www.jec.org.uk

Hi all

I experienced my first high(re) temperature episode on the m1 on Thursday bowling along nicely then traffic in temps of 30 degrees worst still creeping uphill with auto gear box, I didn't boil but gauge was going up and power was down as engine was starting to sound like it might stall. I pulled over in services bonnet up very hot, temp gauge C 85. I suspect the running probs and lack of power may have been fuel vaporisation as the prev ow ever had fitted a modern metal fuel filter with a secondary plastic one which sits quite close to the alloy thermostat housing,

After 10 minutes cooling it all started ok and ran ok turned off to go to chesterfield and straight into another 4 miles of traffic, I pulled over a few times just to be on safe side, a bloke came past me rolling his lighter classic alfa for the same reasons.

Car ran ok after that but this weekend definitely doesn't like hotter weather, same symptoms when idling after a run (heat soak) but when checked with digital infra red thermometer the temperature is below 90 so I guess this could be normal, the placement of the fuel filters could be the culprit for fuel vaporisation?

as a prelude to this I have read and digested the previous forum advice from Martel ecosystem lynx and other learned brothers

Anyway my question is kenlowe fans . given that motorway traffic jams did not exist in the sixties and that they had the good sense to provide hard shoulders for stricken vehicles I would like to have an electric fan to assist in traffic. Problem is I have dynamo with attached power steering pump and a kenlowe fan draws 20 amps, have any of you guys run a kenlowe with a dynamo, kenlowe fans have been around for ages and I can't believe that every time one was fitted back in the day an alternator swop was done.

I understand that at idle very little current is produced and that there would be a risk of discharging the battery in a prolonged jam

I think my cooling system is ok as when I got the car 2 years ago I had an issue with a leaking core plug and a blocked heater matrix, I had a good rake around in the bottom of the block with a long handled wire brush and flushed out a load of sediment in both directions via the core plug hole and the bottom block and back flushed radiator which was not the original removed the heater matrix and cleaned and flushed. It all worked fine after that no cold spots in rad and heater matrix did not fur up again. The heater blew vey hot in my traffic jam situation so it has not become blocked again so hopefully my attention to antifreeze and some anti corrosion water wetter stuff I got from rob beere has worked to prevent recirculating crap

Thoughts on the kenlowe with a dynamo would be most welcome, I guess I could also just get a cheap 16 inch fan off ebay and just wire it with a fuse relay and switch for these situations. The alternative is just to avoid the motorways in this hot weather might work just as well as sitting in traffic for an hour is not the best use of the summer, deck chair and beer prob better use of time

All the best

Richard

I was also thinking of taking my car up to ken Jenkins in worksop to check my recent axle/brake work I understand he doesn't rate kenlowe fans
Richard

A dynamo operated at low revs is rather less productive than an alternator. It is quite possible that the dynamo cannot keep up with demands placed on it by the Kenlowe or other high current systems in use on your car when the car is idling.

I had a Mk2 Triumph Vitesse fitted with a dynamo and Kenlowe. I had similar issues to the ones you describe. I fitted a Lucas ACR23 type alternator and the issue was alleviated. No more red flashing ignition light when slow running and white headlights instead of orange.

Mike

Hi mike

Problem is would have to run power steering differently as that type of charging unit has no provision to run the power steering pump and I really don't want to have to change all that

There are alternators with rear drives but c £400 as opposed to 70 squid for normal

Regards


Richard

i suppose the question is

£400 or a boiled car ?

there is great pressure to keep cars ' standard ' , however , as you said, they are 60's cars, and the world got more efficient , so why tolerate old technology if it doesn't perform in modern traffic





BB

Just to add my penny worth.

If nothing else a chat to Ken on the issue wouldn't go amiss, he has recently taken to answering questions on here.

Ken has told be before that the extra fan reduces the air flow through the radiator and due to a few problems I still have my very big scrapyard electric fan but on a manual switch.

I'm also told sypathetic updates improve the value of the car!

I was out in our MkII on Sunday and noticed the temperature gauge climbered up from an indicated 68 degrees to 71 degrees (in reality it is a few degrees hotter) and I wasn't hanging around (through flow cabin air system was on cool). I also have the added heat of burning LPG.

I would think that if your temperature was above 75 degrees then the problem is in the cooling system.

A look at the radiator (mine is now 14 year old, copper but uprated to 4 row),

Water pump is it OK,

Incorrect timing won't help.

Anti freeze kept just below 50%.

Ken Jenkins is the oracle for me.

I am running an alternator (65 amp) and an XJ6 power steering pump for the variamatic steering but a change to this set up seems to me to be missing the initial problem. Never did like dynamos after hassle with early mini's, an alternator gives more current at lower revs.

Brian

Hi Brian

I am glad you have chipped in, I was going to pm you if you hadn't

I am going to talk to ken, I have done a few things to the jag now and I don't think it would hurt to get him to cast an eye over it I am not far from worksop 50 miles or so

I don't think I have explained this very well the car is sitting nicely at 67 at normal or motorway road speeds, it just doesn't like the hot weather when forced to idle in traffic jams, also I forgot to mention it is an automatic so I guess the engine is having to turn all that gubbins too. On the subject of automatics I am unclear in these situations whether it is best to leave it in drive or to go to park this ups the revs by a couple of hundred rpm which I can't really see offsetting the heat increase by the increase in fan speed

Getting really paronoid have been checking with my digital pointy laser thermometer and this is showing various hoses at significantly higher temps when the indicated is just over 75 that is stopped immediately after a fast run ie heat soaked, the exhausts are c 300 so it is hardly surprising that it gets so hot in there and why Coombs louvred the bonnet . I have also checked brakes for binding these seem ok

I also discovered an intermittent misfire due to a corroded lead, I will check plugs and timing tommorrow

Funny thing is non of this has every bothered me with any of the other old cars i'ved owned, I guess my mg is probably only worth half an xk engine rebuild but I guess it doesn't help to think like that. My good friend who owns a mgc is very different to me he justs drives optimistically and then gets someone else to fix it when it goes wrong

I still like the idea of a booster fan, even with no alternator a large 20 amp fan should run for the best part of an hour even with no charge, plenty of time to find some hard shoulder to stop and hope that the cops understand that not destroying a piece of motoring history is an excellent reason to stop

I have to say when I was stopped chilling out the other day by the side of the dual carriageway, I was heart warmed by the number of (unneeded) offers of help, bottles of water being freely offered and even a tow, restores you faith in human nature

And also I got out for a drive tonight which was great!

Cheers

Richard

Hi Richard,

I was thinking of your problem again and realised I had forgotten the cheapest and most overlooked solution, the pressure cap on the radiator.

I wrote before of a strange occurance on my engine what made me look closer at the cooling system. The temperature sensor in the water pipework before the radiator and the guage on your dash need to be matched. There are several temperature transmitters and I just swapped them about until one showed a reasonable reading (testing by remote digital thermometer as you have and a bakers thermometer in the top of the radiator).

The radiators went through a few changes and so there are two LENGTHS of pressure cap and pressures. One pressure cap reaches deeper than the other and only has one pressure (that is mine) and if you have this radiator and then fit the short reach cap you effectively have an open system that will run considerably hotter.

So as an easy option measure the length of the cap and the depth of the radiator top. If you have the later short cap and radiator you have the option of two pressures. I personally would buy both pressures caps(short) and try them but would prefer the lower pressure possible.

I have been to see Ken with my car with funny noises or the need for ignition curve data or the need for good used stub axles and he has always come up trumps, so you see I have a lot of faith in his advice (but I still have the old electric fan in there)!

Best wishes

Brian

Just to add to this topic, I went last night to our local classic car meeting and I got talking to another guy with a MkII.

It is fitted with a 240 engine, ie it has SU carbs and a strange inlet manifold arrangement that I need to look up, but he was having a lot of trouble with overheating and when he lifted the bonnet there was heavy rust staining at the front of the engine. He said that as he stopped the engine it discharge water onto the floor. The radiator matrix looked in good nick, but there was no driven fan, only a small electric fan. But the most noticeable thing was the shine new radiator pressure cap (7psi).

On removal of the cap it was obvious that the rubber seal wasn't touching the radiator seal face. He has an early long neck radiator which needs a 4psi long pressure cap to seal it and maintain a decent temperature. Also he wasn't using a thermostat which would make the cooling of the rear cylinders marginal at best and likely to seize at worst. A proper pressure cap and thermostat would go a long way to solving his problems.

It was interesting to see another MkII with problems, but another club member then told me of his MkII, he found 3 discs of shiny metal(about the size of a 20p peice) on the floor below his front bumper (the car was backed into the garage) but no oil or water, where did I think they had fallen off from?? no idea.

Brian