4-2-1 exhaust options

So Cal Mark · Post by **So Cal Mark** » Wed Aug 22, 2007 10:34 pm

after installing a set on a customers' car, I wouldn't pay any more than that. I was shocked to find how poorly they fit.

manoa matt · Post by **manoa matt** » Wed Aug 22, 2007 10:58 pm

Poor fit at the flange to block? Did you have to elongate any of the mounting holes?

So Cal Mark · Post by **So Cal Mark** » Thu Aug 23, 2007 12:15 am

flange to head was okay, very poor fit around the crossmember, steering linkage and trans. I wasn't impressed with the build quality of the header either, but that's part of the reason I came up with a system

mbouse · Post by **mbouse** » Thu Aug 23, 2007 8:19 am

i cannot testify to the fit or function of the IAP headers, but the cost comparison might go a little like this....

for a USED 4-2-1 cast iron manifold and steel down pipe you will pay .. if you can find them .. $75-100 .. and plan on searching for a couple of weeks.

and, i would still like to hear how a set of headers (w/out heat shields) combat the heat issue.

So Cal Mark · Post by **So Cal Mark** » Thu Aug 23, 2007 10:26 am

the IAP 4-2-1 header is a problem with the early cars that have the battery mounted under the hood. In the last week I've come across two cars that had the battery case melted because of lack of clearance with the header

spiderrey · Post by **spiderrey** » Thu Aug 23, 2007 2:48 pm

to deal with the heat, you can ceramic coat them. they will look great

manoa matt · Post by **manoa matt** » Thu Aug 23, 2007 5:15 pm

I was planning on ceramic coating the entire system all the way back to and including the rear muffler. The whole exhaust system will be all new steel. I don't want it to rust in the highly corrosive hawiian environment.

I'm now having second thoughts on ceramic coating the headers, maybe just from the down pipes back. Instead I'll make a heat shield for the headers, sandwitch some header wrap or asbestos type material between two aluminum sheets, pop rivet them together and make some brackets. Once the headers are installed I plan on moving a few things around if warranted. The coolant bottle, the coil, and the washer bag.

So Cal Mark · Post by **So Cal Mark** » Thu Aug 23, 2007 10:26 pm

coating the header is a good idea, it improves the thermal efficiency which translates to more hp. Plus it will help with the underhood heat and corrosion issues. Your heat shield is an excellent idea too, just remember that air gaps around everything is extremely important

mbouse · Post by **mbouse** » Fri Aug 24, 2007 8:31 am

i'd think that a shield at the header would be the way to go. then you should be able to get rid of all those other shields...reservoir, dizzy, etc.

and the air gap is a good point. if the shield touches the source of heat, it is no longer a barrier; it merely makes the source of heat a larger item.

manoa matt · Post by **manoa matt** » Sun Aug 26, 2007 4:28 pm

I picked up the headers yesterday. It turns out, there Vick's headers.
The headers themselves, are similar to IAP's but the downpipes have a different design, hopefully for the better.

Mark, I see what you mean about build quality. The headers at the inside of the flange could use some porting. Welds are ok but not great. Glad I didn't pay to much.

Headers are chromed, so I don't think I'll ceramic coat them. I expect them to turn a blueish/purpleish rainbow color from the heat. I'll probably use a heat shield until they weather enough so that a ceramic coating will stick on.

So Cal Mark · Post by **So Cal Mark** » Sun Aug 26, 2007 6:36 pm

before they can be ceramic coated they have to be sandblasted, so none of the chrome will remain if you take the route

racydave · Post by **racydave** » Sun Aug 26, 2007 11:33 pm

There is a powder coat that looks much like chrome, if you made a heat shield that could look pretty clean in the powder coat.

So Cal Mark · Post by **So Cal Mark** » Mon Aug 27, 2007 1:24 am

ceramic coating is good to 1100 degrees F, not sure how powder coating will hold up. With ceramic coating, they polish it after it's coated, so it's close to chrome but not quite as shiny

mdrburchette · Post by **mdrburchette** » Mon Aug 27, 2007 6:07 am

Hey guys, I'm real pleased with my ceramic coated manifold. Not only does it look 100% better than the old rusted hunk of metal, but it brings the temp down significantly in the engine compartment. One of these days, I'll run both Fiats and measure the difference, but I seem to remember it cut the temps on my 72 about in half. My ignition coil is mounted on the exhaust side and I've had no problems with it overheating. It really is worth the money!

CarNut · Post by **CarNut** » Wed Nov 28, 2007 12:18 am

I'll be needing exhaust work on my 78 soon. Interesting to read that you guys don't think the 4-2-1 is much improvement. I was thinking of going that route but maybe not so much now. One source I saw did claim it sounds better.
What other options are there? Mark's header looks interesting but I'm guessing it would probably be wasted without head and cam work. A 34ADF is probably as big as I'd ever go carb-wise. I'm not a tuner junkie but on the other hand I prefer to buy something good or with upgrade potential than spend good money away on throw-away junk.

What about the stainless system from these guys?
http://www.funimported.com/new_exhaust.htm
The stainless system on my Triumph is probably over 15 years old and still like new.