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Head bolt torque and leaking gaskets

Started by BigT, May 22, 2023, 10:14:04 AM

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BigT

I have a major issue with leaking head gaskets and now base gaskets on a 131" crate that I installed higher compression pistons on. I'm using Fueling studs and S&S head bolts and torque to the S&S specified 45 ft lbs in the required steps. I see Feuling has the same torque specs. The head gasket leaked twice. The 1st time I thought I might have somehow screwed up and just tore the top end back down and replaced everything. The second time I had a performance shop machinist check the flatness, and he cleaned up the top of the cylinders.  Tman Performance had previously resurfaced the heads. The head gaskets are holding but now both base gaskets are leaking. I'm using a new Snap-on torque wrench so I doubt that is the issue. Is there a higher torque setting for the head bolts that people are using?

Sunny Jim

Quote from: BigT on May 22, 2023, 10:14:04 AMI have a major issue with leaking head gaskets and now base gaskets on a 131" crate that I installed higher compression pistons on. I'm using Fueling studs and S&S head bolts and torque to the S&S specified 45 ft lbs in the required steps. I see Feuling has the same torque specs. The head gasket leaked twice. The 1st time I thought I might have somehow screwed up and just tore the top end back down and replaced everything. The second time I had a performance shop machinist check the flatness, and he cleaned up the top of the cylinders.  Tman Performance had previously resurfaced the heads. The head gaskets are holding but now both base gaskets are leaking. I'm using a new Snap-on torque wrench so I doubt that is the issue. Is there a higher torque setting for the head bolts that people are using?

I use the torque sequence recommended by cometic!

BigT

#2
Quote from: Sunny Jim on May 22, 2023, 04:41:35 PM
Quote from: BigT on May 22, 2023, 10:14:04 AMI have a major issue with leaking head gaskets and now base gaskets on a 131" crate that I installed higher compression pistons on. I'm using Fueling studs and S&S head bolts and torque to the S&S specified 45 ft lbs in the required steps. I see Feuling has the same torque specs. The head gasket leaked twice. The 1st time I thought I might have somehow screwed up and just tore the top end back down and replaced everything. The second time I had a performance shop machinist check the flatness, and he cleaned up the top of the cylinders.  Tman Performance had previously resurfaced the heads. The head gaskets are holding but now both base gaskets are leaking. I'm using a new Snap-on torque wrench so I doubt that is the issue. Is there a higher torque setting for the head bolts that people are using?

I use the torque sequence recommended by cometic!
I think Cometic states 42 for a final #. I think I may have to take a closer look at the head bolts and cylinder studs to see if bolts aren't binding somehow.

FLSTFIDave

Quote from: BigT on May 22, 2023, 05:13:40 PM
Quote from: Sunny Jim on May 22, 2023, 04:41:35 PM
Quote from: BigT on May 22, 2023, 10:14:04 AMI have a major issue with leaking head gaskets and now base gaskets on a 131" crate that I installed higher compression pistons on. I'm using Fueling studs and S&S head bolts and torque to the S&S specified 45 ft lbs in the required steps. I see Feuling has the same torque specs. The head gasket leaked twice. The 1st time I thought I might have somehow screwed up and just tore the top end back down and replaced everything. The second time I had a performance shop machinist check the flatness, and he cleaned up the top of the cylinders.  Tman Performance had previously resurfaced the heads. The head gaskets are holding but now both base gaskets are leaking. I'm using a new Snap-on torque wrench so I doubt that is the issue. Is there a higher torque setting for the head bolts that people are using?

I use the torque sequence recommended by cometic!
I think Cometic states 42 for a final #. I think I may have to take a closer look at the head bolts and cylinder studs to see if bolts aren't binding somehow.


I do not remember of the top of my head the first two torque values for cometic.  The final torque is turn head bolt 90 degrees. 

I have been in discussions on weather or not that is too much.
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SP33DY

#4
I always use ARP lube on the threads and run all the head bolts on and off before I install the head. I also put a dab under the head of the bolt. S&S M-8 torque routine followed to the letter.

OldMike

I used ARP studs and bolts; the S&S bolts had some problems not long ago. My 131 is new heads and cylinders with higher compression pistons. I used Cometic gaskets, .030 and .010.
 
I used pressure lube from Jim and his instructions:


BigT

Quote from: OldMike on May 23, 2023, 10:35:31 AMI used ARP studs and bolts; the S&S bolts had some problems not long ago. My 131 is new heads and cylinders with higher compression pistons. I used Cometic gaskets, .030 and .010.
 
I used pressure lube from Jim and his instructions:


Thanks!  I have a feeling it is an issue with the S&S bolts and have a set of Feuling bolts in the mail. I'm using Feuling studs already.

ziggy24

Not sure when you bought those head bolts, but S&S had an issue with their machining process. The head bolts had crap left inside them. People were having this issue. Make sure the bolts are not bottoming out before max torque is applied and properly sealing the gasket. Also, make sure you lube the threads along with the flange of the bolts.

Sunny Jim

#8
 I use the torque sequence recommended by cometic!
[/quote]
I think Cometic states 42 for a final #. I think I may have to take a closer look at the head bolts and cylinder studs to see if bolts aren't binding somehow.

[/quote]

I do not remember of the top of my head the first two torque values for cometic.  The final torque is turn head bolt 90 degrees. 

I have been in discussions on weather or not that is too much.
[/quote]

I always use the final tension at 90 degrees.
But before I torque the head bolts, I insist on retentioning the studs into the case.

BigT

Quote from: OldMike on May 23, 2023, 10:35:31 AMI used ARP studs and bolts; the S&S bolts had some problems not long ago. My 131 is new heads and cylinders with higher compression pistons. I used Cometic gaskets, .030 and .010.
 
I used pressure lube from Jim and his instructions:


Just a follow up to my past problem. No leaks after using the suggested torque sequence and foot pounds along with Feuling head bolts.

Ohio HD

Good to know, thanks for following up.    :up:

SP33DY

I use a 12-24 drill tap (self drilling tap) to thread the oil or water holes that come out at the head gasket surface. The drill part barely scratches the inside of the hole but it serves more like a pilot to keep the tap going in straight. I only thread them about 1/2" deep. Then I install a 12-24 X 3/8" set screw with Loctite 545. I started just doing it for big bore builds but now I do it to all of them. It only takes a minute and it's cheap insurance against a potential leak later.

BigT

Quote from: SP33DY on September 15, 2023, 08:28:14 AMI use a 12-24 drill tap (self drilling tap) to thread the oil or water holes that come out at the head gasket surface. The drill part barely scratches the inside of the hole but it serves more like a pilot to keep the tap going in straight. I only thread them about 1/2" deep. Then I install a 12-24 X 3/8" set screw with Loctite 545. I started just doing it for big bore builds but now I do it to all of them. It only takes a minute and it's cheap insurance against a potential leak later.
I had T-Man weld mine up and resurface the heads.