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308 Exhaust headers through guards

Posted: Sun Jun 04, 2017 11:45 am
by Bawag
Thought I would try here before going CRS, just chasing a set of headers for a 308 into an FB EK the ones that exit through the guards.

Image

Cheers Ben
0405 378 448


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Re: 308 Exhaust headers through guards

Posted: Sun Jun 04, 2017 4:06 pm
by TAZ
how much are they to buy?

Re: 308 Exhaust headers through guards

Posted: Sun Jun 04, 2017 6:17 pm
by bumper
Bawag wrote: Sun Jun 04, 2017 11:45 am Thought I would try here before going CRS, just chasing a set of headers for a 308 into an FB EK the ones that exit through the guards.

Image

Cheers Ben
0405 378 448


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Spend a few extra $$$$ and get an exhaust shop to fabricate a custom set and tuck them down, looks heaps better
Image

Re: 308 Exhaust headers through guards

Posted: Sun Jun 04, 2017 7:17 pm
by Blacky
PM Jamie - EKDV8 - on the forum , he is selling a set .

Re: 308 Exhaust headers through guards

Posted: Sun Jun 04, 2017 7:24 pm
by Bawag
TAZ wrote:how much are they to buy?
I think they are about $680




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Re: 308 Exhaust headers through guards

Posted: Sun Jun 04, 2017 7:27 pm
by Bawag
bumper wrote:
Bawag wrote: Sun Jun 04, 2017 11:45 am Thought I would try here before going CRS, just chasing a set of headers for a 308 into an FB EK the ones that exit through the guards.

Image

Cheers Ben
0405 378 448


Sent from my iPhone using Tapatalk
Spend a few extra $$$$ and get an exhaust shop to fabricate a custom set and tuck them down, looks heaps better
Image

That does look good!! I was considering making them myself but I was just looking into the easy option ;) for now anyway


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Re: 308 Exhaust headers through guards

Posted: Mon Jun 05, 2017 3:02 pm
by Harv
G'day Bawag,

I've recently fitted a set of CRS fenderwell headers to my SBC, for my wagon project. Some photos here:
http://www.fbekholden.com/forum/viewtop ... 11&t=21653

I chose the CRS headers as they are off-the-shelf - I can't weld, and wanted a simple solution to get my project moving. The construction of my headers was OK, and the pricing similar to what you would pay for the 308 ones. They fit to the engine pretty well, though I am not too happy with No. 8 cylinder. To clear the steering shaft, CRS directs No. 8 "straight up", with almost no horizontal pipe out of the port. This is going to strangle No. 8 somewhat compared to the other cylinders.

What I thought would be an easy bolt-up was not so easy in practice. There were no decent templates for the holes in the inner guards, which vary dramatically depending on what front-end and engine mounts are used. It was a case of looking at other cars, crossing my fingers, cutting a hole to start with then fit, remove, cut more, fit, remove, cut more...... I got there in the end, but it takes time. Remember that the engine rocks when you push the loud pedal, so you need a bigger hole to allow for the rocking (you work that out after the headers hit the guards the first time :oops: ).

Another issue that I didn't think of is that NCOP may require reinforcement. Section LA 2.7 indicates "Where an exhaust system runs through an inner mudguard panel, the panel cut-out must not weaken the inner guard and if necessary, the panel must be reinforced to compensate for the cutout. Exhaust systems passing through inner guard panels must clear the wheels, tyres and suspension components over the full range of travel of the suspension and steering.". My engineer took the view that the big exhaust cuts weakened the inner guard as they are very, very close to the box sections of the subframe. I had to shape and weld in reinforcing rod all the way around the edge of the cutout (or at least Dave did... thankfully he can weld).

I found the headers generated a fair amount of heat, and needed some form of insulation (don't ask how I found that one out :oops:... thankfully I can rewire a car even though I cannot weld). I was too stingy to ceramic coat the headers, so used header wrap. Happy with the results so far, but again the insulation (or ceramic coating) adds extra cost.

My headers don't clash with the wheels or steering, but they do clash with the brake hoses. I needed to add HR Holden "brake hose spring thingies" from Rare Spares to stop the brake hoses rubbing on the exhaust. You can see these in my thread above.

All up, if I had my time again I'd get an exhaust shop to make up a custom set, and run them beside the block.

Cheers,
Harv

Re: 308 Exhaust headers through guards

Posted: Mon Jun 05, 2017 3:36 pm
by Bawag
Harv wrote:G'day Bawag,

I've recently fitted a set of CRS fenderwell headers to my SBC, for my wagon project. Some photos here:
http://www.fbekholden.com/forum/viewtop ... 11&t=21653

I chose the CRS headers as they are off-the-shelf - I can't weld, and wanted a simple solution to get my project moving. The construction of my headers was OK, and the pricing similar to what you would pay for the 308 ones. They fit to the engine pretty well, though I am not too happy with No. 8 cylinder. To clear the steering shaft, CRS directs No. 8 "straight up", with almost no horizontal pipe out of the port. This is going to strangle No. 8 somewhat compared to the other cylinders.

What I thought would be an easy bolt-up was not so easy in practice. There were no decent templates for the holes in the inner guards, which vary dramatically depending on what front-end and engine mounts are used. It was a case of looking at other cars, crossing my fingers, cutting a hole to start with then fit, remove, cut more, fit, remove, cut more...... I got there in the end, but it takes time. Remember that the engine rocks when you push the loud pedal, so you need a bigger hole to allow for the rocking (you work that out after the headers hit the guards the first time :oops: ).

Another issue that I didn't think of is that NCOP may require reinforcement. Section LA 2.7 indicates "Where an exhaust system runs through an inner mudguard panel, the panel cut-out must not weaken the inner guard and if necessary, the panel must be reinforced to compensate for the cutout. Exhaust systems passing through inner guard panels must clear the wheels, tyres and suspension components over the full range of travel of the suspension and steering.". My engineer took the view that the big exhaust cuts weakened the inner guard as they are very, very close to the box sections of the subframe. I had to shape and weld in reinforcing rod all the way around the edge of the cutout (or at least Dave did... thankfully he can weld).

I found the headers generated a fair amount of heat, and needed some form of insulation (don't ask how I found that one out :oops:... thankfully I can rewire a car even though I cannot weld). I was too stingy to ceramic coat the headers, so used header wrap. Happy with the results so far, but again the insulation (or ceramic coating) adds extra cost.

My headers don't clash with the wheels or steering, but they do clash with the brake hoses. I needed to add HR Holden "brake hose spring thingies" from Rare Spares to stop the brake hoses rubbing on the exhaust. You can see these in my thread above.

All up, if I had my time again I'd get an exhaust shop to make up a custom set, and run them beside the block.

Cheers,
Harv
Thanks heaps for the advice I'll have another look into making some


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Re: 308 Exhaust headers through guards

Posted: Mon Jun 05, 2017 4:57 pm
by Craig Allardyce
Harv I wouldn't get too worried about restriction issues. I was gobsmacked when I saw the end results in this video.

https://www.youtube.com/watch?v=azPKIjxmmdU

Re: 308 Exhaust headers through guards

Posted: Mon Jun 05, 2017 5:37 pm
by Harv
Aaahhh.....watching those guys swing a sledgehammer with the headers still on the heads made my teeth hurt :sick: . Makes me feel better about my No. 8 tube though :D .

Cheers,
Harv

Re: 308 Exhaust headers through guards

Posted: Mon Jun 05, 2017 7:06 pm
by Errol62
I found fitting extractors to a Red Six in the sedan more than challenging enough. As Harv says heat is an issue. Eventually they cracked and started leaking.

If one simply must have a v8 it would be nice if there was a good ol cast iron solution with half decent flow. It should still sound good with a mild cam and sports exhaust. A lot tidier if it could be done. Jus mi too sents werth.


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Re: 308 Exhaust headers through guards

Posted: Mon Jun 05, 2017 10:39 pm
by In the Shed
Harv wrote: Mon Jun 05, 2017 5:37 pm Aaahhh.....watching those guys swing a sledgehammer with the headers still on the heads made my teeth hurt :sick: . Makes me feel better about my No. 8 tube though :D .

Cheers,
Harv
Not to mention them hitting the faces of two hammers together!