Watermota Sea Panther

[gusboy]

The basic problem of converting a petrol engine to diesel with the need for double the compression ratio without there being a starter motor with sufficient oomph to turn it over fast enough. As I suggested, this was a low budget project with very small numbers of engines built and the 24V for starting was the "fix". Starters were a problem on all the 85 bore engines - short stroke and high compression ratios compared with other engines of the time and dear old Lucas could not keep up with developments.

Would you know if the compression I’m getting is okay. It is 295psi on three cylinders and around 245 psi on one cylinder, this test was done on a cold engine.

 

[Tranona]

Sorry, don't know what it should be, but if 3 are the same that suggests nothing wrong with those, but the drop in one might be cause for concern.

 

[gusboy]

Checking on YouTube there a guy there with an elderly diesel ford tractor which ran fine with much lower compression.

 

[Tranona]

As Vics says one of the problems with older style diesels is getting a big enough "bang" to get them going and many used a similar device to the one he mentions to heat the inlet manifold so that you have hot air going into the cylinder with the fuel. Glow plugs would have been the way to go, but I guess it would have meant a new head casting and more electrics to operate them.

Once the engine is going doubt a small drop in compression of one cylinder would make any difference.

 

[burgundyben]

You don't have enough compression.

The compression causes temperature rise to the point its high enough for the diesel to ignite.

In a cold engine much of the heat caused by the starter motor turning over the engine to compress air in cylinders is lost into cylinder walls, head and piston.

Its why introducing heat into a cold diesel works, its elevating the starting temp, the delta caused ny the compression is the same, so the end point is higher, reaching the point fuel will ignite.

I think the engine was borderline when new, now its a bit worn.

 

[PaulGoddard]

Would you know if the compression I’m getting is okay. It is 295psi on three cylinders and around 245 psi on one cylinder, this test was done on a cold engine.

Hi Gusboy,

I've owned a boat with a Sea Panther engine in for the last 3 years.

I'd done a fair bit of work over that time renovating/replacing bits of the engine - So I know it quite well.
It doesn't start on the button, but takes about 3 to 4 seconds to fire up. But fire up it does, reliably every time.

Mine has a thermo start fitted, but I've never used it.

Whilst my Sea Panther starts and runs fine, the exhaust has increasingly put out a lot of white smoke, which I have spent the last few weekends investigating.

Regarding your starting issues I have a few comments:

• The compression of my cylinders if between 270 PSI and 280 PSI. According to the Sea Panther manual, it should be 18:1, which is 265 PSI
• I did have an issue with starting earlier this year, which I initially diagnosed as a duff battery. Eventually it turned out to be my starter motor had given up.
• I removed the starter motor and got it reconditioned at a cost of £120. Refitted it, and it started even quicker than usual. I would recommend doing this, to rule out the issue being starter motor.
• What is your battery doing when you try to start - EG what 's the amp draw and what voltage does it drop to? And how fast if the starter turning over the ring gear?
• Where are you based? If you're in the UK and around the South East, I'd be happy to come and have a look.

My email is paul@pg-it.com, please feel free to message me direct and I can send you some help videos of the starter issue I have, and how to diagnose it.
I've also got a long list of suppliers for various UK parts for the Sea Panther engine, including the starter motor, fuel injectors, gasket set, high pressureinjector pipes, banjo bolts, etc...

Thanks,

Paul.

 

[PCUK]

The Thermostart should burst into flame if the engine is not turned over. Even though it is new that could be the problem. Also, is the air filter clean?

 

[jwfrary]

Your starting gear, motor batteries and cables need to be tip top to get these running. They are petrol engines lazily converted to diesel and therefore have the bare minium of compression to get the job done. Once running they are pretty good all in all and fairly simple to work on.

You may fine slightly advancing the timing will help with starting, I vaguely remember you can rotate the pump on these..... But I may be thinking of a perkins!

 

[gusboy]

Hi. I own a Birchwood 25 cruiser fitted with a Watermota Sea Panther diesel engine. This engine runs okay but it is nearly impossible to start. I've had the compression tested which was 295psi, for three cylinders with one at 245psi. I've had the injectors and injector pump tested and all were found to be operating as they should. I have two questions, any advice on starting the engine and secondly, what alternative engine would be the best replacement with the minimum of work.

I have now solved the poor starting issue, and the engine starts first time, every time. I’ve fitted a truck 12v 225Ah battery and truck battery leads. I still need the thermostart, but at lease I’m not having to put 24v through a 12v starter. A big thank you to everyone who offered advice, all very much appreciated. Gus