GraciaLee

Guys,

I am trying to disassemble a diesel engine and plan to mount it on the engine stand, but I searched through my local retailers, no luck to find M12-1.25 *120mm bolts, it's metric with extra-fine thread, I couldn't even find any matching products on Fastenel.com, so does anyone have ideas?

Updates: so now I can find M12-1.25 *140mm bolts, the problem is it's a little bit long in my case, even if the the thread length is just right! I was wondering if it's okay to use two heavy hex nuts (or more washers) between the bolt head and the back of the stand arms, it's sort of like spacers. Do you guys think that's okay? My engine block is almost 500kg, and the bolts have a strength class of 10.9, not quite sure if the "spacers" will deteriorate the strength.

pogo69

that sounds like a common size...try mcmaster carr or grainger online they would have it

gearheads78

How many do you need?
https://www.boltdepot.com/Product-De...x?product=6357

oldcutlass

Fastenall has them in both 8.8 and 10.9:
https://www.fastenal.com/web/product...endingMachine=
https://www.fastenal.com/web/product...endingMachine=

Home depot has 8.8 as a flange bolt
http://www.homedepot.com/p/Crown-Bol...4058/203539398

gearheads78

I would rather have the 10.9 for an engine stand I would order those Fastenal ones.

I have learned that if they don't stock it at the store you walk in to most of the guys at Fastenal don't have a clue. Its worse than walking in to a modern parts store.

GraciaLee

Thanks for the information, I am sorry that I didn't mention I need to make sure the minimum thread length be 36mm, but typically the standard partial-thread bolts for 120mm only have 30 mm threads. So I prefer fully threaded, but what I can find is just 90mm or 100mm at most...

GraciaLee

I checked both of these you mentioned, but no luck. I forgot to mention that the minimum thread length should be around 36mm, so that makes this kinda difficult

GraciaLee

Actually I just need 2 of them, but I don't mind having a package if they have the dimensions I need and of course the price are reasonable. And I prefer fully threaded ones, because I may need to cut off a little bit.

GraciaLee

Totally agree with you! I cannot accept strength class is less than 10.9, my engine block is almost 500kg, I don't want to mess up...

gearheads78

Don't think you will ever find fully threaded in that length. Better order he ones above and find a 12mm 1.25 die and cut the last few threads you need.

oldcutlass

Going to be tough to find a full threaded bolt in that spec. You might consider all thread rod in the heavier spec and make studs.

https://www.fastenal.com/web/product...endingMachine=

naphtali5725

Tractor Supply sells a large selection of bolts etc. have you tried there?
they have all-thread too, but i don't think it was metric...

allyolds68

Are the bellhousing bolts on a D or DX block metric??? I'd never heard that.

wr1970

I'm lost here on the topic a grade eight bolt is plenty strong enough to use to mount this block to a engine stand. They are not metric bolts are they? I think i used SAE. they are in good supply at any tractor supply store with a good selection bolts, nuts, washers ect. Why would you want a all thread bolt i am confused!!

GraciaLee

Thanks! This is what I am thinking now!

GraciaLee

This is exactly my supervisor's recommendation, I just have a problem with the welding, I don't know if I can make sure the bolt head surface on the welding joint will be good enough for contacting with the mounting arms, is it a problem?

GraciaLee

I looked up but had no luck, sometimes I am really confused why both imperial and metric fasteners exist on my engine...

GraciaLee

It's a GM engine, kinda old product. I think it's once used on Sabb, now we just have the engine to do some researches, not really for a vehicle use.

GraciaLee

The truth is they are indeed metric...so grade 8 should be approximately class 10.9 in metric ones, that's why I said class 8.8 cannot work for this engine, class 8.8 is probably just grade 5 not 8.

As for why I want fully threaded, standard partial thread bolts in 120mm only have a thread length of 30mm, while the mounting holes on my block is 36mm in depth, so I prefer fully threaded so that I can fit the bolt into the bottom of those holes.

oldcutlass

30mm is plenty of thread going into the tapped holes. You may be over thinking this. I also believe a gr5 or 8.8 bolt to be plenty strong enough to accomplish your task.

allyolds68

Just for future reference "non Olds powered" is probably a more appropriate category. I, and at least a few others, thought you were referring to an olds diesel 350 D or DX block

wr1970

I see that this engine is not what i was thinking. It would have helped to know in the beginning what this motor is out of. I am sorry i replied with the assuming that this was a 350 d or dx diesel engine. Please forgive me and i am out of here. Carry on guys i hope someone can give him info that can help him.

oldcutlass

I moved your thread to the non-olds powered section. Hopefully you have found what you need..

D. Yaros

Have not read all msgs in thread so this may be repetitive? ARP Fasteners does not have this item?

Run to Rund

Threaded length on bolts is generally enough for full strength, even if the hole in the block is tapped through to a greater depth.


When I saw that the block weighs over 500 kg, it was clear that you weren't working on an Olds 350 diesel block. To most of us it should have been clear by your first post since the D and DX Olds blocks have nothing on them of that thread size, regardless of pitch.

GraciaLee

Sorry for the confusions, guys! Not realized I used a wrong category, thanks!

GraciaLee

Thank you! But still had no luck, I am thinking about modifying them with the advice that people provided here.

GraciaLee

Sorry for the confusions, and thanks for the explanation for the thread length!!!

pogo69

try the nutty company 203 877 1709 they may have a webpage also but i would call them...they were the only ones in world that had lag bolt i needed for a boat i had years ago

GraciaLee

Thanks for the suggestions! I will try!

allyolds68

I think maybe you should go back and read the first post.


-It was the first post by a member and it was in the "big block" engines section which is supposed to limited to Oldsmobile engines
-it said that the engine was diesel.
-it was not unreasonable to assume the the OP was unfamiliar with Olds engines.
-the 500 kg post was later and it could be reasonably assumed that the OP thought that Olds diesel engines were heavier.


The two of us that saw it this way wanted to save the OP from sticking the incorrect metric fasteners in standard size holes and ruining a block


Nice Monday morning quarterback job

allyolds68

Incidentally if it was a 1,100 lb (500 kg) engine, using a typical Olds configuration, it would impart a force of approximately 2,500 lbs (1250 lbs each) to the upper two bolts of an engine stand (dead weight, not including the torque from wrenching on it). A M12-1.25 bolt is slightly less in diameter than a 1/2" bolt. A grade 5, 1/2" bolt, has a tensile capacity of 17,000 pounds, EACH. I'm sure a M12 bolt has a similar tensile capacity. I believe a typical Olds bell housing bolt is 3/8". 3/8" Grade 5 bolts have a tensile capacity of 3,800 lbs. Obviously an Olds engine weighs less so the total fastener load would be less as well.


I'd be way more worried about breaking or tipping the engine stand but I'm sure the OP is using a large commercial one


I use grade 5 or above fasteners for consistency but you rarely need them for strength in these applications. Non-graded bolts are just generally inconsistent pieces of crap.