Replacing oil pump 1968 lemans 350cid

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j5ball

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Car. 1968 Lemans. 350 CID. I need to replace the oil pump. I have
Read the manual and it says I can remove the oil pan without pulling out the engine. Anyone have any actual experience with doing this?
 
Yes you can but your probably have to disconnect motor mounts and raise the engine.
 
Well. I will let everyone know this coming weekend
 
Are you going to check bearings while you have the pan down?
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You had me at Hello. What do I look for and how? Thanks!!!
 
Lets go back a step, why are you changing the oil pump ?
 
Oil light flickers on an off. When at idle, light remains on. When under load the light goes off. As long as I am giving the engine a little gas the light stays off. No gas, light comes on. Oil Pressure is between 4-7 PSI (measured). So, I conclude its the the oil pump. Are there other issues I should investigate first. I am sure its the original oil pump.
 
Do you also have an engine knock, worn bearings will cause low pressure also which is why I suggested you check them when the pan is down. You unbolt the mains one at a time and check the bearings for signs of copper showing through, gouges, scratches etc. Same with rod bearings. Make sure you put each cap back on the same direction it came off. You can find images of good and bad bearings on the internet.
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I did have a knock in the engine but I fixed that with replacing a worn out lifter and push rod. The bottom of the lifter lobe had worn all the way through to where it was not retaining any oil. I put new lifters and push rods in. Knocking gone and runs great. Except for the oil pump issue
 
Pumps rarely wear out. I would suspect bearing wear is your issue. How many miles on the motor?
 
I just pulled the engine out. And I knew if I pulled it I was putting in a new engine. And here is what I am putting in . . .
- Pontiac 400 block bored 30 over.
- 4.5 stroker eagle rotating assembly
- Comp. performance cam
- Roller lifters and rockers
- 10.5 CC Kaufmann aluminum heads. Ported and CNC'd
- 1000 CFM Edelbrock 4 BBL carb.
- Milodon 7 Qt oil pan
- Edlebrock high flow gas pump

Should be pushing 600-620 HPs . . oh my
 
Make sure it has a good oil pump! :)
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if that 1000 cfm isnt a typo you are making a big mistake.
 
Not necessarily Mel, depending on the grind of the comp cam and how much porting has been done to the heads. It's very possible the cam and heads have been matched up with the carb and intake. It may be a beast to drive on the street, but a lot of fun at the track.
 
Now, the following questions should be asked;
[with the following qualification: assuming the new engine is properly matched and finely tuned to deliver 600+ hp]

1. What will you be doing to the suspension and brakes to accompany this beastly new power plant?

2. What do you anticipate your horse power and torque curves to be?

3. Will you be running this in the 1/4 mile or other competition venue or just enjoying having one of the baddest street machines on your block? :D
 
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