Most of you already know how to do this (and some of you can do it in your sleep :)) but there are those that don't so please bear with me. I've been on this forum since it's inception and about every week or so there's been a post from someone that has run into a problem because they didn't know the proper steps to take BEFORE removing the distributor. They changed cams, intake, or something else that required the removal and replacement of the distributor and wound up with an engine that wouldn't run right or wouldn't run at all. They've burnt the coating off of their headers, destroyed carbs with backfires, ruined a new cam or warped a head due to high temps, etc.. These things didn't happen because they're stupid people, it happened because they just didn't know the right way to do it. None of us are born knowing the right way to do anything (other than how to suck a nipple) and I'm not ashamed to admit that there are a zillion things that I remain ignorant of so this isn't intended as disrespect to anyone that hasn't had a need to know these things previously.


I'm addressing the situation where the camshaft and pistions aren't being disturbed but much of this, but not all, applies if they are. Unless you're broken down on the side of the road with a busted distributor and have no other choice, NEVER remove it without having done the following:

Have a timing light and know how to use it. If everthing else is done right, your timing will probably be close, perhaps even right on, but you won't know for sure without a timing light. What's the point of going to the effort and expense of making a mod or repair and then giving up some or all of it's benefit due to improper timing?

BEFORE you remove the distributor, you need to mark it's position relative to the other components. If you reinstall the distributor in the same position as it was before removing it, your timing will be the same as before. Unless you mark it's position before removal, you won't have a clue as to how it should be reinstalled. If you are not moving or replacing the cam, there's no need to worry about finding TDC but it's still a good idea to start with it there just in case.

1. Remove the cap and put a pencil mark on the distributor housing that aligns exactly with the center of where the rotor is pointed.

2. Put a mark on the intake manifold that aligns with that mark. If you are changing manifolds, put a mark on the firewall that corresponds to the position of the distributor. The goal here is to know what the correct position is upon reinstallation so that timing is not an issue upon reassembly.

3. In the best case scenario, the distributor will drop right in but, often as not, it won't. It's driven gear and the cam's drive gear are helical so the distributor will turn as it's removed. The oil pump drive gear will turn also but only while still engaged with the tang on the bottom of the distributor and the distributor shaft will continue to turn after it's disengaged from the oil pump until it's clear of the cam gear. The end result is that, with the distributor in it's original position as you drop it back in, the tang on the bottom of it may not align with the slot in the oil pump drive. With a long screw driver, you can repostion the oil pump drives slot so that it aligns with the tang on the bottom of the distributor. It may take several tries or it could drop right in the first time. In any case, if the marks you made before removal don't line up, keep trying until they do.

DO NOT turn the engine over for any reason before the distributor has been successfully reinstalled. Doing so will put you back to not having a clue as to where your timing is without unneeded effort and at the risk of serious damage to other components.

 

:thumbs: :cheers:

 

Thanks, I just bought the gasket that goes under the base of the distributor, mine is leaking. :cheers:

 

Vetterodder that is great advice but now I go and accidently turn the motor over.
What now? :)

 

In that case you're gonna have to do it the hard way, the same as if you hadn't marked it's position to begin with :banghead:. You need to locate TDC of the compression stroke on #1. Once you do that, rotate the engine until the timing marks align at whatever initial timing you want (most engines run like crap at 0º). Mark the #1 position on distributor housing (put the cap on temporarilly to see where) and point the rotor at that mark. Keeping the rotor in that position, drop the distributor in, making sure that the housing is oriented properly. You can drop it in anywhere but if it's not oriented properly you'll likely have trouble with some part of it hitting and preventing you from being able to turn it to set timing. This is only a brief summary and I'd highly recommend reading Lar's excellent article on this before you start.
https://www.corvetteforum.com/techti...=107&TopicID=3


[Modified by Vetterodder, 12:04 PM 4/20/2003]

 

Thank you Vettetodder. Have a nice evening.