intake & distributor removal 101

[tonyk72]

I have a nasty oil leak which looks like its coming from the back of the intake manifold. After driving about a total of 30 miles or so, I'm down a quart.
With the Chilton and Haynes manuals in hand, removal of the intake seems like a piece of cake (I think). It's the distributor removal that worries me...I have a stock distributor for my '72 LT-1. I have never done anything like this before, I hear you could mess things up pretty bad if this isn't done right.
Step 1 in Chilton:

1. Rotate the engine until the timing mark on the crankshaft balancer is aligned with the top dead center mark on the timing tab scale.
Can somebody please translate? Maybe provide some step by steps of how to do that? How do I rotate the engine?

2. Remove ignition shielding (I get that)

3. Release the distributor cap hold-down screws (push down and turn counterclockwise). Raise the distributor cap off the distributor and check the firing tip of the rotor is pointed at the #1 terminal of the distributor cap. If it is not; turn the engine one full revolution and again align the timing marks as previously stated. Recheck the rotor position.
What is the firing tip? Again, how to tun the engine? Align the timing marks?

What else should I watch out for during this project? And since I have to drain the coolant, I might as well do the heater core (since my dash is apart already) and change the hoses. I'll also probably change the carb gasket too (another thread, another problem) at the same time...

 

[Bob Chadwick]

Burglar has given is a great tutorial. As I understand it all you have to do is mark the distributor in relation to the engine (make sure you mark the block if you are going to replace the manifold) and then mark the rotor in relation to the distributor, This make sure your distributor goes back in correctly and that your rotor is pointed in the right direction.

The TDC trick is only necessary if you rotate the engine or don't mark the distributor correctly.

Bob

 

[tonyk72]

Thanks Bob, that link was helpful...
I found a few more out on the net for anybody whos interested...

http://www.chevyhiperformance.com/howto/89818/

http://www.edelbrock.com/automotive/general_instr/general_instr.html

 

[6shark9]

Make sure that the oil is not coming from the oil pressure line/fitting right behind the intake, drivers side.

Just in case.

 

[Dave L.]

Tony - I sent you an email. I am interested to know what you find out with this problem.1 quart in 30 miles,wow!

Dave

 

[Tom Bryant]

Make sure that the oil is not coming from the oil pressure line/fitting right behind the intake, drivers side.

Just in case.

I would look at this line and fitting very closely when running if this is the area of the oil leak. There is no oil pressure under the intake in the valley area to force that much oil out that fast. A rear intake oil leak will be more of a seeping thing. Sounds like you are looking for a gusher.

This has to be a pressure leak. Wipe the fitting and line down so it is clean then observe it with the engine running. It should be obvious is short order where the oil is coming from.

Tom

 

[Stallion]

Maybe a mod should make this tutorial a sticky? Because this subject comes up a lot and it is a great writing of it. It gives a great description on intake removal. It would be better if it was stickied I think.

 

[tonyk72]

The "oil pressure line/fitting right behind the intake" that you guys are talking about...This is the line that goes to the oil pressure gague right? If thats what you guys are talking about, I did wipe it down and drive...came back and it looked clean.
I'm pretty sure its the intake thats leaking, I can see a black rubber gasket thats between the intake and the block that sticks out too much...its also pretty oily. The leak is on the passenger side.

If I can get a few clear pics, I'll post them. I'll also post pics as I'm going through this whole project.
If I am leaking oil elsewhere, I figure this will help me troubleshoot better...working from top down to track all the leaks.

 

[yakatak76]

you can rotate the engine by taking a socket and putting it on the front of the engine where the timing mark pulley/wheel/balancer/or whatever it is called and then just turn the engine. the firing tip of the rotor is the metal part that comes in contact with spark plug wire contact points in the distributor cap. once it is pointing toward the number one cylinder, then you can remove the distributor and should be okay. it will take a little twist when coming out to accomodate for the gear that is on it. make sure the gear doesn't get moved between removal and installation and you should be good to go. good luck

 

[714Speed]

I broke my oil pressure hose just as it comes out of the brass fitting last week while I was hand tightening the tach cable located just above it. I did not realize that I had pinched the tiny hose until I started down the road. I looked back and I must have looked like the batmobile putting out a smoke screen. I lost just under a quart of oil in the 1\4 mile trip. Please check the oil pressure fitting before you tear an intake off.

 

[tonyk72]

pic of where I think leak is coming from

rear of the intake manifold, pass. side...

 

[tonyk72]

pic of oil pressure line

wiped the area down clean, went for a ride, looks clean to me...
rear of intake manifold, driver side

 

[tonyk72]

pic of leak after 3 mile ride

this is pass. side, below from where I suspect the leak originates

 

[JohnZ]

Wipe the area down so it's clean, and sprinkle some talc or baby powder around the area, then go for a quick drive around the block and take a look - will make the source of the oil leak easy to spot against the white background. It has to be either valve cover gaskets, rear intake rubber seal, missing distributor-to-intake gasket, or the oil pressure line fitting.

 

[tonyk72]

Don't really need the baby powder trick, it's very obvious when looking at all the components you mentioned that its that rear rubber seal...but just to make 100% sure I'll do that.
Also, this may be a dumb question...do I need a distributor wrench for removing the distributor?

Thanks
Tony

 

[6shark9]

I have fixed this problem before.
I ripped out the rubber gasket.
Cleaned the gap between the block and intake
good with solvent.

Then placed permatex(sp?) into a large syringe
and "caulked" the hole. This was on the front, where
it was easier to reach. I know, I probably would
not do this on a 'vette either.

Note: Most engine re-building material I've read, recommend not using an intake to block gasket (just a bead of the RTV), expecially not the cork ones. Use the rubber one with the tabs that hold it in position.
I've had great luck just snuging the intake on with the wet RTV
on the gaskets and waiting until the next day to torque it down. Because the wet gasket can easily squirt out of place when compressed.

my 2 (maybe 3) cents worth,
6shark9

 

[tonyk72]

So you're saying use of the rubber gasket is not advised? What do you mean by "Use the rubber one with the tabs that hold it in position."

Thanks

The tip about waiting 'till the next day to torque down the bolts makes sense to me, sounds good...

 

[6shark9]

I read not to use one at all, but if I did use one, use the rubber kind with the tabs on them that hold it in the correct position.
I used the gaskets, I didn't trust the sealant alone.

 

[JohnZ]

The end gaskets that come in the gasket kits (either rubber with the little locator tabs or the cork type) all leak eventually, and the rubber ones shift more than the cork ones. Just ditch them and use a bead of Permatex Ultra-Copper RTV instead; clean both the block and mating intake surfaces first thoroughly with lacquer thinner or brake cleaner and dry to get a good bond, and overlap the RTV bead about 1/4" onto the side gaskets. I've done this for years, never had a leaker.

 

[tonyk72]

now it makes more sense all apart

OK, I yanked off the carb, distributor and intake tonight...marking everything, taking notes and pics along the way...
I cleaned up the mating surfaces on the intake & the engine...
looking inside the intake (where the carb sits) I see "crud", probably gas stains...is that good/bad?
Do I leave it as is? Clean it up?
Can I dunk the whole intake and scrub it down real good inside and out? Any special precautions for aluminum?
Thanks!