proposal to improve hp of single cylinder yanmar etc

greg123 · Post by **greg123** » Thu Jan 10, 2008 11:16 am

Another wild though, taken from some experience in diesel engines and experiements with turbos and fuel economy in general.

Essentially most people want more hp, but these little engines don't produce that much - going to a v-twin doubles it but nearly doubles the weight. The common choice is the (relatively!) light weight 10hp.

So, how about a 10hp that pushes out 20-30hp?

These little engines have litreally nothing in the way of inlet tract tuning, gasflowing and exhaust extraction (tuning the diameter of inlet and exhaust and the length to give a good ram effect at the correct rpm, 3000) and I figure some 'working' of the engine in this way would yeild 20% better flow. Flow = hp when you increase the pump to match the availabe air.

Which is nice, but wanting 100-200% is a bit more...

So - how about a small IHI or similar turbo. I have seen them work well on 200cc carts, so our large CC but lazy diesel (diesel flows more air than petrol due to no 'throttle' in the intake) would be very suitable.

The problem then is, the air cooled engine will get too hot and melt the piston/have other issues.

So... How about the following options:

1) ceramica coat the valves, piston head, cylinder head and ports. This provides a LOT of protection and can be done on a full car engine for £300, so relatively cheap
2) fit an air cooled oil cooler - this substantially helps cool the engine internals. Some motorcycles have little to no fins on the engine and exist running on a big oil cooler only, no water cooling - it's proven.
3) fit ax aux oil pump to up the pressure and drill tap and fit an oil jet spray on the underside of the piston, fed by the big end bearing. This is how all turbo engines come from teh factory, it cools the underside of the piston.
4) ensuring good ducted airflow and powder coating the fins matt black with heat conductive paint or similar will increase the efficiency of the cooling

With that, I think it would work.

As a single speed engine I can't see it having any issues. I can see an issue if variable speed, at lower speeds while the turbo is boosting the 'turned up' pump could be injecting too much diesel, resulting in clouds of black smoke till the engine is 'spooled up' and up to operating rpm. A car pump has a control which relates extra fuel to boost, we can't fit anything like this. Or can we? Maybe the throttle can be linked to boost, rather than directly to the injection pump govenor.

Anyhow another fantasy idea for you, no idea if I'll ever get time to do any of this!

Greg.

pietenpol2002 · Post by **pietenpol2002** » Sat Jan 12, 2008 1:03 am

Greg,

As long as we're dabbling in fantasy, how about one of these for our little 406 CC thumpers.

http://tinyurl.com/3cvtcc

Ron

greg123 · Post by **greg123** » Sat Jan 12, 2008 5:04 pm

lol that's pretty rare! Wow imagine that thing winding away. I wonder what would be bigger, the supercharger or the engine???

Post by **Byrdman** » Sun Jan 13, 2008 7:40 pm

Greg, also look at this thread.

http://tinyurl.com/3bcw27

greg123 · Post by **greg123** » Sun Jan 13, 2008 9:53 pm

that's great!

I have a gpz305 I fancy turboing in the future, the other smallest turbo in the world is from a small industrial diesel, the Lombardini TD025M-03C. I gather it's about the same size, the whole unit is smaller than a coke can!