The Place

Cos you didn't design it
Or the last person it happened to fitted it without telling them it could be done wrong. Tell them, decent feedback and constructive criticism is always good to a designer (at least to this one anyway, you should see what I design )

The sump plate is, alas, a standard part of the motor A simple mistake to make with what would appear to be grim results.

Oh right, sorry for my jumpin in. Cheer up ol' bean. My dad raced a gt750 suzuki kettle for a season and finished 2 races I think ( might have been just one) , and seized in every other one. Never did sort it, was just lucky he still had the NSU in the garage to do classic meetings at the same time.
You think it's bad now, imagine Dad with 2 bikes in the garage that both had engines and a norton commando quaife gearbox in bits on the bench

Don't have to imagine that Steve - the memory hasn't gone totally yet Oh, and often with bits of our kettle or Trumph lying about as well

Seen the damage today. One big end shell seriously melted. Crank journal will need a regrind and the rod is scrap. Still we are lucky as Phil as a stroked crank ready to fit (standard not lightened this time), another con rod (they are shorter than standard) etc. so all being equal will be fitting a the motor next weekend.

But what was the cause ? oil stravation ? It will happen again if you dont cure the problem.

Tripps, Mike is right, what caused the motor to starve? Was your oil tank full, oil swill will cause it to starve. Descride the oil set up if you will.

As mentioned above the sump plate was fitted back to front. The oil return is by scavenge and is severly restricted if said plate is put on the wrong way round. When fitted correctly the return is almost ferocious. When fitted back to front more a pathetic dribble. All other bearings etc were fine but as another crank is being fitted the shells will all be new. Phil is more than happy that nothing sinister has caused the failiure.


Oil set up:
Tank mounted behind frame approx 8 - 9 pint capacity. This is fed to the engine via a high flow pump and returns via the oil cooler to the top of the oil tank (via an internal tube). There is a standard Trident oil filter in the engine and the gauze filter under the sump plate.
We run with 6 pints of oil in the tank to allow room for expansion etc.

If it was the plate, happy day's, I dont think you had oil problems last year did you?

No, a few others, but no oil issues.

This use to be my bike me & ruth won dozens of races on this bike with no trouble. There is to much crap talked about oil. The problem is oil feed, it does not mater what oil you use, if you have oil at the big ends all the time and i mean all the time you will not have a problem good luck geoff

Thanks for the reply Geoff. I know you and Ruth did well with her as did Nick Bates and Malc Swan (the previous owners). Sadly when we bought her many things had gone on of which most were very bad. Add this to our own inexperience and this is the result. I fully understand your point about oil.

The dismantling and preperation has all be done and the reassembly will be done over a couple of evenings this week by Phil with collection being done on Sunday.

Things are looking much better now and we will be at Mallory on the 30th to get a few laps in and make sure all is well before the trip to Oulton Park.

Just remember this. Success is the ability to go from failure to another with no loss of enthusiasm. for the big ends to fail in this manner it is always oil feed problems,

Just remember this. Success is the ability to go from failure to another with no loss of enthusiasm

Indded so but there comes a point when you do have to take a long hard think

However we will be at Oulton Park on the 2nd June having spent a load more time and money. Can't knock us for trying

Looking forward to Wednesday and testing at Mallory. Have had a change of gearing to try out too.

Triplebrew wrote:[However we will be at Oulton Park on the 2nd June having spent a load more time and money. Can't knock us for trying

we have spent a lot of time and money on our bike.....


we won't be at oulton