Trying To Find The Timing Marks On The Distributor and Intake Manifold On My 66 L75

[Larry E.]

Trying to find the above on my 66 Base Engine Coupe. Engine is original. We know
the factory(At Flint) chiseled a straight mark on the Intake and Distributor after timing
was set. Having a heck of a time trying to find these marks; awful tight in that area. I
have searched this board and little is said on this subject. It was mentioned that small
mirrors should be used to find these marks. Any idea's to make this procedure easy?
Could these marks be possibly seen from underneath? Any suggestions? Thanks
again>Larry

[Leif A.]

Re: Trying To Find The Timing Marks On The Distributor and Intake Manifold On My 66 L

Trying to find the above on my 66 Base Engine Coupe. Engine is original. We know
the factory(At Flint) chiseled a straight mark on the Intake and Distributor after timing
was set. Having a heck of a time trying to find these marks; awful tight in that area. I
have searched this board and little is said on this subject. It was mentioned that small
mirrors should be used to find these marks. Any idea's to make this procedure easy?
Could these marks be possibly seen from underneath? Any suggestions? Thanks
again>Larry

We do?? If this is a fact, it's the first I've heard of it and I've been playing with these cars for 50 years. I've heard of doing something like that when removing a distributor but never knew the factory did it after setting the timing. Interesting, if true.

[Terry M.]

Re: Trying To Find The Timing Marks On The Distributor and Intake Manifold On My 66 L

Trying to find the above on my 66 Base Engine Coupe. Engine is original. We know
the factory(At Flint) chiseled a straight mark on the Intake and Distributor after timing
was set. Having a heck of a time trying to find these marks; awful tight in that area. I
have searched this board and little is said on this subject. It was mentioned that small
mirrors should be used to find these marks. Any idea's to make this procedure easy?
Could these marks be possibly seen from underneath? Any suggestions? Thanks
again>Larry

Larry
Up front I have to disclaim that I only know about this mark on C3s, but I believe it is reasonable to think the same process applies to C2s. Check your AIM to see if there are timing alignment instructions in the engine installation section. This will only work if you have the original distributor housing and original intake manifold. A change of timing set should not affect this assUming the gear is installed "straight up"., but a change of camshaft might depending on the cam source.

The reason it is there is because after timing the engine on the hot test stand (where the mark is made) at the engine assembly plant (Flint or Tonawanda) the distributor is removed when shipping the engine to St Louis. At St Louis the distributor was reinstalled and the mark used as alignment for timing.

It is not easy to find the mark, but it is on the back side of the junction between the distributor and the intake manifold. It was easy for the assembly plant employees to find as they were "dressing" the engine. Fully assembled and in the car a mirror is necessary and loosening or removal of the distributor shielding will be an advantage. I believe it may be absolutely necessary to remove the distributor ignition shielding to see it, but the difference in the ignition shielding between C2 and C3 leads me to be less than completely sure of this.

[Duke W.]

Re: Trying To Find The Timing Marks On The Distributor and Intake Manifold On My 66 L

Larry


The reason it is there is because after timing the engine on the hot test stand (where the mark is made) at the engine assembly plant (Flint or Tonawanda) the distributor is removed when shipping the engine to St Louis. At St Louis the distributor was reinstalled and the mark used as alignment for timing.

This is new to me, but I'm not disputing it. I didn't think this stake mark was made until the emission control era, maybe not before the HEI era, the reason being that point wear will change dwell angle and dwell angle changes affect timing. I recall one degree of dwell change alters timing by 2 degrees. Since the mag pulse signal timing doesn't change in normal service, the stake mark should remain valid for most of the engine's life.

I assume that the distributor installed and staked at the engine plant was the same as reinstalled on the engine dress line and the reason it was removed was to prevent handling damage and reduce the overall height of the engine assembly for shipping to the plants. Is that correct?

Duke

[Mike E.]

Re: Trying To Find The Timing Marks On The Distributor and Intake Manifold On My 66 L

Attached are pictures from 71 LS6. Hope they help.
Mike
Distributor (17).jpg intake timing mark.jpg

This is from a 71 LS5
distributor (7).jpg

[Mike M.]

Re: Trying To Find The Timing Marks On The Distributor and Intake Manifold On My 66 L

I've never encountered such stampings on any of our c-1 or c-3's. but I'll look over what corvettes we have left.mike

[John S.]

DE06E433-071F-46D4-B18C-EA5C18237B8D.jpg

[Terry M.]

Re: Trying To Find The Timing Marks On The Distributor and Intake Manifold On My 66 L

I assume that the distributor installed and staked at the engine plant was the same as reinstalled on the engine dress line and the reason it was removed was to prevent handling damage and reduce the overall height of the engine assembly for shipping to the plants. Is that correct?

Duke

The distributor installed on the engine at St Louis was supposed to be the same one installed at the engine assembly plant with one exception. If Transistor Ignition (K66) from 1968 to mid-1969 the TI distributor was installed at St Louis. In that case the points distributor was sent back to the engine assembly plant.

And yes the purpose is for clearance on the rack that the engines are shipped in.

[Terry M.]

Re: Trying To Find The Timing Marks On The Distributor and Intake Manifold On My 66 L

I've never encountered such stampings on any of our c-1 or c-3's. but I'll look over what corvettes we have left.mike

Remember Mike I started this by saying by saying I couldn't say this was on C2s. FWIW: It is on a 1967 Chevelle SB engine I have.

[David H.]

Re: Trying To Find The Timing Marks On The Distributor and Intake Manifold On My 66 L

Larry

Excerpt below is from a John Hinckley article on "Small Block Assembly Overview". Text is towards bottom under "HOT TEST".

Article can be found on Camaros web site - link below.

Dave


The operators then fired the engine, checked for oil pressure and oil or water leaks, set the timing, tightened the distributor hold-down clamp and chisel-staked the reference mark on the distributor base and intake, and listened for any unusual noises. Oil and water were drained, all test adapters were disconnected, and the engine was hoisted out of the test stand and placed on another conveyor that took it to the shipping area. Engines needing further attention due to test discrepancies were set aside for repairs; when repairs were completed, those engines were re-tested and sent on their way.

http://www.camaros.org/flintV8.shtml

[Thomas S.]

Re: Trying To Find The Timing Marks On The Distributor and Intake Manifold On My 66 L

I’m surprised this isn’t a judged item. There are so many other seemingly obscured features listed in the judging guides.

[David H.]

Re: Trying To Find The Timing Marks On The Distributor and Intake Manifold On My 66 L

I’m surprised this isn’t a judged item. ...

Tom

Not sure hammers and chisels are a good idea with this group.

Dave

[Terry M.]

Re: Trying To Find The Timing Marks On The Distributor and Intake Manifold On My 66 L

Quote Originally Posted by Thomas Sutcliffe (62028) View Post
I’m surprised this isn’t a judged item. ...


It is in the 1968-69 & 1970-72 TIM&JGs. I doubt many judges of those years look for it because it is almost impossible to see with the ignition shielding in place., except for 1970L to 1972. But that is us Chrome Bumper C3 guys & gals.

I am passionate about it because it is how I time my 1970 LT1. Simple, no timing light. Easy as can be.

BTW Duke: That timing is not what is in the Chassis Service Manual nor what is on the Emissions label on the firewall. Ain't life grand Duke?

[Larry E.]

Re: Trying To Find The Timing Marks On The Distributor and Intake Manifold On My 66 L

Thanks Terry M. for your insight on this subject. Bought a fancy mirror with built in LED
lights on it; will try this today to try to find them. Top part of the shielding has been taken off. Like to hear from other C2 owners if they
have seen them on their cars. Thanks Again>Larry

[Patrick H.]

Re: Trying To Find The Timing Marks On The Distributor and Intake Manifold On My 66 L

I have it on my 72, and it's on the 63 here in the shop. It's how we set the initial timing on that car when the distributor returned from restoration.