Re: [Amc-list] 401 oil mods

[Davis Martin <martin-davis@xxxxxxxxxxxxx>]

Nick,
   How are you getting 60-70 LBS from a stock oil pump? The only way I know is to use a stronger spring or put washers or spacer behind the spring to make it stiffer. This is artificially inflating the pressure. I never said we are loosing 40-50 lbs of pressure. A completely stock pump will see pressure of about 35 to 40 psi at cold idle and warm it drops to 18-20 for the reasons you stated. Factory recommended min I believe is 20 PSI. With nothing changed but our gears in a street kit, typically,  cold idle is 50-60 PSI cold and 35-40 hot. This is also dependent on other bearing clearances throughout the engine and the integrity of your pump housing.
   In our race applications we have made it so you can adjust the pressure and we run about 80 PSI 
   I will try to answer any questions you may have. If I can not answer a particular question i will refer you to my partner Bill.
   Thanks,
   Davis 
  

Nick ALFANO <71amx@xxxxxxxxxxxxx> wrote:
  Davis,

Thanks for the information on what you are doing with the pump. One thing that I have not seen in my experience though is as large of a drop in oil pressure from cold to operating temperature as you have. Gears that expand at a similar rate without going over as the aluminum cover is a good idea and something we have had many discussion about in my connections. But a drop down to 18lbs or less at idle is a lot more than just that. We typically see about a 15-20 drop from cold to hot at an idle. Starting oil pressure typically around 60-70lbs and then down to the 40-50lbs range at idle. There is two reasons for this. The first is the one you stated, gears that don't expand as much as the aluminum causing an increase in clearance in the pump housing. The second is from the oil thinning out at full operating temp verses a thicker cold oil. Tighter clearance would definitely help reduce this loss but if it is dropping more in the realm of 40-50lbs
from cold to hot, I would say that has other clearance issues involved like bearing clearance than just the pump housing. 

Just my thoughts but I don't think this was the only problem you were having in the example given.

Thanks again for the info on your gears. I would like to talk to your further on them.

Nick,

Alfano Performance
4849-76 st.
Kenosha, WI. 53142
262-308-1302
262-942-8271 after 6pm central and weekends 


Message: 11
Date: Sat, 15 Mar 2008 19:49:36 -0700 (PDT)
From: Davis Martin 
Subject: Re: [Amc-list] 401 Oil Mods
To: "AMC/Rambler owners, drivers and fans." 
Message-ID: <945478.56393.qm@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Content-Type: text/plain; charset="iso-8859-1"

Nick,
You make some good points. I have never twisted an amc past 7500 RPMS. I have run a car on the street quite a bit but never road racing. Yes, most of my experience is 1320 feet at a time
As for what we do to make our engines last:
There are 2 issues. 
1... is not enough oil in the system for prolonged hi rpm usage( 5000 rpms) Nor enough for short 6500 RPM floggings.(1320') 
2... is poor oil pressure in a warm engine.
The fix for problem:
# 1 is a deeper oil pan. It can be home made as our first one, or now we use the $334.00 Milodon deep pan with deep sump.

OK, on to poor oil pressure. 
The problem with the stock setup is there is a Powdered Iron gear living in an aluminum housing. The 2 have very different expansion coefficient's. So when you set your nice tight pump clearances on the bench they do not hold up. When the engine heats to operating temp, the gear does not expand as much as the housing, and you have a looser pump then optimum. This is why most see warm engine pressures in 18 PSI or lower. Ok for a stock engine so says amc and it must work cause they go 150K miles or better, but not so great for running 6000 RPMS or more. 
The fix.
Bill figured this out 20 years ago when we were loosing bearings. He found an alloy with the same expansion coefficient as the timing cover. We have gears made from this alloy which is harder on the RC scale then the factory gears. Once we swapped to this set up our amc oil problems were no longer. For our drag engines and my hot street motors we have a race kit where the gears are a tad longer to move more oil and an adjustment to dial in oil pressure. 
For more reassurance in a stock motor, we have a stock kit with the alloy gears.
We have had many repeat customers from as far back as 14 years ago when Bill had sold some kits and wrote an article in AMXterminator, a monthly amc club publication out of fla. (before the internet).
Fast forward to 4 years ago I wanted to build a street strip car and needed a set of gears. Bill only had one kit left. So I set out to have them made. Took some (lots) for foot work and I got it done. Started selling them on the net Through various places and they went like hotcakes. The past year or so I have slowed down as I am having family issues and needed to focus on that so I have not been pushing them or putting kits together. I have sold 3 kits in the last week and have many more to put together now that things are getting back on track for me.
I sell race kits for 220.00 and street kits for 110.00 

Ok now I feel I have rambled on long enough. Thanks for reading. I agree, we need more amcers that think outside the box and more willing to put a buck up and make parts to help our hobbyist improve our favorite Marque
Davis Martin 
Amc Team Racing 
860-997-2732 cell 
4-9pm EST and on weekends.
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