Torque setting on manifold

[james hitchcock]

I don't remember what is the torque setting on the manifolds.

[msmaron]

try 30 Cold....Drive and go to 35...That is ALL i do, i know some folks will say 45 or 55 but not fun when those ears make that fun "SNAP"

[CarlG]

Just "good and tight" with a short handled socket wrench. As Mark said, you don't want them talking back to you!

[james hitchcock]

Thank you.

[BILL WILLIAMSON]

Originally Posted by james hitchcock

Thank you.

James,
Say, "thank you that I didn't reply!" Seems that everytime I mention torque, Loctite, or pre-load, I get folks all stirred up! Bill W.

[28ACoupe]

Sponsored Links (Register now to hide all advertisements)

Of course mentioning that this information is readily available in any of the "must have" books on the Model A ford might not be helpful at the moment.

[Patrick L.]

Like said, 35-40 ish.. They didn't torque them back in the day.. They just snugged up up evenly..

[BILL WILLIAMSON]

They were ignorant about torqueing, that was a looooong time ago. A lot of things were learned since then.
Their motto was probably: little bolt, a little tightening, medium bolt, a little more, a Big bolt, 2 GRUNTS, rear axle nut, 3 GRUNTS! Lots of things they did back then wasn't necessarily the best way. Bill W.

[28ACoupe]

One of the best tools I have in my box is a copy of the Pocket Ref. You can go through an entire car and not know any torque settings for anything and get all the torques correct.

[BILL WILLIAMSON]

Originally Posted by 28ACoupe

One of the best tools I have in my box is a copy of the Pocket Ref. You can go through an entire car and not know any torque settings for anything and get all the torques correct.

Thanks,
I'm gonna order one, handy!
Torque is so important, first to make sure it is tight enough, and also for uniformity. Worked with a shop IDIOT once that was always BREAKING bolts & "squishing" soft gaskets_*&%$#^# I spent a whole lunch hour teaching him TIGHTENING-101! Bill W.

[tbirdtbird]

Bratton's catalogue has a spec and torque table in the front, very handy. Good ol' Walt...
And the manifolds don't wanna be too tight because they are gonna move back and forth a bit from expansion/contraction of exhaust heat. If too tight, somethings gonna snap or warp.

[james hitchcock]

Originally Posted by 28ACoupe

Of course mentioning that this information is readily available in any of the "must have" books on the Model A ford might not be helpful at the moment.

I know this info is to be found the many Model A books, but you guys on the Barn are so dang fast with your responses and I like the fact that you've all been there and done that.
Thanks again.

[28ACoupe]

James - You really need to get a copy of the Model A Ford Mechanics Handbook if you don't have one. It is worth it's weight in gold to us.

[peters180a/170b]

I don't know,, never torqued them before ,,,I just start left and right side nuts of the carb. and work my way out to the two ends. Keep going over and over,, left to right 2 inner to two outer so the gasket works to the outside edge and don't bind up. never had a problem. But everyone is different.Had both manifolds milled together.

[BILL WILLIAMSON]

Originally Posted by tbirdtbird

Bratton's catalogue has a spec and torque table in the front, very handy. Good ol' Walt...
And the manifolds don't wanna be too tight because they are gonna move back and forth a bit from expansion/contraction of exhaust heat. If too tight, somethings gonna snap or warp.

tbirdtbird, (sounds like an echo-echo),
Catalogs are almost like a shop manual, if read completely. Are we too lazy to read?
Shucks, we can a make a Model A run by the seat of our pants & a collection of parts catalogs! They even have PICTURES!
You just gotta' stop & think things out.
Can you imagine the questions a poor Model A parts man recieves, and his Dear Wife wonders why he's GROUCHY?
Most modern manifolds are real tight, so they don't shrink and expand in length & shear off the studs. Datsun & Nissan "Z" cars for example.
I've been around the "Horn" 2,870 times, I aint' no rookie! Bill W. (THORN!)

[jkeesey]

Modern Chevy and ford manifolds are cracking in the centers from being too tight and not leaving room for expansion. I run A manifolds at 45ft lbs after the manifolds have been cut together and the block has been checked true. Ive done over 30 of them in the past few years and have never had a problem.

[Napa Skip]

There are other reference guides, both for specific torque values and for general torquing procedures, some of which are (or were) available gratis. Two that I obtained in 1989 when I was a mechanical engineer for the Oceanic Division of Westinghouse Electric Corporation were free from an automotive parts store across the street from our offices. Both were from Fel-Pro Incorporated of Skokie IL; the first is “Fel-Pro 263-85 Gasket Installation Manual” and the second is “Fel-Pro 486-89 Complete Cylinder Head Torque Specifications” (including torque-to-yield information, not applicable, insofar as I know, to Model A’s).

The “Gasket Installation Manual” has chapters on 'Things You Should Know About Every Gasket Installation'; as well as 'Cylinder Head Gaskets'; 'Manifold Gaskets'; 'Oil Pan Gaskets'; 'Timing Cover Gaskets'; and 'Adhesives, Sealants and Other Products Used in Sealing Gaskets'.

While I suppose Fel-Pro might have a different slant on things than other gasket manufactures, they do appear to provide a “best practices” approach to what – at least in 1985-1989 – was the industry standard for proper gasket installation, assembly closure torquing, and use of gasket sealants.

Here are some excerpts, applicable not only to this thread, but to several recent threads debating the use of not only torque wrenches but gasket sealants, RTV (sacre bleu!; Fel-Pro recommends the use of RTV for multi-part pan gasket joints), hot and cold torquing and retorquing, different approaches for cast iron and aluminum components, and…

“Check for warpage and distortion [by placing] a straightedge lengthwise on the head surface, and slide a feeler gauge between the head and the straightedge. A good rule for flatness is not more than 0.004” out-of-flatness for four-cylinder heads” both lengthwise and widthwise. The same procedure – and specification - is recommended for the block.

"If the [head or block] surface is too smooth, the gasket cannot grip the surface to give a good combustion seal. If the surface is too rough, the gasket will not confirm to the surface, causing fluid leaks. A finish of 90 to 110 micro-inches RMS [Root Mean Square] is preferred. Many head gaskets will not seal when the surface is outside this range.”

“If the head or block has been resurfaced [or] if the threads run up to the surface, chamfer and retap the hole. The threads then will not be drawn above the [head or block] surface when the bolts are tightened [which] is enough to cause gasket failure.”

“Wire brush the threads on all assembly bolts, check the bolt threads for damage and lightly lubricate the threads with engine oil before assembly. Dry…threads can decrease the bolt’s clamping force by as much as 50% [and] lead to false torque readings and possible gasket failure.”

“Older [gasket] designs, such as the steel-faced sandwich-and-perforated-core, require the cylinder head to be retorqued [since] these gaskets take a set after initial engine operation and relax to the point where retorquing is needed to restore the clamping force. Run the engine to a normal operating temperature (usually 5 to 10 minutes), shut off the engine and carefully retorque the cylinder head bolts/nuts for a second time while the engine is still hot if the engine is cast iron. If the head or block is aluminum, cool to room temperature. Follow the torque sequence to the specified amount in the torque tables. Retighten a third time after 300 to 500 miles.” [Note that nothing was mentioned, either way, about breaking torque before retorquing.]

“Some exhaust manifold gaskets have a perforated steel face on one side and a soft face on the other. The steel face is positioned toward the exhaust manifold…because the exhaust manifold expands when it is heated during operation [and] moves. Due to high heat conditions, it is important to retap and redie all threaded bolt holes, studs, and mounting bolts/nuts [to] ensure tight, balanced clamping forces on the gasket. Lubricate the thread with a good high temperature anti-seize lubricant [and] install the bolts/nuts finger tight [and] then tighten in three steps [to] ½, ¾ and full torque following the torque tables. Torquing…is begun in the center of the manifold, working outward.”

Lots of good information from people who make a living making gaskets.

[tbirdtbird]

Good stuff.
Installation manual:
http://www.frontiernet.net/~tmeyer/fpro.html
Torque Tables and the best explanation of torque-to-yield I have seen. None of this really applicable to Model A, but some of us work on lots of different engines
http://olybrake.com/pdf/fel_pro_torque_specs_guide.pdf

Glad to see the mention to re-torque cast iron stuff hot, and not cold. Some posters here are re-torquing cast iron cold, and that goes against any mechanical practice I have ever seen in > 60 yrs

[Mike V. Florida]

Originally Posted by tbirdtbird

Glad to see the mention to re-torque cast iron stuff hot, and not cold. Some posters here are re-torquing cast iron cold, and that goes against any mechanical practice I have ever seen in > 60 yrs

Even the Ford service bulletins call out torque warm.

[Tom Wesenberg]

I never use a torque wrench on manifolds.
Also you must remember that because a certain stud and nut can take some amount of torque, that doesn't mean the part being clamped can take the same amount of torque. Cast iron manifold ears on a soft copper gasket might fit in here.

[tbirdtbird]

excellent point

[BILL WILLIAMSON]

Originally Posted by jkeesey

Modern Chevy and ford manifolds are cracking in the centers from being too tight and not leaving room for expansion. I run A manifolds at 45ft lbs after the manifolds have been cut together and the block has been checked true. Ive done over 30 of them in the past few years and have never had a problem.

jkeesy,
"THEY" say, there's exceptions to every rule, except for DEATH & TAXES!
Who's Ceasar? The Bible says I should pay him too!! Bill W.

[Stl Tkn]

Hey friends! Thanks for the thread....EVERY time I come on this site I get exactly the needed information. I am restoring my 1930 roadster and have decided to buy both intake and exhaust manifolds due to a crack in the exhaust. Have been told that there is no need to mill the new manifolds if bought together(?). Going to install today and wanted to check the FP of torque. Guess from the tread it is somewhere between 30-55fp. Will definitely comply with the cold to warm redo working up to about 40 or 45 methinks. THANKS AGAIN from one rookie out here!! Dennis

[jkeesey]

I think you are right about the new ones not needing milled. I sold a set and they were perfect. Just run a straight edge across them before throwing them on for shits and giggles.

[Dave in MN]

FWIW: The last two new manifolds I purchased from Snyder's had an installation guide with them and it suggested 45#. Probably fine for their new castings. I think 45# is to much with originals. With a freshly surfaced intake and exhaust manifold, I tighten to about 25# and then run the engine for a few heat cycles. Then increase to about 35# as a finish.

[Farrell In Vancouver]

Sponsored Links (Register now to hide all advertisements)

One more reason not to run them up to tight......I had a number three stud pull the side of the water jacket right out of a fresher rebuild. Yes the block had been magna-fluxed and had no issues before the build. I don't think I made it up to 30Lbs. Crack! bleed bleed bleed, swear curse grumble. Remove and strip the block, and had it "stiched" up. I never tighten more than I need to and do it hot.
Cheers!

[tbirdtbird]

"Guess from the thread it is somewhere between 30-55fp."

Specs in Bratton's catalogue are 25-30 for manifold nuts....i certainly would not go over 35, and no where near 50

[columbiA]

You can tighten manifolds with a 3/8" drive ratchet,working out from the center.retighten once or twice more & you will be fine.You only really need a T-wrench on the cyl head & if you have installed as many heads as I have over the years,I would be very close if rechecked with a T-wrench.

[Greg Jones]

Napa Skip, in this context doesn't RMS stand for "rough machined surface?"

Surface roughness, often shortened to roughness, is a measure of the texture of a surface. It is quantified by the vertical deviations of a real surface from its ideal form. Roughness is typically measured in "RMS" microinches and is often only measured by manual comparison against a "surface roughness comparator", a sample of known surface roughnesses

[Napa Skip]

Originally Posted by Greg Jones

Napa Skip, in this context doesn't RMS stand for "rough machined surface?"

In this context I'm fairly certain that "RMS" refers to Root Mean Square, which is one of several approaches to quantifying (in this case) the peaks and valleys of a surface (another approach is Ra, which is the straight mathematical average of the absolute value of the peaks and valleys).

Fwiw, RMS is the [square] Root of the Mean of the sum of the Square of each peak or valley measurement.

As a simplified example [I hope I don't goof this up; I'm typing this reply as I watch "Suddenly, Last Summer" on TCM - fortunately the scene with Elizabeth Taylor in her white bathing suit hasn't come up yet] consider a surface with the following 5 measurements of peaks and valleys (I'll use whole numbers instead of millionths of an inch - or micro inches - to simplify the example): +4, +5, -3, +2, 0.

Ra = 1/5 x (4 + 5 + 3 + 2 +0) = 1/5 x 14 = 2.8. (Remember that the absolute value of the measurement is used, so the "-3" is treated the same as "+3".)

To calculate RMS we use,

RMS = Sqrt (1/5 x (4^2 + 5^2 + -3^2 + 2^2 + 0^2)) = Sqrt (1/5 x (16 + 25 + 9 + 4 + 0) = Sqrt (1/5 x 54) = Sqrt (10.8) = 3.3 (rounded off).

Slow day out here on the left coast...

[I'm certain that if I goofed up anything in the above, those more knowledgeable - or who aren't watching Elizabeth Taylor while trying to type - will jump in.]

[BILL WILLIAMSON]

Well yall' torqueing folks, don't mean to gloat, but just recieved this torkin' goodie from my Son, along with a box FULL of other treasures! He restored it to almost new lookin' condition & The Dog tested it for akuracy & said, "RIGHT ON"!
Who said, "THERE AIN'T NO SANTA CLAWS"?? Bill W.

[Mike V. Florida]

Originally Posted by 28ACoupe

Of course mentioning that this information is readily available in any of the "must have" books on the Model A ford might not be helpful at the moment.

This is one of the areas that the red book has it too high.

[Mike V. Florida]

Originally Posted by 28ACoupe

Of course mentioning that this information is readily available in any of the "must have" books on the Model A ford might not be helpful at the moment.

This is one of the areas that the red book has it too high.

[41plym]

O.K. I just installed my freshly resurfaced manifold and torqued to 20 pounds. I am already getting nervous about going any tighter. I just need some reassurance I can continue without breaking the ears.
Thanks

[Tom Wesenberg]

Originally Posted by 41plym

O.K. I just installed my freshly resurfaced manifold and torqued to 20 pounds. I am already getting nervous about going any tighter. I just need some reassurance I can continue without breaking the ears.
Thanks

I can't give it to you. I saw someone snap the ears before 35 lbs. was reached. I just use my box wrench and common sense. Mine don't come loose.

[Purdy Swoft]

I do mine just like columbiA in post #29 . A few years ago it was recommended to torque 7/16 nuts, including the manifold nuts to 55 ft. lbs.. After warping and cracking several good manifolds I've went back to the common sense approach. I tighten the manifold nuts with a 3/8 ratchet and go by feel. after a few warm and cool cycles the nuts will need to be retightened and rechecked for a few times afterward. Besides warping manifolds, tightening the manifold too tight squishes out and ruins the gaskets, causing exhaust and vacume leaks. Usually the manifold will be found to be warped when removed to replace the squished gaskets after over tightening. A 3/8 ratchet would probably strip before reaching 55 ft. lbs. torque.

[George Miller]

Originally Posted by Tom Wesenberg

I never use a torque wrench on manifolds.
Also you must remember that because a certain stud and nut can take some amount of torque, that doesn't mean the part being clamped can take the same amount of torque. Cast iron manifold ears on a soft copper gasket might fit in here.

I agree with you Tom. I think on some things a good feel is more important.
I do use a torque wrench on rods, mains, head, and things like that

It's all about feel, and common sense.

[steve s]

I think it's helpful if the two little bolts joining the exhaust and intake manifolds are only finger tight until AFTER bolting to block. You want each unit to be able to find its own seating, without possibly exerting a stress on the other. Also, be sure that you're using the thick curved washers with the convex side out, against the nut.

With some hesitation about using the "B" word, I'm surprised to see that Fel-pro's recommendations about oiling the threads and torqueing while warm both go against the no-ifs-ands-or-buts instructions given by a certain legendary manufacturer of Model A high compression heads.

Steve

[Mike V. Florida]

Originally Posted by 41plym

O.K. I just installed my freshly resurfaced manifold and torqued to 20 pounds. I am already getting nervous about going any tighter. I just need some reassurance I can continue without breaking the ears.
Thanks

Does it leak?

[Duffy1]

Also goes against mgf directions as it relates to torquing modern head gasket stone cold and against the fact that adding oil to the threads require reducing the amount of torque .

[Purdy Swoft]

I don't torque the manifold nuts. I don't oil any threads that I intend to torque. I second what Duffy 1 says.