motor mount bolt
 

Did a search on bolt torque for these, thread from 2012 came up...........im trying to figure out why so many different specs for this, on my 66 manual its 30 lbs, but im seeing anywhere from 65-75 on different sites,

Seems if you look up 3/8 torque even on a grade 8 its around 45, i put mine at 60 lbs, now im second guessing myself.

Got the motor and trans in yesterday, wow nothing going right with those dougs headers, but got it done.

Rich

Headers are a PAIN. But tight, nothing wrong with 60. I'm prob there or more with mine. Only things I ever TQ, Rods, Mains, heads and Lug Nuts. Anything else is by feel.

I've never torqued motor mount bolts. I just crank em in until they're tight.

60 lbs should be fine.

Bolts I have never used a torque wrench on.
Carb .
Intake
Trans
Water pump
Timing cover
Motor mount.
Oil pans
Valve cover
Push rod valley pan cover
Exh manifolds

How about you folks?

Let me see what did leave out!

Let me see what did leave out!

You left the " I " out in your sentence.............love this forum, ask a simple question about why so many different numbers on that spec, and you get this.

For future reference.

I was wondering the same thing as being asked above.

60 seems high for the 3/8 bolt from the mount to block. Might be right for the bolt for mount to frame.

steve25, what is the source of those torque specs?

Butler website had a nice chart!

The old HO racing part number & spec book.

OK, I thought that looked familiar!

Ok, this is from the 66 manual i have, shows 30 lbs, its the mount that attaches to the block, im not trying to be difficult but im wondering why so many different numbers for the same thing, as per wallace site and a few others, and usually i dont use the torque wrench because half the time you cant get in on half the nuts on the motor..........but since i was putting in the motor and was able to reach them, i said why not. I know alot of my questions over the years have been , lets say short of being smart, im just trying to learn as i go.,

Rich

In the 1967 Pontiac Service Manual, the engine insulators are torqued to the engine at 70 lb. ft. and the single bolt at 50 lb. ft. The rear (transmission) insulator bolts are torqued to 30 lb. ft.

The bolts that attach the mount to the block just above the oil pan rail are 7/16" anyway, not 3/8".

The spec i have always used is GUTTENTIGHT, an old German spec that works well in almost any application on non critical bolts, the GUTTENTIGHT spec has always worked for over 50 years of wrenching.

If you think back to the early years of wrenching on automobiles a torque wrench was a very specific/expensive piece of equipment, and not everyone had one in their tool set. My father worked on cars and trucks most of his adult life, so he had one for building engines, most guys that worked on their own stuff used the GUTTENTIGHT spec.................;)

Internal engine parts, and the lug nuts, after manufactures started using thin throwaway rotors are about the only parts I use a torque wrench for currently, YMMV.

The single bolt at 50 lb. ft. I believe is for the big car. The Tempest single bolt to mount bracket is 30 lb. ft.

he bolts that attach the mount to the block just above the oil pan rail are 7/16" anyway, not 3/8".....................sorry about that Sirrotica, trying to get this motor and transmission in , im getting numbers confused............got the motor and trans in yesterday, long day for me doing this, im not as fast as some of you guys that been doing this half your lives.

Rich

You are probably correct on that. When I read the 30 lb. ft., it stated bolts as in the the frame bracket bolts and I didn't think that included the long bolt. But full size and Firebird is 50 lb. ft.

50# on those 7/16 bolts sounds right if you want a torque spec, but they were never torqued at the factory, they were installed by a torque limiting impact wrench.

Another thing is when the factory sets a flat rate time for warranty work on any operation on a vehicle, they usually do not allow for use of a torque wrench. Every flat rate operation study is done usually with the technician using impact tools, without going over the torquing operation except on critical torque bolts. Yes there is a torque spec given on almost all bolts that hold a vehicle together, but in reality they expect them to be impacted more times than not on the GUTTENTIGHT method.

Just a little insight into the reality of how the manufacturers know most times how fasteners are going to be tightened by technicians in the field. As long as the part stays attached, and the fastener isn't compromised, is sufficient torque.

In all actuality given the accuracy of most torque wrenches, the GUTTENTIGHT method is plenty sufficient for 95% of all fasteners used in an automobile.

Sounds to me like they were indeed torqued from the factory.

A torque limiting impact is hardly accurate, no more accurate than a torque stick on a lug nut. It may be within a 15/20 lb window, but it is in the ballpark, but not accurate as a torque wrench used properly.

I.E. Discount Tire uses a torque limiting device (torque stick) initially on lug nuts, and then finishes the install with a conventional torque wrench finally torquing the nuts to spec. A limiting device isn't the same as using a torque wrench.

Video here shows how a torque limiting device is not a replacement for a properly torqued fastener. It also shows how inaccurate a torque limiting device can be.

https://www.youtube.com/watch?v=JVY0e5sdWx4

Torque limiting impacts are used on non critical bolts in manufacturing, but they're not using them on rod bolts in an engine. It's not what I consider torqued to a spec. Some people have different definitions of what torquing a bolt are............:rolleyes:

Tightening with a ratchet and socket would likely yield the same result, close enough, but not within 5 lbs. of a spec.

Hopefully this information shows the differentiation between a torque limiting device and a properly torquer fastener to spec with a torque wrench. If you don't know, ya don't know.