Experience installing new oil sump

[Dave Russell]

Rambling a bit, no really important revelations;
I just finished replacing some parts on my BN2 Healey. I was planning on doing this project several months ago, just before some medical problems came up. I just finally felt strong enough to tackle the project. Seems like it took a thousand trips under the car & back out to the work bench, but I and the car survived.

The project included replacing the oil sump & oil pump with Denis Welch parts. As usual with DW parts, although they are of very high quality, they almost always require some modifications to get things right. The new aluminum oil sump is about 3/8" shallower than the original. This required a lot of measuring, trial fitting, & shortening the pump inlet screen to fit. DW said to just mash the screen to fit. Can you believe that they said that! No way - I cut the original spot welds, trimmed the screen, & re-welded the bottom to the screen. The pickup tube & rear main bearing drain tube also had to be shortened. The old oil pump driven gear was stuck to it's drive shaft & put up real resistance to coming apart. I could have gotten a new drive gear & shaft for an additional $350, but didn't, & the original shaft wasn't worn. It fits in the new pump perfectly.

Checked a couple of main & rod bearing clearances which were ok at .002". To my knowledge, this is an original engine bottom end with about 85,000 miles on it. No sludge or gunk on the inner parts & still runs very well. The old oil pump had about 1/2 thousandth wear on the gears & bottom plate. From a previous project to replace the cylinder head with a DW head, I know that the pistons & bores are still standard size & show no wear. These old four cylinder taxi engines are tough.

Finally got everything back together. Previous hot oil pressure was 40 psi at 1000 rpm & 60 psi above 2000 rpm, where the regulator is set. Surprisingly, to me anyway, the new oil pump hot idle pressure came up to 50 psi & the same 60 psi running. I didn't think that such minor oil pump wear would make any difference. Or maybe the oil is cooler now.

Was the project worth the trouble & expense? Not sure, it was just one of those "do it because I can" projects. New finned sump looks good, though I'm probably the only one who will ever see it. BTW, no leaks!
D

 

[aeronca65t]

Is the sump less deep to allow lowering of the car? (rock clearance?)

The other Sprite I'll be co-driving (in a Summit Point enduro in 2 weeks) has an aluminum sump. It's the bees-knees compared to the boring tin thing on my car.

Small differences in oil pumps can make a surprising difference; I found this out a few years ago. The gear pump on my 1500 engine has an aluminum cover plate that was very slightly worn (from the gears bearing against it). I sanded it smooth using a piece of 600 paper on a piece of glass......it brought the idle oil pressure up almost 10 psi.

I know what you mean about the struggles of getting under the car. In my brain, I'm still a kid....but my sore back will remind that I'm not!

The 0.002" rod bearing clearance sounds bigger than I would have guessed.
I seem to recall an Austin diesel version of this engine (for taxis?).

 

[Dave Russell]

[ QUOTE ]
Is the sump less deep to allow lowering of the car? (rock clearance?)

The 0.002" rod bearing clearance sounds bigger than I would have guessed.
I seem to recall an Austin diesel version of this engine (for taxis?).

[/ QUOTE ]

I have no idea why the new sump is shallower. It does create a lot of problems though. In addition to the above circus, the oil dipstick hits the bottom of the pan before it is fully seated. DW said that it should be that way. This would result in a higher than original oil level. I chose to cut off the bottom of the dipstick so that it seats to the original depth. This results in the same oil level but a quart less capacity which doesn't bother me. It still takes 7 quarts to the full mark & I try to run it a quart low anyway. Who knows what has happened to the dipstick & tube along the way in the last 40 plus years.

The .002" rod bearing clearance doesn't bother me. I would normally set up a new engine to .002" on the rods & mains. More flow through the bearings gives more cooling, as long as the oil control rings are not overloaded with the extra oil, no problem.
D