Hi guys
I am hoping to tap in to some experience with custom exhaust installations. I have what I believe to be a GT Racing "European Racing Headers" equal length exhaust system for my 2.23L Type IV build.
The headers themselves are flanged and connect with short exhaust stubs which connect with the internal oval preparation in the cylinder heads with the copper ring seal. Two of these stubs sit between pushrod tubes (cylinders 1 and 4) and two sit to one side of the two pushrod tubes (2 and 3). I have two problems possibly related. Firstly I have interference between the stubs and a pushrod tube (exhaust in both cases) on cylinders 1 and 4. This has resulted in oil leaks from the tube seals due to the seal being pushed to one side.
Investigating the leaks and trying to figure where I went wrong I now realise that there are two sorts of stubs - one where the connections on the stub are perpendicular to each other and one were there is a slight angle. Ill try to show that in a picture.
So question is what am I doing wrong? Do I need to modify the stubs to give me the clearance I need, or does some trick of installation get around the issue? Do the "misaligned" stubs belong in certain positions?
Any relevant comments very much welcomed! I have been doing this for days now........its starting to hurt
Any chance the stubs that are clocked, are that way to avoid the interference with the pushrod tubes? Look at the header primaries to see if any of flanges are clocked to match the clocked stub tubes.
It's also possible the clocking of the flanges is a fabrication error, and that the interference with the pushrod tubes is a design mistake. That would seem a bit odd though. Is GT Racing still selling these? Give them a call and ask about the clocking.
I might be able to get comfortable with lightly dimpling the pushrod tubes if it gets rid of the interference, but the clocking would be tougher if the header flanges don't also have the clocking.
The exhaust studs are not inline with the axis of the exhaust port on one port of each head.
Chris
Now that is a VERY useful fact! Who would have thought that........
Many thanks. Now I know where to start looking
I have that exhaust on my car. I can get some pictures later today.
As many have mentioned, cylinders 1 and 4 stubs are dimpled to clear the push rod tubes. CFR /Tangerine has Stubs and small diameter push rod tubes to help with this. If they touch they will leak. Dimple the stubs or push rod tubs as needed for clearance
I have the same (or at least similar) euro race header setup. It looks like they have improved the quality a bit since I bought mine 10+ years ago. I didn't have any issues with clearing the pushrod tubes on the two motors I have run them on, but it looks like your stubs may be a little beefier? Hard to tell. Are your pushrods stock?
I do remember that the install was very particular about what stub pipe went where, all 4 are not identical, as well as their orientation (they wont work if rotated 180 degrees) may just be a bit of a puzzle to get everything in correctly. The 2nd motor I had mine on I did have to wind up drilling the holes in the stubs slightly larger to accommodate exhaust studs that were not perfectly straight.
Biggest issue I have had with the system the entire time I have owned it is keeping it sealed up at the collector. I after 10+ years though I have given up in that battle and just ordered a setup from @http://www.914world.com/bbs2/index.php?showuser=209 a few months ago. Worked with one of his setups on my buddies car and the construction had MUCH tighter tolerances at the slip joints.
Still a few months out on delivery but interested to see how the tri-Y setup works with the engine vs the 4-1 collector.
I think those stubs might be older, not newer. I've seen a set with that heavy cast section once before. They were welded up using a set of factory stubs cut from heat exchangers. The later ones are made by squishing a heavy wall tube and welding on tubular ears.
The ones made with factory stubs will clear the pushrod tubes when they're positioned as designed.
Did you change the color for your headers? The Eurorace headers I had looked a little different. There was another company selling European racing headers that were made improperly, but that was an issue with one of the primary pipes, not the stubs.
I will say that I fought with leaks with my Eurorace system that I never was able to get right until I ditched them and went back to SSI exchangers. I never got the slip fit collector to fit right and always had a leak there. I got it close, and could keep it sealed for a bit with hi-temp RTV, but that was always a short term fix. With the turbo muffler, it was also LOUD. Sounded mean, but would leave your ears ringing after even a short drive.
Zach
The set I bought came with some instructions. You have to match each stub with each port. I numbered each one of them so easier to track them into the right ports when removing. Stamp or etch them with an engraver. IT takes some time to figure it all out unfortunately.
Guys
Many thanks to everyone for the feedback. I am stuck with this exhaust for the time being so will have to live with the collector issue. I have however decided that the stubs are just wrong. They interfere way too much with the pushrod tubes on 1 and 4. Joel at GT Racing has been fantastic and a new set of ceramic coated stubs are headed my way. That together with machined pushrod tubes will hopefully fix this issue.
Now to go look for some super sealant that will sort the collector out......
Thanks again
IF it helps, I have a set of stubs on the world here:
http://www.914world.com/bbs2/index.php?showtopic=356610&hl=stub+pipes
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