Thread: Project Sebring GT Spyder

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Mike, I'm trying real hard to resist the urge to fire the engine up now. Sure is hard though. A couple of days and it could be running, but I want to wait until I can drive it a little to seat the rings. I will most likely fire it up in the bare chassis just before I stick the body back on.

I’ve done a little head porting over the years, but I’m certainly not an expert. Mostly pocket porting and cleaning up the ports in SBC heads. It’s not real fun and it takes hours and hours. These manifolds were no exception. As a matter of fact, they were worse. Normally with cast iron heads you just get a lot of dust, but these things were steel. Attack a piece of steel with a burr and you get thousands of needle like slivers of metal and, of course, the steel didn’t cut nearly as easily as cast iron.





This is just part of the pile of slivers I wound up with and of course they were magnetized, so that they stood up nicely, like some medieval torture device, on every piece of iron they came in contact with. I’m not sure why these things get magnetized, but it seems like I have a problem with that in my shop. Maybe it’s the welding. Maybe it’s just related to the act of cutting. I dunno.



These are my tools of port destruction. Not shown are the fine tweezers that I was constantly using to pull shards of metal out of my hands. Yeah, I probably should wear gloves, but they don’t let me feel the cutting action like I want to. I did use a full face shield, though. I may be dumb, but I ain’t crazy! Yet, that is! I’m not sure I would attack a set of these things again, but I got it done. I used an air die grinder that I fitted with a short hose and regulator. That way I could alter the speed of the grinder by adjusting air pressure and not by trying to modulate the trigger on the grinder. That works better for me since it can get tiring trying to hold a constant speed for hours and you will burn up a lot of cutters with high speed.







Here is what they looked like before and after opening them up. You can see in the top two pictures how much had to be removed. No, they are not completely round. In a few places the ports fell outside the radius of the gasket opening and I called that good enough. No need to waist energy making them round. I did blend and polish the openings after enlarging them.

I also cleaned them up as far as I could reach beyond the short turn radius, removing quite a few lumps and bumps along the way. Some folks with a lot more experience than me will probably say I was just wasting my time with all this effort for pair of stock manifolds. Maybe there wasn’t a lot to be gained here, but I just couldn’t leave that sharp edge facing the exhaust port. What little I know of fluid dynamics says that’s a flow killer since it causes turbulence in far greater proportion to the actual size of the step. I was already giving up HP and torque by not running long tube headers. I didn’t want to throw away more. At least the effort made me feel better about it.

The last thing I did was bead blast and paint them with VHT as cast header paint. They turned out looking good, but I may pull them after I have the engine tuned for some Jet Hot ceramic coating. That would definitely be a winter type project since the inner fenders would have to come out to remove them after the body goes on. That’s why I went to all the trouble making so many parts easily removable. It’s the only way I will ever be able to service some things.





I installed them with Remflex gaskets. The stock gasket is on the top in the picture. I’ve never used the Remflex brand before, but they got rave reviews on some other LS specific forums. They are thick, well made of some high tech material and look like they will seal up well. I will eventually install Stage 8 locking fasteners. Accessing the manifolds to tighten a loose manifold bolt would be a pain, so I popped for the Stage 8’s. Maybe they will help prevent loosening. I will probably run the gaskets through a couple of heat cycles and retorque before installing the locking tabs on the bolts.



Here they are finally on the car with the stock heat shields. They fit perfectly and the shields should help keep the footwells a little cooler.

Sorry for the long post.

Heck, please don't apologize for a long post! it's great reading!! especially with this mornings coffee. 8-)

Nice job, they turned out really nice! I had a set of headers jet coated for my v8 miata and they are pretty rusty now so I don't know what to think about that stuff. It would be interesting to hear other peoples long term experience with it.

I had these done by Jet Hot about 10 years ago, promptly cooked the finish tuning the EFI and they recoated them free. I've seen some light surface rust a few times, but a bit of Mother's polish fixes it.
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Yeah, I've cooked ceramic coated headers a couple of times myself. Only learned recently that the coating is recommended to be done after break in and tuning. That came directly from JetHot. Also, you are supposed to run it through a couple of mild heat cycles before running them. That's really hard to do if you're breaking in a flat tappet cam and the mixture or timing is a little off. I'll bet a lot of the precoated headers that are sold get torched on initial startup.

Mine was on a relatively stock mustang 5.0 with stock EFI, so tuning was not an issue. I was considering coating my Stude headers I built because some of the "stainless" was of questionable quality and gets surface rust. It's just expensive to do and if it rusts anyway maybe not worth it. Ok, I'm done hijacking your thread, keep up the great work.

Well gang, I'm laid up for a while yet again. I was informed by the rhythm specialist that the medication I was on to control my afib wasn't a long term solution. It is apparently very hard on the liver and kidneys. One year max was all that is typically recommended for this particular medication. It was recommended that I have a procedure to short circuit the extra electrical pathways in my heart that commonly cause arrhythmia. Since I was already into my insurance deductible for the year, I made the decision to have it done now.

This was a 4 hour procedure. That is the longest anesthesia I have ever had and the after effect wasn't pleasant. I do appear to be on the mend, though. I'm on severe restrictions for the next week while I heal. I hate that, since I was making great progress on the car and could have used that time.

I do have some older stuff I will try and get posted next week if I can find the right pictures. Not much else to do.

Good you're dealing with it, ignoring that kind of stuff never turns out well. The hot rod will wait.

Yep, gotta take care of you first, then figure out what needs to be done on the car! Hope things continue to improve on the health front!

Well.. that's a bugger as Johnboy says. but you're on the mend and that's what's important right?. The car, and us, we'll be here when ever you're ready.

There's aroha coming your way from New Zealand too.
I hear you on the restrictions and 'wasted' time too. I know I'd be driven nuts with enforced idleness, I've got to be doing something! Anything!
But as has been said, your wellbeing must be the top priority.

And it is a bit of a bugger.

Look after yourself.
Top priority.

Thanks guys! I appreciate the support. Unfortunately, cardiac issues run in my family, so genetics was bound to catch up with me sooner or later. At least modern medicine has the potential to correct things without too much downtime. Truly, after the meds had my arrhythmia under control, I felt better than I had felt in many years. I still have to take them while my heart heals, but if the procedure takes, I will be able to get off them and the blood thinners.

I'm confident that this will just be a bump in the road.

I feel for you. Fortunately you didn't have to have a valve replacement. take it easy, the car will wait we'll look forward to your progress when you get to feeling better.

For a moment the child side of me wants to write.... are "we" there yet? Sorry.. it just slips out! LOL 8-)

Good you got it taken care of and hope the healing time goes well and quickly for you!