QuestionHi Harry can you tell me if there ever was a diesel engine built for the 92 G20 Mark III Conversion Van? I am thinking about replacing my engine with Diesel becuase I need the power to haul horses and camper. I live in Georgia and also am looking for someone to assist or do the coversion for me. Would be willing to drive the van a few hundred miles to find a good mechanic.
Thanks, Art
AnswerArt,
The 6.2/6.5 GM diesels were offered in G series vans from 1982 until at least 2000. There may have been a few years where diesels were not offered, but 1992 vans had the 6.2 as an optional engine. 6.2/6.5diesels are interchangeable, with the only difference being the bore diameter and the use of computer-control on 1994 and newer 6.5 engines.
The conversion is a bolt-in but there are a number of issues you need to be aware of:
1) The 6.2 used in the van application was not turbocharged. It can be turbocharged, but the cost would be high because the vans require a special intake manifold and center-mounted turbocharger.
2) Without the turbocharger, the 6.2 is rated at 135 hp and 240 lbs-ft of torque. Many vans started out as passenger vehicles and do not have the lower gears in their rear axles that the C/K pickups have for towing. I have carried and towed a lot of weight with my 6.2 G-20 and it did the job, albeit slowly on hills. However, my 6.2 K-2500 is much better suited to the same task and climbs hills with ease. I recently towed a 1985 6.2 Suburban, which weighs about 5,200 pounds, home behind it (the Suburban was towed on all of its wheels, not on a trailer).
3) Conversion requires fuel system modification (addition of proper filters and lines), cooling system modification (a bigger radiator and coolers for engine oil as well as the transmission), possibly a different stall speed torque converter for the transmission, a different and expensive starter, and conversion of the power brake booster to Hydroboost (uses the power steering system for power brake assist).
4) Many states in the USA do not have laws preventing such a conversion, but others do. In the future, you might find it impossible to sell the vehicle and/or even to register it for on-road use. This may be many years in the future, but it is important to consider before conversion.
5) There will be other conversion details to sort out, mostly minor, but complicated somewhat because the van has very little excess space in the engine compartment. I have changed the engine in my G-20, twice, and it requires dismantling the front of the vehicle to remove and replace the engine. It is very difficult, compared to the C/K series and you should expect the labor cost to be higher than it might otherwise be.
I am not trying to be negative here. I would not own a gasoline-powered GM G van or C/K truck. I am very fond of my non-turbocharged diesels, but they are not for everyone. Please consider the potential cost and the fact that a diesel requires more attention to maintenance before deciding whether to proceed.
