The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 10-23-2018, 11:58 PM   #1
GreyGhost85
Registered User
 
Join Date: Oct 2018
Location: Dallas Texas
Posts: 113
Re: 1971 C10 Starter/Timing/Transmission Issue

Ok so I I went ahead and plugged the piston stop in, wrapped end with tape so it doesn’t scratch cylinder head, used a reference point on crankcase cover, turned clockwise marked, turned counter clockwise marked. Split the distance between the two and the initial factory line/groove on the harmonic balancer is perfectly at 0 degrees on the scale. So the piston stop provided some insurance in regards to that factory mark.

So let me get this correct.

1. Disconnect vacuum advance again and set initial timing or base timing to 8-12. If I plug in vacuum advance this rpms will be at least 1400.

2. So with base timing set to 8-12 and vacuum advance plugged into carb,I need to reset the carb idle mixture screws and idle screw per manual? In order to accomplish a perfect mix with a perfect idle?

3. Once everything is set, test vacuum on ports? Most of my full vacuum ports are plugged.

Let me know if my method is off. So far battery starting issue is gone. Side notes*** 3 degrees retarded with advance plugged in and idle set to 700 gives me reverse for 20 seconds or so.
Posted via Mobile Device
GreyGhost85 is offline   Reply With Quote
Old 10-24-2018, 11:57 AM   #2
68 P.O.S.
Registered User
 
Join Date: Jan 2007
Location: Puyallup, WA
Posts: 1,661
Re: 1971 C10 Starter/Timing/Transmission Issue

Quote:
Originally Posted by GreyGhost85 View Post
Ok so I I went ahead and plugged the piston stop in, wrapped end with tape so it doesnÂ’t scratch cylinder head, used a reference point on crankcase cover, turned clockwise marked, turned counter clockwise marked. Split the distance between the two and the initial factory line/groove on the harmonic balancer is perfectly at 0 degrees on the scale. So the piston stop provided some insurance in regards to that factory mark. There you go, glad your balancer matches up with TDC. Makes things a little easier. Read the following links for timing. They're written by a GM engineer and will tell you everything you need to know about timing and vacuum advance and the science of why.
http://www.camaros.org/pdf/timing101.pdf
http://67-72chevytrucks.com/vboard/s...d.php?t=274806


So let me get this correct.

1. Disconnect vacuum advance again and set initial timing or base timing to 8-12. If I plug in vacuum advance this rpms will be at least 1400. Set up this way, can you adjust your rpms down to 750 at idle? If not, you'll have to pull the carb and adjust the transfer slots square. Did you check out the link I posted on doing this?

2. So with base timing set to 8-12 and vacuum advance plugged into carb,I need to reset the carb idle mixture screws and idle screw per manual? In order to accomplish a perfect mix with a perfect idle? Correct, set it up the way you would drive it. Plug your vacuum gauge into the manifold vacuum port on the carb, hook up your timing light so you can view rpms, and follow the procedures in the manual. This will achieve your best lean idle.

3. Once everything is set, test vacuum on ports? Most of my full vacuum ports are plugged. No worries if they're all being used. Using a T, connect your vac advance and vac gauge to the manifold vac port on the carb, then follow the procedures in the manual for setting the IMS

Let me know if my method is off. So far battery starting issue is gone. Side notes*** 3 degrees retarded with advance plugged in and idle set to 700 gives me reverse for 20 seconds or so.
Posted via Mobile Device
I responded above in red.
__________________
72 C10 lwb fleetside -stock 350/350 combo
68 P.O.S. is offline   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

Forum Jump


All times are GMT -4. The time now is 11:55 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com