Racing bike fuel types?

An interesting dilema, Normally the open market would realise the best price for the bike and spares. What does the old boy want to happen?. If it were me I would prefer that a son/son inlaw/grandson took an interest in a wonderfull hobby and kept the bike,loved it, and took it to shows and paraded it. If sold the funds could help with care costs ,but won't go as far as one would think,and a valuable irreplaceable connection with the past would be lost to the family. Castrol R and equivalent oil is availiable as is Race /Aviation fuel. The motor should not be run as is ,the old oil may have solidified. This is a reply to an earlier post that seems to have been deleted.

Hello Terry

You don't say what bike it is - we all want to see a picture!

Whether it is a Manx or Dommie the main point is to AVOID starting the engine unless you have completely stripped and cleaned the engine internals. Castrol R (vegetable based oil) will have crystallised, turned to gum and generally converted into something else.

Once rebuilt, you can still buy Castrol R (grade 40) or better is the Morris synthetic-castor oil. If it is a Manx it will run OK on a mineral oil but if you were racing the mineral oil would not be good for the roller big end. If it is a Dommie with plain big ends then mineral oil should be best. Do not mix vegetable and mineral oils, or their modern synthetic versions.

You don't need any oil in the fuel, and even if it is 10.5:1 compression it will run on best street petrol of 97 octane and ethanol in the fuel will not hurt and even help. To race it again you will need 100 octane fuel that can be bought in large barrels for race cars.

Norm

I would add that in addition Millers Oils Brighouse produce and sell (as do their agents all over the country and they export too) a 'castor based' oil. It used to be called Kasterblend but I think its called M50 now. Just visit www.millersoils.co.uk and enter 'M50' in the search field. (they also do M40 and M30)

I used it in my Inter for years with excellent results. Never mix vegetable oil with mineral.

Yes, you can also get AVGAS aviation fuel from most airports, its 100 Oct and a lot of racers use it. No tax too. (I'm told) Go to the fuel bunker access point not check in by the way they won't have a clue!

I wouldn't use avgas if I could avoid it, it has a different burn characteristic than high octane race fuel, if you can afford it race fuel is a much better bet but it ain't cheap at £20 a gallon for small quantities. I mix 115 octane leaded race fuel with super unleaded at about 3:1 to give approx 105 octane which makes 5 gallons of race fuel lasts a season.

dan

If you were only showing/parading you could have the motor set up with a compression plate and just use top grade pump fuel. And drain it off after use and use it in the car,no worries then about Ethanol issues.I also think Terry should think about the patina of a Genuine racer, He may not realise that its just as valued as a poshed up pose machine.There is more than enough to do in just getting up and running.

'...he went into a speed wobble at 220...'

Kph, presumably.

Terry, super picture, thank you for that.

You must send the engine and frame numbers PRIVATELY to Barry Stickland (see email NOC Technical Experts) and he will date it for you and prove a very helpful contact. I looks like a very early frame with the lowered seat tube (or it is bent?!).

Oh you will have a lot of fun learning about cam timings. Just assume it is still correct from the last time it was run. It has to be done with a timing disc and feeler gauges between pushers and valve stems to detecting opening angles, etc. You cannot 'quickly adjust' the valve stem clearances, if an gap is excessively large then old pushers had shims but new ones are ground to length.

If you mean ignition timing then again, a timing disc under the crankshaft nut holding the sprocket, a big wire pointer coming off an engine bolt, and check with fag paper/smallest feeler that the mag points are opening at 36 deg BTDC.

Those big ALLOY hex nuts are actually holding the ball races in on the camshafts.

Lots to learn on this one and very little written material that you will find on the web!

Norm

Just a small point....you will not get the same power from the engine if you run it on modern ethanol doped fuel....this is because the calorific value or energy contained in methanol is less than petrol. If you run just methanol you have to run much richer but as the knock rating of methanol is much higher than petrol you can run on very high compression ratios to compensate and claw back some power. The other advantage is that ethanol burns more coolly so even with the high CR the engine will not overheat...In UK you can buy a Supergrade high octane petrol (Shell I think) this will provide more power.

Les

If the bike has not been run for many years will not the Castrol R set up into a hard goo? Will the engine need to be dismantled and oil passages cleaned out?

Mike

Previously norman_lorton wrote:

Terry, super picture, thank you for that.

You must send the engine and frame numbers PRIVATELY to Barry Stickland (see email NOC Technical Experts) and he will date it for you and prove a very helpful contact. I looks like a very early frame with the lowered seat tube (or it is bent?!).

Oh you will have a lot of fun learning about cam timings. Just assume it is still correct from the last time it was run. It has to be done with a timing disc and feeler gauges between pushers and valve stems to detecting opening angles, etc. You cannot 'quickly adjust' the valve stem clearances, if an gap is excessively large then old pushers had shims but new ones are ground to length.

If you mean ignition timing then again, a timing disc under the crankshaft nut holding the sprocket, a big wire pointer coming off an engine bolt, and check with fag paper/smallest feeler that the mag points are opening at 36 deg BTDC.

Those big ALLOY hex nuts are actually holding the ball races in on the camshafts.

Lots to learn on this one and very little written material that you will find on the web!

Norm

Barry will also tell you he runs both his Manx, Manx's or Manxes (whichever's the right word and let's not go there again !! ) and his Inter on I think, it's Texaco 100 octane super unleaded pump fuel - no additives with no adverse effect. He advised me on this a while ago after I had been adding Millers octane booster to bunkered pump fuel.

Previously michael_sullivan wrote:

If the bike has not been run for many years will not the Castrol R set up into a hard goo? Will the engine need to be dismantled and oil passages cleaned out?

Mike

Maybe - but I doubt if there would be a problem, my Inter had been in a garden shed for many years as far as we knew but was ok - Barry Stickland said on strip down it was perfect and had the best oil pump he had seen for years.