TR6 TR6 aftermarket headers

[Wilky]

Good evening Chaps,
This is my first post on the forum so please be gentle with me!
My name is Callum and I hail from Scotland. I live and work in south Louisiana
and my hobby car is a 72 TR6.
Over the winter and up until now I have been working on the TR6 and it is now in a good state of repair, however I have one persistent problem I cannot seem to cure and I hope you guys may be able to help.
I replaced the Zenith Strombergs with twin IHI 1 3/4 carbs (the japanese versions of the SUs) and Im very happy with the performance so far they are far easier to adjust and understand, however I fitted aftermarket headers and a single exhaust which I imported from Maniflow in Salisbury England, a very good and trusted "Old School" performance exhaust manufacturer I have used in the past when I raced "real" Mini Coopers in the 80's.
My problem is this, no matter how lean or how rich I run the carbs whether at idle or under load the headers glow red hot at the joins. When I say joins I am referring to the points where 3 pipes go into 1, after that where the 2 pipes go into the y piece and thus into the single exhaust is not affected, nor is the 6 individual pipes that leave the head affected its just where the 2 banks of 3 join and go into 2. I hope my explanation is clear!!!
I have tried everything to no avail, and I'm quite alarmed by the heat they give off.
Naturally I wrapped the headers before I fitted them, I also port matched them before fitting.
Is this simply because running temps are so much higher over here or is it for a more sinister reason I haven't thought of yet?
This is preventing me taking the car out for a decent run. I know the fueling is not the issue, Ive done ignition cut checks and looked at the plugs, my own hunch is that its simply 3 going into 1 (on the 2 sections of the headers) and we need to bear in mind the cars were not really built for the climate over here.
If anyone can offer any suggestions or help I would be most grateful!

Thanks in advance

Callum

 

[DNK]

Callum, not a common problem with our cars, How lean do you think your running? Don't know any one else running those pipes.Maybe Panda.
Can you shoot a temp probe at it.

Maybe to advanced?
Oh by the way ,WELCOME.

Ken you out there?, Randall and all ??

 

[Wilky]

Hello! Thanks for the welcome.
Ive leaned her out and enriched her to stall. switched off cooled down each time. Driven the car like I stole it, idled her in the garage. idling plug checks, WOT ignition cut plug checks, when lean they glow. When rich they glow. When perfect they glow.
Its driving me nuts!

Callum

 

[poolboy]

Yeah, I'm here Don. Welcome, Callum.

Yeah it's hot over here, too, Wilky. I'm a bout 75 miles due north of New Orleans, just barely over the La/Ms state line. Born in Baton Rouge, but moved up here from Hammond 10 years ago.
Glowing headers, well I've got tubular headers and they get hot, but by the time I get home they have had a chance to cool down in the last mile or two before I hit the driveway.
Maybe your timing is a bit too retarded and the mixture a bit too lean or the pipes are too thin.

 

[Wilky]

Hey, thanks for the welcome!
You know I've been so focused on the fueling I have not really looked at the timing....................darn!
Ill have a look at that tomorrow and report back!!

I suppose I had better introduce myself in the new guys section!!

Thanks guys ;-)

 

[Brosky]

Welcome to the Forum Callum. Nice to have you here.

I agree with Ken. Timing is a known culprit for these types of "glowing" problems.

I once found that a tech left a distributor hold down bolt loose on a 232 six cylinder AMC Eagle during a tune up. The owner took the car and drove it about 20 miles and called back and said the car had no power and he was bringing it back. He barely made it back to the dealership and I luckily met him outside and sent him in for coffee while I took the car around back into the shop. When I opened the hood, I could not believe what I saw. The entire exhaust manifold was glowing bright red and it was so hot, you could actually see the threads in the bolts.

I would not let the tech shut the car down. I just reached down and cranked the distributor back to a good advanced state and took it for a ride. In 10 miles all was well again and we set it back up on the Sun machine and sent him on his way.

That car ended up having over 150,000 trouble free miles on it and the only reason that he got rid of it was because his son smashed it up.

 

[poolboy]

From Scotland. I bet you're having a time getting used to this climate and the food and the Cajun accents, cher.

 

[Brosky]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]You know I've been so focused on the fueling I have not really looked at the timing....................darn![/QUOTE]

It's time for my famous quote....

"90% of all fuel problems turn out to be electrical".

Sorry, I couldn't help it and it's been a while since I had a good opportunity to use that one.

 

[bgbassplyr]

I think that these two joints (3 into 1) tend to focus the heat at that join more that at the other joins. I suspect that if you run the engine hard for a while, the six pipes at the head will also glow. I know that they do on dyno runs.

You said that they were wrapped. With what?

Might try having them coated with a ceramic to reduce the heat output.

The difference in temps between here and there (US and England) should not be a factor.

Might also install a carb heat shield.

Only other suggestion would be to go back to the stock cast iron headers.

Others will join in with opinions/cures.

 

[TR3driver]

Ignition timing first, but wouldn't hurt to double-check valve timing too. Although not a common problem, a badly worn chain can sometimes jump a tooth.

Also, a somewhat more common problem is that the timing mark on the front pulley is not accurate.

Apologies if this is "suck eggs", but some folks don't realize : 72 and onwards US-spec TR6 did not have vacuum advance, but rather vacuum retard (which theoretically reduced emissions). There was a special port on one of the original carbs that supplied vacuum to the retard, only when the throttle was closed. (Thus the vacuum retard operated only when the engine was idling.) If your new carbs have an advance port instead, and it was hooked up to a retard module by mistake; your dynamic timing at cruise would be way off, even if timing at idle was OK.

And late timing can definitely make the exhaust glow red, regardless of mixture.

 

[poolboy]

Yep and I'd bet him 5 pounds of crawfish that if he used a timing light to set the timing it is too retarded.
Callum, since you have a 72, you'll have to use the intake manifold's brake servo nipple to hook up a Vacuum Gauge, but try it.
https://automotivemileposts.com/garage/v2n8.html

 

[Brosky]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Also, a somewhat more common problem is that the timing mark on the front pulley is not accurate.[/QUOTE]

Agreed and using the vacuum gauge method will get around this hair pulling issue.

 

[Wilky]

Superb advice Boys!

Thank you very much!

 

[Wilky]

From Scotland. I bet you're having a time getting used to this climate and the food and the Cajun accents, cher.

I've lived in LA for a year now so I've got a pretty good handle on it all, I think its all pretty awesome!

 

[poolboy]

You adapted well then. I'm nearly 65 and every Summer I ask myself why am I still here ?

 

[Wilky]

Hello again Chaps,
Okay, here is todays update........
I went to bed last night knowing you all were right and a bit annoyed at myself for not having realized it myself, I suppose having run a rally car in recent years and being used to dialing in fuel on load rows on a map and balancing the ignition against boost and det, the manual aspect of distributors had left me for a while.
Anyway, my hopes rekindled I left for work super early this morning, did everything I needed to do, massaged the right egos, and played hooky from 1330hrs onwards.

As soon as I lifted the bonnet and thought back to my mini and the Dolomite Sprint, I could tell by just looking at the distributor it was far to retarded.
It does have vacuum retard however it is not active. I took the vacuum gauge off of my brake bleeding kit and did a McGuiver with some hosing onto the vacuum nipple for the brake servo.
I had to fit a small restrictor to get a constant reading, but once warmed up I set up slightly back off my best reading and took the car out for a run.
4th gear, 30-50 slight pinking so I jumped out and much to a State Troopers amusement adjusted the ignition a bit more. No pinking now so I took her onto the back roads............................


My god it can shift!! the car has been transformed!!!! No excessive heat and no red hot headers!!!
My only concern now is if I have cooked anything with driving it for about 20 miles before it was set up correctly, however ill jump that hurdle when I need to.

Thank you very much to everyone who gave the fantastic advice I received last night, it was superb!

Callum

 

[bgbassplyr]

Speaking for all, if I may, you are welcome.

Next question.

 

[Brosky]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]I'm nearly 65 and every Summer I ask myself why am I still here ?[/QUOTE]

Ken, it was high 90's for the past two days and today was over 100 here in southeastern Mass. I played in a golf tournament today and drank seven (7) 16 oz bottles of water and three 12 oz Cokes and never went to the rest stop.

 

[poolboy]

Weatherman said it's been humid up there, too, Paul.
You got the heat shield installed yet ? Good test conditions.

 

[billspit]

Callum
First of all, welcome!! I must say you have an excellent command of our version of the English language. I understood everything you wrote. I often go to Triumph Torque web site and I need an interpreter. You also have a knack for story telling. Happy to have you aboard.

Bill