6066 (1960-1966) GMC Truck Club Bitcoin now accepted here! 
Pay Dues
Pay Dues or become a Site Supporter
 



Go Back   6066 (1960-1966) GMC Truck Club > 6066 GMC Truck Club Forum > GMC V6 and V12 Engines


GMC V6 and V12 Engines Engine repair and rebuilding

Reply
 
Thread Tools
  #31  
Old December 29th, 2015, 06:41 PM
Dave Boboltz Dave Boboltz is offline
Junior Member
 
Join Date: Jan 2013
Location: Waterford, MI
Truck: 1964 K1002 Wide Side Long WB 305E
Age: 68
Posts: 10
Rep Power: 72
Dave Boboltz is on a distinguished road
Default Re: SO who came up with the GMC V6's???

Big Block V6, that is a great question and I don't know the answer to that. I did send Cleary an email so maybe I can learn more. Or there is another guy who lives nearby who has some amount of historical information (Don Meyer).

I suspect that the tooling went somewhere that would be capable of making service parts. It would be interesting to know where that tooling is now.

Dave Boboltz, Waterford, MI
Reply With Quote
  #32  
Old December 29th, 2015, 07:06 PM
bigblockv6 bigblockv6 is offline
Senior Member
 
Join Date: Jan 2013
Location: Rohnert Park, ca.
Truck: 1968 KM2500
Posts: 1,325
Rep Power: 415
bigblockv6 will become famous soon enoughbigblockv6 will become famous soon enough
Default Re: SO who came up with the GMC V6's???

It would be interesting to know what became of the tooling. From what it looks like in the email, Cleary was no longer in the V6 development sometime in 1960. He was not aware of the 379,432 and 637 engines.
Reply With Quote
  #33  
Old December 29th, 2015, 10:12 PM
TJ's GMC's Avatar
TJ's GMC TJ's GMC is offline
Senior Member
 
Join Date: Mar 2015
Location: Cave Junction, Oregon
Truck: 1964 GMC 1500 LWB Wideside 305E V6.
Posts: 1,341
Rep Power: 399
TJ's GMC is on a distinguished road
Default Re: SO who came up with the GMC V6's???

So here's a question....anybody know why a small single barrel and then two barrel carb were used on these engines? I'm assuming for low end power and fuel mileage? Might be a dumb question, but with the large bore I would have thought a bigger carb would have been used.
__________________
"Excuse the rust I use my truck"
1964 GMC 1500 305E/sm420 4 barrel intake mod and dual exhaust.
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

1964 Chevy C20 292/SM420
1966 Chevy C10 292 hotrod 6/TKO600


My youtube channel aka Military Chevy:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Reply With Quote
  #34  
Old December 29th, 2015, 11:33 PM
bigblockv6 bigblockv6 is offline
Senior Member
 
Join Date: Jan 2013
Location: Rohnert Park, ca.
Truck: 1968 KM2500
Posts: 1,325
Rep Power: 415
bigblockv6 will become famous soon enoughbigblockv6 will become famous soon enough
Default Re: SO who came up with the GMC V6's???

The one barrel did not work out well with the 305 engine by 1961 the 305D 2bbl engine came in to replace the 305A even though it was still available. 125 net horsepower to carry around that much weight was really underpowered for the 305. The 2bbl brought it up to 142 net horsepower then with more improvements for 1966 to 157 horsepower. Possibly mileage may have been why a 1bbl was used. Originally the prototype trucks used were lighter 1958-59 trucks and the 1bbl version was more than adequate.
Reply With Quote
  #35  
Old December 30th, 2015, 01:33 AM
TJ's GMC's Avatar
TJ's GMC TJ's GMC is offline
Senior Member
 
Join Date: Mar 2015
Location: Cave Junction, Oregon
Truck: 1964 GMC 1500 LWB Wideside 305E V6.
Posts: 1,341
Rep Power: 399
TJ's GMC is on a distinguished road
Default Re: SO who came up with the GMC V6's???

Quote:
Originally Posted by bigblockv6 View Post
The one barrel did not work out well with the 305 engine by 1961 the 305D 2bbl engine came in to replace the 305A even though it was still available. 125 net horsepower to carry around that much weight was really underpowered for the 305. The 2bbl brought it up to 142 net horsepower then with more improvements for 1966 to 157 horsepower. Possibly mileage may have been why a 1bbl was used. Originally the prototype trucks used were lighter 1958-59 trucks and the 1bbl version was more than adequate.
Ah, Ok. I watched a video of a 305A running...man you could hear that thing Breath. lol I was like yeah....that carb is a bit small. You know what improvements were made in 66? I remember running the numbers on mine with a fellow forum member, and my 305 in my 64 looked to be a 67 series engine. Did the 305E ever come in medium duty trucks? Cause mine had the governed dizzy on it.
__________________
"Excuse the rust I use my truck"
1964 GMC 1500 305E/sm420 4 barrel intake mod and dual exhaust.
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

1964 Chevy C20 292/SM420
1966 Chevy C10 292 hotrod 6/TKO600


My youtube channel aka Military Chevy:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Reply With Quote
  #36  
Old December 30th, 2015, 02:31 AM
bigblockv6 bigblockv6 is offline
Senior Member
 
Join Date: Jan 2013
Location: Rohnert Park, ca.
Truck: 1968 KM2500
Posts: 1,325
Rep Power: 415
bigblockv6 will become famous soon enoughbigblockv6 will become famous soon enough
Default Re: SO who came up with the GMC V6's???

A new cam along with different count timing chain and sprockets were some of the changes, at some point up to 66 larger valves were used on the 305 engines as well. Medium duty trucks used 305 engines from their beginning in 1960 all the way up to the very last in 1974
Reply With Quote
  #37  
Old December 30th, 2015, 02:36 AM
bigblockv6 bigblockv6 is offline
Senior Member
 
Join Date: Jan 2013
Location: Rohnert Park, ca.
Truck: 1968 KM2500
Posts: 1,325
Rep Power: 415
bigblockv6 will become famous soon enoughbigblockv6 will become famous soon enough
Default Re: SO who came up with the GMC V6's???

I should have included this in my previous response. Yes 305E engines they were used in 3500, 4000 and 4500 series medium duty trucks.
Reply With Quote
  #38  
Old December 30th, 2015, 02:41 AM
bigblockv6 bigblockv6 is offline
Senior Member
 
Join Date: Jan 2013
Location: Rohnert Park, ca.
Truck: 1968 KM2500
Posts: 1,325
Rep Power: 415
bigblockv6 will become famous soon enoughbigblockv6 will become famous soon enough
Default Re: SO who came up with the GMC V6's???

Light duty trucks too were available with governors.

Last edited by bigblockv6; December 30th, 2015 at 04:26 PM. Reason: two with's used!
Reply With Quote
  #39  
Old December 30th, 2015, 06:37 PM
TJ's GMC's Avatar
TJ's GMC TJ's GMC is offline
Senior Member
 
Join Date: Mar 2015
Location: Cave Junction, Oregon
Truck: 1964 GMC 1500 LWB Wideside 305E V6.
Posts: 1,341
Rep Power: 399
TJ's GMC is on a distinguished road
Default Re: SO who came up with the GMC V6's???

Quote:
Originally Posted by bigblockv6 View Post
A new cam along with different count timing chain and sprockets were some of the changes, at some point up to 66 larger valves were used on the 305 engines as well. Medium duty trucks used 305 engines from their beginning in 1960 all the way up to the very last in 1974
Quote:
Originally Posted by bigblockv6 View Post
I should have included this in my previous response. Yes 305E engines they were used in 3500, 4000 and 4500 series medium duty trucks.
Quote:
Originally Posted by bigblockv6 View Post
Light duty trucks too were available with governors.
Ah ok, yeah....I had to get a new dizzy cause the old was was frozen up....the governed vacuum pump was seized or something. Here's another question....any particular reason why the compression was made so low?
__________________
"Excuse the rust I use my truck"
1964 GMC 1500 305E/sm420 4 barrel intake mod and dual exhaust.
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

1964 Chevy C20 292/SM420
1966 Chevy C10 292 hotrod 6/TKO600


My youtube channel aka Military Chevy:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Reply With Quote
  #40  
Old December 31st, 2015, 01:27 AM
bigblockv6 bigblockv6 is offline
Senior Member
 
Join Date: Jan 2013
Location: Rohnert Park, ca.
Truck: 1968 KM2500
Posts: 1,325
Rep Power: 415
bigblockv6 will become famous soon enoughbigblockv6 will become famous soon enough
Default Re: SO who came up with the GMC V6's???

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

Bookmarks

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
351 V6 swap to 478 V6 5500 GMC GMC V6 and V12 Engines 10 December 27th, 2013 02:29 PM
Re:GMC Diesel V6 & last year V6 used Archiver Previous Forum Posts 0 January 6th, 2002 12:07 AM


All times are GMT +1. The time now is 06:21 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2013, Jelsoft Enterprises Ltd 681711554703|1710436907|0