Header collector bolts loosening constantly

FoundNemo · 10-01-2021, 07:36 AM

Anyone have some tips/tricks for header bolts near the collector (CSP) loosening frequently? Lock washers are in use and some loctite blue but no dice, still seems to loosen pretty quickly over time.

Vigilante375 · 10-01-2021, 08:46 AM

Blue loctite, or anything like it, will just melt away with the temps.

I think most people use anti size, torque to the correct spec and are good to go.

I'm not sure what the torque spec is but what are torque are you seeing them to?

EV2DEMON · 10-01-2021, 09:09 AM

Get rid of the lock washers and use thick, flat washers.

Camaro1973 · 10-01-2021, 09:38 AM

Quote:

Originally Posted by FoundNemo

Anyone have some tips/tricks for header bolts near the collector (CSP) loosening frequently? Lock washers are in use and some loctite blue but no dice, still seems to loosen pretty quickly over time.

What bolts are you using? If using the stainless bolts that came with them or other stainless bolts, no Good. Use grade 8 2 1/2” bolts with flat and lock washer, they won’t come loose. I went over this in another post.

overdriv · 10-01-2021, 09:46 AM

Get a set of Percy's multi layer aluminum gaskets. I have them om several cars, no leaks an no loose bolts.

Evansa22 · 10-01-2021, 11:21 AM

Quote:

Originally Posted by Camaro1973

What bolts are you using? If using the stainless bolts that came with them or other stainless bolts, no Good. Use grade 8 2 1/2” bolts with flat and lock washer, they won’t come loose. I went over this in another post.

You happen to know the diameter of the bolts?

Camaro1973 · 10-01-2021, 11:39 AM

Quote:

Originally Posted by overdriv

Get a set of Percy's multi layer aluminum gaskets. I have them om several cars, no leaks an no loose bolts.

This is a ball flange connection with 2 bolts, there’s no gaskets.

Camaro1973 · 10-01-2021, 11:39 AM

Quote:

Originally Posted by Evansa22

You happen to know the diameter of the bolts?

3/8 x 2 1/2” Grade 8 Flange Bolts

FoundNemo · 10-01-2021, 01:13 PM

Quote:

Originally Posted by Camaro1973

3/8 x 2 1/2” Grade 8 Flange Bolts

Thats what I am using, Grade 8 not stainless and they keep coming loose. Antiseize to hold them tight? I can try with flat washers too if that will help.

FoundNemo · 10-01-2021, 01:14 PM

Quote:

Originally Posted by Camaro1973

What bolts are you using? If using the stainless bolts that came with them or other stainless bolts, no Good. Use grade 8 2 1/2” bolts with flat and lock washer, they won’t come loose. I went over this in another post.

So flat washer first against the flange, then lock washer against the flat and the bolt through them? Will give that a shot now.

SFV1LE · 10-01-2021, 02:18 PM

For any header or other ultra high temp exhaust application like this (like a turbo hotside) I recommend Stage 8 locking fasteners.

https://www.stage8.com/

Once installed correctly they cannot loosen, they're mechanically locked and easy to remove.

Another option are Nord-lock washers, they work well too but not as 100% certain.

https://www.nord-lock.com/nord-lock/products/washers/

Evansa22 · 10-01-2021, 02:26 PM

Quote:

Originally Posted by Camaro1973

3/8 x 2 1/2” Grade 8 Flange Bolts

Thanks

Camaro1973 · 10-01-2021, 04:23 PM

Quote:

Originally Posted by FoundNemo

Thats what I am using, Grade 8 not stainless and they keep coming loose. Antiseize to hold them tight? I can try with flat washers too if that will help.

They should not be coming loose. Make sure the rest of the exhaust is tight and there’s no slop that could vibrate either your cat pipe or off-road pipe. Should be no Movement. If there’s movement the ball socket can move which would have an effect on the tightness of the bolts.

Flat washer on the flange side, lock washer nut side. Crank them down until they are tight, but don’t bend the flanges.

JonDaddy82 · 10-01-2021, 05:03 PM

Safety wire? Commonly used in motorcycle road race applications.

10-01-2021, 07:36 AM	#1
FoundNemo Drives: 2019 ZL1 Join Date: Oct 2019 Location: GA Posts: 573	Header collector bolts loosening constantly Anyone have some tips/tricks for header bolts near the collector (CSP) loosening frequently? Lock washers are in use and some loctite blue but no dice, still seems to loosen pretty quickly over time.

10-01-2021, 02:18 PM	#11
SFV1LE Drives: 2018 Hyper Blue ZL1 1LE Join Date: Dec 2018 Location: CA Posts: 1,360	Stage 8 Locking Fasteners For any header or other ultra high temp exhaust application like this (like a turbo hotside) I recommend Stage 8 locking fasteners. https://www.stage8.com/ Once installed correctly they cannot loosen, they're mechanically locked and easy to remove. Another option are Nord-lock washers, they work well too but not as 100% certain. https://www.nord-lock.com/nord-lock/products/washers/

10-01-2021, 05:03 PM	#14
JonDaddy82 Drives: 2018 ZL1 Coupe NFG M6 Join Date: May 2017 Location: Nolensville, TN Posts: 618	Safety wire? Commonly used in motorcycle road race applications. __________________ 1989 Forumla 350 WS6 <- High School 2000 Trans Am Firehawk <- After High School 2017 Colorado Z71 <- Daily 2018 ZL1 M6 <- Not Daily

10-01-2021, 08:46 AM	#2
Vigilante375 Drives: 2018 Camaro ZL1 Join Date: Aug 2018 Location: Georgia Posts: 1,370	Blue loctite, or anything like it, will just melt away with the temps. I think most people use anti size, torque to the correct spec and are good to go. I'm not sure what the torque spec is but what are torque are you seeing them to?

10-01-2021, 09:09 AM	#3
EV2DEMON Drives: 2004 Z06, 2017 1LE Join Date: May 2017 Location: Indiana Posts: 57	Get rid of the lock washers and use thick, flat washers.

10-01-2021, 09:46 AM	#5
overdriv Drives: 1969 Chevelle SS 2019 2SS Camaro Join Date: Jul 2018 Location: IL Posts: 246 View My Garage	Get a set of Percy's multi layer aluminum gaskets. I have them om several cars, no leaks an no loose bolts.

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