GM announced two newsworthy items today regarding their diesels. Note that I said "diesels," as in more than one... The first being info on the 2007 Duramax 6.6L found on their heavy-duty pickups. As you might expect, the changes are clearly in the "refinement" area, with little ground-shaking news...
The other announcement does fall in the "ground-shaking" category: GM has officially announced that they would have a light-duty diesel for trucks under 8600 pounds, and it will be on the market after 2009. Well, you could say this was expected, as there will be more diesels on the market in the next few years. Yeah, but here's the catch: This new GM diesel will be a DOHC engine, with four valves per cylinder! Here we have GM, the torchbearer for OHV truck engine design, is now giving in to DOHC technology for full-size trucks. Could this mean that DOHC gas engines for their big trucks are just around the corner also?
You can read about the specifics here.
ateixeira says:
01:48 PM, 08/25/06
Emissions are supposed to be way better so I look forward to seeing these engines in production.
mikesright says:
05:29 PM, 08/25/06
Don't expect GM to move away from the pushrod V8's. The small-block is best-in-class, whether you consider fuel economy, power, etc. Besides, the current Duramax is a DOHC design too!
rsholland says:
06:40 PM, 08/25/06
DOHC? Not according to this site.
http://www.truckinweb.com/brandpages/chevy/0508tr_2006_duramax_diesel/
The Duramax 7800 is an OHC (not DOHC) 4-value unit. This inline 6-cylinder engine is used on their larger trucks, 6500 and above.
http://www.shadetreemechanic.com/duramax_diesel.htm