Question For Joe Lucia;Oil Pump Spring GM#3814903

[Larry E.]

Joe>We know from previous post that this is the spring to use to get the oil pump back
to the proper pressure in Small Blocks. Question:Would this spring have any uses in the
Chevy Big Block? Would it even physically fit in a Big Block Oil Pump? Thanks in advance>Larry

[Joe L.]

Re: Question For Joe Lucia;Oil Pump Spring GM#3814903

Joe>We know from previous post that this is the spring to use to get the oil pump back
to the proper pressure in Small Blocks. Question:Would this spring have any uses in the
Chevy Big Block? Would it even physically fit in a Big Block Oil Pump? Thanks in advance>Larry

Larry------


The GM #3814903 had no big block applications, at all. It's 7/32" shorter than a big block spring so how it would work if used in a big block I have no idea. I definitely would not be tempted to find out, though.

[Stewart L.]

Re: Question For Joe Lucia;Oil Pump Spring GM#3814903

I have a Melling high volume oil pump in a 396 that was there when I purchased the car, it pegs the oil pressure gauge. I talked to the Melling tech support, the internal parts in a high volume pump are different than in a standard pump so if you have a high volume pump, simply changing the spring won't really help. There is also 2 different springs for the standard volume pump, one for hydraulic lifters and one for solid lifters. My new pump came with the standard spring and I had to swap it out. If you have a Melling pump, I would call their tech support and talk to them.

[Joe L.]

Re: Question For Joe Lucia;Oil Pump Spring GM#3814903

I have a Melling high volume oil pump in a 396 that was there when I purchased the car, it pegs the oil pressure gauge. I talked to the Melling tech support, the internal parts in a high volume pump are different than in a standard pump so if you have a high volume pump, simply changing the spring won't really help. There is also 2 different springs for the standard volume pump, one for hydraulic lifters and one for solid lifters. My new pump came with the standard spring and I had to swap it out. If you have a Melling pump, I would call their tech support and talk to them.

Stewart-----

All GM high volume oil pumps that I know of are also high pressure. I don't know what would happen if a standard volume spring were to be installed in a high volume pump. A high volume oil pump, big block or small block, has longer gears than a standard volume pump. This means the pump body and both gears are different for high volume versus standard volume. The covers are the same.

As far as Corvette oil pumps go, there are 2 springs for each of the big block and small block oil pumps. One small block spring is used for all standard pressure small block pumps. This includes all hydraulic lifter engines as well as early 1963 mechanical lifter. The other was used for all other mechanical lifter small blocks.

For big blocks there were 2 different springs, one for hydraulic lifter and the other for all mechanical lifter.

No high volume oil pump was EVER factory installed for any PRODUCTION small block. With one exception, no high volume oil pump was ever installed for any PRODUCTION big block. The exception? 1969 ZL-1.