The Stovebolt Site Forums The Shop Area Engine Shop ? Size & length bolts do I need?

I just got my engine stand together (no instruction wow!). Chevy 250 engine. How long & what thread do I need?
Thanks!

What are these bolts for? It really isn't clear what you are asking.

glennj3,

How about posting some pictures of your engine stand so we may better offer good information that makes sure your engine mounting to the stand is safe and secure???

Dan

I apologize I did a bad post! I plan to mount the engine to the stand to begin working on it.
Im assuming I use the same size thread & bolt that bolts the bellhousing to the engine? I measured about 4 inch bolt souls do but I do need to remove the clutch?

glennj3,

Thanks for posting the pictures. The arms on your stand may not be long enough to reach the back side of the block mounting holes with the clutch and pressure plate in place.

I would remove those for sure. If you are doing a full tear down for rebuilding, the flywheel will eventually need to be removed anyway. Better to remove it before mounting it to your stand as the stand will definitely get in the way later.

The length of the bolts needed must span the length of the arm bolt sleeves PLUS enough for full thread depth engagement into the bell housing mounting holes and as you noted must match the diameter and thread count for the existing holes.

DO NOT use unknown or un-rated/un-graded quality bolts. They will be carrying a bunch of suspended weight and need to be good known quality products. Others will probably chime in on what minimum "Grade" of bolt is recommended.

Dan

I always use grade 8 or comparable metric when hanging an engine on a stand, on heavier engines, I add support at the front.

Thank you for this advice!

My stand plate does not fit my bolt pattern on the back of the engine.
I can get 3 bolts in but the motor is slanted. Also I have all threads on the bolts, not a non threaded shaft?

Won't that one on the bottom right reach the bottom right hole on the engine if the others are loosened to slide to the right?

1. I have no idea what this means "Also I have all threads on the bolts, not a non threaded shaft?" or if it is a question.
2. Engine stands are made to accomodate every possible bolt pattern for at least 4 bolts.
3. Did bolts come with the stand?
4. If by slanted, you mean rotated, just rotate the stand barrel to level motor.
5. There is nothing on our trucks or on a motor stand that would ever need grade 8. Folks say grade 8 because someone else says grade who heard someone else say grade 8. Grade 8 is exrtreme overkill and expensive. Just have it in your mind that grade 5 is all you will ever need. The math supports this.

This is commentary, not aimed at anyone.
Lots of folk ask about sizes of bolts to use in varioius places. All who work on mechanical things need to get familiar with size and pitch. Hardware is pretty simple. Asking others to size something is not necessary. Several methods to use are:
1. Measure the bolt OD with calipers you need to buy.
2. Measure the thread pitch with a pitch gauge that comes with your tap and die set which you also need to buy.
3. For length it's just a matter of the "stack up"of parts and washers plus the depth of blind hole or the nut thickness + stickout.
4. You can find a bolt that screws into the threads and take that test bolt to the hardware store. Same for a nut.
5. Carbon steel Bolts are marked with radial hash marks, add 2 to the number to get grade. A grade 5 has three hash marks. A grade 8 has six.
6. Don't use stainless steel bolts/nuts/washer.
7. Use stainless steel trim screws.

Everybody needs to get reasonably familiar with hardware. You will get good at it quickly. You can't ask the internet on every bolt and screw.

As far as torque. After a while (20+ years ) you will know how tight is tight. Except for some critical things. You just get a feel. Small hardware is the most dangerous. You keep your hand close to the fastener end of wrench on those.

glennj3,

Before you do anything, reattach your engine hoist/lift to the engine as you are going to need to undo and reinstall at least 1 of the adjustable support arms as well as loosen and adjust the positioning of the others so your engine is properly connected, positioned and supported by the stand.

The weight of the engine needs to be fully supported by the hoist so you can safely move the engine around a bit. Safety First!!!

The mount/support arm that you are holding by hand in your 2nd picture needs to be first properly mounted to the stand plate in the same fashion as the other 3, then it can be repositioned and the longer bolt used to attach through extension end of the arm to the block. When you change that arm to become adjustable on the main plate (the way you have it now it freezes the engine position to the stand), you can then shift the engine and arm positions to allow for the 4th arm to reach the opposite mounting point from the lower left of the block. See the 1st pic below of an engine similar to yours mounted an a portable engine stand to see how it should look.

Once you get all 4 arms repositioned and secured to the block, and the bolts properly tightened, then you can remove the engine hoist and allow the stand to support the engine to continue work.

Another IMPORTANT SAFETY point! The pivot/rotating shaft collar of the engine stand has a hole for a locking pin or bolt to keep the engine from all of the sudden rotating and turning upside down on you while working on it. See my modified copy of your pic to see where I am indicating. You need to make sure there is a pin or bolt in place anytime you are not trying to rotate the position of the engine as such a sudden uncontrolled movement can have very serious consequences (think major injury)! Your engine stand should have come with a set of instructions. Please take the time to read them and follow any warnings.

Dan

Having had multiple grade 5 bolts fail, I am going to disagree with you here. Grade 8 bolts are a few cents more expensive for 25% more strength.

The added strength and peace of mind is more than worth the trivial cost difference.

The other thing I will add is that you should go to some place like fastenal to get bolts that are *actually* graded rather than just marked. Ace Hardware is particularly bad about selling garbage hardware as grade 8. Pro-tip: if you can twist the head off a 5/8 bolt with a 9" ratchet, your vendor lied about it being grade 8.

If you're using all thread rod instead of bolts, you're building a deathtrap- - - -it's grade 2 at best. Ignore anybody who recommends ANYTHING but Grade 8 bolts to hold the engine to the stand- - - -if you think those bolts are expensive, check out the hourly rates at your local emergency room!
Jerry

Please explain your grade 5 bolts that failed and where they were used and their size. Not just a blow-off story. They don't fail on any of our uses on our trucks.
Obviously a rusted bolt or over torqued by user or fastened part failure is not what we are talking about. We are talking about the strength of the bolt to carry the load.
As for people who say grade 8 is necessary and disregard others. They are not able to do strength analysis, just be antagonists trolling posts. Wannabe engineers. Telling you to ignore members. Not a good look but very typical behavior..... over and over. Nasty wording.

You can use any grade you want, anywhere. The strength, in shear, of four Gr 5 3/8 bolts is about 18,000 lbs.

I was rebuilding a 292 from an 84 GMC. It was attached to the stand with 4 grade 5 bolts into the bellhousing holes. I mounted it and everything seemed fine until I went to pull the dampener. I put a bar on the puller to break it loose and head a ping.

The dampener still appeared tight, so I leaned into it again and the whole thing twisted to the side and the engine stand fell over barely missing my foot.

The first ping was one of the 4 bolts holding it to the stand starting to give up and when I pushed it again there was enough force to finish snapping that bolt and the rebound overcentered the stand and dumped it.

That story is also a good reminder of the suggestion above to support the front of the engine because it it long/heavy enough that it puts more force on the stand than you think.

Gentlemen,

Maybe enough on the "bolt" topic and "stories" please and thanks.

The point has been made that he needs to use the best quality bolts available for a safe work space.

Shall we get back to helping him get his engine safely and properly mounted so work may progress?

Best Regards!

Dan

thanks Fibonachu. thanks Gdads51
One more caution that I don't think was covered. Try to only buy an engine stand with FOUR wheels. Wheels spaced the same distance apart, front and rear. These will also enable timbering across the bottom beams if you desire front motor support and still roll.
Also I bolted a plywood piece to my stand plate to clamp on, and work on, small outboard motors.

First my definition of the threaded bolts I have, the bolts are fully threaded no smooth area. So I’m thinking I should replace them?
Dan, the engine hoist is holding the engine but I didn’t have the pin in the hole.
I studied in this thing for a long time today while trying every possible configuration bolt pattern.I even took 2 arms off and put the bolt through the spacer to try to get them to align with a bell housing bolt pattern. So with 3 supports bolted up the 4 th needs about 2 more inches to reach the bolt hole.
I’ll do it some more tomorrow.
I am somewhat mechanically inclined so I get pretty frustrated when I can’t make this fit.
I assume I need to have all 4 bolts equally spaced for balance.
Wish I could locate someone to look at it with me!
Thank everyone for jumping in!

I always take the engine stand mounting plate off of the stand and mount it to the block with the engine on the floor. That way you can have all four mounting arms loose while you center the plate up. In you picture you have the mounting pipe offset to one side, that's dangerous as the engines weight is not centered.

Be safe!

Mike B

Dan/Glenn, your side view where we can see the garden hose looks really good. I see three bolts but can't see what is going on on the other side. That pic seems like your best shot. Need more pics of that forth bolt in that pic.

I got confused with the word "all thread" . That word means threaded rod, not a bolt. Then I saw some threads coming thru a nut which seemed to confirm threaded rod.. Now after your latest comments I think you just meant bolts threaded all the way and I was seeing bolts which hold the arms on, coming from the inside out. Looking like "all thread". Is that all correct?

If so, using full thread bolts is OK. Markings on your bolt heads indicate possible "off shore" metric, probably registered somewhere in America as to strength. Can't read even when expanded.

I will see if I can get a different angle picture (I found that on online and just snagged a portion of the pic to show a more centered/balanced mounting) to show how the arms and main mounting plate all align/marry up together.

If I am understanding glennj3's description correctly, he is using fully threaded bolts (not "all-thread" rod), which bartamos indicates are "OK" to use. As others have mentioned, it wouldn't hurt to make sure those bolts are "Grade 8" for maximum safety.

I would also 2nd Mike B's suggested method of mounting up the plate and arms to the engine, with engine supported by the hoist but sitting on the floor. Easy enough after getting the arms and plate properly centered/mounted to then lift the whole thing up and slide the plate pivot tube into the main engine stand support tube.

Will try to add more pics as I can find them in the morning.

Dan

Sorry Dan, I was speaking to Glenn and looking at your post. I didn't realize it was your post using one of his pics and one from internet, Got discombobulated. I even said "Dan". Oh MY Gosh....Just saw black and red colors. Glenn if you want help with bolting spots, I guess we need more pics. Also Glenn, would turning the stand plate 45 or 90 deg before bolting do anything?
If it does you can drill a new pin hole (not on same plane as the other).
For one of the mounts you can go straight thru plate into block and just use a portion of the arm as a spacer. No arm offset with that one. That may give more oportunities. Need longer bolt for that maybe. You may have tried that already.

If Dan gets more pics from the example that may really help.

This is a picky me deal. I never mount a block to one of those cheapy stands with out using a flat washer flipped so the shear burr won't dig into the block, maybe even sand them a bit. Those arms that the bolt goes through sometimes has burrs and or uneven cuts on them.
And mostly noticeable on Al blocks will dig or mark the block. Yeah its bad OCD. Its a machinist thing I guess.
Also a bit leary about hanging an inline engine off of them without supporting the front of the block or assembled engine.

I understand, it is hanging by the hoist so the engine mount is loose. It appears to me that the mounting arms just won’t reach all 4 positions. Very frustrating!

Yes I have turned the plate upside down & sideways. I’ll go at it again but I don’t see how I could drill another hole that would help.
Thanks!

Thanks!

I don't know if this will help, but. I used one of those stands (looks similar). I had to use the top 2 arms as a spacers and the bolts screwed into the block on the top 2 holes left and right of the center bolt hole. The lower arms were used as you have them in your picture, bolted into the lower bolt holes in the block. Bolt it on while engine is on the floor and then lift the engine up and slide the tub onto the stand.

Glenn,

I have attached below additional pictures that display where the engine stand arms need to be positioned for proper mounting.

As previously mentioned, you need to unbolt the one upper left arm from the stand and engine and reattach it correctly to the stand first (same as the way the other 3 are attached) so that will allow all 4 arms to move/adjust to match up with the engine mounting points.

Hope this helps. Be patient and check/recheck the pictures and your mounts to get them where they need to be.

Dan

Pictures of my situation.
IK I’m putting her on the ground.

Replying to my pictures. With the motor on the ground & turned the mount plate upside down it reaches the bottom holes in the block, but not enough to screw the screws in completely.
I plan to use a round file & try to make it ( the adjuster.hole) a bit larger.

Try lifting the whole motor up relative to the plate. Or take the plate off the stand so you can manipulate it easier.

It looks like if you lift it up, the top right arm can rotate counterclockwise and the bottom left arm can move in enough to get the bottom right arm into place.

I ground it down some. It’s on. I guess just tighten as much as I would if putting it back to the transmission?

Yes. Try to get the spacers to rest flat on the engine to take stress off the bolts. Maybe you need a crush washer or something.

Sizing bolts in US trucks are almost always NC std. if threaded into cast iron or Al, bolts threaded into steel usually are NF std. of course there may always be exceptions. No metric bolts in US vehicles.

Ed Pruss

Just a reminder, with your pivot point so low on the block the engine with the head on will be VERY top heavy. When rotating it from straight up to upside down make sure you have a long/strong cheater bar handle and go slow so you stay in control...if it gets away from you it will flip right over and be on the floor.

Be safe!

Mike B

I will, I’ll remove the head first while it’s low if I can.
Thank you guys for helping me!

Nicely done Glenn!

Don't forget about the pin/bolt to lock the rotating plate tube in position to keep the engine from flopping over unexpectedly (refer to the picture of yours I added a big arrow to for where that securing pin/bolt needs to go).

Mike B makes a very good point too about using a large/long pipe or cheater bar handle to control the rotation when you do want to do that. Much easier to control and less chance of injuring oneself.

SAFETY FIRST!

Dan

Drill another hole in the upper arms about an inch or a little more closer to the standoffs. That will allow you to move the pivot tube up closer to the top of the engine block and minimize the top heavy condition.
Jerry

The pin is in there!