6.2L and 6.5L Chevy Diesel

The 6.2 and 6.5 were designed by Detroit diesel and were a vast improvement from the 5.7 debacle. They were built as a diesel from the ground up, so the reliability was vastly improved.  The main difference between the 6.2 and the 6.5 is .3 liters of displacement, and a Turbo charger on the 6.5.  The 6.2 had a mechanical lift pump and the 6.5 had an electric lift pump.  Although the 6.2 and the 6.5 engines are not bad engines, they are not really great engines either. They tend to have trouble with the bottom ends, and a failed crank shaft is a common cause of death for these engines.

They are equipped with a Stanadyne injection pump, that has proven reliable with veggie oil. The pump has a Normal life cycle of about 80K , but I have seen them go much longer. ( I had one that had 160K on veggie.) They are not as strong as an inline injection pump, but they are good, and relatively cheap to replace. $450 vs $2000 for an inline pump.

The later model 6.5 diesels had an electronic control module that was married to the side of the injection pump (little black box) that has a reputation of malfunctioning and causing problems when hot. Although it can be a problem, there is a fairly simple aftermarket fix for it, and I wouldn’t worry about fixing it until it broke.  Although not my first choice for an engine, it can be considered as a good candidate for conversion.

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