Jump to content

Hot gear lever/knob


Recommended Posts

Took the GT6 on a long run today to Silverstone. This was the longest drive I've done since buying the car. It was a very hot day  but I was concerned at how hot the metal part of the gear knob became. Is this normal or could there be an issue I need to look at? 

Thanks

Link to comment
Share on other sites

Pretty normal as the box gets hot after long drives and of course the exhaust runs through that area as well. The biggest problem is stopping the heat coming through to the cabin....

The last of the spitfires used a single rail gearbox whose lever had a thermal insulator incorporated to stop the exact problem youve found!

Link to comment
Share on other sites

All that heat, but ALL of it, is from the engine, via the radiator.   No internal combustion engine is more than 50% efficient, ours are a lot less and most of that wasted energy comes out as heat.    WE dump it into the air via the radiator and of course it all flows under the car and around the transmission tunnel and gear box.   This was proved to me by my experimental "Silverback" car, that had a radiator in the back.     It was a rather cold car to drive!

Insurancepics2006015netsize.jpg.4353b8725083e505eb9d58a28a9583b1.jpg

Not a solution for a GT6, but better air extraction from the under bonnet might help.   Possibly - never done it! - some barrier to air flow into the gearbox cover and transmission tunnel?

John

Edited by JohnD
  • Like 1
Link to comment
Share on other sites

On air extraction, those bonnet wing ports on the LeMans Spitfires are more or less "Meh"!   They do not extract!

Spitfire Le Mans Bonnet (Page 5) : Spitfire & GT6 Forum : The Triumph  Experience

 

A less elaborate and better designed extractor vent induces a vortex in the mouth of the vent which should be enclosed with an angle floor.  The vortex energises the air in the mouth which then is pulled out of the back of the vent.   May I, modestly, refer you to the vents that  my Old Blue had?   The lip on the front edge of the vent is important!

Closeupextractorduct.jpg.037d9f8ecfef0e81bc92b8b369d55d70.jpg

Internally it looks like this experimental model, which shows how the ducting behind the hole makes it much more effective - the tufts move OUT not just back in the breeze from the airgun.

Bonnetventexperiment.jpg.32c739a7e372db131ab0896a3c1aacdf.jpg

John

 

  • Thanks 1
Link to comment
Share on other sites

When I raced a Jaguar mk2 I had the bonnet on 4 pins for easy removal and access. I had the back raised a good inch or more to let hot air out. Not possible on our cars as it would spoil the lines. Another option is to remove the bonnet/bulkhead seal but then you'll die of fumes..... I'm having a problem with fumes in my Vitesse! 

Iain

 

 

Link to comment
Share on other sites

Did that really work, Iain?

On most cars, including the Jag, the rear of the bonnet is close to the lower edge of the windscreen, and so there is a pocket of high pressure there.       I presume that Jaguar knew this - Triumph did as that is where the intake for the internal air ventilation  is sited.

image.png.5dd0014b3c47db817bd1f642e3de6953.png

John

Link to comment
Share on other sites

42 minutes ago, JohnD said:

Did that really work, Iain?

Probably not John! As you say the air pressure is positive not negative. In my defence in the early 80s a lot of the JDC pre 68 racing saloons opted for a raised bonnet rear. As soon as I finished a race the bonnet came off to the smell of hot engine and hotter brakes. That smell still lingers in my nasal memory! So the only time it had any effect was the minute or so of panic at the start line.....😳. I did also let louvres in the bonnet a la Coombes specials. As you know once off the grid the sounds and smells take over and it's only on a straight I glanced at oil and water temp or the big orange oil pressure lamp!

Iain 

Link to comment
Share on other sites

I always say that unless you are Hamilton or Fangio, you win the race in the workshop!

But I'm sorry to burst the Coombs bubble - louvres look the business - but are, again, lousy extractors!    The first is OK, but it has a very small area.  The next is working in turbulent air, the one after that even more so, so that after that they don't extract at all!

Bests,

John

 

Link to comment
Share on other sites

17 minutes ago, JohnD said:

But I'm sorry to burst the Coombs bubble - louvres look the business - but are, again, lousy extractors

Again we now know they don't work for racing cars but in normal road stop start driving they do let out heat. Saying that I'm not a fan as they also let  water in when stationary!

Iain 

Edited by Iain T
Link to comment
Share on other sites

My racing days long gone as has the jaguar. I did a few races and hill climbs in my TR3A in the late 80s and Monty Challenge in 2000 then retired as work took over. I've tried to post photos but it won't work! 

Iain 

Link to comment
Share on other sites

It says unable to complete due to low memory. It's a common problem for me. I've cleaned up including history and have plenty of memory. 

Iain 

Me on the right

Head gasket blew on day one of five on Monty. Changed overnight but it blew the rear seal so it was like the Torrey Canyon all the way there and back! No photos of the TR3A but it was also red. 

IMG-20220203-WA0006.jpg

IMG-20220203-WA0007.jpg

Edited by Iain T
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...