Engine stand bolts

[mh434]

Hi all
Can anyone definitely confirm what size / length bolts I need in order to mount a 352 on a cantilever engine stand. (engine stand rather than cradle). Looks like it would use the bell housing mounting holes on the engine block. From what I can find they are a 7/16 UNC thread and need to be 3 to 4 inches long and grade 8.8
Thanks in advance

Jon

[simplyconnected]

Yes John, the engine stand uses bolt locations that are normally used for the bell housing. Yes, the engine block holes are tapped for 7/16" (course thread) bolts. We have no idea what stand you are using or the length of the arm bushings. You will need to measure for length. The bolts need to enter the block at least an inch (or more). Use one of the bell housing bolts to find the depth. They do not need to be extremely hard. Grade 5 will do nicely but if grade 8 is also available, they are always better. - Dave

[mh434]

Thanks Dave

As always, much appreciated.

Jon

[Tbird1044]

Just as a side note, grade 8.8 is a metric term and is comparable to a U.S. Grade 5. 10.9 is equal to a grade 8 bolt. I agree with Dave that either should work fine.
Nyles

[simplyconnected]

Thank You, Nyles. I should have picked up on that difference.

American bolts are required to show their hardness by the number of hash marks on the head of each bolt. If the bolt has no hash marks it is assumed to be grade 2 (suitable for fastening wood). If you see three hash marks it is a grade 5 (because 2+3=5). Grade 8 bolts have six hash marks, like the head bolts on your engine.

The metric standard is still new to many of us as we are not familiar with the numbers on the heads. At first, I assumed they had something to do with the size and thread pitch. Later I learned, like American bolts, this is a hardness number, then it all made sense.

For many years, our cars had a mix of American and Metric bolts because engines and transmissions were carried over after we switched to metric. This forced everyone to buy two sets of tooling including thread cutting taps and dies. AmphiCars were built in Germany but they had (English) Triumph Herald engines. So, you guys did the same where half the car was on the English standard and the other half was metric.

You will find the term, 'SAE' associated with our bolts. It stands for, Society of Automotive Engineers. So, this is a standard across all car brands. Some places abbreviate using 'NC' for National Course threads. Fine thread pitch are usually called, SAE threads.

SAE (or fine thread) bolts were used on Ford body panels as standard fare. The idea was twofold, the minor pitch diameter was greater which offered more steel diameter under the threads (making it stronger) and a fine thread takes longer to 'walk out' if it ever comes loose. - Dave

[scumdog]

In reference to Dave’s last post: here in NZ we refer to the bolts as UNF for the fine thread bolts and UNC for co**** thread bolts

And d^#*€~!!! if you somehow end up with a Whitworth bolt in the mix!