This posting is one in a series. If you have not yet read the earlier postings in the series, you’ll need to, as this posting won’t make much sense without having done so! Just do a search using the word “SLURP”.
In my last posting, I covered some critical odds and ends, and mentioned that we are waiting for the return of the high tech composite mono leafsprings from Flex-a-Form. That has given me some time to address exhaust manifolds and steering. This posting I’ll cover exhaust manifolds, and next posting will be an over-the-top steering analysis.
Those ’98 Corvette exhaust manifolds that Daniel at Colvin Automotive sold me are quite high tech.
Quoting Will Handzel from his book “How to Build High-Performance Chevy LS1/LS6 V-8s:
“The exhaust manifolds on the early Gen IIIs were pretty high-tech to get the catalytic converters up to temperature very quickly to minimize startup emissions. The ’97 to ’00 car-based Gen III LS1 V-8 engines used fabricated exhaust manifolds that were made of 0.8-mm-thick 309 stainless steel inside a 1.8-mm 409 stainless steel wall, with a 3mm air gap between the two walls. This obviously expensive exhaust manifold was replaced with a conventional cast iron manifold in the 2001 model year vehicles once the engine management system was improved enough at startup to keep the emissions in line.”
These manifolds should do a great job of minimizing exhaust heat loss into the engine compartment, and they sure do look trick, as well as being one of the slimmer options to fit inside Red’s available space. Note that their inside diameter at the flange is a full 2 ½ inches.
Last evening, I took about 70 minutes to first clean them with an electric drill-powered wire wheel, then wash them down with Brakleen (so no deposits left), and finally to paint them with 1200 degree stove paint.
Here is how much of a difference just the wirebrushing made:
One manifold here has been partially wirebrushed, while the other is still untouched. The wirebrushing produces a beautiful patina, but of course 409 stainless does not stay that pretty in the presence of heat and humidity.
And here is a photo of the painted manifolds:
And finally, the passenger side manifold installed temporarily again:
It sure looks great beside Gerg Ducato’s wonderfully finished 700R4 tranny!
The color is “aluminum”. As soon as I began spraying this paint, I knew I had bought quality paint. The spray quality and the coverage were both incredible. NO comparison to the chain store spray paints. One 12 ounce can was enough to GENEROUSLY coat both manifolds, on all sides, from every angle. The paint is called “Stove Bright” high temperature stove paint, and is manufactured by Forrest Paint Company. It cost me about $10 per can, and I had bought two cans, not realizing that the quality of the coverage would be so good.
Daniel had unfortunately thrown away the factory ’98 Corvette downpipes that attach to these manifolds. Randy had explained to me that no aftermarket flanges would seal nearly as well as the factory GM ones, so I had asked Daniel, but the originals were long gone. I need to find a pair somewhere, and that will be another tedious search!
In the meantime, on with the steering, which will be a genuinely “over the top” posting coming soon . . .
Jim G
Linear Mode
