86' L98 Distributior and timing question
Race Director
Joined: Aug 2000
Posts: 11,470
Likes: 764
The thing is that everybody tells you to align the oil pump with a screwdriver. If you suggest some other method then people freak out. That's why I put "politically incorrect" in quotes.
My experience is that if you get the rotor headed in the right direction then you know the gears are meshed correctly. The distributor will sit about 1/4" too high because the pin in the distributor gear is not down in the slot in the shaft of the oil pump. Tapping the starter will allow the distributor to drop into position and then you can just time as usual.
If you have a small mirror you can insure that the distributor in in correctly by lining up these marks put there by the factory after the timing is set:
My experience is that if you get the rotor headed in the right direction then you know the gears are meshed correctly. The distributor will sit about 1/4" too high because the pin in the distributor gear is not down in the slot in the shaft of the oil pump. Tapping the starter will allow the distributor to drop into position and then you can just time as usual.
If you have a small mirror you can insure that the distributor in in correctly by lining up these marks put there by the factory after the timing is set:
edit: if they are there, I can't see them. oh well, doesn't matter...
Last edited by Joe C; Mar 16, 2014 at 09:56 AM.
Le Mans Master
Joined: May 2006
Posts: 7,708
Likes: 266
From: indy indiana
just a heads up for folks. The Dist. in your alum headed TPI is a bit base smaller than a regular dist that chevy uses. If I remember correctly, a reg. one hits the manifold where the runners bolt up.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
interesting. I've had three L98 C4's, and have had the distributors (and manifolds) out on all three. I've never noticed the factory timing marks. not doubting you, and not that I've ever looked for them, but just never noticed them. think i'll check this AM - if they are there, i'll see just how close I am to the initial factory setting. as a side note, I somewhat remember those marks on my 69 small block coupe.
Safety Car
Joined: Aug 2009
Posts: 3,752
Likes: 277
From: Melbourne, Victoria, Australia
Don't forget to check your valve lash, i came across this issue when putting my new engine together. The standard lifters need a full turn when you cannot turn the pushrod, my new lifters need only a quarter turn.
That caused my engine to back fire pop and not wanting to start, just something else to consider. A compression check will show if any valves are not closing fully.
That caused my engine to back fire pop and not wanting to start, just something else to consider. A compression check will show if any valves are not closing fully.
