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Old 05-28-2014, 06:13 AM
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wjvail
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Err... Commenting on the topic of this post - baffle piston diesels - it seems to me that a question to asked and answered would be how to key the sub-piston to the cylinder. If you built a diesel with a baffled piston it would have to slot into the head to have anywhere near enough compression. Since most all model diesel engines have a sub-piston and tommy-bar compression adjustment, you'd have to find a way to make sure the sub-piston didn't rotate. Keying the sleeve is the obvious answer but cutting a slot into a sleeve could lead to a stress point and cause the sleeve to go out of round with temperature change.

A solution might be similar to the Drone diesels from many years ago. They didn't have adjustable compression and compression was altered but using head shims. Since I don't own a Drone, I can verify what they had.

Further, the overwhelming drawback to baffled pistons is that they do key into the head and effectively divide the combustion chamber in half. In a glow motor this is a nightmare and in a diesel it could lead to half the fuel air charge not burning.

Anything is possible but I see all kinds of problems with this and there would have to be some considerable advantage to go down this path.

The short answer is I don't know if any model diesel engines have been built with a baffled piston, but if there were, there were not many.

Cheers,

Bill

Last edited by wjvail; 05-28-2014 at 06:22 AM.