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tapp

Posted: Tue Feb 10, 2015 7:40 pm
by dave randall
hi car almost finished just a small ? is tappet gap as Haynes/m or different for high comp engine and modern fuels thank you dave r

Re: tapp

Posted: Wed Feb 11, 2015 9:13 pm
by howardjs
Hi,
The Haynes recommends 6 to 8 thou when cold. If I set to this I fine I get power loss when hot and hard to start when hot. I set to 12 thou. Basically, if you can not hear them the gaps are too small! (I am told) ;)

Re: tapp

Posted: Wed Feb 11, 2015 11:30 pm
by Jimmy Cooper
I too set them with more clearance when cold (about 12 thou as stated by howardjs) as the engines are normally fan cooled with their ducting in the 2CV so cylinder temps are lower. Our fresh air version run a bit hotter creating more expansion of parts so the valves can just lift on their seats a fraction. Result is burned valve seats etc etc. Safe than sorry!!!!

Re: tapp

Posted: Thu Feb 12, 2015 6:37 pm
by dave randall
hi 12 thou it is then . next job /hover craft fan/ dave r

Re: tapp

Posted: Fri Feb 13, 2015 6:27 pm
by hutchii
Dave,
Bearing in mind what's been said in the topic "Alternator output" I assume that you'll be fitting a switch for the alternator if you live in an area that's hilly. Otherwise when you switch the fans on to cope with the additional heat generated by climbing a hill, you'll have less power available to climb said hill :D
In my very limited experience of a Lomax, and even less of 2cv, a fan can be useful. Mine is fitted with a Continental bonnet, which covers more of the cylinders/heads than the standard version, and when I bought it was fitted with a standard fan. In my ignorance I removed it as mine was the only 2cv based car I'd seen with a fan. A week or so later I was kept waiting for 20 minutes in relatively high temperatures, before entering a show. and sat watching as the oil pressure dropped from around 25psi to 10ish as the engine got hotter and hotter. When I got home, thankfully with the engine still intact, the fan was replaced, and has not been touched (nor will it be) since! A fan, whether crankshaft or electrically driven undoubtedly uses some of the available power, but a sized engine won't get me home.
I have considered fitting an electrically driven computer fan in front of each barrel on a right angle bracket, using the 2 M7 holes which retain the standard cylinder cooling cowl, but so far I haven't got round to it. Given the hostile environment they probably wouldn't last long anyway. Even though they''re low power consumption they do shift quite a lot of air. I prefer the idea of having them in front, as the hottest part of the barrel must be at the top and blowing hot air from the bottom towards the top doesn't work for me!

Re: tapp

Posted: Fri Feb 13, 2015 8:08 pm
by dave randall
hi huchii I built the front end with space for the original fan/no duckting/ but find it keeps r/h cyl cooler than l/h /as I race my cars they get some stick so cooling is quite important .can you tell me your average oil temp .my sender is in the sump regards dave r

Re: tapp

Posted: Sat Feb 14, 2015 8:29 am
by hutchii
Dave,
I'm sorry, I can't help with oil temperature as I don't have gauge. Only one for pressure. All I can comment is that as per previous contribution, rising engine temperatures = lowering oil pressure!
The relative values of too much information from too many gauges has been the subject of much debate on this forum in the past. My excuse for not having a temperature gauge is that I revamped the dash layout some years ago, (before the incident previously described) and as I didn't have a gauge, I didn't include one in the new layout.
Unlike your car, mine gets used for leisurely runs in the country, generally to a pub selling good beer and food! Waiting too long to get into shows is thankfully, a rare event.

ps, sorry for the spelling error in previous submission!