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 March 4th, 2023, 06:02 PM
Prowbar Prowbar is offline
Senior Member
 
Join Date: Dec 2020
Location: Friesland, the Netherlands
Truck: 1965 GMC 1500, 478 V6, SM420
Posts: 383
Rep Power: 181
Prowbar is a jewel in the roughProwbar is a jewel in the roughProwbar is a jewel in the roughProwbar is a jewel in the roughProwbar is a jewel in the roughProwbar is a jewel in the rough
Default Re: Got a 478...

Starting to look like an engine again.
Attached Images
File Type: jpg 20230304_170713.jpg (3.47 MB, Multiple views, 12 clicks)
File Type: jpg 20230304_170721.jpg (3.41 MB, Multiple views, 10 clicks)
Reply With Quote
  #32  
Old March 25th, 2023, 04:52 PM
Prowbar Prowbar is offline
Senior Member
 
Join Date: Dec 2020
Location: Friesland, the Netherlands
Truck: 1965 GMC 1500, 478 V6, SM420
Posts: 383
Rep Power: 181
Prowbar is a jewel in the roughProwbar is a jewel in the roughProwbar is a jewel in the roughProwbar is a jewel in the roughProwbar is a jewel in the roughProwbar is a jewel in the rough
Default Re: Got a 478...

Another piece of the puzzle is the front pulley. I wrote about this in the 65 GMC build thread: I wanted to originally use the 478 pulley. However, it looks out of place, and it didn't fit after all. You would end up with an overdriven water pump as well.

Therefore modification of the 305 pulley is in order. I designed an adapter plate that can be used to bolt on external weights. It mounts onto the bolts holding the pulley in place, and nuts are used to fixture it. I am also working on a balancing fixture to determine the exact weight needed. The 478 pulley serves as a guide here.

Another 'upgrade' that I'm doing to the 305 pulley is the addition of the tapered sleeve, found in the bigger pulleys. This is a copper sleeve, that tightens onto the crankshaft when the front crankshaft bolt is tightened. It is easily added to the 305 pulley by machining a 15-degree taper into the bore.

More to follow.
Attached Images
File Type: jpg 20230325_155446.jpg (3.15 MB, Multiple views, 1 clicks)
File Type: jpg 20230325_155451.jpg (3.02 MB, Multiple views, 1 clicks)
File Type: jpg 20230325_155502.jpg (3.93 MB, Multiple views, 1 clicks)
Reply With Quote
  #33  
Old April 24th, 2023, 08:30 AM
Prowbar Prowbar is offline
Senior Member
 
Join Date: Dec 2020
Location: Friesland, the Netherlands
Truck: 1965 GMC 1500, 478 V6, SM420
Posts: 383
Rep Power: 181
Prowbar is a jewel in the roughProwbar is a jewel in the roughProwbar is a jewel in the roughProwbar is a jewel in the roughProwbar is a jewel in the roughProwbar is a jewel in the rough
Default Re: Got a 478...

Balancing fixture in action. I had to add a 2mm thick steel plate to the adapter. The 2mm plate followed the same contours as the underside of the adapter. As you can see, I had to remove as much material as seen in the picture to recreate the balance. I also had the timing indicator and adapter and weight zinc plated to recreate the factory look. All bolts were secured with LocTite and the front pulley was installed and torqued to spec. The tapered sleeve helps it stay rigid to the crankshaft, which is a worthwhile addition with the added weight.

Since we're nearing the end of the engine build the following posts will be continued in the 65 GMC build thread, where we install the engine.

Any comments are, of course, welcome
Attached Images
File Type: jpg 20230422_144501 1.jpg (3.72 MB, Multiple views, 5 clicks)
File Type: jpg 20230422_145521 1.jpg (4.01 MB, Multiple views, 4 clicks)
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
Re: [6066 GMC Truck] 478 gas vs. 478 diesel Archiver Previous Forum Posts 0 March 31st, 2004 02:37 AM
RE: [6066 GMC Truck] 478 gas vs. 478 diesel Archiver Previous Forum Posts 0 March 31st, 2004 12:46 AM
Re: [6066 GMC Truck] 478 gas vs. 478 diesel Archiver Previous Forum Posts 0 March 30th, 2004 12:23 AM
RE: [6066 GMC Truck] 478 gas vs. 478 diesel Archiver Previous Forum Posts 0 March 30th, 2004 12:21 AM
RE: [6066 GMC Truck] 478 gas vs. 478 diesel Archiver Previous Forum Posts 0 March 30th, 2004 12:08 AM


All times are GMT +1. The time now is 01:36 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2013, Jelsoft Enterprises Ltd 681711554703|1710463016|0