Tom Wesenberg
Well-known member
Has any coolant been added yet? If so, be sure to drain it first, then loosen all the nuts and pull #1 stud to check the threads. If you need a helicoil then you'll have to pull the head.
Is 65 lbs torque too much for a HC head?
- Thread starter buyitsmart
- Start date
Dave in MN
Well-known member
Buyitsmart,
From my experience: Your description... "When I went to 65 lbs stud #1 seems to spin rather loosely for 1/8th of a turn and then it caught and held at 65 lbs. I didn't have any 'pulling' like that on the other studs." is typical of pulling a thread from the block. You may luck out as the stud grabbed and held. Subsequent re-torques may bring the stud to block connection to failure but let's hope not. (It is possible there could have been an inconsistency between the mating surfaces of the nut and the head and the offending metal yielded…causing the loose spin.)
At this point, you are not out anything to try it with stud # 1 as it is. I would do as Tom Wessenberg suggested and reduce the torque down to 55# and then warm it up as the instructions with the gasket suggest. Heads up: After warming it up at a starting torque of 55#, the torque will drop between 5-10# as it cools.
If you want to follow normal convention: After the warming cycle, with the engine stone cold, start with stud # 1 and back the nut off 15 to 20 degrees and immediately bring it back up to 55#. Move to #2 stud and do the same...continue through the proper sequence until you have all of them re-torqued.
Important: Each time you re-torque the head, note the position of the torque wrench on each stud before you loosen the nut to start the procedure. As you bring the torque back up to 55#, note if the wrench passes the initial position of the wrench. If it goes past, the gasket is still seating. If the re-torqued position is equal to the starting position, the gasket has seated.
Fire ring crush: The gasket you are using has a metal "fire ring" surrounding each combustion chamber. This ring is compressed or "crushed" when the head is torqued. Taking the torque to 65# may have crushed the ring beyond rebound tolerances if you loosen it to 55#. If this is the case, you may have a bit of combustion gas leaking into the cooling system or an adjoining cylinder. Watch for bubbles rising in the radiator...if there are no bubbles...you may be good to go. Drive it but check for bubbles for the first couple hundred miles as it may take a while for the bubbles to show. They have to make their way past the silicone seals at the water pasages. If you have bubbles, start over and replace the gasket. Use the same studs and nuts. If combustion gas is leaking into an adjoining cylinder, you will experience a rough running engine. If the engine is not running smoothly, the leaking can be confirmed with a compression test or cylinder leak down test. The fix is the same...replace the head gasket.
If the #1 stud will not hold, you will need to remove the head to install a Helicoil. Before you remove the head, consider drilling the hole for the Helicoil tap with the head still on the car. The installed head will properly align the drill bit as to perpendicular and center. The last thing you want is a misaligned grade 8 stud fighting you as you try to slide the head over the studs. Drilling the block with the head on the car will also eliminate any chance of getting metal cuttings in a cylinder. Plug the spark plug holes to avoid chips entering the cylinders. Blow out the chips from the hole prior to removing the head. Be careful to only drill to the existing depth. Measure or guage the depth of the existing hole from the top of the head boss and then transfer the depth to the drill bit. Wrap some tape around the drill bit with the edge of the tape at the proper depth so you have a reference to the top of the boss when drilling. Use a sharp bit for drilling the hole for the tap as a dull drill will most likely oversize the hole. The OD of the Helicoil tap is greater than the stud hole ID of the head, so you will need to remove it to tap the newly sized hole. Be very careful to have the Helicoil tap perpendicular to the top of the block when tapping. Don't fret over the use of a Helicoil...I think a Helicoil in the block is much stronger than the original cast iron threads.
At this point, anything that has happened can be fixed…don’t fret. A 7/16" NC Helicoil kit is around $22.00 on ebay.
Auction # 380272068452
A gasket is around $30.00....worst case...About $60.00 to recover...I've had much worse.
Take one step at a time and work through it.
Good luck!
From my experience: Your description... "When I went to 65 lbs stud #1 seems to spin rather loosely for 1/8th of a turn and then it caught and held at 65 lbs. I didn't have any 'pulling' like that on the other studs." is typical of pulling a thread from the block. You may luck out as the stud grabbed and held. Subsequent re-torques may bring the stud to block connection to failure but let's hope not. (It is possible there could have been an inconsistency between the mating surfaces of the nut and the head and the offending metal yielded…causing the loose spin.)
At this point, you are not out anything to try it with stud # 1 as it is. I would do as Tom Wessenberg suggested and reduce the torque down to 55# and then warm it up as the instructions with the gasket suggest. Heads up: After warming it up at a starting torque of 55#, the torque will drop between 5-10# as it cools.
If you want to follow normal convention: After the warming cycle, with the engine stone cold, start with stud # 1 and back the nut off 15 to 20 degrees and immediately bring it back up to 55#. Move to #2 stud and do the same...continue through the proper sequence until you have all of them re-torqued.
Important: Each time you re-torque the head, note the position of the torque wrench on each stud before you loosen the nut to start the procedure. As you bring the torque back up to 55#, note if the wrench passes the initial position of the wrench. If it goes past, the gasket is still seating. If the re-torqued position is equal to the starting position, the gasket has seated.
Fire ring crush: The gasket you are using has a metal "fire ring" surrounding each combustion chamber. This ring is compressed or "crushed" when the head is torqued. Taking the torque to 65# may have crushed the ring beyond rebound tolerances if you loosen it to 55#. If this is the case, you may have a bit of combustion gas leaking into the cooling system or an adjoining cylinder. Watch for bubbles rising in the radiator...if there are no bubbles...you may be good to go. Drive it but check for bubbles for the first couple hundred miles as it may take a while for the bubbles to show. They have to make their way past the silicone seals at the water pasages. If you have bubbles, start over and replace the gasket. Use the same studs and nuts. If combustion gas is leaking into an adjoining cylinder, you will experience a rough running engine. If the engine is not running smoothly, the leaking can be confirmed with a compression test or cylinder leak down test. The fix is the same...replace the head gasket.
If the #1 stud will not hold, you will need to remove the head to install a Helicoil. Before you remove the head, consider drilling the hole for the Helicoil tap with the head still on the car. The installed head will properly align the drill bit as to perpendicular and center. The last thing you want is a misaligned grade 8 stud fighting you as you try to slide the head over the studs. Drilling the block with the head on the car will also eliminate any chance of getting metal cuttings in a cylinder. Plug the spark plug holes to avoid chips entering the cylinders. Blow out the chips from the hole prior to removing the head. Be careful to only drill to the existing depth. Measure or guage the depth of the existing hole from the top of the head boss and then transfer the depth to the drill bit. Wrap some tape around the drill bit with the edge of the tape at the proper depth so you have a reference to the top of the boss when drilling. Use a sharp bit for drilling the hole for the tap as a dull drill will most likely oversize the hole. The OD of the Helicoil tap is greater than the stud hole ID of the head, so you will need to remove it to tap the newly sized hole. Be very careful to have the Helicoil tap perpendicular to the top of the block when tapping. Don't fret over the use of a Helicoil...I think a Helicoil in the block is much stronger than the original cast iron threads.
At this point, anything that has happened can be fixed…don’t fret. A 7/16" NC Helicoil kit is around $22.00 on ebay.
A gasket is around $30.00....worst case...About $60.00 to recover...I've had much worse.
Take one step at a time and work through it.
Good luck!
Last edited:
buyitsmart
Member
I spoke with Tom at Snyder's. He said that normally he would say, since I have reached 65 lbs, stay with it. It won't make much of a difference.
However, since stud #1 slipped he recommends going down to 55 lbs. Just like you guys recommended.
I am going down to 55 lbs and then starting the car.
Hopefully everything will be fine.
The best thing I got going for me is that my worst case scenario isn't so bad.
Stud #1 is an easy one to get to with the engine in the car.
I will keep you updated.
Thanks for your input.
However, since stud #1 slipped he recommends going down to 55 lbs. Just like you guys recommended.
I am going down to 55 lbs and then starting the car.
Hopefully everything will be fine.
The best thing I got going for me is that my worst case scenario isn't so bad.
Stud #1 is an easy one to get to with the engine in the car.
I will keep you updated.
Thanks for your input.
buyitsmart
Member
All is well. I backed everything down to 55 lbs and it is holding.
The car runs strong!!
I'm excited.
It is in the cool down stage now and when it is cool I will re-torque.
Thanks.
The car runs strong!!
I'm excited.
It is in the cool down stage now and when it is cool I will re-torque.
Thanks.