Oil Pump & Camshaft Gear Oiling Modification

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RustyRatRod

RustyRatRod

I was born on a Monday. Not last Monday.
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I am going to run a high volume oil on my current slant 6 build project. Most of us know that is a taboo thing to do, because of the once rumored, now proven oil pump gear drive failures. Doug Dutra talks about a modification to get pressurized oil to the oil pump and camshaft gears in this article:

Title

I believe I have found an easier way. All it includes are two holes drilled, one tapped and one modified 5/16 allen head bolt. I have done everything here, except the allen head bolt and I will procure one maybe later on this afternoon. This mod requires a 6 bolt slant 6 oil pump. I'm unsure of anyone offers a six bolt HV oil pump anymore, and if I cannot find one, I will suffice with a new or rebuilt standard volume six bolt pump with the MP high pressure relief spring.

Here is my method.

In this picture, I am holding the small drill bit in the hole I drilled through the main oil galley into the rear pocket. This will pressurize that pocket.

DSCF1533.JPG


Here, you see the hole I drilled through the block that I tapped to 5/16-24.

DSCF1536.JPG


Finally, here is a 1/4 bolt in that hole for demonstrative purposes. What I am going to do is get an allen head 5/16-24 bolt, drill a hole through the head down the center of the bolt just shy of the end. Next, I will drill a hole through the side of the bolt that will be just in line with the oil pump and camshaft gears that will intersect with the center hole. Then I can direct the hole directly at the camshaft and oil pump drive gears and have pressurized oiling. The research that Dutra and company did showed that there was insufficient splash lubrication to those gears when a lot of resistance and heat from a high volume oil pump was present. This should remedy that problem.

DSCF1537.JPG
 
I disagree on the use of a HV pump. I don't feel the engine requires the extra oil volumm. A stock aftermarket replacement pump is a HV pump compared to the OEM pump.
 
Charrlie_S said:
I disagree on the use of a HV pump. I don't feel the engine requires the extra oil volumm. A stock aftermarket replacement pump is a HV pump compared to the OEM pump.
Click to expand...

Well, I'm doing a couple of different things to this. First, I am going to run full grove main bearings. Whether I have to get an extra set, or if I luck up on some. Then, I am doing the oil pump gear mod. Finally I have drilled a small hole through the front oil galley plug. So all those things will take a little extra pressure. But you're correct. Most of the standard volume oil pumps are higher volume than the originals.....but not all. You gave the measurements once...I think the originals had a 5/8 rotor the replacements 7/8 and the HV 1"? Somethin like that. I don't remember.

Anyway, I HAD a six bolt pump for sale and just removed it this morning. I'm gonna put the high pressure spring in that and it should suffice. But if I find a six bolt HV pump in the meantime, I won't be skeered of it doing this mod.
 
I tried to drill through a black oxide stud with a high speed cobalt 7/64 bit. Almost made it, but broke the bit. dangit. I'll get another stud or three tomorrow and a few more bits and give it another go. I'll get it did.
 
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RRR I have a couple HV slant pumps ( bought before I knew about the issues ) if one is a 6 bolt you are welcome to it. ( i will try and look at them this week )
 
vitamindart said:
RRR I have a couple HV slant pumps ( bought before I knew about the issues ) if one is a 6 bolt you are welcome to it. ( i will try and look at them this week )
Click to expand...

That would be really great. I've looked and the 6 bolt doesn't seem to be available anymore, much less in an HV version. I almost wonder if they ever were. Please let me know. Thank you!
 
I made a little more progress today. I bought four studs so if I broke another bit off in one I'd have more. I did break a bit off, but the piece fell right out. Going in tomorrow for a couple more bits. I made it almost to the point I need before it broke. I'll get it done tomorrow.
 
I'm not sure which way I'm going on my oil pump. I have a new but ancient Melling rebuild kit for the original pump, and I have a new "McQuay Norris" pump here too (it is a 6 bolt, I believe it is actually a sealed power pump, reboxed. Also old stock.

On the new pump I see some casting slag that I am gonna have to clean up on that pump if I decide to go with that route.
The old Melling kit's gaskets were shrunk, creased (bent over) and broke. So I found new fel pro replacements for those. I'm gonna have to dismantle the new pump if I use that one as far as I can/ because grinding means chips, which have no place in a fresh engine. I hope the cover plate o ring/gasket is the same, between an original pump and the replacement pump. Because the catalog never specified oe pump or aftermarket pump.
 
On trying to drill thru the Allen bolt, I thought the black oxide was just a surface coating, and not part of the metallurgy of the screw?
 
I still have not found a high volume six bolt pump. I would like to try an HV pump, even is people don't think it's necessary. That's really the whole point of doing this, to make the gears last using an HV pump. With the full groove mains, the timing chain oiling mod and the oil pump gear oiler, I'm losing a little pressure from those. Probably splittin hairs, but I still want an HV oil pump, but as of now, I haven't seen a 6 bolt version.
 
volaredon said:
On trying to drill thru the Allen bolt, I thought the black oxide was just a surface coating, and not part of the metallurgy of the screw?
Click to expand...

Crapped if I know. They seem pretty hard to me. lol
 
$16 for 8 if money is no object......
s-l1600.jpg


5/16-24 Stainless Steel Hollow Bolts with 1/4" hex drive (8 bolts) | eBay

What if you pressed in a brass tube and bent it as a squirter? Or...drilled a jet i the back wall at a matching angle to hit the pump gear from the pressurized pocket instead of the uni-directional threaded hole with your aiming bolt? Just thinking inside the pocket on this.......
 
pishta said:
$16 for 8 if money is no object......
View attachment 1715768357

5/16-24 Stainless Steel Hollow Bolts with 1/4" hex drive (8 bolts) | eBay

What if you pressed in a brass tube and bent it as a squirter? Or...drilled a jet i the back wall at a matching angle to hit the pump gear from the pressurized pocket instead of the uni-directional threaded hole with your aiming bolt? Just thinking inside the pocket on this.......
Click to expand...

Those holes go all the way through. I'm not going to do it that way. I thought about a tube, but then, kinda tho whole point of this was to do it differently. Doing it this way, there's nothing to shake loose and fall off or break and fall off. It'll be one piece secured by being screwed into the side of the block and retained with a nut and internal lock washer. That ain't gonna go anywhere.
 
RustyRatRod said:
I still have not found a high volume six bolt pump. I would like to try an HV pump, even is people don't think it's necessary. That's really the whole point of doing this, to make the gears last using an HV pump. With the full groove mains, the timing chain oiling mod and the oil pump gear oiler, I'm losing a little pressure from those. Probably splittin hairs, but I still want an HV oil pump, but as of now, I haven't seen a 6 bolt version.
Click to expand...
You could be right, not sure.
I have heard ( among other places it was in dutra's book, and @my68barracuda has mentioned this in the past as well.... The 81+ slants had a cast iron pump which was slightly higher vol than the 80-older alum bodied pump. 7/8 " thick rotors vs 5/8". Would that be "hi vol" enough for you?
This McQuay Norris pump I have appears to be the 7/8 version, got it via eBay and strangely the next town away. As I remember (it's been a couple of months since I got this one) I think he had 2 of them available at the time. Maybe he still has the other? Mine is definitely cast iron and 6 bolt.
You get into HV and you get into higher load on the oil pump drive.... Maybe defeat the purpose of what you are trying to accomplish? Just a thought there.
 
Mig weld the end closed ......What do you think about the drilled jet idea? would it work?
 
volaredon said:
You could be right, not sure.
I have heard ( among other places it was in dutra's book, and @my68barracuda has mentioned this in the past as well.... The 81+ slants had a cast iron pump which was slightly higher vol than the 80-older alum bodied pump. 7/8 " thick rotors vs 5/8". Would that be "hi vol" enough for you?
This McQuay Norris pump I have appears to be the 7/8 version, got it via eBay and strangely the next town away. As I remember (it's been a couple of months since I got this one) I think he had 2 of them available at the time. Maybe he still has the other? Mine is definitely cast iron and 6 bolt.
You get into HV and you get into higher load on the oil pump drive.... Maybe defeat the purpose of what you are trying to accomplish? Just a thought there.
Click to expand...

They've pretty much all gone to that pump design now. I have three or four. That's what I'll use if I cannot find an VH pump. Like I said, it's probably splittin hairs anyway. lol
 
pishta said:
Mig weld the end closed ......What do you think about the drilled jet idea? would it work?
Click to expand...

I thought about a jet....like maybe an idle fuel restrictor. But a 5/16 bolt ain't got a lot of room to tap jet threads in the side. What's wrong with just a hole drilled in the side? Is there some reason you think it won't work? Trust me. an 1/8" hole at 20-60 PSI, it's GONNA spray some oil. lol
 
I wasn't thinking HV when I bought the pump that I did, bought that one mostly because I saw it was a 6 bolt mount.
 
Hey RRR, did you see the HV pump that circlepilot just listed for sale?
 
RustyRatRod said:
I thought about a jet....like maybe an idle fuel restrictor. But a 5/16 bolt ain't got a lot of room to tap jet threads in the side. What's wrong with just a hole drilled in the side? Is there some reason you think it won't work? Trust me. an 1/8" hole at 20-60 PSI, it's GONNA spray some oil. lol
Click to expand...
not in the hollowed bolt, just in the back wall of the pocket at a 30 degree to hit the gear....? no bolt needed........
jet.jpg
 
pishta said:
not in the hollowed bolt, just in the back wall of the pocket at a 30 degree to hit the gear....? no bolt needed........
View attachment 1715768361
Click to expand...

At this point, I'd need to tap to a pipe thread and come out with like a 45 and put a plug on the end and drill and tap that. I might look at it. It's another option. Thanks.
 
I just checked my stock. I have a MP high volumn pump made by Melling, with the box dated 8/25/1999. It is a 5 bolt. Since I don't use them, myself, I can't say whether I have ever seen a 6 bolt HV pump.
 
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