Lifting Engine, What size bolts
Safety Car
Joined: Oct 2007
Posts: 3,729
Likes: 267
From: Austin Texas
Corvette of the Year Winner 2017
2016 C3 of Year Finalist
so what is the pull out strength of 1/4" tapped used holes into 50 year old aluminum intake ? ?
this is the unknown factor... the strength of the bolt is not, what concerrns me.
opps bubba cross threaded those holes 30years ago, no worries they only held the carb. on.
me personally, I would not chance a lift plate using a aluminum intake lifting 1000lbs BB,
over a plastic/fiberglass fender to remove a motor.
much saver with chains and 3/8's bolts into steel block and heads.
everyone makes their own judgment call on safety, I prefer the safe side vs the risk side.
to the original poster your minor lift is just fine, with the lift plate.
this is the unknown factor... the strength of the bolt is not, what concerrns me.
opps bubba cross threaded those holes 30years ago, no worries they only held the carb. on.
me personally, I would not chance a lift plate using a aluminum intake lifting 1000lbs BB,
over a plastic/fiberglass fender to remove a motor.
much saver with chains and 3/8's bolts into steel block and heads.
everyone makes their own judgment call on safety, I prefer the safe side vs the risk side.
to the original poster your minor lift is just fine, with the lift plate.
Last edited by 69Vett; May 4, 2015 at 03:49 PM.
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
so what is the pull out strength of 1/4" tapped used holes into 50 year old aluminum intake ? ?
this is the unknown factor... the strength of the bolt is not, what concerrns me.
opps bubba cross threaded those holes 30years ago, no worries they held the carb. on.
me personally, I would not chance a lift plate using a aluminum intake lifting 1000lbs BB,
over a plastic/fiberglass fender to remove a motor.
much saver with chains and 3/8's bolts into steel block and heads.
everyone makes their own judgment call on safety, I prefer the safe side vs the risk side.
to the original poster your minor lift is just fine, with the lift plate.
this is the unknown factor... the strength of the bolt is not, what concerrns me.
opps bubba cross threaded those holes 30years ago, no worries they held the carb. on.
me personally, I would not chance a lift plate using a aluminum intake lifting 1000lbs BB,
over a plastic/fiberglass fender to remove a motor.
much saver with chains and 3/8's bolts into steel block and heads.
everyone makes their own judgment call on safety, I prefer the safe side vs the risk side.
to the original poster your minor lift is just fine, with the lift plate.
Steve
Drifting
Joined: Jan 2012
Posts: 1,908
Likes: 129
From: Fredericksburg Virginia
FYI, my engine builder had a HOLE conveniently placed through his hand (as in through...front-to-back) while lifting an engine with a carb plate. It "let go" when he was guiding the engine over the fender. Knarly scar. And please don't say "he didn't know what he was doing"...he is one of the very few people I know who is more ****-retentive than I am when it comes to doing things right.
Needless to say, that was the last time he used a carb plate.
Even an iron intake is cast. Internal graining is inherent/fundamental to a cast iron part and they simply are not constructed or intended to act as stress members or to have a great deal of torsion/tension/shear applied to them.
This is "one of those things" that is done regularly by a lot of people. And rarely does anything happen. But there is no reason on God's green earth to take the chance.
Use bolts in the heads. There just isn't any guesswork involved.
Needless to say, that was the last time he used a carb plate.
Even an iron intake is cast. Internal graining is inherent/fundamental to a cast iron part and they simply are not constructed or intended to act as stress members or to have a great deal of torsion/tension/shear applied to them.
This is "one of those things" that is done regularly by a lot of people. And rarely does anything happen. But there is no reason on God's green earth to take the chance.
Use bolts in the heads. There just isn't any guesswork involved.
Instructor
Joined: Aug 2009
Posts: 218
Likes: 5
From: OR
FYI, my engine builder had a HOLE conveniently placed through his hand (as in through...front-to-back) while lifting an engine with a carb plate. It "let go" when he was guiding the engine over the fender. Knarly scar. And please don't say "he didn't know what he was doing"...he is one of the very few people I know who is more ****-retentive than I am when it comes to doing things right.
Needless to say, that was the last time he used a carb plate.
Even an iron intake is cast. Internal graining is inherent/fundamental to a cast iron part and they simply are not constructed or intended to act as stress members or to have a great deal of torsion/tension/shear applied to them.
This is "one of those things" that is done regularly by a lot of people. And rarely does anything happen. But there is no reason on God's green earth to take the chance.
Use bolts in the heads. There just isn't any guesswork involved.
Needless to say, that was the last time he used a carb plate.
Even an iron intake is cast. Internal graining is inherent/fundamental to a cast iron part and they simply are not constructed or intended to act as stress members or to have a great deal of torsion/tension/shear applied to them.
This is "one of those things" that is done regularly by a lot of people. And rarely does anything happen. But there is no reason on God's green earth to take the chance.
Use bolts in the heads. There just isn't any guesswork involved.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
The "proof load" of a Grade 2 5/16"-18 bolt is 2900 lbs. That's for one bolt. A grade 5 bolt has a "proof load" of 4450 lbs. Now, that doesn't speak to the strength of the aluminum threads, but I think you folks can see that four (4) 5/16"-18 bolts, secured tightly over a steel plate into even aluminum threads (of any age and 'reasonable' condition) would safely lift a 1000 pound engine (fully dressed big block).
Would I agree that lifting with a good chain and two steel lift-loops bolted via the intake manifold would be somewhat safer? Well, probably. But, that depends on the chain, doesn't it?
If you just spin 4 bolts through the carb plate and don't tighten them securely, I wouldn't lift it on a bet....
Would I agree that lifting with a good chain and two steel lift-loops bolted via the intake manifold would be somewhat safer? Well, probably. But, that depends on the chain, doesn't it?
If you just spin 4 bolts through the carb plate and don't tighten them securely, I wouldn't lift it on a bet....
Drifting
Joined: Jan 2012
Posts: 1,908
Likes: 129
From: Fredericksburg Virginia
Respectfully, he is neither.
The aluminum manifold failed, not the bolts. The bolts are not at issue. You can bolt as many Grade 8 bolts as you want into something...if the engine is on the ground and the cast intake is broken in half, it doesn't make a damn difference what type of bolts you used.
A manifold is made to connect a carb to the heads. It is not made, designed, constructed, cast, modeled, optimized, built, nor INTENDED to hold a 1,000 lb engine in the air.
999 out of 1,000 people may not have a problem. That's fine. My engine builder, having dealt with thousands of engines over his life, finally had it catch up with him.
At worst, that makes him unlucky. But not inept or incompetent, thank you.
The aluminum manifold failed, not the bolts. The bolts are not at issue. You can bolt as many Grade 8 bolts as you want into something...if the engine is on the ground and the cast intake is broken in half, it doesn't make a damn difference what type of bolts you used.
A manifold is made to connect a carb to the heads. It is not made, designed, constructed, cast, modeled, optimized, built, nor INTENDED to hold a 1,000 lb engine in the air.
999 out of 1,000 people may not have a problem. That's fine. My engine builder, having dealt with thousands of engines over his life, finally had it catch up with him.
At worst, that makes him unlucky. But not inept or incompetent, thank you.
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Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
Respectfully, he is neither.
The aluminum manifold failed, not the bolts. The bolts are not at issue. You can bolt as many Grade 8 bolts as you want into something...if the engine is on the ground and the cast intake is broken in half, it doesn't make a damn difference what type of bolts you used.
A manifold is made to connect a carb to the heads. It is not made, designed, constructed, cast, modeled, optimized, built, nor INTENDED to hold a 1,000 lb engine in the air.
999 out of 1,000 people may not have a problem. That's fine. My engine builder, having dealt with thousands of engines over his life, finally had it catch up with him.
At worst, that makes him unlucky. But not inept or incompetent, thank you.
The aluminum manifold failed, not the bolts. The bolts are not at issue. You can bolt as many Grade 8 bolts as you want into something...if the engine is on the ground and the cast intake is broken in half, it doesn't make a damn difference what type of bolts you used.
A manifold is made to connect a carb to the heads. It is not made, designed, constructed, cast, modeled, optimized, built, nor INTENDED to hold a 1,000 lb engine in the air.
999 out of 1,000 people may not have a problem. That's fine. My engine builder, having dealt with thousands of engines over his life, finally had it catch up with him.
At worst, that makes him unlucky. But not inept or incompetent, thank you.
Steve
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
Race Director
Joined: Oct 2008
Posts: 19,228
Likes: 1,672
From: Long Island
It's no so much the grade of the bolts but the fit.(thread %) 
That is why the tap charts show different drill for different % fit.
I almost lost a finger helping a friend lift a big block with a 4 speed when the rear bolt came out of the engine head, he is cheep and used box store bolts. the threads came off the ice-cream soft bolt.
Most manufacturers know people use the manifold to lift and include this in the design. Otherwise the manifolds would be 1/2 the thickness. There would also be warnings in the box, on the box, on the manifold and stickers everywhere not to use it for lifting.
I would guess that if you "port" the crap out of a manifold and leave thin spots it will crack.
Yes I was a design engineer...
That is why the tap charts show different drill for different % fit.
I almost lost a finger helping a friend lift a big block with a 4 speed when the rear bolt came out of the engine head, he is cheep and used box store bolts. the threads came off the ice-cream soft bolt.
Most manufacturers know people use the manifold to lift and include this in the design. Otherwise the manifolds would be 1/2 the thickness. There would also be warnings in the box, on the box, on the manifold and stickers everywhere not to use it for lifting.
I would guess that if you "port" the crap out of a manifold and leave thin spots it will crack.
Yes I was a design engineer...
Last edited by BLUE1972; May 6, 2015 at 08:03 PM. Reason: spelling
Drifting
Joined: Oct 2005
Posts: 1,528
Likes: 148
From: East London/SW Essex UK
My son is in to BBF's - currently has a '62 TBird with warmed over 390 and an early Dord ex-Shelby Cobra style dual quad Ford inlet manifold. Now that you most certainly wouldn't use that inlet for 'lifting' - being also a dual plane configuration (just think about it - dual quad AND dual plane) its really quite a delicate casting
Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
My son is in to BBF's - currently has a '62 TBird with warmed over 390 and an early Dord ex-Shelby Cobra style dual quad Ford inlet manifold. Now that you most certainly wouldn't use that inlet for 'lifting' - being also a dual plane configuration (just think about it - dual quad AND dual plane) its really quite a delicate casting