BrianO-delete

I'm curious about the use of diesel engines for marine racing applications. For the smaller glow engines it is quite usual to use a gearbox to convert some of the revs to torque and thus turn a reasonably efficient prop. Diesels being lower reving, but with greater torque, might be a viable alternative.

Comments?

Ron Olson

My Feedback: (1)

I tried running a Davis Deisel conversion years ago in my R/C truck with an OS .12Z motor. I told you that it was a long time ago! Anyway, I had a lot of trouble with it, I couldn't get anything higher than off-idle with it and it wouldn't run. The glow head went back on. A Co-Owner of the LHS tried one also and had the same problems. Not worth the hassle in my book. If they were good, more people would have tried them long ago.

BrianO-delete

Hi Ron and thanks for your input.

I also used diesels about 35 years ago when I was a kid. (In the days of ED, Taplin, Frog and Oliver Tiger).In the main I managed to get them to run OK when I realised they had to be adjusted on load. (Pretty tough with a car or truck I suppose).
I was thinking with the porting and tuned pipe (did they exist 35 years ago?) improvements that have taken place since the they would be far better behaved.
One fact I have discovered that drives this enquiry is the higher CV (and hence energy) in the base ingredient kerosene v methanol.

Perhaps there is an expert out there with recent practical knowledge who can add further to this debate.

David Smith

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I remember running an ED Super Racer diesel in a flattie hull about 30 years ago, nothing like as fast as a glow powered model, but it was fun while it lasted.

Does anyone make a marine diesel these days? I am mostly involved with model helicopters now, but the urge to run a boat sometimes comes over me, and I ma surrounded by lakes and rivers here.

(edited 'number of years ago', don't they go fast!)

BrianO-delete

Hi David

Thanks for your input. Again we're talking about diesels before the days of schneurle porting and tuned pipes.

Is there an expert out there who can answer my questions?

David Smith

My Feedback: (1)

Brian,

In fact, I was running an ED pipe on the Super Racer. I think that ED were the first to make tuned pipes available commercially.
Have you tried talking to PAW? They are still making engines up in Macclesfield and may know if anyone has tried one in a boat. I would be interested to hear if they have, as I have a few PAWs sitting around.

Aeromodelling experience suggests that a diesel will offer more torque at lower revs, potentially eliminating the need for a gearbox and also be more economical. I remember seeing Oliver-powered steering models at Eastbourne as a child.