Home page
  Home Page   Contact Us   Our History   Advertise with Us   Sponsor List   Link to Us   Compare Levels   Member Agreement   Privacy Policy   About C3VR
  Community Forums   Active Threads   Forum Search   Top Posters List   Private Messenger   C3VR Email System   C3 Corvette Quiz
  Members Vettes & Pictures   Member Stories   Member Stats   Real Time Member Map   Member Search   Lifetime Member List   Member Calendar Entry Form   Who's Online
  C3 Registry Data   C3 Corvette Statistics   C3 Corvette Tips & Tricks   C3 Corvette How-Tos   Corvette Club Listing   Corvette Event Listing   Mechanic Directory   Corvette VIN Decoder   Save the Wave   Corvette Emblem History   C3 Corvette Birthday Calculator   C3 Corvette Build Dates   Corvette Parts Illustration Catalog   Shark Bytes - Online
  C3 Corvette Parts Auctions on eBay   Corvette Books   C3VR In-Stock Apparel & Accessories   C3VR Member Name Badges   C3VR Custom Apparel & Accessories @ Zazzle   C3VR Window Stickers   C3VR Member Deals & Discounts   C3VR Member Calendars   Shop Amazon.com
☰
SPONSOR AD

Topic: setting timing

in Forum: C3 Engines


Already a Member? Click Here to Login

setting timing

Posted: 5/19/05 10:42am Message 31 of 39
Profile Pic
kstyer
Lifetime MemberLifetime Member
Moderator
Send PM
CUYAHOGA FALLS, OH - USA
Joined: 12/2/2003
Posts: 6424
Vette(s): 1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!
It sounds like the stop for the mechanical advance are worn away, allowing too much advance.


SPONSOR AD:: (Our Sponsors help support C3VR)

setting timing

Posted: 5/19/05 2:31pm Message 32 of 39
anips
Former Member
Send PM
sonoma, CA - USA
Joined: 8/9/2002
Posts: 784
Vette(s): 72 LT-1 AC coupe,69 l-36 coupe
Sounds weird to me, how did it even idle at 8 degs retarded? did you have the vac. adv. hooked up, that can add 10+ degs to the total, what was your procedure, did you use a "dial back timing light or a degreed vib. dampner. here's how you do it, set idle to factory spec's, disconnect the vac. adv. plug the vac. outlet at the hose or cap at carb,run the motor up to 3-K, with a "dial back light"set at 36 degs advanced on the light advance or retard the dist. till the mark on the dampner is steady on the 0 deg. mark on the timng tab, lock down the dist. there, now return engine to idle. turn the dial back to 0 on the light, now check to see what initial timing you have, hooking up the vac. adv. is the last thing you do,
    If you don't have a dial back light you can still do it with a regular timing light but you need a degreed vib. dampner, you can't dial any adv. into the light because its not a "dial back" but the process is the same you lock down the dist. when the 36 deg. mark on the dampner is steady with the 0 degr. mark on the timing tab.     anips38491.6156597222


setting timing

Posted: 5/19/05 4:15pm Message 33 of 39
petecorvettepa
Lifetime MemberLifetime Member
Send PM
SHOHOLA, PA - USA
Joined: 8/31/2004
Posts: 67
Vette(s): 1978 Dark Brown coupe auto 1977 White coupe auto 1974 Dark Green coupe man 1969 Yellow coupe man 1994 blue coupe 6spd

hi,

yes i did it as you said wth my snap-on timing light,

it just about ran. is it poss the dampener has shifted on the rubber cushion?

pete




setting timing

Posted: 5/19/05 7:08pm Message 34 of 39
Profile Pic
kstyer
Lifetime MemberLifetime Member
Moderator
Send PM
CUYAHOGA FALLS, OH - USA
Joined: 12/2/2003
Posts: 6424
Vette(s): 1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!

If the dampner shifted, it probably would not have the wide span of readings you have.  It would be low or high in both ranges, not just one.  Unless the dampner was constantly shifting, but then you would pick that up due to inconsistant readings.

Another possibility is slop in the timing chain or wear in the gear at the base of the distributor.

At 8 deg ATDC it has to be a real dog.




setting timing

Posted: 5/19/05 7:28pm Message 35 of 39
anips
Former Member
Send PM
sonoma, CA - USA
Joined: 8/9/2002
Posts: 784
Vette(s): 72 LT-1 AC coupe,69 l-36 coupe
Yes, it is a possibility that the outer ring has spun, along with Ken's theory, take a close look at your dampner there might be two marks on it,the one on my 72 had two marks on it, don't know why, had to pull #1 plug bump the starter to bring #1 up on comp.,checked the cap to make sure the rotor was pointing to #1 to know which one to use, if your dist. is shot you might want to check with Performance Distributor in Memphis Tenn, They have a web site, they will hand build you a new one for your car's spec's probley for the same cost of rebuilding yours, elec.tack is around 275.00, tack drive is 500.00, I'am real happy with mine


setting timing

Posted: 5/19/05 7:43pm Message 36 of 39
petecorvettepa
Lifetime MemberLifetime Member
Send PM
SHOHOLA, PA - USA
Joined: 8/31/2004
Posts: 67
Vette(s): 1978 Dark Brown coupe auto 1977 White coupe auto 1974 Dark Green coupe man 1969 Yellow coupe man 1994 blue coupe 6spd

hi all,

the timing chain and gears and new, but i did pull the dist and the springs and weights were just about on there, ready to fall off.

so i guess i will get a new dist.

thanks for all the help!!

pete




setting timing

Posted: 5/21/05 3:52pm Message 37 of 39
Profile Pic
longhorn294
Lifetime MemberLifetime Member
Send PM
DeBerry, TX - USA
Joined: 2/27/2002
Posts: 1006
Vette(s): 1971 383 Stroker- mille miglia red...5 speed

I hooked a vac. meter to my intake and it bounced from about 14 to 16. I did plug advance but nothing else. After moving the dist., it now bounces between 15 and 18. Shouldn't I be getting more of a steady reading? What would be making it fluctuate? It did seem to run better for a tired old original engine. Any ideas? Thanks for any help..........




   I know the voices aren't real, but they have some pretty cool ideas...

setting timing

Posted: 5/21/05 8:01pm Message 38 of 39
Profile Pic
kstyer
Lifetime MemberLifetime Member
Moderator
Send PM
CUYAHOGA FALLS, OH - USA
Joined: 12/2/2003
Posts: 6424
Vette(s): 1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!

The vacuum fluctuations can be caused by a few different things. 

Worn and leaking valves, low compression, vacuum leak on a intake runner, weak valve spring, worn cam lobe.

Quite a list.  Some testing is in order starting with a vacuum leak check, then a compression test, followed by a leak down test.   Of course if you find a vac leak, you may not need to go further.

kstyer38493.835


setting timing

Posted: 5/21/05 9:08pm Message 39 of 39
Profile Pic
longhorn294
Lifetime MemberLifetime Member
Send PM
DeBerry, TX - USA
Joined: 2/27/2002
Posts: 1006
Vette(s): 1971 383 Stroker- mille miglia red...5 speed

Thanks Ken. I figured there wasn't going to be an easy answer. I probably have all those ailments! I think I'll continue with plans to get another one built and mothball this original engine. Appreciate the reply..... Dwain




   I know the voices aren't real, but they have some pretty cool ideas...

in Forum: C3 Engines


SPONSOR AD: (Our Sponsors help support C3VR)