Jase Posted June 22, 2020 Report Share Posted June 22, 2020 What is the general rule of thumb here? My TR4A with Stromberg 175s does not have a heatshield? Do they need them? I have one on my Spitfire, it wouldn't travel down the street without one even with the jet conversion. Thanks Quote Link to post Share on other sites
RogerH Posted June 22, 2020 Report Share Posted June 22, 2020 Generally the carbs do not need a heat shield. Heavy stop/start traffic and restarting after a few minutes at the end of a long hard drive might cause vapourisation but not normally. However if you go for an Alternator then that does need a heat shield - otherwise the back simply melts. Roger Quote Link to post Share on other sites
Jase Posted June 22, 2020 Author Report Share Posted June 22, 2020 Should have included rubber diaphragms in my title. Since when did these reach silly prices? I remember them being about £5 a side, they seem to be more like £20 a side now?? Quote Link to post Share on other sites
RogerH Posted June 22, 2020 Report Share Posted June 22, 2020 1 minute ago, Jase said: Should have included rubber diaphragms in my title. Since when did these reach silly prices? I remember them being about £5 a side, they seem to be more like £20 a side now?? I think the E5 petrol did for them. Roger Quote Link to post Share on other sites
AndyR100 Posted June 22, 2020 Report Share Posted June 22, 2020 Not usually considered an essential item, but If you do choose to add heat-shields I’d suggest going for two separate ones rather than a one-piece shield - a cleaner path for linkages and you can tweak the shape of each independently if needed. ....... Andy Quote Link to post Share on other sites
Z320 Posted June 22, 2020 Report Share Posted June 22, 2020 If you touch your carbs every time you drive the car, they are cold because of vapourisation of the petrol. Before you add a heat shield check this and answer yourself if you need one. Ciao, Marco Quote Link to post Share on other sites
ChrisR-4A Posted June 22, 2020 Report Share Posted June 22, 2020 Hi Jase, I've used my 4A in temps from zero up to 36 deg in France and never needed any form of heat shielding for the Strombergs. I do still run a Dynamo but with mostly LED lighting have never found this a problem. Chris Quote Link to post Share on other sites
DavidBee Posted June 22, 2020 Report Share Posted June 22, 2020 (edited) 2 hours ago, Jase said: What is the general rule of thumb here? My TR4A with Stromberg 175s does not have a heatshield? Do they need them? Not unless you are fitting a rally or race extractor manifold of the Phoenix or Lawrence Tune kind. Edited June 22, 2020 by DavidBee Quote Link to post Share on other sites
Jase Posted June 23, 2020 Author Report Share Posted June 23, 2020 10 hours ago, DavidBee said: Not unless you are fitting a rally or race extractor manifold of the Phoenix or Lawrence Tune kind. Well it does have a triumphtune exhaust manifold. Quote Link to post Share on other sites
stuart Posted June 23, 2020 Report Share Posted June 23, 2020 14 minutes ago, Jase said: Well it does have a triumphtune exhaust manifold. I have a 4 branch SAH copy on mine with Dellortos and not needed heat shields yet. Obviously as stated you do need one for alternator if fitted. Stuart. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted June 23, 2020 Report Share Posted June 23, 2020 To open the worm can.... I chose to wrap my Ivor Davis << https://www.ivormdavis.co.uk/ >> manufactured 4 into 1 stainless steel manifold to help reduce the under-bonnet temperature. The idea of restricting access even further in that area by adding sharp bits of tin seemed illogical. OK on a wind-up window car where you have so much more space available. This is of course possibly frowned upon due to any view held, be it corrosion, look, sound, colour, finish, originality, etc Peter W Quote Link to post Share on other sites
Bleednipple Posted June 23, 2020 Report Share Posted June 23, 2020 No carb issues for me with a 4-branch (but with SUs rather than Strombergs). Nigel Quote Link to post Share on other sites
tthomson Posted June 23, 2020 Report Share Posted June 23, 2020 My TR4A has SUs, and a tubular steel manifold, (Coated by Zircotec), and I have never needed any shields. Tony Quote Link to post Share on other sites
peejay4A Posted June 23, 2020 Report Share Posted June 23, 2020 Just to add the opposite view, I've got a standard exhaust manifold (because it's better than many tubular ones) with an ARE heat shield and cold air feed. It's fine. Quote Link to post Share on other sites
tim hunt Posted June 23, 2020 Report Share Posted June 23, 2020 35 minutes ago, tthomson said: My TR4A has SUs, and a tubular steel manifold, (Coated by Zircotec), and I have never needed any shields. Tony +1. I have exactly the same set up and have never found the need for heat shields under any driving conditions. Tim Quote Link to post Share on other sites
DavidBee Posted June 23, 2020 Report Share Posted June 23, 2020 3 hours ago, stuart said: I have a 4 branch SAH copy on mine with Dellortos and not needed heat shields yet. Stuart, I'd love to see photos of your car. Engine bay too! Quote Link to post Share on other sites
Geko Posted June 23, 2020 Report Share Posted June 23, 2020 I made my own at no cost with a piece of thick high temp gasket I had on shelf. Quote Link to post Share on other sites
stuart Posted June 23, 2020 Report Share Posted June 23, 2020 4 hours ago, DavidBee said: Stuart, I'd love to see photos of your car. Engine bay too! This was taken a while ago, been upgraded a bit more since. Stuart. Quote Link to post Share on other sites
DavidBee Posted June 23, 2020 Report Share Posted June 23, 2020 (edited) 3 hours ago, stuart said: This was taken a while ago, been upgraded a bit more since. Nice! What I notice is the Lucas Sports Coil on the inner wing, away from the heat, and dem ram pipes with no mesh. Dell'Ortos look similar to Webers. Your response begs the question as to your more recent updates, but that is off topic, I guess. Edited June 23, 2020 by DavidBee Quote Link to post Share on other sites
ianc Posted June 24, 2020 Report Share Posted June 24, 2020 (edited) Stef - you appear to have an adjustable stabiliser bar, with red sleeve, running to the left from the front of the engine. Is this similar to the device which I described in TR Action 130 many years ago (May 1996, also in Technicalities CD G15-G19)? Mine links to the cross tube mounting. And Stuart has a remote header tank for the coolant, an improvement which I described in TR Action 112 (February 1994, Technicalities CD B18). Guarantees that the radiator is always completely full of coolant. I just wanted to clarify that a heat shield for the alternator, clearly seen in Stef's shot, is NOT the same as a heat shield for the carburettors. Ian Cornish Edited June 24, 2020 by ianc Stef for Stuart Quote Link to post Share on other sites
peejay4A Posted June 24, 2020 Report Share Posted June 24, 2020 I think you’re referring to Stef’s picture Ian. Quote Link to post Share on other sites
mike3md Posted June 26, 2020 Report Share Posted June 26, 2020 Nope, remote header tank is in Stuart's pic. Quote Link to post Share on other sites
peejay4A Posted June 26, 2020 Report Share Posted June 26, 2020 Yep. If you look at Ian's post you'll see he has altered the reference to the stabiliser bar from Stuart to Stef. Quote Link to post Share on other sites
DavidBee Posted June 27, 2020 Report Share Posted June 27, 2020 On 6/24/2020 at 9:25 AM, ianc said: I just wanted to clarify that a heat shield for the alternator, clearly seen in Stef's shot, is NOT the same as a heat shield for the carburettors. Ian, is your point that a heat shield is indispensable to protect the alternator, if pipe type extractor manifold, but not for carbs? Quote Link to post Share on other sites
ianc Posted June 27, 2020 Report Share Posted June 27, 2020 DavidBee - yes, all the advice on alternators with a 4-branch exhaust says that an alternator heat shield could save you the cost of another alternator. Even Mr Revington, despite having re-built 4VC for me (which had a heat shield, fitted in 1962, for the dynamo - still there for the alternator) made the mistake of not fitting a shield when he changed 6VC to alternator - learned the lesson (and now sells shields, too)! Heat shield for carburettors: 4VC has the SAH-style 4 branch as fitted in 1962 - not the original as it disintegrated and was beyond repair, so then I fitted the Moss version which is built to the same pattern. Heat shield is not easy to install and, although Tony Sheach gave me one, I haven't fitted it. If the engine is hot and I stop, I release the bonnet catch to let out the hot air and let convection do its job. My Kenlowe stops as soon as I turn off the ignition. Ian Cornish Quote Link to post Share on other sites
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