Petrol in oil???

[erictharg]

Wierdest thing. Checking the racer over ready for the new season. Dipped the oil to see is was about 1" above max mark, and looking thin. Smelled the oil - had a lot of petrol in it. Drained it and it was very thin, and stinking of fuel. No idea how so much fuel got there. Must have been the best part of a litre in there. The carb is higher than the fuel in the tank so can't have siphoned. Couldn't do that via the float chamber anyway. Unless someone switched on the fuel pump while I was not there...
I run a Bendix electric pump so no mechanical pump to leak into the crankcase. Otherwise looking good.
The clutch problem turns out not to be a "problem". Seems if you run a thick centre plate (like my recent AP racing plate) you can get a situation where at full pedal travel the diaphragm fingers actually touch the centre plate pushing it back in contact with the flywheel. Use a little less than full travel on the pedal and its fine. Thanks to the internet for that one. Midget clutch systems seem very marginal, based on all the posts out there, but this was the first problem I'd had with mine. Stripped and cleaned the salve cylinder anyway and bled it all.
Also pulled the timing chain cover and used as much RTV as I dare to try and stop the oil leak from the gasket. The covers get really distorted with lots of removal and fitting (esp if overtightened...), so a bit of gentle peening of the holes and the RTV should sort it out. Or at least reduce the leak to an acceptable level!
Fresh oil and filter and new coolant. Road test this afternoon maybe.
First race Easter Monday at Oulton Park. Full International circuit. With the HVRA guys. 40 American V8 racers, all with with 400 to 600 hp. Guess who'll be at the back of the grid...
Practising the circuit on Power n'Glory as not driven Oulton before.

[Westfield 129]

Fuel in the oil is not that unusual with carbureted cars that have manual chokes. Sticking chokes make for very rich mixtures, which end up diluting the oil with raw fuel.
Assuming that yours is a racing engine, finding some fuel in the oil is to be expected, especially with the rich mixtures that you may be running at low speeds.

However, the quantity of fuel in your oil is likely due to the float bowl(s) syphoning into the intake ports, draining into the cylinders, then past the rings and into the crank case. This is likely due to the fuel pump running when you didn't want it to. Perhaps a short in the switch or switch wiring? It is always a good idea to keep the master switch (its' a race car, right?) off when it is not being run. It might also be a good idea to check the carburetor's fuel pressure, float valve(s) and float(s) as well. This is the only place you can introduce the fuel into the oil pan, as you don't have a mechanical pump. I had a similar problem with one of my Renault R5Turbos, where a stuck starting injector allowed the cylinders to fill with fuel in just a couple of minutes during a tuning session.

I have been using Hondabond or Yamabond (motorcycle engine sealer) on the front cover, and that has eliminated the leaks. Peening the holes and the mating surface helps as well. The front seals also have a problem with leaks, and need to be seated with RTV or the Yamabond.

[adamwilkinson]

Hi Charles,

Never experienced petrol in the oil so cant help there.

If you ever get to look in our pedal box you'll notice a wooden block behind the clutch to stop exactly what you describe happening, although once up and running I don't actually press the clutch down fully when changing gear.

[erictharg]

Like you, when racing I only dip the clutch as much as needed. Only when unloading from the trailer did I notice what I thought was a "problem". And of course it turns out to be nothing of consequence! A lot of fuss about nothing. But an easy fix!

[Westfield 129]

Properly set up, there should be no problems with pushing the clutch pedal all the way in. Perhaps an adjustable slave rod might be the fix, or a different slave cylinder?

I had a problem with a noise with the clutch pushed all the way in. It turned out to be the oil pump housing cover and my Rivergate Datsun conversion. A small dent fixed the problem.

[bobwhittaker]

CLUTCH PROBLEMS ,I experienced the same symptoms , however it does cause problems when out on the road ( Not the Track ) when in traffic and having to constantly stop and start and select a gear from a standstill and you are repeatedly depressing the clutch fully . This gives a feeling that the pedal has gone " Over Centre " it then locks the clutch and the gear is difficult to engage . Some form of stop at the pedal is required either a " Wooden Block " or an adjustable threaded device . If the slave cylinder travel is not limited in some way there is always a chance that it's piston could pop out of the end of the cylinder ,a bit extreme but there is nothing to stop it .
I'm hoping the Type 9 Gearbox conversion may eliminate this but the hydraulics remain the same as the Midget so I will probably make up some form of travel limiter .
Regards the Type 9 conversion , it is now in place with minimum modifications ( No Welding ) however still waiting for the propshaft and gearlever from Westfield . Have bought a gearlever off ebay for £5.00 till the new one arrives . One annoying problem is the speedo drive,which is cable,as there insufficient room to get a proper sweep on the cable where it comes out of the gearbox . I begrudge paying the absolutely extortionate price charged for the 90 degree bevel gearboxes , but at the end of the day I may well have to . BOB

[Westfield 129]

Westfield's Type 9 Conversion includes a right angle speedo drive that is easy to install, and allows the speedo cable a nice path to the instrument.

[bobwhittaker]

Type 9 gearbox speedo drive , Westfield list in the gearbox conversion kit " A speedometer driven gear " . What was supplied was a nylon /steel worm wheel (Red in colour , colours indicate ratios ) and spindle to fit in the tail of the gearbox to mesh with the output shaft and then drive the cable, definitely no 90 degree drive , I am still waiting for the prop shaft so will tackle them at the next phone call . Cheers BOB

[Westfield 129]

You have been shorted a part. The Westfield supplied T9 installation kit includes the 90º speedo drive. It was included in the RHD car I recently built. Mine was hidden in the parts inventory. There was not much rhyme or reason to the kit's packaging... It was also listed in my parts inventory sheet.

Very easy to install. You can screw it in from above with the tunnel cover off.