Cabin heat build up – gear jump

As above

23 September 2010 at 02:13 #47899

I am new to the forum and have a V12 Short Chassis Saloon. Over the last 2 years it has been “refurbished” and is now in good running order (once being owned by Jim Whitehead). Two annoyances:

1. Despite plugging every hole to be found, heat still leaks into the cabin from the engine bay. Is this a “standard feature” or does anyone have a fix? (OK in Winter, but in Sydney Summers, devastating)
2. On trailing throttle, Second gear sometimes jumps out. Under load there is no problem. Again, can anyone comment, please?

Peter S30

25 September 2010 at 17:36 #47901

Dear Owen,

two remarks about your point 1: heat leaking into the cabin:

– Arnold Daveys book on page 136 tells you that you are in good company: ” comparing the merits of the two models (LG6 and V12), for his extra GBP 300 or so the V12 customer got a reduction in 0-60mph time of about 3 seconds and silky smoothness at all speeds. He also got hot feet and the indefinable cachet of owning the “in” car of the period..”

– I can confirm the engine is producing much heat. I have remade such a cowling over the exhaust manifolds of my midsize V12 de Ville like they had it often originally (A.Daveys book page 134). I think it improved when I bent it down so that some of the upper part of the grille in the bonnet side is not covered by it and allows some of the other hot air under the bonned to get out. This works good enough for me. I think even better might be not to use this but to wrap the exhaust manifold with some of the modern heat shield, but I have not tested it and can not compare. It will keep the under bonnet temperatures low but the exhaust pipes will heat up more under the car..

As above

27 September 2010 at 05:48 #47903

Peter, thanks for the tip on exhaust covers. We ( my mechanical wizard and me) have a pattern from Marc Whitehead and will now seriously move to get copies fabricated. The exhaust manifold has been ceramic coated (looks like galvanising) so we have probably done as much as may be possible. Will report back on covers when they are made.

h14

30 October 2010 at 21:38 #47926

Hi Owen,

I have a V12 dhc…the lower bulkhead area & much else is “plated” with what appears to be perforated zinc mesh retaining presumably asbestos. Mine is a 1940 car so benefits from factory improvements, but it’s possible yours has lost these original features & is un-insulated? You should also have a wind-up vent in front of the windscreen, which I seem to recall was quite efficient at directing air into the car.
Mine has the exhaust cowlings you mention, they have a black felt strip to efficiently seal them against the bonnet sides.
My LG6 G10 gearbox jumped out of 3rd gear all the time. I’ve had it rebuilt by Mel Cranmer, who specialises in these, & he is adamant he couldn’t find anything wrong with it! He maintains it’s likely to be a poorly adjusted selector for that particular gear. I’m dubious because I fitted the V12’s gearbox & that didn’t jump out…but I won’t know for certain until I get the car out here (just moved to France) & get it back on the road. The selectors are certainly individually adjustable, but be sure you make a note of the starting point before experimenting.
Laurence

As above

19 January 2011 at 04:10 #47998

On cabin heat, in the Sydney summer found that opening the ventilator flap mitigates the problem (heat wash over the knees). Whether it is acting as a chimmney or not is the question. However, a bit cooler.

As above

19 January 2011 at 04:18 #47999

Laurence,

just noticed your rep-ly – many thanks. it makes sense that there was some form of insulation in a car selling to the ‘quality” market. At some stage, if you could post some pics of the “plating”, I would be most grateful. The window opener is in working condition but, on first use, found the windscreen frame, without the stiffening of the galss ,flexed and produced an alarming cracking noise in one corner. It may be a fault in the wodden frame under the skin, but, for the time being, the window satys shut as a precaution against a crack in the bodywork.

h14

19 January 2011 at 20:21 #48005

Hi Owen,

Unfortunately too cold here in France to delve into the car. Recently delivered here following mechanical rebuild, seats & floor all loose so I should be able to picture flooring for you, but present garage too narrow to open doors (DHC) wide enough to get seats out…it took all of our strength (3 of us!) to push it in place & only 2 of us here now! So please bear with me, hope to work on the car once things warm up (ironic whilst you’re troubled with the heat!).

Laurence