop. Everybody was amazed how awesome it ran. So, my Brother ended up buying it. When it eventually needed a rear seal he tore it down. On inspection it was all bs - a 350, cast crank, cast piston motor with 2 sleeves.
Plus - years back a friend had a bad *** 68 Camaro. Had a screaming 302 built by a high end local race shop. Everybody was amazed how awesome it ran. So, my Brother ended up buying it. When it eventually needed a rear seal he tore it down. On inspection it was all bs - a 350, cast crank, cast piston motor with 2 sleeves.
#33
Le Mans Master
Thread Starter
Well, it's back from the shop and it's sleeved in the one hole and it turned out nice. They used a MUCH thicker sleeve than whatever was in there before. Sure fortunately that the damage it encountered happened to be in the hole that was already sleeved anyway! Also note this motor had a lifter bore sleeved from the factory, which I've heard of but not actually seen before.
Last edited by davepl; 03-27-2018 at 11:22 AM.
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#35
I have never heard of a lifter bore sleeved at the factory. GM would have tossed the block.
#36
Le Mans Master
Thread Starter
Now that said, I've never seen anything like that on a modern LS motor. Or any aluminum motor, actually. So they may have changed over the years.
Last edited by davepl; 03-28-2018 at 12:10 PM.
#37
I don't know how many motors you've looked inside, but I've seen lots of block repairs right from the factory. No way GM tosses an entire good casting for a small defect like that. Common? No. Rare? Not really.
Now that said, I've never seen anything like that on a modern LS motor. Or any aluminum motor, actually. So they may have changed over the years.
Now that said, I've never seen anything like that on a modern LS motor. Or any aluminum motor, actually. So they may have changed over the years.
#38
Race Director
I remember when the automotive industry was geared around the concept that items were repaired. In the late 70's or early 80's the concept changed and it became common to remove and replace complete components because the thought was it was cheaper to swap a major component even a complete motor than to disassemble it, sleeve a bore, install a new piston and reassemble it.
Back then I can imagine auto manufactures taking the time to repair a defected block over tossing it as they would today.
Today when you purchase one of the nice create motors everyone thinks are the best thing since a Subway sandwich, look closely at the detailed list of components, or talk to their tech support and you will learn that most of them are using reconditioned blocks and not new.
That's some input from someone who has been around since sliced bread was really something.
Back then I can imagine auto manufactures taking the time to repair a defected block over tossing it as they would today.
Today when you purchase one of the nice create motors everyone thinks are the best thing since a Subway sandwich, look closely at the detailed list of components, or talk to their tech support and you will learn that most of them are using reconditioned blocks and not new.
That's some input from someone who has been around since sliced bread was really something.
Last edited by OldCarBum; 03-31-2018 at 11:55 AM.