Hey guys, Im going to use a 1000lb rotating stand for the big block. It doesnt come with bolts though, I need to find out how long and what thread. Id assume some good grade 8 bolts, thanks. Hope you can help smile.gif

Ok, so 3/8" Grade 8 bolts, Length I will measure how long the little spacers are, how much thread in inches should I have left after it goes through the spacer into the block? That didnt make sence to me, but it should get the point across smile.gif

Some guy's want to have bolts long enough so they can install their flywheel/flexplate while the motor is on the motor stand so if you might want to do this, mock it up and buy long enough Grade-8 bolts along with a box of washers to space it out far enough to do it!!

Then go for it!!

I didn't b/c I installed my flywheel with my motor hanging off a cherry-picker..

pdq67

Cherry picker way sounds better to me smile.gif So how far should the thread of the bolt actually go into the motor? Id imagine the stock bolts that bolt to the bellhousing/tranny and just ad the measured ammount of the spacer, then buy that size bolt and some washers... should be ok, I just dont want this to fall off, kind of scares me!

I'd take the bolts in as far as they will go before they bottom out. Each one will only be holding about 150 lbs each or a little less. I think the rule is it should go in 2 times as deep as the bolt is thick. I used 5 inch grade 8s to hold my 427, and my 350 for over a year.

Grade 5 bolts will do just fine unless our motor exceeds the rating of the stand by a factor of 20. The grade 8's have a clamping force of about 7000# while the grade 5's are a mere 5000# each.

I'm kinda anal about bolts b/c you are right about the grade-5 Bolts being adequate.

And it's three threads in will hold the strength of the bolt if I remember my old Machine Design class problems right..

It's the root area of the number of threads that equal the root of the thread's cross sesction of the bolt sorta deal if not mistaken??

pdq67

I got some grade 8's which is what I usually use for things. I bought them in 4" even when screwed all the way in there will be alot of play left, it would take a few washers to tighten up. Its ok to do that isnt it?

I haven't had a problem. I searched for the right length but I had to use 3, 3/8 washers on each bolt to take up the play. I wondered about having an iron head big block on it but it held it. I did weld the engine stand together instead of the bolts only and I put a bolt on knee brace from the back leg to the bottom tube. I also rewelded some of the shoe string welds. Mine had a pin that you put through the holes when you got the engine turned but I replaced that with a welded on 3/4" nut and took a 2"long, 3/4 " bolt and ground down the first 3/8" of threads and that is what I used to hold the engine rotator in place.

Just make sure that you have enough room that the crank will rotate all the way around without binding up on your bolts.. And washers are no problem..