Has any one used SVO in the 2 cycle DD engine. If not, does anyone know of anyone who has? If not, has anyone or does anyone know about using SVO in any 2 cycle engine.

The best advice I could get out of DD was if I was going to try it, I better carry along a bicycle so when it broke down, I could ride out for help!

Hi Bill
Svo in a DD is a very interesting proposition, It should work as they are slow reving engines, but the fuel in them is designed to have a high flow rate through the injectors and back through the fuel return in order to cool the injectors.
So in a nutshell I dunno if it will work, can only suggest try it and see, maybe mix it 50/50 with diesel or biod to try and improve its ability to absorb heat quickly
Regards
Greg

HI Greg!

I appreciate your response. So far DD Corporation is no help at all!

I plan to use SVO in an older, converted to a motorhome, Greyhound type bus traveling continuously starting in September, 2002. I won't be able to purchase the conversion for another 6 months or so, so I cannot experiment starting as soon as I like.

I know that the older 2 cycles, first out in 1937, were a very different breed of engines. I find very little information on them, and so far everyone I have talked with who seem to know the engine are purists and are aghast that I might think of using anything but "Corporate approved petro-diesel"!

You sound like you are familiar with the engine and are also in this weird fringe group who think there is a better way. Any information or advice you or anyone else would be willing to share will greatly appreciated!

Regards, Bill

Being an old bus, the flexible fuel lines will be rubber. You will have to replace them. In fact strip the whole fuel system and replace anything suspicious - gaskets, pump diaphragms, etc. At least it will give you chance to clean out the fuel tank and fix anything on it's way out.

The injection pump might have some rubber parts. I think you should strip it and get new non rubber seals and O rings (if there are any). You might find that the only soft seal fitted is on the drive shaft.

Injectors should be OK - they see far too much pressure for soft seals. A new set would be a good idea along with new heater plugs.

I'd personally get the pump professionally rebuilt (you supply the new seal(s). Stripping it down is one thing - rebuilding is another kettle-a-cod (see another recent thread on that).

All this might sound mucho hassle, but an elderly fuel system is unlikely to be reliable whatever fuel you use.

Bill
I was talking to a friend today, (see email) and he tells me that the GM should be ok for svo as the fuel pump is a gear pump,(metal gears) which rarely, if ever, needs repair. The type of gears was my uncertainty, but now I wouldn't have any hesitation in using svo in the GM. All the injection is done by the injectors, pushrod operated, the pump purely supplying fuel under pressure to them via a fuel manifold.
I hope this helps
Regards
Greg

Dave

The costs of rebuilding a fuel pump and replacing injectors in a GM like the Greyhounds ran, are so insane for a personal or hobbyist to consider that you'd often look for another vehicle of this age in better nick than pay for the work unless you were personally capable of the work.

Despite this the engine is highly likely to have been exceptionally well maintained anyway if it's actually still running (EVERY professional driver cannot afford to do differently), and if not, a jimmy is still renowned for its bullet proof nature, second only to that "screamin' demon" engine tone. There are several examples here of old Kenworths nursing various 6/53s, 8v/71s etc having done 3+ million kilometres in searing outback heat and dust, with only regular maintenance and rebuilds. This is the whole reason GM is part of the so-called 'big three' with Cummins and CAT - bomb proof, and certainly not likely to ever be considered 'elderly' and in need of the odd hip replacement. Age has nothing to do with it in this case, I believe.

On the rubber fuel line, Bill; is it steel? If my cheapo 20 year old Hino features all-steel fuel tubing (barring some elbows & joints) I'd be surprised to see any different there.

Greg; does this pre-existing design mean that so-called common rail/unit injection ain't the 'new idea' the other guys want us to believe it is??

Wooly of the SBC (archives section)

[This message was edited by Wooly on 15 June 2001 at 08:33 AM.]

[This message was edited by Wooly on 15 June 2001 at 08:37 AM.]

Dave
The fuel fump is a gear pump, no valves, its only job is to pump fuel oil, which the Australian military used heavy fuel oil in these engines, so temps for svo are probably not as critical for the injectors but maybe are for complete combustion, I dunno on that one just have to suck it and see. The injectors are normally good for around 1-2 million MILES between o'haul, in a Michigan loader we serviced the injectors at 20,000hrs to be on the safe side and they had new needles and seats fitted.Cost wise I don't remember as it was to long ago. The fuel pump was never o'hauled to my knowledge in about 35,000hrs. BTW 100hrs is considered to approximate 5000 miles. All our machines were serviced at 100 hourly intervals.

Wooly
Thats right, the difference is that the new TDI's have electronic control of the timing and amount of fuel delivered and the GM's and Cummins NH series, which also featured common rail injector systems, are camshaft controlled unit injectors.
Regards
Greg