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
  #41  
Old October 16th, 2018, 09:10 AM
Cayoterun's Avatar
Cayoterun Cayoterun is offline
Senior Member
 
Join Date: Jan 2013
Location: Guymon, Ok.
Truck: GMC V12 powered '46 Chevy pu
Age: 84
Posts: 167
Rep Power: 114
Cayoterun is on a distinguished road
Default Re: Gmc V12 in trucks

Quote:
Originally Posted by Cayoterun View Post
Thanks, BillT for a good belly-laugh to start the day. Did the floor boards shake, and you looked in the rear mirror to see how much pig iron was scattered on the pavement??

Since on irrigation wells, the motors ran at a constant speed, we'd tune them at night and use the exhaust as a guide. With the stub pipes on each head, blue flame would be at the pipe tips, so we could tune each distributor on each side of the motor, by tuning in each distributor to max blue flame.
More V12 trivia: Since the irrigation motors run at a constant rpm, under load,

spark advance wasn't necessary, so if you find on the distributors the advance may be locked, rusted, or disabled, in one position, that is the reason. It was tuned at the operating rpm it normally ran.
__________________
Cayoterun
Okla Panhandle

I think I'll fix it myself, and pay the extra $500.
Reply With Quote
  #42  
Old October 16th, 2018, 01:23 PM
Motiv8 Motiv8 is offline
Junior Member
 
Join Date: Aug 2013
Location: Plympton, MA
Truck: 1962
Posts: 11
Rep Power: 68
Motiv8 is on a distinguished road
Default Re: Gmc V12 in trucks

Gentlemen, I believe the conrods of 351 will swap w/ 702 (never bothered), you may find 351's are Arma cast iron and 702's are forged steel. Some think 702s are configured as 2-351 V6s. I believe they are 2 inline 6 cyls . Each bank timed and tuned separately, then combined. Have built many V 12s including Lincoln, Packard and many today obscure makes. Many stagger each inline bank from the other a few block angle degrees to reduce harmonics. That necessitates separate bank tuning.
Synchronizing carbs can be done accurately w/ exh analyzers.
Fuel mileage is one -two mpg they tell me. JMHO David
Reply With Quote
  #43  
Old November 3rd, 2018, 12:15 AM
Cayoterun's Avatar
Cayoterun Cayoterun is offline
Senior Member
 
Join Date: Jan 2013
Location: Guymon, Ok.
Truck: GMC V12 powered '46 Chevy pu
Age: 84
Posts: 167
Rep Power: 114
Cayoterun is on a distinguished road
Default Re: Gmc V12 in trucks

Quote:
Originally Posted by Cayoterun View Post
Thanks, BillT for a good belly-laugh to start the day. Did the floor boards shake, and you looked in the rear mirror to see how much pig iron was scattered on the pavement??

Since on wells, the motors ran a constant speed, we'd tune them at night and use the exhaust as a guide. With the stub pipes on each head, blue flame would be at the pipe tips, so we could tune each distributor on each side of the motor, by tuning in each distributor to max blue flame.
BillT: If a muffler had blown off at the header, and clattered around under-neath, you may have had a heart attack. LOL------Love the ol' 12s and stories.
__________________
Cayoterun
Okla Panhandle

I think I'll fix it myself, and pay the extra $500.
Reply With Quote
  #44  
Old November 3rd, 2018, 03:25 AM
Cayoterun's Avatar
Cayoterun Cayoterun is offline
Senior Member
 
Join Date: Jan 2013
Location: Guymon, Ok.
Truck: GMC V12 powered '46 Chevy pu
Age: 84
Posts: 167
Rep Power: 114
Cayoterun is on a distinguished road
Default Re: Gmc V12 in trucks

Quote:
Originally Posted by Cayoterun View Post
BillT: If a muffler had blown off at the header, and clattered around under-neath, you may have had a heart attack. LOL------Love the ol' 12s and stories.
OOps: I forgot you said it didn't have mufflers.
__________________
Cayoterun
Okla Panhandle

I think I'll fix it myself, and pay the extra $500.
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
6066 GMC Trucks, The Breakthrough Engineering Trucks! Archiver Previous Forum Posts 0 November 27th, 2001 02:13 AM
Re: [6066 GMC Truck] will 50-80 series GMC trucks grills fit the 10-30 series trucks? Archiver Previous Forum Posts 0 October 16th, 2001 06:10 AM
Re: [6066 GMC Truck] will 50-80 series GMC trucks grills fit the 10-30 series trucks? Archiver Previous Forum Posts 0 October 14th, 2001 01:57 AM
RE: [6066 GMC Truck] Name for our Trucks, as a groups of trucks. Archiver Previous Forum Posts 0 June 27th, 2001 01:46 AM
Re: [6066 GMC Truck] Name for our Trucks, as a groups of trucks. Archiver Previous Forum Posts 0 June 27th, 2001 01:29 AM


All times are GMT +1. The time now is 03:08 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2013, Jelsoft Enterprises Ltd 681711554703|1710511712|0