How much torque on manifold

Logan

Logan

Well-known member
I am installing a new intake and exhaust this week. I have heard from some people that 45 lbs of pressure is to much for the ears on the manifolds. What do yall torque them to? I dont want to ruin my two new manifold, so i want to be carefull.
 
When I install a set of manifolds, I tighten them enough so they don't leak. I don't shoot for a specific amount of torque, but if I had to guess it would be around 35# or so.

Make sure the manifolds have been planed together, the concave washers are installed correctly, and you use a good gasket.

Good luck.
 
Deluxe Coupe Chris said:
I torque mine to 50lbs. while the engine is cold then once again when the engine is warmed up.
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I dont know 50 lbs seems way to much. One of my buddies did his to 50 and it broke the ears off. Ive got about $300 in manifolds im putting on so that seems a little risky to me.
 
Logan,
I just installed mine and torqued them to 45 lbs. using a new copper gasket. I have run the motor until warmed up and retorgued again twice. I didn't have any problems.
I torque from the inside out. Make sure the bolts holding the two manifolds together are loose until you get them torqued the first time.
Good luck and have fun.
Jon :)
 
So you got your new manifold, are you going to be running a Weber dowmdraft then instead of the tow motor carb? Let us know how it works out....
 
Jim Parker Toronto said:
So you got your new manifold, are you going to be running a Weber dowmdraft then instead of the tow motor carb? Let us know how it works out....
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You are mistaken Jim. Two cars = two different carbs. Dont hate on the "tow carb" unless you have tried it. It works great, and are reletively inexpensive. And I will be sure to let you know how it works out. and yes it is a weber

So what do you torque your manifold to? still need some more input so i can make a good decision. (not that anybody's is wrong, i just would like as much input as possible)
 
I don't use a torque wrench. I use a 3/8 rachet and tighten until it feels right. If you get a leak, tighten a bit more. I only use a torque wrench for head nuts and rear axle nuts. Henry didn't use them at all.
 
I just put mine on yesterday before reading this post using my normal method of a 3/8 ratchet by "feel" using the copper gaskets. I just checked it with the torque wrench starting at 35 pounds. 2 clicked at 37 - 38 pounds, the other two were 40 - 41 pounds. If anything I think I'll use the torque wrench at 40 pounds from now on for consistency. 4 pounds seems like a little too broad of a range to me.
 
Don't say the word torque.
It's a screw down till makes contact with the block and a a tad of grunt afterword.
Don't need to squeeze the water out of the hardened studs.
Let the gasket do the sealing.
Use a one piece gasket and NO gland circles.
But most importantly, make sure the intake and exhaust manifold when bolted together are dead flat. Other wise it'll be crack city since castings don't bend.

skip.
 
Kevin - Illinois said:
I just put mine on yesterday before reading this post using my normal method of a 3/8 ratchet by "feel" using the copper gaskets. I just checked it with the torque wrench starting at 35 pounds. 2 clicked at 37 - 38 pounds, the other two were 40 - 41 pounds. If anything I think I'll use the torque wrench at 40 pounds from now on for consistency. 4 pounds seems like a little too broad of a range to me.
Click to expand...

Kevin, Don't be in a rush to think your "feel" method is less consistent than a torque wrench!

Two reasons: 1st, as an experienced wrench twister, you feel a point where the applied torque starts to 'ramp up' quickly in relation to the degrees of turn you apply to the wrench. That's the point of complete compression of the gasket and parts. You are suddenly feeling only the stretch of the stud, not a combination of gasket/parts compression and fastener stretch. At that point the experienced mechanic generally gives it 'just a bit more' which is inevitably an unconsciously applied measure of rotation, say one fastener flat or something. At that point the fastener (stud) which is actually a spring when stretched, is stretched a controlled amount by that final measured additional twist.

2nd, although there are multiple identical fasteners, they will not all have the same friction characteristics, NOR will they all bring the parts and gasket to complete compression at the same ft/lbs point. THAT is a matter of experienced feel finding the 'ramp-up' point when wrench twisting.

Guess what? Many new car fastener spec's indicate torque to xx ft/lbs then add xx degrees rotation!! Yep, they took the stupid out of it for all those inexperienced mechanics coming out of auto tech training. They can no longer wait years for 'experience'.

I would have more confidence in where you now have your studs than what you will get if you re-torque them with only the indication of a torque wrench that cannot 'feel'.

When I do use a torque wrench, it is for apps with so much torque that I am struggling to pull the wrench, making it more difficult to feel for that all-important ramp-up point. I always use a moving beam wrench, which permits you to observe the rise in torque in relation to degrees of turn as you progress. You can SEE the ramp-up point even if it is at a torque point beyond your personal ability to feel it. To me, the biggest piece of s**t tool ever invented was the 'click' torque wrench. No visual, designed to keep inexperienced mechanics who lack the 'feel' in the dark, and a sure way to break off more bolts and nuts than a thinking man ever would.
 
I had my engine rebuilt at Schwalms, a highly regarded Lancaster Co.,PA shop. My manifold was torqued at 30#. About 1000 miles after break-in, I was told to keep it between 20# and 25. F.W.I.W.
 
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