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 > I-6 Engines
#Sponsored

I-6 Engines For GMCs that came with the Inline 6 Engines

Reply
 
Thread Tools
  #21  
Old February 21st, 2017, 06:11 AM
Pops Pops is offline
Member
 
Join Date: Jul 2014
Location: Clarkston, Michigan
Truck: 1966 GMC
Posts: 69
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 82
Pops is on a distinguished road
Default Re: inline six woes

Wow, it's been a long, long time. This was such a lengthy post I thought I'd take a minute and share what I did and what the status is now.
Misfires, shaky steering wheel on take off, vibration, whining noise, etc. are partially corrected.
Whining was related to rear end (of course). the seal at pinion was shot. The tiny spring around the seal was spun and broke. While removed, I also had the bearing changed (easy and cheap at that point) it was weak. also put a redi sleeve added to assure no more leak. Bal drive shaft and added u-joints. NO more noise.
Still have shakiness on take off; pretty smooth after that. exhaust is still stinky which leads me to think carb (rochester B). GMCDAC wrote about this. I have a remanned carb but that doesnt guarantee anything. Im wondering if the seal around mixture screw is crushed. When I set the carb it only requires about 1/4 turn to satisfy vacuum and idle. I was told if the inner seal is crushed it will probably run rich. Since my plugs carbon up quickly it sounds like a rich running engine.
Doug do you sell Roch 250? Esp rebuilt by you? If so, what is the process?
Reply With Quote
  #22  
Old February 21st, 2017, 07:27 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
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 402
TJ's GMC is on a distinguished road
Default Re: inline six woes

Yeah the rochesters are junk, I tried rebuilding two and still had rich running or flooding issues. I got lucky with the reman I purchased for one of my 292's. It's a monojet 1 barrel. No issues thus far. I dumped the rochester on one of my 292's for an eddy 4 barrel. lol!

If you still have issues a common upgrade is the weber 32/36 2 barrel. Kind of a pain to tune, but you will get a nice mileage increase and a little increase in power once tuned.
__________________
"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
  #23  
Old February 21st, 2017, 07:46 PM
turbobill turbobill is offline
Member
 
Join Date: Feb 2013
Location: northern NY when not flying
Truck: 1968 HM80 with a 478M and a few engines plus a Toro-Flow
Posts: 99
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 97
turbobill is on a distinguished road
Default Re: inline six woes

Quote:
Originally Posted by TJ's GMC View Post
Yeah the rochesters are junk,
No they aren't. People say the same thing about Q-Jets.

Just have to know what you're doing.
Reply With Quote
  #24  
Old February 21st, 2017, 07:59 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
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 402
TJ's GMC is on a distinguished road
Default Re: inline six woes

Quote:
Originally Posted by turbobill View Post
No they aren't. People say the same thing about Q-Jets.

Just have to know what you're doing.
Might need to have a pro do one of mine then. Last rebuild I did I cleaned and replaced and set everything to stock specs. Still had problems, Ran much better than before though! Acted like it had a vacuum leak some where....had some hesitation when given throttle, couldn't find the leak. Replaced with a small 4 barrel and headers and never had any hesitation issues again.

Forgot to mention, I did not mean ALL are junk, just that particular line. All 3 of my 6's had problems with them, and all of us 250 and 292 enthusiasts have had the same common issues.
__________________
"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.

Last edited by TJ's GMC; February 21st, 2017 at 08:12 PM.
Reply With Quote
  #25  
Old February 22nd, 2017, 01:57 AM
GMCDAC's Avatar
GMCDAC GMCDAC is offline
Senior Member
 
Join Date: Jan 2013
Location: Green Valley, east of Rapid City,SD
Truck: I have 4 GMCs, none with a V-6 - YET! Have had 2 in the family.
Age: 67
Posts: 553
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 213
GMCDAC is on a distinguished road
Default Re: inline six woes

I have had good luck with the Rochesters, the only reason I went from the Model B that was on my '55 GMC (mid 1960's 230 Chevy engine) was to get the "kick down" fast idle with the choke cable. I got 3 parted out Rochester Model M carbs and was able to build one out of the three.

Pops, the Model B I sold to a member on this site came from a '64 Chevy truck I parted out. I didn't build it but the carb had a fairly fresh rebuild. I put it on my 230 for awhile and it ran well. It sounds like it worked ok for the buyer. No I don't build carbs for anyone but myself.

DAC
__________________
Doug Crawford
Rapid City, SD

1970 GMC K5 Jimmy Mom drove 30 years
1972 GMC C2500 owned since 1979
1955 GMC 100 driver-project
2006 GMC Yukon Denali---wife's truck

Hope to have a '60 GMC Suburban again someday
Reply With Quote
  #26  
Old February 23rd, 2017, 02:44 AM
Pops Pops is offline
Member
 
Join Date: Jul 2014
Location: Clarkston, Michigan
Truck: 1966 GMC
Posts: 69
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 82
Pops is on a distinguished road
Default Re: inline six woes

thanks for feedback. I would prefer the Roch because linkage, air cleaner, man choke would all work. But, I am pretty much fed up wtih rich burn, exhaust smell, and mileage. and slight shaky on take off. I agree it acts like vacuum leak. Which opens up another posibility. My booster is a cardone with a 67 dual barrel master. I replaced check valve - no change. I sprayed around carb - no change. I change pcv - no change. I ran vacuum test and got a pretty steady needle +- 17 pnds. So I am back to carb which leaks at upper gasket around bowl.
Tj, why is weber 3236 diff to tune. and, does linkage and man choke need to be reorganized?
Reply With Quote
  #27  
Old February 23rd, 2017, 06:11 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
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 402
TJ's GMC is on a distinguished road
Default Re: inline six woes

Quote:
Originally Posted by Pops View Post
Tj, why is weber 3236 diff to tune. and, does linkage and man choke need to be reorganized?
Jetting and fine tuning was the main pain for the last read up I did on it. Linkage I believe has to be redone, choke cable would be a matter of lengthening if needed. I'll search for the write up on it, been a year or so. lol Most of us convert to 4 barrels, but there are a few that convert to webers or holley 2 barrel carbs.
__________________
"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
Reply

Bookmarks


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
Clutch Woes Archiver Previous Forum Posts 0 July 14th, 2007 02:17 AM
brake woes Archiver Previous Forum Posts 0 September 15th, 2005 01:26 PM
Transmission woes Archiver Previous Forum Posts 0 January 16th, 2005 01:55 AM
More head woes Archiver Previous Forum Posts 0 November 17th, 2002 04:05 AM
hydraulic woes Archiver Previous Forum Posts 0 October 3rd, 2002 03:27 PM


All times are GMT +1. The time now is 02:43 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2013, Jelsoft Enterprises Ltd 931731597221|1730555034|0