jpc647

When installing a performer intake, does it matter what vacuum ports are used for what? For example, there is a line from the modulator on the transmission going to a vacuum port next to the thermostat housing(currently), and there is a vacuum line coming from the power brakes going to the back of the intake. The instructions don't say if there is a difference between the ports.

Just curious. Swapping intakes this weekend, got the old one unbolted, everything disconnected and ready to remove and started thinking about it.

Any other tips or suggestions? Going to buy new bolts in the morning.

joe_padavano

All manifold vacuum ports on the intake are equivalent. Yeah, there might be minor differences in actual vacuum readings due to flow, etc, but you won't notice it in practice. Use the port that's most convenient.

MDchanic

Yeah - Don't hurt your back!

- Eric

jpc647

Thanks guys!

Should I use a thread locker on the intake bolts? I know I have to retorque them after I do a heat cycle on the motor, but won't the thread locker dry by then and then crack apart inside and not lock the bolts?

MDchanic

No, you don't need any. In fact, you should put a bit of oil on the bolts, which would kind of negate the thread locker.

- Eric

oldcutlass

I prefer plumbers pipe dope with Teflon, especially in the water passages.

jpc647

Well my rear end seal blew out. Noticed a puddle of oil next to the distributor today and I reached down, and there was a nice little piece of gasket sitting there on the back of the engine.

I drove the car the day after I put the manifold on, probably put 100 miles on it no problems, and it decided to blow out today, when I was in the yard checking/adjusting the timing. WTF!?

Some say to see RTV on the end seals, some say to use the gaskets. I don't know anymore. Maybe I'll try the ones without the valley pan. They're cheaper, but might be easier.

MDchanic

RTV. This is why.

- Eric

ent72olds

Did you use the rubber end seals? Throw them away, and use a tall wall of RTV...did you move the intake much trying to line it up?

jpc647

I did use the end seals. I found part of one of the rubber ends laying on the back of the motor next to the distributor. In a moment of "haste" I assumed it was a blown out seal... While the gasket shouldn't have fallen apart, it's actually leaking out of the distributor.

It's coming out of the base. I removed the distributor today, put a new gasket in it. Still leaks. I removed it again, I put a bead of RTV silicone around the top where it meets to the engine, and it still leaks..

I don't get it. I'm baffled. I even thread taped the hold down bolt, for extra insurance

Does the gasket go where it is, or where the arrows are pointing? I put a bead of silicone where the arrows are, and it certainly slowed the leak down, only a small puddle came out now, but it allowed me to track it down.... Back to the drawing board.

20130622_145758_zps3e6b080e.jpg

jpc647

I don't see anything obvious... the o ring is supposed to be in the groove, correct? Not flush against the end.

joe_padavano

The O-ring goes in the groove, where it is. It does look a little flattened. Is it new? Might be worth a replacement anyway. O-rings have different cross sections and if this one is too small it won't seal properly.

MDchanic

Yes, the O-ring goes right in that groove, and should seal well if it isn't the consistency of glass.

- Eric

jpc647

I think so. The little beveled clip that holds the distributor down is sort of on a angle, but I think it should be. I pushed the distributor down, it doesn't go down anymore. I'll take a picture, maybe it's not down all the way.


See above. It looks like it's coming out of the dizzy.

Wouldn't I see a line or trail down the back of the motor?


The o ring in that picture is the one that came in the box with the intake. I bought a felpro 424 o ring and tried it, and put some rtv silicone on the mounting surface of the distributor.

I could see it leaking out of the rtv silicone. Only a small amount, but still leaking.

I then tried using both o rings. One on the slot where it belongs, and one on the mounting surface. Still leaking. I can't see any sort of an oil trail coming out of the back of the intake. I'll post a picture of the part of the gasket that broke away.

oldcutlass

Remove the RTV you stuck on the distributer as it will never seal, and you don't want it to seal with it because you need to have movement to adjust your timing.

Clean the base of the distributer, around the mating surface, and around the rear of the manifold. Blow some baby powder or baking soda around the area, start the engine, and look to see where the oil is weeping from. Repair the leak and rinse off the powder.

Octania

Agreed.
Spray some brake cleaner or carb cleaner in the area to totally clean everything, especially the intake to block rail area. Then run it and ck for leaks. Remember that oil will travel from its leak origin, generally back and down due to gravity and airflow.

There is no gasket on the Olds dist'r, just the O-ring which you have properly installed and is just not known to fail unless old and brittle or missing. There is really not much in the way of pressuized oil in the neighborhood of that o-ring and distributor seal.

The shoulder on the distributor must sit directly on the block, and then you must have a small amount of end play in the distributor shaft. If your oil pump drive rod is too long or something like that, it might prop up the distributor too high. I have never seen that happen though.

The clamp bolt passes into the flexplate cavity, so sealing that should have no effect.

Indications are strong that the leak is NOT at the distributor to block junction.

jpc647

The oil is due for a change. It's "dirty", but I'm hoping that is making it easier to see it. I've wiped the intake down 5 times, carb cleaner-ed it, short of waxing and polishing it, it's a clean as it can be, and I don't see any indication of oil running between the intake and the block.

When I used both O-rinigs, one in the groove where it belongs, and one on the mating surface of the distrubutor/motor, the leak changed. It doesn't leak as much and it no longer fills the area where the distributor sits. Maybe it's not pushed down all the way, I'll give it a hell of a push down tonight and see.


I've been doing this. Using a mirror and a flashight, just watching. The oil only seems to leak while driving. I go for a quick .2 mile spin around the block and I can't find the source. I'll try to post pictures tonight... not a lot of room in there.



Thanks for the baby powder suggestion, I'll try that.


Thanks. I'll post a picture of the distributor "height" tonight. And you guys can tell me what you think. The bolt was wet with oil, so originally I thought it might make a difference.

jpc647

Well the oil trail looks as if there is a hole in the distributor. The oil seems to come out of the dizzy, drip down to the base, and them move around the back of the intake.

My only thought is maybe it's "spraying" out of the back of the intake hitting the dizzy and dripping down..

Unfortunately I don't have a whole day to spend replacing the damn shitty gasket. I should have left well enough alone. The old RPM manifold didn't leak, I thought this one would be an improvement, and albeit the car does downshift more and is slightly more responsive, I don't think the improvement is worth two days or work. Thankfully I have a Harley I can ride to shows for the interim.

Really wishing I had pulled the trigger on that LS motor and did a project last winter... You never have time to do it the right way, but there is always time to do it again... // End rant. Thanks for the help guys.

Redog

I used those rubber gaskets with no problems. You just have to make sure the pegs are in the holes and use RTV on the ends. I refuse to use the turkey tray gasket.

Orginal question: Yeah, vacuum is vacuum. The only difference is on the carb. There is ported vacuum which means when you floor it, no vacuum from that port

MDchanic

No vacuum from any port when you floor it.

The "ported" source has no vacuum at idle.

- Eric

jpc647

I don't get it. Some use them, some don't. Car was fine for 200 miles then it started leaking. Part of the end seal in the back just fell right off. Maybe I over torked it. Edelbrock said 25ft lbs, I went 30. Others on the forum went to 35 on the aluminum intake.

Honestly, it's going to be close to 90 all week, so the car is just going to sit in the garage for the time being. I'm only going to be more frustrated doing this again with the heat.

On the other hand, I could just remove the dizzy to make room, and put a bead of high temp rtv in the crack between the intake and the block, let it cure real good and hope the bandaid fixes the problem. That kinda sounds like a really good idea to me.

On a side note, does the valley pan really matter? The new gaskets I got don't have a valley pan, and the gaskets I took off didn't have the valley pan. Does it actually help the motor run cooler?

MDchanic

Since you've got some downtime coming, that's what I'd do - cheap and easy, and won't hurt anything if it doesn't work.

Just be sure get all of the old seal out and to clean the surfaces REALLY well, then put in just enough sealant, but don't make a mess.

Good luck!

- Eric

jpc647

Thanks. I'll try to carb cleaner then down, remove the intake and put a bead along the seam. Kinda of a half-assed way to do it, but I can't really see anything wrong with doing it that way. I'll take it out for a ride after and see how it goes. If it was a big leak, it'd certainly change the gasket, but it's really spitting out at one spot. Almost looks like a pinhole in the gasket.