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Lifting Engine with Aluminum Heads


CC57

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About to pull the small block out of Mod and drop it off to have it freshened up when a concern occured to me: on aluminum head engines, is it ok to pull the engine using bolts in the head as lifting points?

 

All of the previous engines I've removed had steel heads, not aluminum.

 

Thanks all

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Regarding the lift plate, I'm aware of them but discounted using one. My reasoning was that seemed like an excessive load to place on 4 smaller diameter (smaller when compared to the bolt size used in the heads) bolts. Addtionly I thought using the lift plate would place a heavy vertical load on the aluminum threads in the intake, whereas if I used the bolt-in-the-heads approach, the load would (should?) be distributed more along the bolt. Is none of this true? Or not a concern?

 

Mac70, if you can do that, is it safe to say you're friends on occasion refer to you as "Mongo"?

 

Thanks again all

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Lift plates are great. Easy to use and no fumbling with chains. However, "when" those 1/4" bolts beak or strip and the motor slams the ground, it is exceptionally expensive to replace a oil pan, pump, pickup tube, and hope for no damage to the crank. Had that happen once. Ive used plates again since then but they are not without risks.

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Question? What is your concern with pulling it? The heads are still torqued to the block, correct?

 

Yes, they (the heads) are still in place.

 

My concern was (is?)with regards to how the weight of the long block may stress the aluminum in either the heads or the intake. That's all.

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For a nominal bolted joint the bolt tensile strength equals the shear strength of the threads when the engagement depth is equal to the diameter of the bolt. The tensile strength should be about 40,000 PSI for 2024 aluminum. For a 5/16 bolt that leaves a yield strength of about 2000 lbs. The threads in the manifold should then match the bolt strength for 5/16" engagement regardless of bolt material. The ultimate tensile strength will be the sum of the tension from bolt torque plus whatever tensile load is applied.

 

For four bolts, finger tight and engaged to at least 5/16" into the manifold, you should be able to lift almost 8000 lbs. Start torquing the bolts tight and the available lift strength decreases. Put a 50% safety margin on it and you are still at 4000 lbs.

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For a nominal bolted joint the bolt tensile strength equals the shear strength of the threads when the engagement depth is equal to the diameter of the bolt. The tensile strength should be about 40,000 PSI for 2024 aluminum. For a 5/16 bolt that leaves a yield strength of about 2000 lbs. The threads in the manifold should then match the bolt strength for 5/16" engagement regardless of bolt material. The ultimate tensile strength will be the sum of the tension from bolt torque plus whatever tensile load is applied.

 

For four bolts, finger tight and engaged to at least 5/16" into the manifold, you should be able to lift almost 8000 lbs. Start torquing the bolts tight and the available lift strength decreases. Put a 50% safety margin on it and you are still at 4000 lbs.

 

 

WELL DUH!!!! LOL

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I have used lift plates for many years and hundreds if not thousands of times and never had a problem.Like somebody said use case harded washers grade 5 or8 bolts, The big thing I have found that you do not bottom out bolts but get as many threads you can get also make sure the threads are good in the intake not half stripped out. good luck oh by the way I have lifted big Blocks on and off the dyno with a plate.

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Used the lift plate on my aluminum intake/head small block. Oh yes, my intake has studs for securing the carb, not bolts that I thread in and out.

 

Anyway, seemed to work fine....

on the way out anyway. And as long as nothing breaks when I putting the engine back in, all is good B)

 

Thanks for all of the replies all.

 

 

1-Crew, interesting stuff. I would like to read more on a the subject. Was this something you got off of the web?

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Most of the information presented came from web sources just because it was quicker to get to but I have it in text as well in "Technical Statics and Strength of Materials" by James R. Thrower and ""Engineering Materials: Properties and Selection" by Kenneth Budinski. Those two, especially the Engineering Materials book, are the college textbooks I continue to reference. You won't find a specific reference to thread pullout strength (or at least I didn't) but you can find the tensile strength of materials and minor diameter of threaded fasteners pretty quickly.

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