Ford Racing 427W ate cam gear

[DAVID GAGNARD]

Originally Posted by Luce

David, that is not exactly apples to apples. A better example is your new, in spec engine has a total open clearance (not sure how you would measure such a thing) for discussions sake equivalent to a hole .2". If you push x gal/ hr through that hole, you will have y PSI of back pressure getting that much oil through that hole. Now open that hole to .3". If you increase the flow to some x', you can achieve the same pressure, but at a higher flow rate. The pressure is what assures that oil is getting everywhere. With some miniscule (maybe 2-5 PSI) you could maybe get some oil to the first main bearing, but not stand a chance of it getting up the pushrods to the rockers. A larger swept volume oil pump will hold the same pressure with a larger clearance and/or lower viscosity oil. A larger volume oil pump will also spend more time bypassing excess flow

No, not exactly apples to apples, but close...think about this: your oil pump pickup/tube is a specific diameter and can flow X gal/hr thru it,now the oil is sucked up thru the pickup in the bottom of your oil pan and into the pump, where it is pushed under pressure thru the oil filter and into a hole in the block feeding the engine oil....

Now, go look at the diameter of any stock or after market oil pickup and the look at the size of the hole in the block where the oil enters under pressure....I can assure the hole in the block is quite a bit smaller than the diameter of the pickup,it has to be,otherwise the pickup would not be able to flow enough oil to maintain the output of the pump.....
I'm not a fluid dynamics engineer,it is all regulated by the pump bypass setting...one could change that setting and achieve more pressure with a HV pump, but according to Melling, they are all sent out with the same setting....

David

[Luce]

If the pressure is below the bypass pressure, all other things being equal in a loose engine, the HV pump will read a higher oil pressure than a standard.

The bypass setting will be the absolute maximum oil pressure you see. I don't know if the bypass pressure is the same between the two pumps. Doesn't matter to me. I want the HV for when the bypass is closed and I'm hot idling after kicking it in the teeth. I want my hydrolic lifters to not bleed flat.

If you tell me I should have the correct bearing clearances instead and the HV pump is a bandaid masking a bigger problem, I'll have to agree. But the HV pump might make a tired old engine make it through the season and that's good enough reason for me.

My problem was having a iron cam and thinking it was steel. Shame on them for the poor documentation I got with the motor, but shame on me for not calling and getting the answers I should have. And it's no longer a problem!

[dallas_]

Originally Posted by Luce

My problem was having a iron cam and thinking it was steel. Shame on them for the poor documentation I got with the motor, but shame on me for not calling and getting the answers I should have. And it's no longer a problem!

So you confirmed you had an iron cam gear?

Interesting since they say it's steel.

[DAVID GAGNARD]

Luce:

If the pressure is below the bypass pressure, all other things being equal in a loose engine, the HV pump will read a higher oil pressure than a standard.

Yes, I agree with that statement........

The bypass setting will be the absolute maximum oil pressure you see. I don't know if the bypass pressure is the same between the two pumps. Doesn't matter to me. I want the HV for when the bypass is closed and I'm hot idling after kicking it in the teeth. I want my hydrolic lifters to not bleed flat.

o-k, I agree with that also,in that case, a HV pump is not a bad choice...

If you tell me I should have the correct bearing clearances instead and the HV pump is a bandaid masking a bigger problem, I'll have to agree. But the HV pump might make a tired old engine make it through the season and that's good enough reason for me.

Not saying your bearing clearances are out of whack,I have no idea what they are.
Second sentence, most definitely,a HV pump will help a tired old engine go many more miles....

Not saying nor never said that one should NOT use a HV pump, they have their place,I just think they are over used.....
Ever pull a valve cover off and start the engine,just to see how much oil is flowing out of the pushrods???? I have, on many occassions,actually the last time was yesterday, changing a seeping valve cover gasket on a newly built 331 stroker... the engine had been run for 30 minutes, the oil temp was 160 and the idle oil pressure was 40 psi, while I had the valve cover off, I started the engine, the back 4 pushrods were shooting a stream of oil that cleared the head by 6 inches!!!!! the front 4 pushrods were shooting a stream of oil that was just cleared the head.not quite,but close to a solid stream of oil coming out of them all this at 40 psi, can't imagine how much oil would be pumped thru the pushrods at 60+ psi.....this engine had 15/40 Shell Rotella T oil and a Melling High Performance STANDARD volume/STANDARD pressure oil pump on it.

David

[Luce]

Regardless, I'll be pulling this distributor every few hundred miles to make sure nothing is going south until I have the confidence of a few thousand miles under my belt.

[zrayr]

I do run newly overhauled engines with both pumps. The HV pump will produce more pressure. The bypass is set so high (100 psi) that it not reached with either pump.

In my last '66 GT350, with a new overhaul to minimum stock clearances, the std pump had 50 psi of hot oil pressure. The HV pump had 72 psi.

Z.

[mike harter]

You will be changing a bronze gear every 3 to 5000 miles. Stick with a steel gear