NonMember Posted September 13, 2021 Report Share Posted September 13, 2021 1 hour ago, johny said: The manifold if cold (even in summer) impedes atomisation Not really. It may encourage condensation but that's a different thing. The atomisation occurs in the carb venturi or around the throttle, where there's plenty of air turbulence. A hot manifold will encourage vapourisation, admittedly, but that's another different thing. Acutally there is an effect that reduces choke time with a heated manifold. The condensation of fuel when cold produces a puddle ("wall wetting") which the heated manifold will begin to evaporate faster than an unheated one. However, this happens slightly later, when the engine is already nearly warm enough to run without choke. As Colin says, someone thought it necessary. However, they didn't think it necessary on the 1200 or the Mk1 Spitfire. The benefit is mostly the longer-term fuel economy and smooth winter running, not any small reduction in choke time. Link to comment Share on other sites More sharing options...
johny Posted September 13, 2021 Report Share Posted September 13, 2021 cor pedantic... well as the running temperature of my manifold is certainly hot enough with no coolant flow (after all it is bolted to the exhaust manifold!) its good to hear that by using that flow through the engine and radiator Im not increasing choke time😄 Link to comment Share on other sites More sharing options...
PeteH Posted September 13, 2021 Report Share Posted September 13, 2021 Whilst I have no evidence to back it up, I assume it is possible that this "warming" device was part of an early attempt at mitigating emmisions,?. Perhaps by "improving" charge quality?, as opposed to just a more rapid warmup?. Pete Link to comment Share on other sites More sharing options...
johny Posted September 13, 2021 Report Share Posted September 13, 2021 oh no dont go spoiling my cunning modification! Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 13, 2021 Report Share Posted September 13, 2021 32 minutes ago, PeteH said: I assume it is possible that this "warming" device no .............Hot spots were around on manifolds years ago even on side valves before and after WW2 Pete Link to comment Share on other sites More sharing options...
Chris A Posted September 13, 2021 Report Share Posted September 13, 2021 51 minutes ago, PeteH said: "warming" device Ford had a better warming device option for the Model T. Someone I know has a model T with this and it does work. apparently it was aimed at the travelling salesman market as they could be in the middle of nowhere at lunch time. https://www.modeltford.com/item/T-COOK-SS.aspx I've become very French, everything revolves around food 😉 Link to comment Share on other sites More sharing options...
johny Posted September 13, 2021 Report Share Posted September 13, 2021 Now if you put a roast in there that would help with engine cooling! Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 13, 2021 Author Report Share Posted September 13, 2021 2 hours ago, NonMember said: As Colin says, someone thought it necessary. However, they didn't think it necessary on the 1200 or the Mk1 Spitfire. Possibly, like many things, they found after the cars had been on the road for some years that something was needed; maybe it was necessary to improve running or economy, maybe it was just out of the 'sounds like a good idea' box, and so the later cars got it factory-fitted. The cooling layout changed between the earlier 948 / 1200 cars and the later 1200s; perhaps the increased size of the 13/60 engine required more modification. I could run a bypass pipe, or remove it altogether, but it's the challenge that gets my blood going. I've located a manifold locally, will collect on Thursday, and see what options there are then; in all probability an initial swap to cure the water leak, then a look at the removed manifold for repair or upgrade options. Link to comment Share on other sites More sharing options...
daverclasper Posted September 13, 2021 Report Share Posted September 13, 2021 5 hours ago, Pete Lewis said: what it does to the fan blades when it can only suck the top half of the rad probably broke a lot of metal blades by excess cavitation Hi. Don't understand this Pete?. Have used plastic corrugated sheet, in front half area of the rad in winter?. Is this an issue?. Link to comment Share on other sites More sharing options...
daverclasper Posted September 13, 2021 Report Share Posted September 13, 2021 (edited) Hi Colin. Not sure if this is any use, regarding access to your leak and not wanting to remove manifold?. About 7 years ago I had pin hole leak on the top cavity of rad (brass I think), after I had rubbed it down to repaint. Made a key in the area using course sandpaper and put a blob of Araldite on it. Lasted about a year. Re did it with JB weld and still ok now (car used regularly). I have also heard chewing gum has lasted a while😃 Edited September 13, 2021 by daverclasper Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 13, 2021 Report Share Posted September 13, 2021 if the fan is partly masked it will pull air through the open zone easily as the blade rotates to the covered zone it has no air to pull through so the blades are fatigued with load /less load as it rotates plastic seem more compliant but a metal fan can end up with a fractured blade and if the thermostat is working there wont be any flow through the radiator anyway so you dont achieve very much by adding a baffle Pete Link to comment Share on other sites More sharing options...
daverclasper Posted September 13, 2021 Report Share Posted September 13, 2021 Thanks Pete. Interesting, It never occured to me about the stat aspect. Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 13, 2021 Author Report Share Posted September 13, 2021 2 hours ago, daverclasper said: Made a key in the area using course sandpaper and put a blob of Araldite on it. Lasted about a year. Re did it with JB weld and still ok now (car used regularly). I have also heard chewing gum has lasted a while😃 I had considered that, I have an unopened pack of some chemical metal-type stuff on the shelf for ages that I'm itching to try, but want to get a spare manifold to work on rather than taking the car off the road so haven't really experimented yet as to what works and what will stay in place. I don't even know where my own manifold is actually leaking from yet, but am just wary of it worsening whilst on the road. Chewing gum lasts a while with me too - used to use a lot of it at work - but the 'while' usually runs out at the most inconvenient moment.. I've been offered a manifold locally - the owner needs a few other parts that I have so we'll do a swap - and Chic Doig has let me know that he has some, so all being well I can experiment with metal inserts and other repairs and report back to the forum. Link to comment Share on other sites More sharing options...
NonMember Posted September 13, 2021 Report Share Posted September 13, 2021 1 hour ago, Colin Lindsay said: I don't even know where my own manifold is actually leaking from yet, Once you've swapped it out, it should be easy to close off one end of the pipe (I think the LH/back has a T so hose from one outlet to the other) and put a garden hose on the other end. Mains water pressure is higher than the 7PSI the engine gets to so your leak will show up as a fine spray, probably, or a rapidly building drip. Either should be easy to spot. Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 16, 2021 Report Share Posted September 16, 2021 aha wet suit and goggles rules apply here flippers are optional Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 16, 2021 Author Report Share Posted September 16, 2021 One in the post and of course collecting a local one tonight, which appeared after I had purchased the former. One to fit, one to keep as spare, one to play with. I think I'll also need an exhaust manifold given the way the exhaust appears welded on, but I'll have to wait for a mortgage to cover postage costs. Link to comment Share on other sites More sharing options...
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