The Ford Barn

jeepguy1948 · 05-10-2026, 11:56 AM

What is the proper torque for the bolts that hold the flywheel housing to the engine block? I have 55 Lb in my head, is that correct? Thanks.

J Franklin · 05-10-2026, 01:27 PM

Just cinch it up, maybe with a drop of blue lockTite for peace of mind. 55# seems unnecessary.

nkaminar · 05-10-2026, 02:55 PM

I used 60 foot-pounds on my Burtz engine.

Oldgearz · 05-10-2026, 04:16 PM

I use a 3/8" rachet with regular handle, and just pull it up tight. Good enough for me.

J Franklin · 05-11-2026, 11:32 AM

Quote:

Originally Posted by nkaminar

I used 60 foot-pounds on my Burtz engine.

Can you explain why?

J Franklin · 05-11-2026, 11:34 AM

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Quote:

Originally Posted by Oldgearz

I use a 3/8" rachet with regular handle, and just pull it up tight. Good enough for me.

This is basically the way it was done at the Rouge plant.

nkaminar · 05-11-2026, 04:28 PM

Per the Burtz instruction manual:

"Flywheel Attachment Bolts
"Instead of using the original 7/16 UNF x 13/16-inch-long flywheel attachment
bolts, we recommend 7/16 UNF x 1.25-inch-long Grade 8 bolts (McMaster Carr
92620A697) or equivalent with Blue Loctite Threadlocker and a torque of 55 lb-ft."

With the grade 8 bolts and Burtz crankshaft, I elected to use 60 foot-pounds torque. There was not enough room for any lock washers and the heads on the bolts were not drilled for safety wire. I used the Threadlocker but wanted a little more torque as a slight increase in the factor of safety.

The flywheel face runout should be checked after it is installed. Installing the flywheel and checking the face runout is best done with the engine in a engine stand and nose down. The flange on the crankshaft and the the flange on the flywheel should be clean as any dirt or debris can lead to runout. The bolts need to be torqued to make sure that the flywheel and crankshaft are mated securely. The torque on the bolts should be brought up in increments and in a cross pattern. The face runout should be 0.003 or less. If your runout is excessive, try mounting the flywheel 180 degrees from the current position.

Y-Blockhead · 05-11-2026, 04:41 PM

Quote:

Originally Posted by jeepguy1948

What is the proper torque for the bolts that hold the flywheel housing to the engine block? I have 55 Lb in my head, is that correct? Thanks.

Quote:

Originally Posted by nkaminar

Per the Burtz instruction manual:

"Flywheel Attachment Bolts
"Instead of using the original 7/16 UNF x 13/16-inch-long flywheel attachment
bolts, we recommend 7/16 UNF x 1.25-inch-long Grade 8 bolts (McMaster Carr
92620A697) or equivalent with Blue Loctite Threadlocker and a torque of 55 lb-ft."

With the grade 8 bolts and Burtz crankshaft, I elected to use 60 foot-pounds torque. There was not enough room for any lock washers and the heads on the bolts were not drilled for safety wire. I used the Threadlocker but wanted a little more torque as a slight increase in the factor of safety.

OP was asking about the flywheel housing, not the flywheel.

nkaminar · 05-12-2026, 04:54 AM

Opps.

The flywheel housing bolts should be 55 foot-pounds. Here is what Burtz says:

"Flywheel Housing/Cylinder Block Attachment Bolts
"When using an original flywheel housing that is 1/2-inch thick at the 4 lower attachment bolts, use the original 7/16 UNC × 1 1/16-inch long bolts. If using our new flywheel housing that is 7/8-inch thick at the 4 lower attachment bolts, use 7/16 UNC x 1 1/2-inch long Grade 8 bolts (McMaster Carr 92620A673). With either the original or the new flywheel housing, use the original 7/16 UNC × 1 11/16-inch-long bolts. A torque of 55 Ib-ft is recommended.

"For judging, lock washers are required at the 2 upper bolts, and we recommend
Blue Loctite Threadlocker for the 4 lower attachment bolts."

updraught · 05-12-2026, 07:40 PM

AI Overview

"The Ford Model A flywheel housing-to-block bolts should be torqued to approximately 55 ft-lbs. These 12 bolts secure the cast iron housing to the engine block, and it is recommended to use a star pattern to ensure even pressure during tightening.Flywheel Housing to Block: ~55 ft-lbsFlywheel to Crankshaft Bolts: 65-80 ft-lbs (using Locktite is essential)It is crucial to use a gasket between the housing and the block. Some builders prefer to use a slightly lower torque (around 45-50 ft-lbs) to avoid cracking the older, brittle cast iron housing, but 55 ft-lbs is the commonly cited specification for proper securement."

From my reading, bolt torque settings only came out during WW2.

05-10-2026, 11:56 AM	#1
jeepguy1948 Senior Member Join Date: Jan 2022 Posts: 1,049	Bolt Torque? What is the proper torque for the bolts that hold the flywheel housing to the engine block? I have 55 Lb in my head, is that correct? Thanks.

05-10-2026, 01:27 PM	#2
J Franklin Senior Member Join Date: May 2010 Location: Oregon Posts: 6,586	Re: Bolt Torque? Just cinch it up, maybe with a drop of blue lockTite for peace of mind. 55# seems unnecessary.

05-10-2026, 02:55 PM	#3
nkaminar Senior Member Join Date: Jan 2012 Location: Western North Carolina Posts: 6,855	Re: Bolt Torque? I used 60 foot-pounds on my Burtz engine. __________________ A is for apple, green as the sky. Step on the gas, for tomorrow I die. Forget the brakes, they really don't work. The clutch always sticks, and starts with a jerk. My car grows red hair, and flies through the air. Driving's a blast, a blast from the past.

05-10-2026, 04:16 PM	#4
Oldgearz Senior Member Join Date: Aug 2020 Location: Sagle, Idaho Posts: 417	Re: Bolt Torque? I use a 3/8" rachet with regular handle, and just pull it up tight. Good enough for me.

05-11-2026, 04:28 PM	#7
nkaminar Senior Member Join Date: Jan 2012 Location: Western North Carolina Posts: 6,855	Re: Bolt Torque? Per the Burtz instruction manual: "Flywheel Attachment Bolts "Instead of using the original 7/16 UNF x 13/16-inch-long flywheel attachment bolts, we recommend 7/16 UNF x 1.25-inch-long Grade 8 bolts (McMaster Carr 92620A697) or equivalent with Blue Loctite Threadlocker and a torque of 55 lb-ft." With the grade 8 bolts and Burtz crankshaft, I elected to use 60 foot-pounds torque. There was not enough room for any lock washers and the heads on the bolts were not drilled for safety wire. I used the Threadlocker but wanted a little more torque as a slight increase in the factor of safety. The flywheel face runout should be checked after it is installed. Installing the flywheel and checking the face runout is best done with the engine in a engine stand and nose down. The flange on the crankshaft and the the flange on the flywheel should be clean as any dirt or debris can lead to runout. The bolts need to be torqued to make sure that the flywheel and crankshaft are mated securely. The torque on the bolts should be brought up in increments and in a cross pattern. The face runout should be 0.003 or less. If your runout is excessive, try mounting the flywheel 180 degrees from the current position. __________________ A is for apple, green as the sky. Step on the gas, for tomorrow I die. Forget the brakes, they really don't work. The clutch always sticks, and starts with a jerk. My car grows red hair, and flies through the air. Driving's a blast, a blast from the past. Last edited by nkaminar; 05-11-2026 at 04:45 PM.

05-12-2026, 04:54 AM	#9
nkaminar Senior Member Join Date: Jan 2012 Location: Western North Carolina Posts: 6,855	Re: Bolt Torque? Opps. The flywheel housing bolts should be 55 foot-pounds. Here is what Burtz says: "Flywheel Housing/Cylinder Block Attachment Bolts "When using an original flywheel housing that is 1/2-inch thick at the 4 lower attachment bolts, use the original 7/16 UNC × 1 1/16-inch long bolts. If using our new flywheel housing that is 7/8-inch thick at the 4 lower attachment bolts, use 7/16 UNC x 1 1/2-inch long Grade 8 bolts (McMaster Carr 92620A673). With either the original or the new flywheel housing, use the original 7/16 UNC × 1 11/16-inch-long bolts. A torque of 55 Ib-ft is recommended. "For judging, lock washers are required at the 2 upper bolts, and we recommend Blue Loctite Threadlocker for the 4 lower attachment bolts." __________________ A is for apple, green as the sky. Step on the gas, for tomorrow I die. Forget the brakes, they really don't work. The clutch always sticks, and starts with a jerk. My car grows red hair, and flies through the air. Driving's a blast, a blast from the past. Last edited by nkaminar; 05-12-2026 at 05:00 AM.

05-12-2026, 07:40 PM	#10
updraught Senior Member Join Date: Feb 2015 Location: Australia Posts: 2,289	Re: Bolt Torque? AI Overview "The Ford Model A flywheel housing-to-block bolts should be torqued to approximately 55 ft-lbs. These 12 bolts secure the cast iron housing to the engine block, and it is recommended to use a star pattern to ensure even pressure during tightening.Flywheel Housing to Block: ~55 ft-lbsFlywheel to Crankshaft Bolts: 65-80 ft-lbs (using Locktite is essential)It is crucial to use a gasket between the housing and the block. Some builders prefer to use a slightly lower torque (around 45-50 ft-lbs) to avoid cracking the older, brittle cast iron housing, but 55 ft-lbs is the commonly cited specification for proper securement." From my reading, bolt torque settings only came out during WW2.