I've heard it referred to as this on here, for some reason I cant find the threads that I was reading that mentioned it, but a friend of mine was telling me about a badass motor he has that keeps going through starters and ruining flexplates, he made the comment that he's been through "about 10 starters" with it, and it reminded me a LOT of this issue.
I was telling him I thought I remembered there being a problem with one of the machines over GM putting the mounting holes for the starter in the wrong place for years and years and they have a separate part number for starters to fix it.
Any of you guys know anything about it? It sounds suspiciously similar to what he's tlakin about...
But I remembered hearing that it mostlya ffected 70s blocks, he said his was an 85 454 block.
I was telling him I thought I remembered there being a problem with one of the machines over GM putting the mounting holes for the starter in the wrong place for years and years and they have a separate part number for starters to fix it.
Any of you guys know anything about it? It sounds suspiciously similar to what he's tlakin about...
But I remembered hearing that it mostlya ffected 70s blocks, he said his was an 85 454 block.
TGO Supporter
you're correct, but i don't have any details other than what you already said. his starter problem could be cheap rebuild starters. if they were new GM starters and not rebuilds i'd be more inclined to think something was up.
Supreme Member
I've got a 350 from a 72 nova in my girlfriends car and never had an issue with starters.
My brother had a 70 Chevy truck with a 350 that had the problem, a stock unshimmed starter would chew up a flywheel in no time or one time the starter quit turning the engine over after a loud bang, he looked under the truck to find the starter hanging by the wires, it had broken both bolts off!!! I had to "fix" it by finding the right shims to put under the starter, I think it took about .045 shims to get it working right.
There were actually several items referred to over the years as "The Problem" with block castings.
The very common one was in the machining of the starter mounting, whereby the starter mounting holes were drilled and tapped in a less than optimal position, outboard of the crank centerline by a few thousandths.
A related and sometimes coincidental "Problem" was evidenced by insufficient material cast at the outer starter boss to provide adequate support, and the subsequent breaking out of the starter bolt hole. The combination of barely adequate material cast at the starter outer bolt and machining of the holes out of position is common in mid-'70s SBC cylinder cases.
Another "Problem" in SBC block machining (and BBC blocks) was the location and angle of the lifter bores. In SBC engines, there was a series during the mid-'70s where the lifters were bored out of position in relation to the cam's longitudal centerline, and in some cases, the cam was not bored dead center between the lifter banks. This can cause otherwise inexplicable lifter rapid and lobe wear, and create variation in the valve timing of 5-8º between cylinders and banks.
Yet another "Problem" occurred on mostly truck blocks, where the engine mount bosses were machined a little shallow, making installation of a four-bolt truck block into a typical passenger car mounting difficult.
Careful checking can reveal many of "The Problem" areas found in any case, and machining can correct them, but the expense of machining may make the block undesirable as a core. Some of the blocks from any era can have these or other problems, but given the higher risk of any of "The Problem" blocks being produced in the mid-'70s, along with the higher risk of that vintage of blocks having thin/lightweight castings, and the fact that they don't support the less expensive and proven factory roller lifter system may take them out of consideration as a core for building an engine. In some rare exceptions (like 400 CI blocks or aluminum 427s) there is little choice but to use the older castings, but be aware of the potential problems and the potential costs to repair them.
Personally, I've about thrown in the towel on old blocks. Between the various production problems, limits of the flat-tappet cam in possible ramp, and now the fact that most lubricants are no longer flat-tappet friendly, I'll probably restrict my choices to 1987 and later blocks and fight the one-piece RMS in favor of being assured of better castings and a roller cam.
The very common one was in the machining of the starter mounting, whereby the starter mounting holes were drilled and tapped in a less than optimal position, outboard of the crank centerline by a few thousandths.
A related and sometimes coincidental "Problem" was evidenced by insufficient material cast at the outer starter boss to provide adequate support, and the subsequent breaking out of the starter bolt hole. The combination of barely adequate material cast at the starter outer bolt and machining of the holes out of position is common in mid-'70s SBC cylinder cases.
Another "Problem" in SBC block machining (and BBC blocks) was the location and angle of the lifter bores. In SBC engines, there was a series during the mid-'70s where the lifters were bored out of position in relation to the cam's longitudal centerline, and in some cases, the cam was not bored dead center between the lifter banks. This can cause otherwise inexplicable lifter rapid and lobe wear, and create variation in the valve timing of 5-8º between cylinders and banks.
Yet another "Problem" occurred on mostly truck blocks, where the engine mount bosses were machined a little shallow, making installation of a four-bolt truck block into a typical passenger car mounting difficult.
Careful checking can reveal many of "The Problem" areas found in any case, and machining can correct them, but the expense of machining may make the block undesirable as a core. Some of the blocks from any era can have these or other problems, but given the higher risk of any of "The Problem" blocks being produced in the mid-'70s, along with the higher risk of that vintage of blocks having thin/lightweight castings, and the fact that they don't support the less expensive and proven factory roller lifter system may take them out of consideration as a core for building an engine. In some rare exceptions (like 400 CI blocks or aluminum 427s) there is little choice but to use the older castings, but be aware of the potential problems and the potential costs to repair them.
Personally, I've about thrown in the towel on old blocks. Between the various production problems, limits of the flat-tappet cam in possible ramp, and now the fact that most lubricants are no longer flat-tappet friendly, I'll probably restrict my choices to 1987 and later blocks and fight the one-piece RMS in favor of being assured of better castings and a roller cam.
So would an 85 454 be affected by these problems that seemed to hit their peak in hte 70s?