Small Diesel Engines

[svm_invictvs]

I've been lurking for a bit and I've always liked the idea of a diesel bike and would love to build one one day. I've been looking at the smaller 6hp and 10hp Yanmar and Yanmar-Style Knock Offs. Those would be the engines based on the Yanmar L100 and L70 series. I was curious if anybody had successfully converted one to oil cooling, or if that was even possible. I thought I'd at least ask before ordering one and trying myself.

[BertTrack]

Pardon the quetion but why would you want to make it oil cooled? What's the basis for this line?

[gearhead1951]

San Diego can be a very hot place to be ! An air cooled diesel might have a problem without the oil cooler !!

[svm_invictvs]

I wanted to build a small genset that I could run in an enclosed space to reduce the noise. Because it would be enclosed, I thought switching to oil cooling would be a viable alternative to buying a much more expensive water cooled engine.

I know it's not exactly on topic for motorcycles, but I asked because I'm sure more than a few people know those small engines inside and out.

Unrelated, yes, I've bene fascinated with the idea of a diesel bike as well. So...kind of casting a wide net.

[cheesy]

I doubt any of this helps, but I'll throw this out there.

When I was a noob where I work, a customer built some really nice aluminum enclosures for some Lombardini powered gensets that I had installed on some railroad motorcars. Too bad he didn't put in any thought into cooling because all the plastic bits melted and the engines croaked. We didn't warrant the units and someone was handed a pink slip.

On the other hand, Hatz has their fully enclosed 'Silent Pack' units, which are fairly quiet for a diesel and may be oil cooled. I've never really paid attention and I've got several units at the shop. I'll need to look now.

[cheesy]

I take that back re:the Hatz being oil cooled. I looked. Lots of fancy duct work that moves a ton of air.

[svm_invictvs]

The Yanmar single cyl ones seem to have an oil pump integrated onto the side of the engine, as demonstrated in this video

https://www.youtube.com/watch?v=YZ0p8hVF7D4

From what I can see, I'd have to do this:

• Remove the protruding draw tube, and plug.
• Drill and tap a new hole in the side of the engine at the same level
• Tap the input of the oil filter
• Install pipe/tube fittings in the newly tapped holes
• Route the oil through an external filter and a heat exchanger

The question is, after all that work I've permanently modified the engine housing and will that draw enough heat away from the engine to sufficiently cool this. I talked to some tractor mechanics who said that some tractors are oil cooled and it works great. I just wasn't sure if I"m missing anything.

I also found a cheap used Lombardini 6 hp engine. That one appears to have screw-on oil filter, if I am not mistaken. With that I could just bypass the filter through a heat exchanger and wouldn't need to drill/tap and risk ruining the engine. Or am I mistaken on that one?

[klondikekid]

There is also a external oil filter adapter that fits between the oil filter mounting base and oil filter that has two threaded holes for oil cooler lines, it comes in two or three sizes metric and std. it's about 1 1/2" thick, made from aluminum, I am using one on my diesel bike with a 3cyl kubota wich has a small filter. I used an fittings and lines to a small cooler up front. check flebay, I think thats where I got mine.

[klondikekid]

http://www.ebay.ca/itm/Turbo-Feed-Line- ... Np&vxp=mtr

[svm_invictvs]

THat's nice because I was looking for an oil filter bypass for my boat. The oil filter is so hard to change and I wanted to move the filter somewhere else, and yeah it's a small water-cooled Kubota engine.

[svm_invictvs]

Er, maybe I misread how that works.

[UAofE]

The Kubota OC95 in my bike uses an oil cooled cylinder head.