Chevy 427 Oil pump in 390 Cadillac

[Kevin Aspevig]

Hello, I was reading on the THE ALLARD REGISTER about their 19 Cadillac Engine Tuning Tips, article seen here: http://www.allardregister.org/blog/2013/5/23/19-cadillac-engine-tuning-tips.html
#15 states "Oil pump – use the one with a piston in the relief valve, not the one with a ball. Or – adapt the pump from a 427 Chevy.". Has anyone done this conversion, or heard about it? I don't know if they are talking about fitting the 427 pump to the 390 block, or if you use the 427 internals in the 390 pump? I plan to tear my 60's 390 down this fall and I can get a 427 oil pump for comparison, I just wanted to see if anyone has done this before. Thanks for the help.

 

[El Diablo]

I've never heard about this modification, but that would be great if you can do this. Plus there is a HUGE selection of oil pumps out there for the bbc that will outperform the stocker in every way.

With that being said, even though the Allard used a 390 Cad, I believe it ran looser tolerances for the extended RPM. If you are not going to road race your car, the original pump should be sufficient providing the housing is not wore out. The 390 has a windage tray/pan baffle that works pretty good. I never had any lubrication related issues with my 390.

Now the 500 is a different story. A few of us here are looking for better oiling options that what the factory offered .

 

[Kevin Aspevig]

That makes sense with the looser tolerances. I'm not going to race mine I just wanted to look into any modifications or upgrades I could do to extend the life while giving it a little more power. I only want to rebuild this engine once in my life if I can help it so I want it as reliable and probably overbuilt as I can. On the 500, not sure if you've seen this but Cad Company has a higher volume, higher pressure oil pump that they build that they claim they have Dyno pressure graphs to show other high performance pumps drop pressure at higher rpms while theirs has a consistent pressure increase curve with the rpm. Here's the link if you haven't seen it before. https://www.cad500parts.com/catalog/page23.htm
Thanks for the info!

 

[Darius]

That makes sense with the looser tolerances. I'm not going to race mine I just wanted to look into any modifications or upgrades I could do to extend the life while giving it a little more power. I only want to rebuild this engine once in my life if I can help it so I want it as reliable and probably overbuilt as I can. On the 500, not sure if you've seen this but Cad Company has a higher volume, higher pressure oil pump that they build that they claim they have Dyno pressure graphs to show other high performance pumps drop pressure at higher rpms while theirs has a consistent pressure increase curve with the rpm. Here's the link if you haven't seen it before. https://www.cad500parts.com/catalog/page23.htm
Thanks for the info!

Hello Kevin,

Glad to have you here on the forum.

I found your post (above) interesting and somewhat provocative in that you are saying that something is available that we've all been told for a very long time is not available. That being a stock style oil pump with greater volume. I won't go into any details but will leave that to other who may chime in (blueprinted STOCK pumps do flow better than non-blueprinted but the question is "by how much?).

Best,

bro. d (Darius)

 

[Ted in Olympia]

Used of an internal oil pump where a external one used to be? Interesting concept. Maybe the 390 has an internal pump and I only tore down the 429 but I thought they were a similar engine?

Not sure I agree of his point on high pressure flow less? What you are doing is changing the point where the relief valve opens you are not putting your thumb over a garden hose or restricting the volume in anyway. The only disadvantage of higher pressure is that it takes more power to drive the pump and may overload the pump driveshaft but I think this would take a lot of pressure.

Also I'm not sure how you will make your own front engine cover, this is a complex part on the 429 and I assume it is on the 390 also?

Ted

 

[Kevin Aspevig]

Used of an internal oil pump where a external one used to be? Interesting concept. Maybe the 390 has an internal pump and I only tore down the 429 but I thought they were a similar engine?

Not sure I agree of his point on high pressure flow less? What you are doing is changing the point where the relief valve opens you are not putting your thumb over a garden hose or restricting the volume in anyway. The only disadvantage of higher pressure is that it takes more power to drive the pump and may overload the pump driveshaft but I think this would take a lot of pressure.

Also I'm not sure how you will make your own front engine cover, this is a complex part on the 429 and I assume it is on the 390 also?

Ted

Ted the 331/365/390's had an internal oil pump driven off the distributor. In not sure when Cadillac went to the external oil pump but the "early" 390 from '59-62 was internal. What I'm not sure of is the Cadillac 365/390 at least up to 1962 was opposite distributor rotation from Chevy SBC engines so I'm not sure how they where modifying the Chevy 427 for this, or maybe it doesn't matter but I think it should right? Anyway, I find it very fascinating that it supposedly can be done I just wish there was more info on it. As far as if I need it I'm not sure but I always like to find ways to modify older things with newer more reliable parts, or at least more readily accessable parts...

 

[richie49]

I might be thinking wrong about this but isnt the 390 engine an internal oil pump with the distributer in the back? I was thinking they were useing a 427 inside guts inside the 390 pump..

Im confused

Richard richie49

 

[48Austin]

If I am not mistaken. the 429 pump is in the timing cover AND is different from year to year. Abortion engines. Transformations from the 390's to 472's.

I might be thinking wrong about this but isnt the 390 engine an internal oil pump with the distributer in the back? I was thinking they were useing a 427 inside guts inside the 390 pump..

Im confused

Richard richie49

Ed McMahon "You are correct Sir"

 

[kzhurley]

The early 59?-62 engines had the oil pump and ditsributor in the rear like the 331 and 365s... The 63-up 390s are more like the 429
I'm no expert, but before I decided to stuff a 500 in place of my 365 in my 56 coupe I was looking for a pre-62 390. It was pretty close to bolt in for my 56.

Never had any luck finding a 390, so I decided to use up a 500 instead.

 

[El Diablo]

The early 59?-62 engines had the oil pump and ditsributor in the rear like the 331 and 365s... The 63-up 390s are more like the 429
I'm no expert, but before I decided to stuff a 500 in place of my 365 in my 56 coupe I was looking for a pre-62 390. It was pretty close to bolt in for my 56.

Never had any luck finding a 390, so I decided to use up a 500 instead.

The 1962 390 was a one year wonder as well. It was the 1st year for Cadillac to use an bottom mount oil filter as opposed to the Lube R Finer. Also, 100% of the oil passed through the filter on the 62. Earlier engines gave the oil a choice of which path to follow.

 

[Kevin Aspevig]

The 1962 390 was a one year wonder as well. It was the 1st year for Cadillac to use an bottom mount oil filter as opposed to the Lube R Finer. Also, 100% of the oil passed through the filter on the 62. Earlier engines gave the oil a choice of which path to follow.

I don't know if they all had true full flow filtering, but I do know that the 60-62 had the spin on oil filter on the bottom side of the engine, the 59 still had the canister on top.

 

[El Diablo]

There I go spreading bad information again.

 

[Lou Baksa]

A 427 is a MK-IV Chevy engine. No different than any other BBC when it comes to oil pumps. I think that the MK-IV BBC oil pump in a 59-62 Caddy 390 is an old wives tale. The mount on the BBC pump isn't even close to fitting onto the bottom of the #5 Cad main cap. The drive shaft is in the wrong place as well. Not only that, the BBC pump wont work well if rotated opposite to the direction that it was designed for. HV Cad 390 pump will work just fine below 5500

 

[Schurkey]

1. As somewhat explained already, Cadillac "updated" the 390 for '63. The cylinder head style was retained from the earlier engine, but the block was totally different from the '62 390. That was when they switched from rear distributor to front-mount. The "new" '63 390 was physically smaller and lighter than the "old" '62 390. The "new" 390 morphed into the 429, and then in '68 they introduced the totally-new 472.

2. There's a version of the 348/409 "W" Chevy that was built in limited numbers as a 427 in '63 only. This engine would use a "small-block Chevy" oil pump as did the other versions of the "W" engine. But this spins the same direction as the BBC oil pump, although the design is smaller.

 

[Roothawg]

I know this is an old thread, but I was wondering if anyone has any more info on this? A guy dropped into the hamb and was mentioning that he raced Allards and they have a process for modifying the rear main cap to accept an Olds 455 pump. He threw the grenade in and left.........we never did get any more info out of him.

Thoughts?

Root

 

[G-92985]

I have a couple 390s here that Im just waiting for extra time to pull apart. I'm curious to see the side by side difference between the 390 and big block Chevy pump.