jeepguy1948
Well-known member
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.
Bolt Torque?
- Thread starter jeepguy1948
- Start date
J Franklin
Well-known member
Just cinch it up, maybe with a drop of blue lockTite for peace of mind. 55# seems unnecessary.
J Franklin
Well-known member
Can you explain why?
J Franklin
Well-known member
This is basically the way it was done at the Rouge plant.
nkaminar
Well-known member
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.
"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.
Last edited:
Y-Blockhead
Well-known member
nkaminar
Well-known member
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."
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."
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updraught
Well-known member
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.
"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.