273 intake/valve cover bolt torque

[Traikun]

Anybody help me out with torque specs for the intake manifold & valve covers on a 273 in a 64 Valiant? Thermostat housing too, perhaps? (Figured I'd just snug it up and give a 1/4 turn or so beyond that for the Tstat)

thanks!

 

[belmateo]

intake manifold = 35 ft lbs

 

[warwagons]

Anybody help me out with torque specs for the intake manifold & valve covers on a 273 in a 64 Valiant? Thermostat housing too, perhaps? (Figured I'd just snug it up and give a 1/4 turn or so beyond that for the Tstat)

thanks!

For the intake, it's 40 ft lbs.
Tightening sequence:
11 7 3 1 5 9
12 8 4 2 6 10
(Each number is a bolt)
I just go old school on the others. Snug em down evenly but don't get carried away on the valve covers. To loose or to tight.......leak!

 

[Traikun]

For the intake, it's 40 ft lbs.
Tightening sequence:
7 3 1 5 9
8 4 2 6 10
(Each number is a bolt)
I just go old school on the others. Snug em down evenly but don't get carried away on the valve covers. To loose or to tight.......leak!

I take it that's ordered in bolt sequence? So first bolt to tighten is dead center, passenger side (or driver?)

Awesome, Yeah I think I may just do the valve covers like I did my jeep valve cover. hand-tight, barely snug with a socket, then 1/4 turn each bolt until no other bolt is loosened by tightening another one. No leaks on the jeep so far...

 

[coffeedart67]

Would that be the same for a 67 273?

 

[warwagons]

I take it that's ordered in bolt sequence? So first bolt to tighten is dead center, passenger side (or driver?)

Awesome, Yeah I think I may just do the valve covers like I did my jeep valve cover. hand-tight, barely snug with a socket, then 1/4 turn each bolt until no other bolt is loosened by tightening another one. No leaks on the jeep so far...

Yes. thats the order. Pick either side but do not torque all the way. Keep snugging each bolt in sequence a little at a time until you reach the torque spec.
Have fun

 

[warwagons]

Would that be the same for a 67 273?

Yes. 273/318 through the '60s

 

[mopardude318]

intake manifold = 35 ft lbs

Would that be the same for a 67 273?

Yes. 273/318 through the '60s

The intake manifold bolts are a 3/8" bolt, same for any year big or small block....Generally the torque specs for any 3/8" bolt would be 35 ft lbs. So I'd have to say Guy (belmateo) is also correct...

 

[340mopar]

I believe a '64 273 has 5/16" intake bolts and 35ft lbs will snap them.


Chuck

 

[65Vart]

I believe a '64 273 has 5/16" intake bolts and 35ft lbs will snap them.


Chuck

Yup, 65 too they changed to 3/8 when the heads changed (bolt angle).

 

[66fs]

Some of you guys are scary! Torque specs on "64" and "65" 273, with 5/16 bolts are 60 INCH pounds to start, and 270 INCH pounds to finish. I hope he did not torque the intake yet!!!
valve cover bolts are 40 INCH pounds, and Thermostat housing is 25-30 foot pounds if you have a cast iron Intake.

 

[Traikun]

I haven't torqued anything down yet. Intake is painted, valve covers getting painted tomorrow morning or tonight, then reassembly Saturday! It is cast iron.

Well curse me for not having an IN-lb torque wrench. since 270 IN-lbs is 22 ft-lb, could I safely hand-tight them, snug them gently with a wrench, then maybe start at 10 ft lb, snug them all down, then 15, then 20, then 22?

I think for the valve cover I'll do it the way I was planning, and t-stat housing I didn't measure, just eyeballed it and didn't tighten it too much.

 

[belmateo]

Some of you guys are scary! Torque specs on "64" and "65" 273, with 5/16 bolts are 60 INCH pounds to start, and 270 INCH pounds to finish. I hope he did not torque the intake yet!!!
valve cover bolts are 40 INCH pounds, and Thermostat housing is 25-30 foot pounds if you have a cast iron Intake.

The spec I gave you (35 ft lbs) is from the Chrysler Service Manual FWIW

 

[warwagons]

Some of you guys are scary! Torque specs on "64" and "65" 273, with 5/16 bolts are 60 INCH pounds to start, and 270 INCH pounds to finish. I hope he did not torque the intake yet!!!
valve cover bolts are 40 INCH pounds, and Thermostat housing is 25-30 foot pounds if you have a cast iron Intake.

Very scary!
You are absolutely correct with regard to 64-65's odd 5/16 intake.
I have always gone 40 but that was not with 5/16 bolts. Just the way I was taught.
I did dig up old service manuals & liturature & each showed 64-71 anywhere from 35-40ftp with the majority showing 35ftp. Goes to show nothing is 100%
Glad the FABO eyeglasses are always on! Good job.

 

[66fs]

"64" and "65" 273's were rare. You almost had to have one and wrenching on it to know. My "64" 273 has had "72" 340 heads and intake for decades. I really had to dig to find the right torque. I'm sure we have all found mistakes in manuals. So much to keep track of. Best to All.

 

[chewy]

The spec I gave you (35 ft lbs) is from the Chrysler Service Manual FWIW

Not from '64 or '65 Dodge or Plymouth Tech service manual. Best read from the correct service manual for these. They run about $55 for a repro book. Used you can usually find for less. I think its the first purchase that should be made after buying the car.

The max on a grade 8 5/16 bolt should be about 18 ft'lbs which is about 220 inch-lbs. Breakage or stripping at 25-30 ft-lbs

IMO, an Inch-pound torque wrench is essential to any work on an old 273. Most torque wrenches, (Unless its an expensive one) arent accurate below 20.

 

[bamacuda]

The plymouth service manual for the 64-65 273 intake manifold with 5/16 bolts calls for 270 inch pounds which is 22.5 foot pounds.
(If you want to check this out, you can use the calcualtor at this link:
http://www.unitconversion.org/unit_converter/torque.html )

Start in the middle, gently snugging, working your way out. Snug about 3 times, and on the third time, you'll probably feel the torque wrench clicking ( or the dial will be at 270/22.5)
warwagons suggested pattern is:
Tightening sequence:
11 7 3 1 5 9
12 8 4 2 6 10

Matters not which side you do first, just go middle out.