^^^i was specifically referring to fullsize trucks. Whats the combined sales numbers for chevy/gmc trucks with gasoline small block engines? Gotta be in the neighborhood of 100-300K I assume, all of which should have the gen 3/4 architecture. Sorry I dont keep up with truck engine options.

 

OK, I'll try again. Sorry if I was confusing.

2007 Chevy truck sales 1,960,000
2007 GMC truck sales 615,000

Chevrolet plus GMC = 2,575,000 or just a tad (75,000) over 2.5 million

I estimated 1,000,000 of those were not full size trucks or had diesel engines. (I was being conservative.) That left 1,500,000 full size trucks with Gen III or Gen IV engines.

1,500,000 / 12 months is 125,000 per month or over 4000 per day if you sell 7 days a week. Few dealers do.

That's still a heck of a lot more than 100-300K annually. It's actually 5 to 15 times as many.

OK, let's say that TOTAL Gen III Gen IV engine production from 1997 to date is over 15,000,000 (15 million). I heard 17 mil recently, but I can't find the reference. Producing that many engines is hard to imagine unless you have visited/worked in an OEM engine plant. If a plant can produce 100 complete engines an hour, it would take 15,000 hours to make the 1.5 million. At roughly 2000 working hours per 40 hour week in a year, that's 7-1/2 40-hour shifts evey week. It takes at least a couple of engine plants to do that.

We are into the 13th year of the C5-C6 (Gen III, Gen IV) era. At 30,000 Vettes per year, that's 390,000 or just over 3 months normal truck sales of these engines. Being generous with Camaro and TransAm 1998-2002 sales, that might amount to maybe 100,000-125,000 more engines, about one month's production.

So if you like numbers, 4% of all Gen III & Gen IV engines have gone into cars and 96% into trucks. My guess that is pretty close to the plan when the Gen III was conceived in the early-mid 1990s.

My highly-opinionated $.02

Jon

 

thank you very much JON for your input on many subjects posted here ,I learn alot from your response to all the question on this forum.

 

With the non-cathedral port heads (mentioned above), how much of a compromise is the offset rocker arm...?

The force/torque on the rocker arm is now not contained within a single plane, how does this affect durability, and are any special considerations required...?