C3 Vette Registry - The Best Resource on the Net for C3 Vettes! C3 Vette
Forums -> C3 Electrical
Not Logged In! Login or Register!  Users Online: 17 / Help 
Features  Find C3 Parts on ebay in only 2 or 3 clicks!  | Add YOUR C3 to the Registry

Supporting Vendors
Bair's Corvettes
Mid America Motorworks
Volunteer Vette Products
CorvetteClothing.com
VetteBookStore.com

C3 of the Month
None Current
Enter Yours Today!
Online C3 Show
13
C3s are Registered

Vanity Plates
ATOMIK
JonFish
Featured Links

Buy Now
Chevrolet Corvette Restoration Guide
Chevrolet Corvette Restoration Guide


Motor Trend - $5 for 12 issues.
Motor Trend
Only $5 for 12 issues.


Chevrolet Corvette: 1968 thru 1982, All V8 models (Haynes Manuals) (Paperback)
Chevrolet Corvette: 1968 thru 1982, All V8 models (Haynes Manuals) (Paperback)


Corvette Fuel Injection & Electronic Engine Control: 1982 through 2001
Corvette Fuel Injection & Electronic Engine Control: 1982 through 2001



| Hide Signatures and Profile Pics

 New Topic New Topic Post Reply Reply New Poll New Poll Search     Search Page [1]  
11/13/13 10:34pm - Original Message: 'Delco HEI Distributor Rebuild'
daveo76
Standard Member
- Send Private Message


Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Joined: 8/25/2005
Posts: 831
So I've been struggling with what to do with my distributor.  I have been running (for the past 7 or 8 years) a cheapie aftermarket HEI.  The electrical connections at the module and at the cap are junk and they are loose and causing it to miss, I believe.  I was faced with multiple options, including buying a high performance aftermarket, rebuilding this one, buying a reman from a parts house, etc.  This last weekend I dug out my original and was pleased to find that the shaft bearings are nice and tight, really the only thing that might be a show stopper.  I also verified that it was the correct part number with my Black Book - good news there.  So I'm heading down the road of rebuilding the original.  I have several parts on order: 1) new Delco pole piece/magnetic pickup (I know it's bad on the original - that's why I pulled it in the first place) 2) Pertronix capacitor and harness and 3) Pertronix adjustable vacuum advance.  I already have the existing parts: 1) Accel high performance module 2) decent quality cap, rotor, and coil 3) aftermarket mechanical advance kit.  

Questions:
1) anything I am missing or any problems with my method?  I know it might not be the cheapest or highest performance option, but I'm a big fan of using original parts, especially when I can rebuild and upgrade a little.  

2) It looks like you have to remove the shaft to replace the pole piece?  Drive the roll pin out of the gear, remove the gear, and the shaft will come right out or is it more involved than that?  

Here's a link to a few pics.  I'll add more after the rebuild.  The shiny distributor is the cheapie.  (But the delco seems to be cleaning up pretty good.  






|UPDATED|11/13/2013 8:34:22 PM (AZT)|/UPDATED|


____________________________________

 

1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
 Reply Reply  Quote Reply w/Quote
 
Support C3VR!
Suport our advertisers
11/13/13 10:49pm - Reply: 'Re: Delco HEI Distributor Rebuild'
Adams' Apple Lifetime Member
Lifetime Member
Moderator
- Send Private Message


Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19457
daveo76 said:
2) It looks like you have to remove the shaft to replace the pole piece?  Drive the roll pin out of the gear, remove the gear, and the shaft will come right out or is it more involved than that?  

Here's a link to a few pics.  I'll add more after the rebuild.  The shiny distributor is the cheapie.  (But the delco seems to be cleaning up pretty good.  



Knock the roll pin out...yes. Shaft come right out? If yer dang lucky. LOL Usually, there is so much old oil gunked up inside, between the bushings, that the shaft will only move 1/2" or so. Spray that puppy down a day or so before trying to disassemble it. Then you'll prolly wind up twisting back/forth on the shaft, while pulling it out at the same time.
Word of caution...be sure to note the orientation of the gear. You would be surprised at how many have tried to put the gear on upside down. Also, there is a thin, steel shim between the gear and the housing. DO NOT LOOSE IT!. Once the shaft is out, it's pretty much self explanatory after that. Use some engine oil, or a light grease on the shaft, and bushings when re-assembling it.

In the pics....I see a big problem with the gear on the "new" dist. Compare it to the original gear...see the difference?
Do you have a stock, or a non-roller cam, or is it a roller?


____________________________________
Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
 Reply Reply  Quote Reply w/Quote
11/13/13 11:22pm - Reply: 'Re: Delco HEI Distributor Rebuild'
daveo76
Standard Member
- Send Private Message


Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Joined: 8/25/2005
Posts: 831
It's a SpeedPro non-roller cam.  Are you talking about the different shape of the teeth, as in the original teeth are wider at the tips?  Would that screw up my cam?  I think I only have 1500 miles or so on the motor so far.  Any concerns about going back in with the original?  I just went out to the garage and looked more closely and the original gear seems to be in good shape, a little bit of a wear pattern in some spots, but nothing too bad.  

____________________________________

 

1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
 Reply Reply  Quote Reply w/Quote
11/14/13 7:17am - Reply: 'Re: Delco HEI Distributor Rebuild'
Adams' Apple Lifetime Member
Lifetime Member
Moderator
- Send Private Message


Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19457
Definitely go back with the original gear. Looks to me(from the pic) that the other gear might not be cut right....the gear may allow some sloppiness when meshing with the cam gear. Prolly won't actually damage either gear, but certainly might cause some timing issues.... 

____________________________________
Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
 Reply Reply  Quote Reply w/Quote
11/14/13 2:16pm - Reply: 'Re: Delco HEI Distributor Rebuild'
rraider1
Former Member
- Send Private Message


Woodland, WA - USA

Vette(s):
1977 T-Top,350,Auto Black Ruby Pearl,Steeroids R&P conversion

Joined: 10/14/2003
Posts: 1152
I have one of the generic dist, and have not have any issues that I know of yet.
 
To set the dist. for performance this is what I have found and have some questions?
 
Stock 26 deg total initial and centrifugal at 2500 RPM
8 Deg initial timing.
15 to 18 Centrifugal timing. 
24 deg of vacuum advance to get close to 52 at cruise.
 
Performance 36 deg Total initial and centrifugal in at 2500 RPM 
12-16 initial adv.
would need to change weights to get 20 deg centrifugal adv.
would need to change vacuum adv to 16 deg to get the 52 deg at cruise.
 
 
If this is all correct then what does changing the ign module do?
What does the hotter spark do?
 
The mods Coil, ign module, weights, vacuum adv adjustable?
 
then you need to balance this with the cam that you have.


|UPDATED|11/14/2013 12:16:54 PM (AZT)|/UPDATED|


____________________________________
Bob R
 Reply Reply  Quote Reply w/Quote
11/14/13 10:02pm - Reply: 'Re: Delco HEI Distributor Rebuild'
daveo76
Standard Member
- Send Private Message


Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Joined: 8/25/2005
Posts: 831
Adams' Apple said: Definitely go back with the original gear. Looks to me(from the pic) that the other gear might not be cut right....the gear may allow some sloppiness when meshing with the cam gear. Prolly won't actually damage either gear, but certainly might cause some timing issues.... 


Thanks for the helpful insights, Joel.  I like to think I would have got the gear on correctly since I'll have another distributor sitting right next to it, but I've made dumber mistakes before.  Info on the shim and dis-assembly will be very helpful.  And I now feel like I'm definitely rebuilding the correct distributor (my original).



____________________________________

 

1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
 Reply Reply  Quote Reply w/Quote
11/14/13 10:19pm - Reply: 'Re: Delco HEI Distributor Rebuild'
daveo76
Standard Member
- Send Private Message


Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Joined: 8/25/2005
Posts: 831
rraider1 said: I have one of the generic dist, and have not have any issues that I know of yet.
 
To set the dist. for performance this is what I have found and have some questions?
 
Stock 26 deg total initial and centrifugal at 2500 RPM
8 Deg initial timing.
15 to 18 Centrifugal timing. 
24 deg of vacuum advance to get close to 52 at cruise.
 
Performance 36 deg Total initial and centrifugal in at 2500 RPM 
12-16 initial adv.
would need to change weights to get 20 deg centrifugal adv.
would need to change vacuum adv to 16 deg to get the 52 deg at cruise.
 
 
If this is all correct then what does changing the ign module do?
What does the hotter spark do?
 
The mods Coil, ign module, weights, vacuum adv adjustable?
 
then you need to balance this with the cam that you have.




Bob, your performance specs seem about right for most Corvette small blocks.  Lars Grimsrud has written articles and papers on this subject that seem to be pretty easy to follow.  Here's the one that a lot of folks seem to use:


I always meant to use the method outlined there after I got my engine running last year, but I just set initial somewhere 12 to 14 and it ran pretty dang good so I decided not to mess with it.  I think now I'll need to do some more detailed tuning, though, to make sure I get the advance curve right.  The way I understand it, centrifugal advance is the important part for performance.  Vacuum advance may be more for economy - I'm going to have to research that more before I tune it.  Changing springs is how you adjust the centrifugal: lighter springs = more advance.  You want the most advance you can get without detonation.  High performance module is probably more important for high RPM operation - stock modules are generally good for mild street motors.  My rationale with the high perf one was more an attempt to get better reliability.  A hotter coil simply produces more voltage so theoretically you can increase the plug gap for a hotter bigger spark.  Seems like you can definitely overkill in this area, though.  Thanks for the info.


____________________________________

 

1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
 Reply Reply  Quote Reply w/Quote
 New Topic New Topic Post Reply Reply New Poll New Poll Search     Search Page [1]  
 Forums -> C3 Electrical
(Moderator: Adam Wartell, Norsky, Adams' Apple)
 

 
Official C3 Vette Registry Community:
Home | Forums | Email | Who's Online | Clubs | Events | Member Stats

Other Official C3 Vette Registry Areas:
Members | Research | Shop | My Account | About C3VR
 

Corvette is a registered trademark of the General Motors Corporation(GM) & Chevrolet Motor Division. Vette Registries, LLC is responsible for all site content (except for member submitted content or where otherwise noted) and does not claim or imply that Chevrolet or GM is responsible for Official C3 Vette Registry content. Vette Registries, LLC is independent from GM and is not affiliated with, sponsored or supported by GM.  Copyright/trademark/sales mark infringements are not intended, or implied and are in fact used to support GM, Chevrolet and Corvette

Official C3 Vette Registry content is Copyright 2001-2017, Vette Registries, LLC. Content may not be reused without written consent. All Rights Reserved. NS

Corvette (Vette) Model Years on this site: 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 30