I have a stock '72 350Sb with a Holly 650 w/ electric choke carb.

I am going to replace my intake manifold with a Edelbrock 2701 so that I can match up the square bores. Looks rather simple to do...part for part...item for item.

Are there any tricks to pulling out the distributor and putting it back in correctly without disrupting the timing/points? marking it in a certain way? etc.

Anything that I may run into that surprised you?

rt

 

It is a very straightforward job. I would first bring the engine to top dead center and double check that your distributor is in the #1 firing position and not 180 degrees out. Then just put it back in the way it came out.

 

If you mark the dist housing where the rotor is pointing after you lift it up (be careful not to move it by bumping it or anything- have a sharpie ready) and also mark the manifold and dist shaft housing b4 you take it out, you will only need to line up your marks and drop it back in.

 

It's a good idea to chase the threads in the heads with a thread chaser or bottom tap so there wont be any resistance when torquing the new manifold down.

 

as mentioned, it's best to first bring the motor to TDC and check that the rotor is pointing to the #1 plug wire.

next, use a piece of tape to mark the orientation of the vacuum can so you know when you drop it back in that you are pretty close to correct timing as a starting point.

I also like to use a marker to make reference marks to show the orientation of the rotor against the distrbutor housing.

when you go to drop the dizzy back in if the marks on the rotor lines up to the maeks on the dizzy housing and the vacuum can is lines up with your referenced mark against the piece of tape (or marker or whatever you used) than you know you are installed correctly and probably within just a couple degrees of correct timing.
Throw a timing light on it and adjust for proper timing and go drive.

 

Thanks for all your thoughts...

I did not think of TDC as a starting point....that idea is great! I did think the sharpie would become beneficial as a way of marking...but where to mark? If I mark the shaft to the manifold, I am marking the shaft to a piece that I am remove and not returning. I was thinking of marking the shaft and measure the mark back to the firewall in two locations...triangulation.

Again the forum is a great place to learn....

rt

 

Take a digital foto of the installed distributor before you remove it. This will give you a good picture of how it's oriented (i.e., vacuum can position) before removal. I like to do mine where the engine runs (advanced 12 degrees) but TDC is fine also- just make a mark with a sharpie on the distributor body directly below the rotor tab. When you reinstall, line up the rotor tab to the mark and you should be able to easily start the car and time it with a light. BTW, if you're still running a points distributor you can 'dead time' it by setting the crank where you want the plug to fire (say, 12 degrees BTDC), pulling and grounding the #1 plug, and dropping the distributor, getting the rotor and housing in the ballpark and then rotating the housing back and forth with the ignition on until you see a spark. Said spark will have occurred at whatever advance setting you placed the crank at, and you'll be timed. Check it with a light-you won't see any difference as long as your distributor and timing chain are tight.

 

every time i pull my distributor i bring it to TDC
as every everyone as mentioned, confirm the
rotor is pointing to #1 on the cap and lift it out
remember though that as it comes up it will turn
counter clockwise.
my rotor always ends up pointing right between
my #7 valves once out.
when going back in i line that point back up with
the rotor and it drops right back in to place without a problem

 

Something else to think about is the intake gaskets. I have a friend with a big block Chevelle who just replaced his intake with an Edelbrock w/electric choke and found he was boiling the gas in the carb. It turned out the gasket set he used had open exhaust cross-overs that allow hot exhaust gas to flow under the base of the carb. I think in stock configuration these ports are partially closed by a metal tab in the gasket and is used to heat/open the stock choke. He used a fully closed gasket and the problem was solved.

This got me thinking about my set-up so I checked and found I have the same issue. I don't plan on running my car in the winter months so, I ordered the new gaskets and started pulling the motor apart last night. I might as well take care of it now while I have easy access.

 

sine the intake gasket subject has been brought up, I'd recomment NOT using the rubber end rail gaskets that come with the intake gasket sets. They tend to slip and cause leaks. Use Permatex RTV instead. I like the Ultra Copper myself.

First, make sure all the mating surfaces are scrapped free of any old gasket material and very clean than use something like Permatex High Tack Gasket Sealant to arrach the intake gaskets on the heads. The High Tack keeps the gasket from moving.
run a continious bead of the RTV from one end of each end rail to the other. At the very corners where the end rails meet the heads it a common leak spot so I use a bit extra RTV to make sure it seals well. I also fun the bead up and around each of the corner water jacket ports just as an extra precaution. Let the RTV set up for about 5-10 minutes.
Now you can carefully lower the intake onto motor. Be sure to lower it very straight and do not shift it around to change position once it's down or you can mess up the RTV bead on the end rails and get leaks. To make life easy when lowering the intake so it's aligned proper the first time I use a sawed off broom handle and stick it into the distributor hole in the blok. Than I slide the intake down the handle with the handle going thru the distributor hole of the intake. This aligns the intake correctly to the block and as you slide the intake down the handle it will go right to the correct alignment without needing the shift it or move it once it's down.
Pull the broom handle out of the distributor hole and loosely set all the intake bolts than torque them down to correct torque specs in the order listed in your shop manual.

Here is a pic of the gaskets and RTV bead in place on my '78 motor just before setting the intake down. You can see the beads of RTV on the side rails and up around the water jacket ports on the heads. If you look carefully you can also see the bead of RTV is also a bit heavier in the of the four corners where the end rails meet the heads.

 

The intake install instructions call for a 1/4" bead of RTV front and back. The mistake I made was assuming this meant 1/4" wide. When I first installed the intake I had a gap. 1/4" high is the answer. (learned the hard way!) Notice the the open cross-overs in the above pic?

 

It has been a long time since I did main engine work....when my dad made me clean the parts, he did the work, and I watched as a young teenager. It would be great to have him clean the parts now and have him watching over my shoulder.

Barry K....thanks for the picture.....Itw as terrific help

thanks for all the thoughts....you made the porject easier.

I will have this car in the paint booth and chrome shop sooner than later.


rt

 

Now I know I'm going to sounds like an idiot, but just to make sure...

You all say "bring the engine to TDC." I'm assuming you mean to bring cylinder 1 to TDC, right? Because there's 8 TDCs...

 

yes, bring #1 to TDC on the compression stroke

 

I always use a piece of chalk to mark the rotor tab before I pull it out. The mark will either be on the firewall, the intake, etc. When you drop it back in, if it is off by a tooth or two, you will definitely see it. They you can just pull it back up, rotate it and drop it back in.