70 L46 distributor installed position

[Bill L.]

Well I thought I was okay but I think I may be a tooth off.

When I go to set the timing the vacuum advance hits the shield support. Based on the AIM I installed to #1 position and the vacuum advance was behind the support. However, when I go to properly set the timing I cannot get there without hitting the top shield support.

It may be important to note that I did the timing chain as well.

The good news is she fired right up after being down for over a year and the fuel stabilizer worked!


Thanks, Bill

[Rick B.]

Re: 70 L46 distributor installed position

Bill I recently found myself in the same predicament. Then I remembered that in order to overcome the same problem years ago I re-assigned the respective wire-to-cap positions and was able to cheat things enough to clear the support. At first I thought I was off a tooth as well but do not believe this to be the case. I will let you know how I make out shortly.

Rick

[Duke W.]

Re: 70 L46 distributor installed position

Rather than just starting to swap wires around like bubba, check that they are indexed IAW the CSM.

We've been through this a zillion times with C2 small blocks. The dimple in the drive gear has to be indexed properly as do the wires.

C3 SBs have a different installed position, but the same basic approach - BY THE BOOK - should be followed or it will be all screwed up.

Duke

[Bill L.]

Re: 70 L46 distributor installed position

HI Duke,

I thought I followed the AIM and instructions to what I thought was the correct location. When I dropped the distributor in it took me a few attempts. I set motor to TDC and set the rotor to the #1 position and it lined up with the cap perfectly or so I thought, vacuum advanced seemed right, tach cable coming out in proper location, yet it seems likely I made a mistake.

Do you have a picture of exactly what the dimple looks like. The AIM indicates there is a stake mark but I could not find one and some of the C3 guys say it can be really tough to see if it can be seen at all.

I do not really want to start swapping wires around.


Thanks,



Bill

[Bill L.]

Re: 70 L46 distributor installed position

Hmmmm Duke,

I had the distributor rebuilt by one of the best corvette shops. However, I was reading the archives regarding the dimple on the distributor housing and dist. gear per your posts.

I wonder if it is the same for C3s.

Hmmm. Bill

[Terry M.]

Re: 70 L46 distributor installed position

Yes the dimple is the same for C2 or C3, but the distributor position and spark plug wire placement on the cap is different between the two body styles. The tach cable is also oriented differently between the two body styles.

The stake mark (only works if the distributor and intake manifold are original to the car, and if the timing gear set is properly installed -- oh and the cam gear teeth have to be cut exactly like the original) is on the rear of the distributor, and can easily be seen with a mirror.

I have not used a timing light since I discovered the stake mark.

[Bill L.]

Re: 70 L46 distributor installed position

Thanks Terry.

I will look closely since I know the motor and cam are original. The distributor is original as well but rebuilt for a very reputable shop.

When I had the distributor out I looked closely but could not see the stake marks you mention.

Maybe I need new glasses

Bill

[Terry M.]

[Paul L.]

Re: 70 L46 distributor installed position

Bill,
You can see the dimple in this pic.

[Bill L.]

Re: 70 L46 distributor installed position

The dimple should line up with the stake mark on the distributor housing?

Sorry for the dumb questions. I just want to make sure when I pull the distributor I know exactly what I am looking at.

Bill

[Larry M.]

Re: 70 L46 distributor installed position

The dimple should line up with the stake mark on the distributor housing?

Sorry for the dumb questions. I just want to make sure when I pull the distributor I know exactly what I am looking at.

Bill

Bill:

I am going from memory and haven't had my usual four cups of coffee yet this morning (disclaimer)......but the dimple should line up with the distributor rotor. At least that's the way it is for C2 cars.

Larry

[Bill L.]

Re: 70 L46 distributor installed position

Thanks Larry. Now I got it


Bill

[Paul L.]

Re: 70 L46 distributor installed position

Larry,
It's the same for C3s. Dimple and rotor tip pointing in the same direction. The gear can be installed 180* wrong. Don't ask me how I know that....

[Harmon C.]

Re: 70 L46 distributor installed position

Is #1 position on the cap the same or are some Corvettes different? I think I read this somewhere.

[Terry M.]

Re: 70 L46 distributor installed position

Is #1 position on the cap the same or are some Corvettes different? I think I read this somewhere.

I am laboring from memory here, but I believe for C3s #1 wire goes just to the passenger side of the little door in the distributor cap. A check of the AIM timing instruction page will show a drawing of the wire locations in the distributor cap as well as the orientation of the distributor. I personally like the K66 page in the 1969 and 1970 AIMs, but not everyone has a collection of half dozen AIMS.