Oil consumption & smoke on a 327/350 hp

[Gene M.]

Re: Oil consumption & smoke on a 327/350 hp

Okay, ready to address my pegged oil pressure gauge. I guess I'll pull out oil pump over the winter and where would I order the correct spring for my 327/350?

In addition, I have another oil pump in my parts shelf that has a tag on it that states: DM55 98317A. Anyone know what this tag represents?
Thanks,

Jerry

Even with the correct (I think it's green) spring in the Melling pump the pressure will be higher than was original. It will not pass PV in 67 class. You need to be about 10 to 15 lbs lower. This requires the spring be custom massaged. I will have a real original GM pump at Carlisle. Also should use a 10W30 weight oil. Higher than necessary oil pressure robs horse power.

[Joe C.]

Re: Oil consumption & smoke on a 327/350 hp

Joe,

Thanks! I just took the spring out of this pump and it looks like it was yellow and seems to be pretty "springy". Let me check this site out to see if they sells low pressure springs that would fit this DM 55 pump.

Jerry

Jerry,

Springs are all interchangeable between manufacturers of that model pump. I have heard that you need the green spring, but as Gene indicates, judges vary in their "anality" (is that a word?) . BTW, I use the yellow one because I have plenty of stinkin' horsepower.

Earl pressure also depends on your bearing clearances and whether or not the engine was rebuilt, as well as wear on the bearings, etc. Many cars back then used straight 30 weight oil. I think that if a judge breaks your balls if you have a green spring installed, that you should jump up and down and threaten to call your momma. I'd also put a hex on him/her.

"Submitted for your perusal" as Rod Serling used to say:

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwiOqcvikb_OAhWFpB4KHZLjCZsQFghCMAA&url=http%3A%2F%2Fwww.melling.com%2FPortals%2F0%2FSPRING%2520PACKS%2520announce.pdf&usg=AFQjCNHR2H1Sm0LGN7NdRh_3xAGqOMsBmQ&sig2=RXKLz7gIxIQfYWx8WzZqWQ&bvm=bv.129422649,d.dmo

[Gerald C.]

Re: Oil consumption & smoke on a 327/350 hp

I just ordered the GM spring # 3814903. Based on what I've read on various posts, it is the correct spring for my 350 hp rebuilt 327. Here's hoping!

Thanks

[Gene M.]

Re: Oil consumption & smoke on a 327/350 hp

I just ordered the GM spring # 3814903. Based on what I've read on various posts, it is the correct spring for my 350 hp rebuilt 327. Here's hoping!

Thanks

You will be pulling the pan again when your oil pressure is way higher than The oil pressure specification of 40-45 psi HOT at 2000-up as Duke pointed out. The newer pumps put out more than the old 60's stuff...........

The stock GM spring is stronger than the Melling green one as I compared the two.

[Duke W.]

Re: Oil consumption & smoke on a 327/350 hp

I just ordered the GM spring # 3814903. Based on what I've read on various posts, it is the correct spring for my 350 hp rebuilt 327. Here's hoping!

Thanks

According to my '80 P & A catalog that is the correct spring for your application. The 55-60 psi spring used on late '63-up mechanical lifter SBs with 80 psi gages is 3848911.

According to the catalog the ...907 has 21 coils and 2 7/32" free length. The ...911 is also has 21 coils, no free length specified, but it does say "stripe of white".

Duke

[Gerald C.]

Re: Oil consumption & smoke on a 327/350 hp

Okay, one final question--If I install the new GM spring # 3814903, hopefully "green" should allow the oil pressure to be below 60 lbs. when cold????

Jerry

[Joe L.]

Re: Oil consumption & smoke on a 327/350 hp

Okay, one final question--If I install the new GM spring # 3814903, hopefully "green" should allow the oil pressure to be below 60 lbs. when cold????

Jerry

Jerry------


It depends. If you install the spring in an original or replacement GM oil pump (possibly excluding the latest iteration, GM #93427692), it will produce correct oil pressure. At least, it will produce the same oil pressure that your engine produced when the car was brand new (regardless of what some may THINK it produced when new).

However, if you install the spring in an aftermarket replacement oil pump, then I'm not so sure. I do not think that aftermarket replacement oil pumps use the same springs as OEM nor do they necessarily use the exact same internal parts/configuration as OEM.

Find an NOS oil pump of GM #3764547 (the oil pump that was originally installed in your engine) or GM #12555284 and you'll have it right.

[Gerald C.]

Re: Oil consumption & smoke on a 327/350 hp

Gene,

I will be going to Carlisle. Is your pump rebuilt or NOS? How much are you looking for for the pump?

Jerry