Torque Specs. on 302

Topic: Torque Specs. on 302 (Read 1324 times) previous topic - next topic

Torque Specs. on 302

November 12, 2006, 10:11:04 PM

My Haynes book is strange it gives 3 steps to torque the Head Bolts.. Step 1 35 ft.lb. Step 2 55 ft.lb. I stopped there until I find out something. Step 3 says to turn the bolts after step 2 about 90 degrees More.. what the Hey?? why can't they just give me another Torque. these are the 7/16 d bolts..Thanks for your help

Torque Specs. on 302

Reply #1 – November 12, 2006, 10:24:27 PM

what year 302? sounds like you have TTY specs.

Torque Specs. on 302

Reply #2 – November 13, 2006, 12:12:22 AM

I would say it was a 88 5.0 EFI

Torque Specs. on 302

Reply #3 – November 13, 2006, 03:49:53 AM

Quote from: VictourBII;113190

I would say it was a 88 5.0 EFI

Cylinder head bolts 65-72 ft.-lbs.
^^^^^^^^^^^^^^^^^^^^

Main cap bolts        60-70 ft.-lbs.
Outer main cap bolts,       35-40 ft.-lbs.
Connecting rod bolts       19-24 ft.-lbs. (40-45 ft.-lbs. for 289 HP Boss 302)
Cylinder head bolts       65-72 ft.-lbs.
Rocker arms       17-23 ft.-lbs.
Intake manifold bolts       23-25 ft.-lbs.
Oil pump bolt       23-28 ft.-lbs.
Cam bolts       40-45 ft.-lbs.
Cam thrust plate bolts       8-10 ft.-lbs.
Harmonic damper bolts       70-90 ft.-lbs.
Flywheel/flexplate bolts       75-85 ft.-lbs.
Pressure plate bolts       35 ft.-lbs.
Front cover bolts       12-15 ft.-lbs.

Torque Specs. on 302

Reply #4 – November 13, 2006, 10:05:51 PM

To evenly tighten the head down first do step one to all the bolt then step 2 then step 3 usually there are 2 steps example (40-60 foot lbs) means first tighten all bolt to 40 foot lbs then retighten at 60 lbs from the center out.

Torque Specs. on 302

Reply #5 – November 13, 2006, 10:13:22 PM

Thanks so much that is what I was looking for..
Engine Photo's under Bronco II, Link below

Torque Specs. on 302

Reply #6 – November 14, 2006, 09:53:45 AM

Quote

My Haynes book is strange it gives 3 steps to torque the Head Bolts.. Step 1 35 ft.lb. Step 2 55 ft.lb. I stopped there until I find out something. Step 3 says to turn the bolts after step 2 about 90 degrees More..

My Haynes book says Step 1: 55 to 65, Step 2: 65 to 72 (page 78). Are you using the same book (#1338)? It's possible a later printing is using a different method, with a lower initial setting of 55 lb/ft (to get everything equalized) plus a calculated crush value (x degrees with thread pitch y gives gasket crush z), similar to, but not the same as using actual Torque To Yield bolts.

Torque Specs. on 302

Reply #7 – November 14, 2006, 10:45:58 PM

Wish I had some 4 bolt mains..

Torque Specs. on 302

Reply #8 – November 14, 2006, 11:58:27 PM

I would use the Haynes proceedure. They have learned how to get a more accurate clamping pressure since these cars where built.

For example, here is the head bolt proceedure from the '01 Crown Vic shop manual:

Step 1: Tighten to 28-31 lb-ft
Step 2: Tighten an additional 85-95 degrees
Step 3: Loosen the bolts a minimum of one full turn (360 degrees)
Step 4: Tighten to 28-31 lb-ft
Step 5: Tighten an additional 85-95 degrees
Step 6: Rotate an additional 85-95 degees

Torque Specs. on 302

Reply #9 – November 15, 2006, 12:24:02 AM

That really sounds strange to Me rotating 85 to 90 degrees should have a foot Lb. torque . 01 isn't that the 4.6 with the overhead cams ? , I see what you are saying about the fact they are still using that proceedure..

Torque Specs. on 302

Reply #10 – November 15, 2006, 11:08:30 AM

Quote from: VictourBII;113687

That really sounds strange to Me rotating 85 to 90 degrees should have a foot Lb. torque . 01 isn't that the 4.6 with the overhead cams ? , I see what you are saying about the fact they are still using that proceedure..

I wouldnt use those 4.6 specs there TTY and will cause issue's with your TTS bolts (yes there is a differance) and they do not apply to your 5.0

Torque Specs. on 302

Reply #11 – November 15, 2006, 03:13:59 PM

After trying to educate myself I see that Sleeper is correct. You are never too old to learn something. Measuring how many degrees the bolt turns does only apply to TTY bolts.

When bolts are stretched in their "elastic" range they will return to their original length when loosened. (Standard bolts)

When they are stretched beyond the "elastic" range to the "plastic" range they will not return to their original length. They cannot be reused. (TTY bolts)

Is it possible that the 3.8 bolts are TTY? Maybe the Haynes manual is giving the 3.8 specs?

The '84 shop manual says to always use new bolts for the 3.8.
It has a four step torquing sequence, then loosen them and do the torquing sequence again.
This sounds similar to the TTY proceedure.

For the 5.0 it has a two step proceedure. Does not say to use new bolts.
Step 1: 55-65 ft-lb
Step 2: 65-72 ft-lb