Evil Homer

Just bought my first Diesel, an MVVS 15, where can i get instructions for this little gem, never been run, so i have to go through the run in process.
Additionally the compresion adjust does not seem to have any locking device on it, is this normal.

thanks
Steve

pe reivers

Have a look at my pages first for fuel. You can use Davis diesel fuel if you can get it.
MVVS engines do not have a lock nut. As far as I know, they do not need one. I had several diesels without a lock device, so MVVS is not alone in this.
For starting, find the compression setting, where the piston just touches the counterpiston. Then back off about 3/4 turn. That should be the starting position. Mark it.
Open the needle about two turns. Prime the engine with a few drops in the carb, and two drops of fuel on top of the piston. (beware: do not prime too much!) Next open the carb to half throttle.
Now smartly flick the prop. It should pop or start. If not, slowly increase compression, all the while flicking the prop. Do not increase compression more than 3/8th turn.
When it starts, find the compression it runs best at with a free, open exhaust note. The sound should not be muffled and labouring. leaning out will cause the engine to misfire. If you can inrease compression again without a labouring sound, that is the way to proceed. When Max rpm have been found, back off compression a bit, and open the needle to get the engine running in a nice two-stroke pace.
Unlike glow plug engines, Diesels should use a larger prop for running in. I suggest you start out with a 9x4. A heavy prop also helps during the first running in.
Do not use a start motor if you can avoid it. When you do not know your engine, the risk of fluid lock is too great, and you may damage the engine beyond repair.

DarZeelon

Steve,


Congratulations on your new Diesel MVVS.

This engine is different from the .15 glow engine, in having a steel sleeve, not a chromium plated brass one.

It needs a very rich, very slow break-in so it will last a long time.


You can enter the Diesel engine forum, where dieseldan, Hobbsy, JCB, AJC and others will be very glad to give you tips.

Adjusting a Diesel model engine needs you to adjust two things, compression and the fuel needle.
A Diesel cannot be made to 'lean-run' and if set too lean, will just misfire.

The compression should be balanced between black oil exhaust and misfiring.

These are basics.
Go to the [link=http://www.rcuniverse.com/forum/Everything_Diesel/forumid_87/tt.htm]Diesel forum[/link] for more info.

Evil Homer

Thanks for the information, I am having a look at sourcing some fuel at the moment here in the UK.

Should the contra piston be really tight to move with the adjustment, reason being is even when i loosen the compression off a bit the contra does not move even when turning the engine over....

DarZeelon

Steve,


The contra-piston is tight.

Compression forces may move it, but they just as likely may not.

Combustion forces will move it for sure.

[link=http://www.modeltechnics.com/diesel/diesel.html]Model Technics[/link] in the UK makes ready-to-use Diesel fuel, with Iso-Propyl Nitrate as the ignitor.
You should use the high Castor type for your engine and play with the ingredients to produce something close to the MVVS recommended blend. This is 45% ether, 25% Castor oil and the remaining 30% kerosene.

Since the ignitor allows the engine to run at a lower compression setting, it actually reduces the loads on the engine's internal parts.

Evil Homer

Got some fuel today, and just got the little running, put 100ml through the little beasty!!!