Oil Pump

[WhiteKnight]

Trying to decide if I should replace the oil pump while I have the pan off.

I was looking for the source of a squealing noise from the front of the motor last week. Found the AC belt had hit the lower hose and caused a good nick. While replacing the belts I saw the balancer had seperated and was back against the timing cover. Ah ha.. source of noise found - ouch! So I figured since I'm going to replace the balancer and possibly the timing cover I might as well replace the chain and gears, oil pan gaskets, valve cover gaskets, water pump gaskets, timing cover gaskets, radiator hoses and clean up and paint as much as possible on the motor.

So now that the oil pan is off I found lots of plastic chunks in the pickup. Lots of grit too. Not sure where or what the plastic is from does not look like a gear, maybe a bushing from somewhere? It did have a HEI distributor in it when I got it (now a dual points Accel) so I'm not sure if the origional dist had a failure and that is why it was changed. The oil pressure runs around 40-45 at startup and 35 when warm at idle. With load it runs 35-40. I have checked against a secondary test gauge as I did have to repair the gauge when I got the car, and I wanted to verify it was semi accurate.

Anyhow should I just clean out the debris from the pickup or replace the pump, shaft and shaft guide? If I do replace the parts should I get a stock or a high volume pump ? This is a base motor 350 - 270HP with AT that is used on weekends for crusing. I've put maybe 1100 miles on it since October last year and it does get winter use, but only because of the mild weather here in Texas.

One last question.. if I do replace it, should I put the timing chain/gears back on first before pulling the pump?

-thanks

 

[JohnZ]

Anyhow should I just clean out the debris from the pickup or replace the pump, shaft and shaft guide? If I do replace the parts should I get a stock or a high volume pump ? This is a base motor 350 - 270HP with AT that is used on weekends for crusing. I've put maybe 1100 miles on it since October last year and it does get winter use, but only because of the mild weather here in Texas.

One last question.. if I do replace it, should I put the timing chain/gears back on first before pulling the pump?

-thanks

I'd replace the pump - they're cheap - just get a standard pump; no need for the high-volume or high-pressure pumps - they just wear out the distributor drive gear faster. I always use an aftermarket drive shaft with a steel collar. Doesn't matter what the sequence is between the timing set and the oil pump - there's no relationship.

 

[WhiteKnight]

Thanks John.

I'll replace it.

I was thinking that the pump is driven by the cam, indirectly I guess as the cam really drives the distributer and that drives the oil pump. So I was concerned with somehow causing the cam to move while the timing chain is off. Which would cause the crank and cam to be out of time and possibly big trouble. :confused Maybe I'm just paranoid. :W

 

[AKRAY4PLAY]

don't worry about the distributor when setting cam timing. just align your little dots as per the book and set the distributor after the cam is locked to the crank via the timing set. as John said, no need to go high pressure / high volume. you only need 1 psi oil pressure per 10hp. your pump is putting out more than enough pressure for your motor, so replacement is not needed unless you have high miles. then again, it's apart and pumps are cheap. now is also a good time to replace the rear main seal, especially if you pull the pump.

 

[TJay]

I agree with the others, replace the pump/assy while you have the pan off with a new stock one. Clean the pick-up and tube assy/ oil pan/ check the threads on the pan & drain plug etc.

 

[WhiteKnight]

Good advise.

I stopped on the way home and got a new Melling pump #M55 and a steel collar shaft #IS-55E. Forgot to get a new pickup tube assy. The old one is a bit gummed up in the screen. I think I'll just pick up a new one tomorrow.

I installed the timing gears first.. dots aligned, which I remember is #6 TDC compression and #1 TDC exaust stroke. That is how I had it rotated when I pulled the gears off. The rotor is pointing at #6 so it should be ok. Although I'll probably pull it back out and (drill) prime the new pump.

Didn't pull old the pump apart (yet) but the old shaft collar (nylon) fell to pieces after I got it out. There is a bit of wear on the shaft that is part of the pump.

I thought about replacing the rear seal, but it does not look like it was leaking. OD shows 59K on the clock so it may not have too high of miles, or it may have 159K. The timing cover had been off before and the chain had been replaced already, it still looked ok, but I had some concerns as the timing cover had been banged up. Not just from the balancer failure but from the last chain replacment. The part of the cover that the oil pan fits into had been hammered giving it a wavy apperance. They had also used a white sealant to try and seal the gap between the cover and pan. Looked like household grade silicone. That is where the main leak had been coming from as best I could tell.

Now that I have the timing chain and cover back on, I have this balancer sleeve thing that can with the timing cover gasket set. Looks to be for use on an old balancer to smooth the grove from the old seal. Should I use it or not since I'm installing a new balancer?

 

[AKRAY4PLAY]

that sleeve is a speedy sleeve. you should not need it as you suspected. it is for "reconditioning" the old balancer to seal. are you planning on running a one piece oil pan gasket?? Felpro makes a nice rubber one that works great. kinda spendy, but reusable.

 

[Jack]

Felpro makes a nice rubber one that works great. kinda spendy, but reusable.

Correct fitting one-piece oil pan gasket for 1974 and older is felpro P/N OS34509T ... correct fit for a 71 sbc with 71 oil pan.

FYI ... 75-85 have a different pan & use a different gasket ... also, most aftermarket pans are configured for 75-85 ... correct fitting one-piece oil pan gasket for 75-85 sbc is felpro P/N OS34510T.

Either one should be available through your local parts house for around $25 ... they work real well ... Do ENSURE rails/lips on both block & pan & lower timing cover are VERY clean & .... lower timing cover lip & pan's rails are VERY straight. If it were me ... I would replace the rear main seal while I had pan & pump off.
JACK:gap

 

[WhiteKnight]

Okay Okay.. I'll pick up the rear seal when I get the new screen and while I'm at it I'll take the multi piece gasket back and get the one piece.

I should get a brass punch too I guess.

What do I need to braze the pickup tube in place? I have a little portable propane torch kit, but I think I need to get a new bottle. What do I use to tack it? Solder or something?

 

[vette-dude]

Okay Okay.. I'll pick up the rear seal when I get the new screen and while I'm at it I'll take the multi piece gasket back and get the one piece.

I should get a brass punch too I guess.

What do I need to braze the pickup tube in place? I have a little portable propane torch kit, but I think I need to get a new bottle. What do I use to tack it? Solder or something?

You can braze it on but remove the pressure relief spring and piston/valve before you apply heat to the pump body. Also be sure you have the pickup at the correct height from the bottom of the pan. On the rear seal, offset the parted halves 1/8 inch in the cap groove and block groove. This will prevent leaking past the block/cap parting line. Further, I always put a very THIN coating of spray on copper seal gaskt sealant on the mating surface of the rear main cap wear it contacts the block. You can buy pumps with the pick up already brazed on them from Summit Racing and others.

Randy

PS: I am not sure but doubt the propane torch will get everything hot enough to braze the pick up on.