Distributor Replacement

[norcalsvt]

After a few months of owning this stang, I have discovered my mileage is around 6-7 mpg. The engines a 302 w/650 Holley DP, w/edelbrock rpm heads, performer intake, mallory ignition system & C4. Including a mallory distributor that has no V.A. I have ordered a Holley street Avenger 570 carb & would like to also replace the distributor with one that has vacuum advance. One thing is, I wonder how much the mileage will improve. Secondly, I have no experience with distributor removal or install. Is this something an unknowledgable mechanic can do? I really don't know much, probably enough to get me into trouble. I did a search & the only thing I came up with was making sure the engines at #1 TDC. Not only do I not know how to do this, I don't know what that means. One last thing I have a vintage air frontrunner system installed,(A/C lines not hooked up yet) but I can't see any timing marks between the bracket for the pulleys. For some reason I think the PO may have removed the marks & pointer. How would I set the timing afterwards?

 

[faultlessfocus]

I am sure the mileage should be better than 6-7MPG's. I am not sure how much it will improve though, sorry. #1 TDC means to make sure it's at Top Dead Center. You can pop out the spark plug to tell. The piston needs to be at the VERY tip top to where if you were to crank it a little, it would come back down. Once it is all the way to the top, you are at TDC.

 

[jerry S]

After a few months of owning this stang, I have discovered my mileage is around 6-7 mpg. The engines a 302 w/650 Holley DP, w/edelbrock rpm heads, performer intake, mallory ignition system & C4. Including a mallory distributor that has no V.A. I have ordered a Holley street Avenger 570 carb & would like to also replace the distributor with one that has vacuum advance. One thing is, I wonder how much the mileage will improve. Secondly, I have no experience with distributor removal or install. Is this something an unknowledgable mechanic can do? I really don't know much, probably enough to get me into trouble. I did a search & the only thing I came up with was making sure the engines at #1 TDC. Not only do I not know how to do this, I don't know what that means. One last thing I have a vintage air frontrunner system installed,(A/C lines not hooked up yet) but I can't see any timing marks between the bracket for the pulleys. For some reason I think the PO may have removed the marks & pointer. How would I set the timing afterwards?

You have to know what kind of cam you have and make sure that the gear on the new distrib is compatable with it. For example, when I swappd out my stock distrib for an MSD pro-billet with vac advance when I installed the 6AL ignition, I had to change the gear to bronze and that can involve some very precise work. The tolerances are not very forgiving. When I do it again, I will use a polycarbonite gear. They last much longer. Maybe it is better to have a shop do this for you, especially since you don't seem to have the timing pointer anymore. It cannot be more than 45 minutes of shop work. Of course it took me all day because I did not have the right puller to get the gear off the shaft and spent more time driving around trying to find one than I did on the install. If I had to do it all over again, I would have paid somebody $50 to do it.

 

[Capt Dan]

I am sure the mileage should be better than 6-7MPG's. I am not sure how much it will improve though, sorry. #1 TDC means to make sure it's at Top Dead Center. You can pop out the spark plug to tell. The piston needs to be at the VERY tip top to where if you were to crank it a little, it would come back down. Once it is all the way to the top, you are at TDC.

I believe you also want to make sure it is in a compression stroke vs. an exhaust stroke. Check this by pulling off your distributer cap and making sure the roter is pointed to the # 1 cyl. firing point. When you re-install the new distributor, you will want it to end up pointing the same direction.

 

[iskwezm]

TDC is when a piston is at the furthermost travel in the cylinderon the compression stroke.The easiest way I find TDC is to remove the #1 plug and coil wire.Put a finger over the spark plug hole to seal it.Use a starter button and "bump" the engine over till you feel it blow your finger out.There should be marks on the balancer unless they are covered with paint or grease.Some timing covers dont have pointers, so you might have to add one.But if you have marks on your balancer it should be near TDC at this point.Then use a 15/16 socket on the balancer bolt to turn the engine by hand to get it right on TDC on the balancer.Then drop in your distributor and point the rotor to #1 on the cap.Since it spins counter clockwise,put it a little before,because sometimes they done bo all the way down unless you bump the engine again.Its not a hard process,but it takes practice and ive had A LOT this past week pulling mine out a few times due to a bad cam.

 

[norcalsvt]

Thanks for the tips & suggestions guys. Since there is a Mallory Unilite in here already, I'll probably just order he same model with VA. May just have a shop install it. With my luck I'll have a non running car when I'm done.