Thread: Please help with sbc torque specs.

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Started assembling my 350 Chevy today, got the crank mains torqued to the specified 77 lbs, but when I looked up the rod torque specs in the manual, they said " Step one..........20 lbs, then tighten an additional 55 degrees." I had heard something from our Techs at work about this, but I only have my trusty torque wrench.

What should I torque them at to be in the ball park? 45 lbs?

Also, the head torque specs are:

Step one, tighten to 22 lbs.
Short bolts........... tighten an additional 55 degrees

medium bolts.........tighten an additional 65 degrees

Long bolts.............tighten an additional 75 degrees

Can someone give me normal torque specs for all these?


Thanks,

Don

Torque to Yield bolts, you CANNOT reuse these, you need new for any time there removed. you need to get ahold of a Snap On guy and get a " Torque Angle Meter " ( a parts house might even have 1 ), it has a 1/2" female drive, and a male 1/2" drive, and degrees marked, around this dial, and a pointer is moveable, it also has a stiff flexible rod ( like what clip lamps have ) connected to an alligator clip. what you do is torque your bolt to the specified torque, then hook up the angle meter, clamp it to the block, zero it out, and tighten until the specified degree. the TTY bolts are pre streached, that's why you cannot use them, there is no " normal " torque specs if you use the TTY bolts, you would have to buy them for an older motor.

Matt: I did buy ARP head bolts from Summit, so would older Chevy torque specs work? I want to finish putting this thing together tomorrow, so I can't be waiting to get one of these angle finder things you described. There must be a torque value that will get me close.


Don

Don, I'm far from being an expert, but I think the old specs would work just fine.

Originally Posted by NTFDAY

Don, I'm far from being an expert, but I think the old specs would work just fine.

I kind of agree. After all, I am just using steel heads and normal stuff. I just don't want to torque it wrong and pay the price later. What do you think for the rods? 45?


Don

Originally Posted by Itoldyouso

Matt: I did buy ARP head bolts from Summit, so would older Chevy torque specs work? I want to finish putting this thing together tomorrow, so I can't be waiting to get one of these angle finder things you described. There must be a torque value that will get me close.


Don

Use the specs. ARP sent with the fastners.
If your bolts go into a water-jacket make sure you use ARP's thread sealant on the threads.

Huh, I hadn't opened the box yet. Never thought they may have specs in there. I'll have to look tomorrow. Thanks for that info. What about the rods? 45, or something else?


Don

Originally Posted by Itoldyouso

Huh, I hadn't opened the box yet. Never thought they may have specs in there. I'll have to look tomorrow. Thanks for that info. What about the rods? 45, or something else?


Don

What kind of rod bolts do you have??

use what ARP specifies, there Mil Spec, so it's bound to be diffrent than even the older stuff, but there website has the specs. if you bought TTY ARP ( don't know if there made but maby ) than you would need the TAM, because the TTY bolts are pre streached to yeild, so the 55* you have, would put that bolt right at yield, any more and you would snap it off. the old SBC torque specs could work otherwise.

When I ordered the bolt set from Summit, I wanted stainless, but they had none , except for the intake manifold. So the salesman told me to buy these ARP bolts, and I don't think they are the TTY version, because I told him my engine originally had some strange bolts, and he said these were a direct replacement, but that they were normal bolts.

Should I just go with torque specs for a non vortec? I thought Chevys were supposed to be a piece of cake.

Don

Originally Posted by Itoldyouso

When I ordered the bolt set from Summit, I wanted stainless, but they had none , except for the intake manifold. So the salesman told me to buy these ARP bolts, and I don't think they are the TTY version, because I told him my engine originally had some strange bolts, and he said these were a direct replacement, but that they were normal bolts.

Should I just go with torque specs for a non vortec? I thought Chevys were supposed to be a piece of cake.

Don

Chevy's were a peice of cake, until this modernization of TTY bolts swept thru the manufactures ( ford 4.6 was the first american to use them ). if the bolt has threads all the way up, it's TTY, if it has an unthreadded area, it's a regular bolt.

TTY's help torque the head more evenly, therefor less head gasket faliures

Well, even the old bolts had shoulders without threads, I just looked at them tonight. Does that mean they are not TTY?? BTW, I guess Chevys get sealant on the head bolts since most pass into the water jacket?

Don

45 on the rods shock gm bolts i have built 6 of them 96and up and all the rods are still hanging on i used all the old gm TQ specs and on the heads to if you look at the spec they give tty on the older gms 350 and they did not used them back in the 80s

There you go, that is what I wanted to hear. I will treat this thing just like an earlier engine, and should be ok.


Thanks guys for all the help. I'll look in the ARP box tomorrow for their specs too.

Don

These are the values I use unless a fastener manufactor says different


Small Block Chevy

7/16 in. outer main cap bolt 65 ft.-lbs.
7/16 in. inner main cap bolt 70 ft.-lbs.
3/8 in. outer main cap bolt 40 ft.-lbs.
11/32 in. connecting rod bolt 38-44 ft.-lbs.
3/8 in. connecting rod bolt 40-45 ft.-lbs.
Cylinder head bolts 65 ft.-lbs.
Screw-in rocker arm studs 50 ft.-lbs.
Intake manifold bolts (cast iron heads) 30 ft.-lbs.
Oil pump bolt 60-70 ft.-lbs.
Cam sprocket bolts 18-20 ft.-lbs.
Harmonic damper bolt 60 ft.-lbs.
Flywheel/Flexplate bolts 65 ft.-lbs.
Pressure plate bolts 35 ft.-lbs.
Bell housing bolts 25 ft.-lbs.
Exhaust manifold bolts 25 ft.-lbs.