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Old 02-25-2023 | 06:38 AM
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1QwkSport2.5r's Avatar
1QwkSport2.5r
 
Joined: Oct 2006
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From: Cottage Grove, MN
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Originally Posted by LLRCFlyer
Just my opinion that converting a glow engine to diesel may not work as well as one would like. The higher compression ratio of the diesel creates much more stress on the connecting rods and wrist pin. I converted a K&B Sportster .28 to diesel operation. The power increase was not as significant as I expected and in fairly short order, the diesel operation beat up the cheap non-bushed connecting rod ends. Pick the glow engine carefully for a very robust rod and crank. Also glow engines ported for very high rpm don't always do as well when converted to diesel.. In my experience, it is usually better to just buy a good quality diesel to start with rather than try to convert a glow engine.
While I do agree to a point, converted glow engines are an inexpensive way to get “into” diesels. Diesels aren’t for everyone, so getting your feet wet for the cost of a conversion head and a quart of fuel is pretty little compared to a purpose built diesel. However not all glow engines make good conversions.

I disagree on the Sportster not being a good diesel conversion. It doesn’t become this adamantium infused beast, but they do gain an edge over the glow plug side with being able to pull an even bigger prop without much consequence. However, the fuel composition and needle/compression settings are critical. If you run it over compressed constantly and improper fuel composition, sure, you’ll wipe the rod out. Those rods are pretty stout even though they aren’t bushed. I have a .20 and .28 Sportster diesels - they are sweethearts with glow plugs and even sweeter as diesels.