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Triumph TR6 - Manifold Coolant Pipe

Hi Guys,
While I have my carbs off I really noticed the coolant line passing thru' the intake manifold to the heater core and wondered if it is still neccessary to do that ? maybe in a car that's driven in cold weather a lot but in our warm to cool weather driving ??.
With all the talk about the heat that builds up under the hood from the exhaust manifold and hot summer driving which affects the carbs is 160 degrees running thru' the manifold not adding unwanted heat ?
Has any one by-passed this and noticed any change ?

Cheers
Charlie
Charlie B.

Charles- some where I saw a note about bypassing the tube. I have a pic somewhere and I will hunt it down and put it up.
dk
DON KELLY

Charlie

There was an earlier thread on a similar topic (?) in which one bbs'r mentioned putting a ball type valve in the hose to the manifold so that it could be turned off in the hot months. I still havnt done it myself though want to because i think there is too much heat to the weber carbs i have. I am also looking at using a Thermo-Tec manifold blanket on the exhaust manifold to act as a heat shield..just havnt pulled that winter project trigger yet. I posted a thread asking if others had looked at using this approach but no response yet.

bob
Bob Craske

Bob
The valve idea seems good...I'll look into that

Don
If you can find the pix that would be great

I'm also thinking of running a tube of some sort and guide air from the front to the base of the carbs or a heat shield .....or a ???...

thx
Charlie
Charlie B.

Charlie

we need to get together sometime since i am looking at the same options, the manifold blanket to reduce heat to the carbs and some type of air vent/hose directing a stronger stream of cool fresh air to the air filters (2 x weber DGV)



bob
Bob Craske

Charlie- Found the pics, they were still in my camera. What is your e-mail?
dnk
DON KELLY

I'll try something

http://static.flickr.com/37/107465447_c510b29569_m.jpg

http://static.flickr.com/55/107465448_350737fde4_m.jpg

dnk
DON KELLY

I have bigger images if any one needs them
dnk
DON KELLY

Don

I would appreciate "bigger photos" I am getting older!

What I am trying to figure out is posted in the thread preceeding this one titled intake water feed. Do I close off the hot water feed to my pierce adaptors or to the intake manfold or both..its just a matter of where I place the ball valve.

One would assume that the purpose of the water feed was

a: to provide some colling to the manifold
or
b: to provide heating to the manifold
or
c: neither, just another TR engineers idea of fun

Its possible that by placing the thremo blanket on the exhaust manifold that I will reduce the heat to the carbs and intake manifold enough to preclude revamping the plumbing...but thought I would start the investigation now before summer finally arrives!

thanks

bob



Bob Craske

Thanks Don,
Now what we really need to know is by no longer having hot water going thru' the manifold does it make a difference ??.
I'm sure originally it was to heat up the manifold for all year/cool climate driving...but now since they are driven mostly in fair weather maybe it's not needed.
I think Bob and I will try it this summer and compare notes

Charlie
Charlie B.

Don

I got the photos, thanks, but i dont see in the photo where a shut off vavle was incorporated. I guess it comes down to Charilies questions, what difference might this alteration make, i still thin the manifold blanket will produce the greatest in heat shield for the carbs and then second would be cut off to the pierce adaptors and lastly would be a cut off to the intake manifold. But somehwere you have to guess that the water jacket in the manifold should also produce a cooling affect by drwaing heat into the flowing collant?

hmmm
Bob Craske

still looking for that one. don't know if a valve is needed with the situation of last photo. But could be up for discussion with the members.
dnk
DON KELLY

I hink your right Bob...the 195 or less coolant degrees is probably way less than the heat pouring off the exhaust manifold under a good drive,
Charlie
Charlie B.

So is what you are saying is that the coolant going thru the pipe also has a colant effect and helps lower tempat carbs?
dnk
DON KELLY

Thats what I'm staring to think Don, it's a lot of heat that pours off the exhaust manifold even at idle as anyone knows while working on a idling car.
Maybe the blanket / shield is the way to go to minimise the heat from the carbs. Or now that I'm installing SU's I won't have the same problems I had with my ZS as far as summer and a hot engine goes.

Charlie
Charlie B.

I bought Joe Alexander's carb heat shield this winter and will install it soon. It fits both ZS & SU carbs. A good idea to prevent your carb bowls from becoming percolators. See it at http://the-vintage-racer.com/. NFI.

Rick O.
Rick Orthen

I bypassed the manifold pipe (straight from the thermostat area to the heater core), wrapped the exhaust as well and fabricated a cold air intake. Before I did this in the summer, if I pulled over after driving 60-70 mph, I couldn't touch the intake manifold (hot). After the modifications, when I check the temp after some spirited driving, the manifold is cool/cold to the touch even on a hot day.

As for performance increase I think there was a little. Cold air is more dense, so more power.

The only problems I see, besides the winter aspect, is possible carb icing in humid climates. You can get carb icing at as warm as 70F given the proper conditions. But given the dry climate I live in, no problems.
Ryan

Last summer I disconnected the preheat for my intake as described here. It ran like crap, slow to warm up (in summer) and always ran like it was a little cold (read lean). I reconnected the hose and all the nasties went away. I would suggest a cold air box and leave the intake preheat in.

Don
Don Ho

Ryan

Any chance you can provide some photos of your setup?

thanks

bob
Bob Craske

Pics, unfortunantly, no. The car is currently torn apart for a body off restoration. Don, does bring up one thing I forgot, when the car was cold, you could not go WOT without it breaking up at high RPM, but this did not bother me since I generally let it warm up before beating on it.
Ryan

Charlie B.: You mention that switching to SUs will relieve any heat sink problems you had previously with the ZS carbs. I think that SUs are probably more prone to exhaust manifold heat problems than the Strombergs. Note that heat shields are critical to MGBs for that reason. At least on the ZS the jet is somewhat insulated by the carb body and the flow of fuel, unlike the HS6.
The setup from Joe Alexander looks like a great item. I would consider it.
Andrew Blackley

Thanks guys

Don, i figured the engineers must have been thinking about something when they added the water flow. I am going to focus on the manifold blanket and try that for some "hot" runs before even touching the water flow.

I will post some facts once its installed and tested.

bob
Bob Craske

Andrew,
A friend who switched to SU's last year noticed a big difference in how the car runs in all weather compared to the ZS...I think just getting away from those bypass valves and temp comps is one of the main things.
I'll try it out first but yes I am planning on a heat shield as the next stage.
Charlie
Charlie B.

Charlie,
The SU's are better by far, hands down, end of story. As far as the water tube goes, I've removed mine and there are no nasty after affects. I see no reason to heat the manifold in the temperature range that we use our cars. The inverse cooling effect is minimal. Idling for an extended period on a hot summer day will heat up the engine bay and the surrounding air supply to the carburetors. They run a little rough. Select neutral and speed up the rpm's temporarily cures the problem. This moves hot air out of the compartment and cools the water jacket. I've added another opening to my original air box to get more air top the rear carburetor. This helps. I do like the idea of a heat shield and will probably add one this summer. I'm a little worried about directing all that super heated air at the starter. The best idea is to get the heat out of the engine bay. Don't block the intake with auxiliary lights and other stuff. Keep the radiator free of critters and check for bent fins. Itís the total package.
Last summer on a run of over 1600 miles, in some high temps (30-35 C), I had no problem with overheating.
I might add that there was also a change of altitude over over 4500 ft.
Hope this helps,
Steve
Steve Crosby

This thread was discussed between 27/01/2006 and 13/03/2006

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