24V headers

Jim K
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Re: 24V headers

Post by Jim K » Tue Apr 15, 2014 6:52 am

The #1 reason I don't like the upward curving headers. I have yet to think of a valid reason for their existence! The heat shield you see in my 24v car is a sandwich containing an insulator. I cut it out from a large protection piece from some new Alfa. Note that the small starter has its own shield also. I can't fathom why many V6's don't have these starter shields -or do the mechanics leave them out?
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kevin
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Re: 24V headers

Post by kevin » Wed Apr 16, 2014 4:06 am

That's neat . I must start collecting old heat shields. Most of all the factory heat shields have been lost . I'm not sure how much it helps but it try wrap the solenoid and starter with heat shield wrap hoping for it to reflect heat . Also the fuel pipes on the GTV come up lose here so I also wrap those just to keep the fuel cooler .
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Jim K
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Re: 24V headers

Post by Jim K » Wed Apr 16, 2014 4:52 am

I'd say that wrapping a functional component like the starter is not good, as it also keeps the heat IN the part, not being able to radiate it. Isolating the sources of heat like exhaust manifold pipes is the right thing to do. Let everything else have the benefit of air flow.
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75evo
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Re: 24V headers

Post by 75evo » Wed Apr 16, 2014 7:31 am

Jim,

The stock 75 starter's heat shield is right up against the starter body, well partly because of the starter size. There's really not much air gap to speak of. I guess if you have the motronic starter it would make sense. BUT if your long tube headers are used, can the stock shield still be used? Didn't you say the motronic starters are mandatory then? Sounds like you need to make a custom shield or modify the stock shield to fit underneath those headers then?

Between wrapping and not wrapping the starter I'd say go for wrapping. A heat shield with an air gap is better, but wrapping is definitely better than nothing! I wrapped mine, and I can tell you for sure without wrapping sometimes the starter just clicks because the circuit going to the starter solenoid is un-relayed and the heat just makes the resistance too high. With the wrap, while not ideal, it is much better.

The other good thing to try is to ceramic coat the inside of the headers. Especially for non-stainless headers. Keeps the heat in and lengthens the lives of the headers and other things around it.
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Re: 24V headers

Post by Jim K » Wed Apr 16, 2014 9:00 am

The starter heat shield you barely see in the pic is the std 164Q4 shield for the 'small' oem starter. It fits without mods under the headers. The old big starter does NOT fit these headers.
Its a very good idea to drive the solenoid through a relay. Works much better and eliminates ignition switch wear.
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Re: 24V headers

Post by 105gta. » Sat Jan 07, 2017 1:52 am

This is my version. Taken the opportunity of peace and quiet while the workshop is closed over the Xmas break get stuck into the project
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Re: 24V headers

Post by 105gta. » Sat Jan 07, 2017 2:00 am

One from the rear, as can be seen the right hand side has to sit a little higher due to the starter motor taking up valuable space.
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KevinR
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Re: 24V headers

Post by KevinR » Sat Jan 07, 2017 4:05 pm

Great job there . Those look like 42mm OD or is it larger . I see you had to shave the web on left side of block . I did this on one of the " banana " sets I made . It's only way to make it work . I would like a set like this but then join it into a collector where you have first flange . This would be for a road track day car where you can afford to "drop" a bit of hp .
I assume you would have to bolt these on first before you drop the engine or have no studs coming off the heads . Having the smaller starter motor always helps .
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Re: 24V headers

Post by 105gta. » Sat Jan 07, 2017 5:16 pm

Hi Kevin, yeah I trimmed a little off the lower left webbing for more clearance, I could of left it but made things a little easier, they are stepped headers, 42mm for the first section nearly to the joining flange then 45mm from there past the block and below and into the collector. Tucked up as tight as I could for maximum ground clearance, same for the collectors which sit partially In the void between the bell housing and the tunnel. I made the lower sections on the car to make sure they fit. im making these to fit past the big starter ;). You can see I had to make the right flange sit lower for this reason, With room for a heat shield. Very tight but can be done. They will be ceramic coated when I'm done to help with heat and longevity. I'll be using an engine stay bar to help limit engine movement which allows a tad more usable space. Still in progress at the moment but getting there.
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Re: 24V headers

Post by gtv-racer » Tue Jan 02, 2018 10:00 am

Nice headers. Like the collector setup!
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SydneyJules
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Re: 24V headers

Post by SydneyJules » Sat Jul 21, 2018 11:22 am

They are hot!
Fixing it bit by bit....
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