C2 oil pump and gaskets

[Richard S.]

I need information before looking for replacement of my oil pan gaskets, oil pump, connecting rod and pickup screen for my stock 63 340 hp car.

Are the oil pump, connecting rod and pickup screen and gaskets the same for the 4 and 5 quart oil pan cars.
Suggestion for source of materials for same appreciated.

Thanks Rich

[Duke W.]

Re: C2 oil pump and gaskets

I'm pretty sure the pickup tube is the same for both small and big small block oil pans. The pickup tube is a press fit into the pump housing with no gasket. The same applies to the pump cover, no gasket, and there is no gasket between the pump and main bearing cap. No gaskets at these connections might mean small internal oil leaks, but they are minor and have no measureable effect on oil pressure.

I don't understand what you mean by "connecting rod" in the context of the oil pump.

Duke

[Richard S.]

Re: C2 oil pump and gaskets

oil pump drive shaft
Rich

[Richard S.]

Re: C2 oil pump and gaskets

In looking at options for new oil pump I noticed with Corvette Central they have two pumps available. One listed as standard pump for stock C2 engines and one for high performance engine. Did the low horsepower motors, 250 and 300 have different a oil pump and perhaps pickup and screen from the 340 HP cars?

[Dorsey F.]

Re: C2 oil pump and gaskets

Richard, 4 pumps are available, two castings. Normal volume and pressure: Normal volume and high pressure: High volume and normal pressure: High pressure and high volume. The high volume pumps have wider gears and housing than the stock, normal volume. The high pressure pumps have a higher pressure relief spring. Your engine (250/300) came with the normal volume, lower pressure. Solid lifter engines (340+) came with the normal volume high pressure pump. If you chose the high volume you may need a different pick up as the body is wider. It was not an OEM pump.

[Joe L.]

Re: C2 oil pump and gaskets

In looking at options for new oil pump I noticed with Corvette Central they have two pumps available. One listed as standard pump for stock C2 engines and one for high performance engine. Did the low horsepower motors, 250 and 300 have different a oil pump and perhaps pickup and screen from the 340 HP cars?

Richard------

The oil pump pick-up was the same for all 1963-74 small blocks regardless of which oil pan was installed. The oil pumps differed only by the installed pressure relief spring. All hydraulic lifter engines from 1963-74 utilized a standard volume, standard pressure oil pump. 1963-72 mechanical lifter engines utilized a standard volume, high pressure pump. NO 1963-96 PRODUCTION small block ever utilized a high volume oil pump and I absolutely do not recommend that any such pump be subsequently installed.

[Duke W.]

Re: C2 oil pump and gaskets

I'll add that '63 340 and 360 HP engines did not get the high pressure spring oil pump until late in production, like maybe May.

The "low pressure" pump pressure spec is 40-45 psi at 2000, engine fully warmed up, and 55-60 psi with the high pressure spring pump.

GM never specified an idle oil pressure, and idle oil pressure is highly dependent on idle speed, so a SHP/FI engine that idles in the range of 750-900 will show higher idle oil pressure than a 250/300 HP engine at 450-500.

Installed engines with the high pressure spring pump should have a 80 psi gage and a 60 psi gage with the low pressure pump spring. It's never been clear to me how St. Louis lined up the low pressure pump engines with the 60 psi oil pressure gage IP assembly and the high pressure pump spring engines with the 80 psi IP gage assembly during the late '63 transition... or maybe they didn't.

Duke

[Mark M.]

Re: C2 oil pump and gaskets

I agree with you Joe that there is no reason to use the hi volume oil pumps that are available. An engine builder I've been using since the early 80's recently told there's no reason to use them especially with stock oil pans. There can be cavitation with small volume pans. He seemed surprised how often they are used without understanding them. I trust his word as he's built and dynoed every engine you could imagine.

[Richard S.]

Re: C2 oil pump and gaskets

Thanks I have the 340HP version. As noted, normal volume and high pressure for the 340 HP version. I wanted to make sure I don't get a version that by itself could cause leaks. So with my 340HP the pickups for the 250, 300 and 340 HP cars are the same using pump you describe. Is the oil pump drive shaft the same on each of the HP cars?

Thanks again for the information.
Rich

[Richard S.]

Re: C2 oil pump and gaskets

Understood thank you.
Rich

[Richard S.]

Re: C2 oil pump and gaskets

Wow. That is interesting. My car is a 62 year build and it has the original 60 psi gage. Was there some issue with oil leak with the higher pressure pump? Perhaps the normal pressure normal volume version is a better choice.
Glad I waited to order parts.
Thanks again
Rich

[Dorsey F.]

Re: C2 oil pump and gaskets

I agree with you Joe that there is no reason to use the hi volume oil pumps that are available. An engine builder I've been using since the early 80's recently told there's no reason to use them especially with stock oil pans. There can be cavitation with small volume pans. He seemed surprised how often they are used without understanding them. I trust his word as he's built and dynoed every engine you could imagine.

[Richard S.]

Re: C2 oil pump and gaskets

Dorsey
Is there any difference in the pump drive shaft with the various versions of 63 HP cars over years late 62 63?


Thanks
Rich

[Dorsey F.]

Re: C2 oil pump and gaskets

Dorsey
Is there any difference in the pump drive shaft with the various versions of 63 HP cars over years late 62 63?


Thanks
Rich

[Joe L.]

Re: C2 oil pump and gaskets

Dorsey
Is there any difference in the pump drive shaft with the various versions of 63 HP cars over years late 62 63?


Thanks
Rich

Rich-------


No difference whatsoever with the shafts. In fact, they are the same from 1959-82. Originally, GM #3764552, later GM #3998287, and currently GM #19434521