TedH

I'm really giving serious consideration to swapping my restrictive 2" exhaust manifolds for headers in my '80. I want a set that doesn't require clearancing of components (read, denting the headers, grinding off rag joint plates, grinding steering box, bending the headers, etc.). Also, Jet-Hot, or HTC inside/outside on the headers is also a 'want to have'.

A thread here describes a number of folks that have had trouble with the Dynomax (looks like some header manuf - was it 'Blackjack'? - either renamed themselves or got bough out by Dynomax; when you go to the dynomax site, the header 'style' names remind me of some other header company).

So, Dynomax has me worried...

Hedman offers uncoated, non-AIR headers for about $100; emissions headers for about $189. Jet-Hot sells the Hedman emissions headers for over $500 (God, that sounds expensive). So I have to wonder if Dynomax is selling a cheap (read trouble) header with Jet-Hot coating for the $209 advertised at Jegs.

Bottom line: I want something that installs without clearancing and that is Jet-Hot coated.

Are Dynomax (trouble) and Hedman my only options? How about some Hedman, Thorley, etc. installation stories/nightmares... Anybody?

Ganey

Dynomax Coated flow & fit great. Formerly Cyclone @ 200. These are well made. Many have installed these w/o problems !
Also they have a cheaper one based on the Blackjack & not rec. @100.

@=about

Should fit yours fine.

Ingar, Norway

The Dynomax headers had perfect fit on my 1980, no clearance problems.
Mine are uncoated though. Went for that since I wanted to add O2 sensors.
Could it be that they are bent during the coating process, guess they use high temperatures?

They are of very thin tubing, although that shouldn't matter if they are coated on both sides.

TedH

Thinner than Hedman 1 5/8" tubing? Are the Dynomax/Cyclones 1 1/2" tubes?

Forgot you were talking tube thickness vs. diameter. TGIF... :rolleyes:


[Modified by TedH, 8:50 AM 2/15/2002]

fauxrs

Judging from the recent spate of people having install problems with dynomax headers leads me to believe one of the following two conclusions.

1. There is a small amount of manufacturing variances in the assembly of the Dynomax product that occasionally, small clearancing issues sometimes develop during the installation.
2. There is some variance in the location and installation of the various componants in the vette engine compartment (less likely I would think) causing occasional interferance with proper installation of the headers.

If I had to choose between the two, Occams Razor would force me to choose #1.

On a side note, i just purchased a set of headman jet hot coated emissions legal headers and when I get around to installing them I will report back with results of fit.

Hedman and Dynomax are your two primary choices for affordable headers, sanderson makes shorty style headers at an incredibly inflated amount.

Ganey

Dynomax/Cyclones are 1 5/8 thick pipes & flow much better than is commonly known. Headers generate HP & heat. They are not for everyone. If you think these trivial fit issues are a big deal, hang in there & someone will tell a nightmare. Headers are probably not for you.

:cool:

TedH

Ganey,

Sorry for, in your opinion, being such a light-weight. But sorry, paying for a Jet-Hot coated set of headers and then clearancing them; damaging that coated surface, or modifying other engine components related to steering, brakes or other critical auto functions is not trivial to me. If trivial to me, I wouldn't have posted it.

If you find it trivial, don't bother to respond.

Smart-a## remarks I don't need. Valuable advice is welcome.

Bill W

The ceramic coated Hookers (1 5/8 tubes) I installed a couple years ago fit like a glove. $325.00 from the local speed shop. Just seems to be a beefier unit than the Dynomax units.

Noel Carboni

I use Dynomax coated, and yes, they're the spittin' image of the BlackJack headers. However, they work, and have even held up for years under a nice, thick blanket of Thermotec insulation. They fit my engine compartment without mods, though I had to pull off the dipstick tube (on my '73 400 block) to get them on.



-Noel


[Modified by Noel Carboni, 7:23 PM 2/15/2002]

Corvettes White

Ted:

I installed Thorley on our 1969 small block. They will sell them without a coating. I pre-fit the headers into the car to check clearances. Only tight spot was the idler arm. I put a small dimple in the headers just for caution but they actually cleared when the arm was loosened, shifted, and retightened. Every other part of the car cleared. My car I think was built a bit off in its original manufacturer so my best guess is that the Thorleys were right on dimensionally. You can pull the spark plugs and get the wires on the plugs without them resting near the tubes and burning no problem. We welded on a support for the back side of the AC, it looked better that the AC brackets that bolt on. Gasket matched the headers to the heads a bit. Had connector tubes fabricated up to connect the exhaust. Pulled the headers back off and sent them off to Jet-Hot. It is all installed now and looks great.

I can’t tell you how the car runs yet because the interior is going back together but I can say that if I were to do headers again I would do the same way. Cheep headers are a pain in the butt. They don’t fit and they warp. No :smash:

George

Jvette73

Ive had no trouble with my Dynomax coated headers. Look good, fit good, good ground clearence, good price. The Dynomax have a slight downturn at the collector. They may be a tad shorter than some other headers. They dont hang down below the frame at all. Good value in my opinoin.

Steve Grodin

I have Hooker ceramic coated in my '74, fit like a glove. Another thought to your possible fitment problem would be to buy the headers uncoated. After you are satisfied with the fit, then send them out for coating. Down side is the down time plus probably cost more than buying them already coated.

vettecor

Ted,

I agree with Bill W and Steve. Hooker Competition Headers (ceramic coated) fit GREAT on my '77. No modifications needed.

Larry :seeya

Jason Staley

I have Dynomax Ceramic coated headers on my 76 and I love them. Look great and they didn't have any fit problems, even on a ZZ4 which has the exhaust ports .100" higher than stock. Only thing I did to be safe was shorten the top mounting bolt for the idler arm (it was excessively long from the factory) - only took a few minutes. Clearance was just a little too close for comfort, and I didn't want to the header to hit the bolt under hard acceleration.

Not a bad deal for only ~$200. :cheers:

gearheadz

See: http://forums.corvetteforum.com/zerothread?id=239403

VETDRMS

I have the dynomax ceramic coated headers, jsut finished installing them, i did have installation problems, but if you not an idiot, you can pretty much fix it within a few hours. I had to put some small shims on my steering gear box to tilt the rag joint in a bit. Did a little filing on the rag joint, and all clears well, they fit well, look good, no leaks or bends, and we'll see if they help the power :) Hooker/Dynomax, pick one, both good :D

KenSny

TedH - a couple of comments, then I'll leave this thread and any of your postings slip on by.

1. Your response is totally off the wall.
2. When you are modifying any car with aftermarket parts, expect to make modifications to some things. These are TRIVIAL - people have been doing it since hot-rodding began.

Maybe you should leave your car completely stock.
Maybe you should have a mechanic do ALL the work, so you don't have to see modifications being done.
If you want help from people here, be respectful, and they in turn will treat you as such.

TedH

Ken,

Nobody likes to be referred to as being trivial or having trivial thoughts or concerns. It's all in the delivery.

As for leaving my car stock, too late for that bub. I've gone too far down that path doing all of my own repairs/modifications. But, if I can avoid purchasing an inferior product by soliciting the 'free advice' from this forum, I will do it now and forever; regardless of how trivial you or others think I am in asking; or responding.

Ingar, Norway

Vetdrms: I wonder if there are differences between years, as my 1980 has approx. 1.5 inch gap between rag joint and header.

BTW: I asked Dynomax if the coated/painted are different and their answer was:
"The only difference between the 85008 painted
and 86008 ceramic coated headers is the coating, the routing and dimensions are the same."

Ken74Conv

Apparently the 3 choices are Dynomax, Hedman, & Hooker.
Do all 3 manufacturers use the same thickness flange. I think this could be an important consideration to prevent leakage.