SO who came up with the GMC V6's???

[Ed Snyder]

Originally Posted by Dave Boboltz

Or there is another guy who lives nearby who has some amount of historical information (Don Meyer).

Dave Boboltz, Waterford, MI

I'm glad to hear that Don Meyer is still alive, Dave. I corresponded with him a few times several years ago. I sent him color copies of all my 60-66 GMC sales brochures that he didn't have. He seemed really appreciative. I don't remember exactly where I first got his contact info, but do remember him being identified as the official GMC historian. I'm guessing he might be in his 80s by now.

[BobBray]

I talked with Don Meyer a few times over the years, he is is very knowledgeable about GMC in the old days.

As for the low compression, there are a couple of factors. First, large bore engines can be more prone to knocking, all other things being equal. Also, gasoline truck engines of the era were designed to use low octane (cheap!) fuel. None of the GMC V-6's contemporaries had very high compression, most were in the 7:1 to 8:1 range. These engines were designed to be abused!

[TJ's GMC]

Originally Posted by BobBray

I talked with Don Meyer a few times over the years, he is is very knowledgeable about GMC in the old days.

As for the low compression, there are a couple of factors. First, large bore engines can be more prone to knocking, all other things being equal. Also, gasoline truck engines of the era were designed to use low octane (cheap!) fuel. None of the GMC V-6's contemporaries had very high compression, most were in the 7:1 to 8:1 range. These engines were designed to be abused!

You got that right. lol I've ran 87 in this thing no problem at all. Though I prefer 91, it's nice to know the engine will run happily on low octane.

[TJ's GMC]

Originally Posted by Ed Snyder

I'm glad to hear that Don Meyer is still alive, Dave. I corresponded with him a few times several years ago. I sent him color copies of all my 60-66 GMC sales brochures that he didn't have. He seemed really appreciative. I don't remember exactly where I first got his contact info, but do remember him being identified as the official GMC historian. I'm guessing he might be in his 80s by now.

Wish I could meet this guy!

[TJ's GMC]

Originally Posted by bigblockv6

I'm not absolutely sure but from what I recall The idea of having low compression was for achieving low end torque.

That makes sense, but man....imagine what a compression boost would do. lol

[bigblockv6]

GMC did have what the called the HC(High Compression) series of V6 engines, never installed in trucks. They were sold for industrial purposes, though they called them high compression the ratio did not exceed 9 to 1.

[BobBray]

Originally Posted by bigblockv6

GMC did have what the called the HC(High Compression) series of V6 engines, never installed in trucks. They were sold for industrial purposes, though they called them high compression the ratio did not exceed 9 to 1.

Yes they did. I think the idea was that those engines were primarily for use with propane/LNG/CNG fuels.

I wonder if any of the high compression engines ended up in forklifts.

[TJ's GMC]

Originally Posted by bigblockv6

GMC did have what the called the HC(High Compression) series of V6 engines, never installed in trucks. They were sold for industrial purposes, though they called them high compression the ratio did not exceed 9 to 1.

Originally Posted by BobBray

Yes they did. I think the idea was that those engines were primarily for use with propane/LNG/CNG fuels.

I wonder if any of the high compression engines ended up in forklifts.

I'll bet the extra compression boost helped alot though. Would be neat to find one.

[Clyde]

Don Meyer, GMC Historian can be reached at 248-693-1227, he is in Michigan. My 1966 Owners manual specifies 92 octane gasoline, back when these trucks were new this was considered regular gas, today this is considered high octane. Anyone over 65 will remember being able to purchase 110 to 120 octane gas without any problem at most all gasoline retailers.

[Cayoterun]

Originally Posted by BobBray

Yes they did. I think the idea was that those engines were primarily for use with propane/LNG/CNG fuels.

I wonder if any of the high compression engines ended up in forklifts.

Great thread. Enjoy reading it.

All the the V12s, I've ever been around came factory equipt with hi-compression pistons since all of them was used as irrigation power plants, and used natural gas or propane.
I was never around V6s, except a few 478s on pumps, too.