Dowty Model » Model Dowty Turbocraft project « previous next.

I've finally decided to bite the bullet and replace the block on shameless lady. I think there is a crack some where and the previous two owners have had no luck with the engine either!!! I bought a Consul mk2 Engine to replace the existing which is a Zephyr 4 engine. The original specifications for the two engines says that the zephyr is the more powerful of the two engine. I know this is part down to the head being a different compression and valve size.

My question is does anybody know are the two different in any other way, such as cam profile? The Zephyr 4 was basically the Mk3 Consul. The name Consul was dropped from the Mk3 range.

The Mk2 Consul (204E) engine has a slightly lower compression ratio than the Mk 3. Hence the slightly higher power output of the Mk 3. I have a feeling that the Mk3 has a different start motor layout.

Pinion/Flywheel ring gear ratio is lower to overcome the higher compression. I think the Bell housing layouts are different between the Mk 2 ad Mk 3 engines because of this. From the Haynes Manual: Mk 2 engine was 7.8:1 compression ratio and produced a nominal 59HP net Mk 3 engine was 8.3:1 - ' ' - 68HP net I don't think from memory there was any special cam magic except on the Raymond Mayes conversions, but these are fairly easy to sort out later.

I don't think there was an increase in the valve size (without dredging through the manual). Home Audiometer Hearing Test Keygen Generator on this page. The standard head is not that well ported.

The Raymond Mayes conversion had much better porting and larger inlet valves Various Carburettor options are available but don't do much for a boat. Lot's of large carbs just improve the 0-40 mph time of a car and increase the fuel consumption My Simmonds engine is a Mk2, with a Weber ICH34 carb conversion.