Oil pump: high volume or high pressure

[SilverXJ]

Despite the on going sound in my engine it appears I have another issue. After the initial build I had an issue with the crank thrust bearing surface. Everything else was fine (except that on going sound). So.. I tried to clean the crank surface up my self with 1000 grit sand paper. I finish it and put the pan back on. Immediately I have extra lifter noise and a hesitation and stalling issue that wasn't there before. Pull it back apart and the cam is dead. I think I may have done the damage by rotating the engine with the starter with out oil (not firing the engine, mind you).

So I replace the cam, lifters, bearings, oil pump, etc. Get it fired up and run the cam break in, which went fine. Now I notice my oil pressure isn't as high as it was with the original pump. Hot idle was 40 psi, now it is 15 psi. I also have a noisy valve train and seems to be lacking in performance until 2000 RPMs or 30 minutes of driving. At which point the valve train quiets down. Even thought the cold oil pressure is ~40 PSI I still have the noise and slight lack of performance when cold. Its not that loud either, not like the sound that a faulty lifter will make when it has sat for a while and needs to be pumped back up. Its a bit quieter, and its almost like a lifter is soft. Also, when the valve train does quiet down it seems like it gains the performance back.

Now I also have my lifter bores grooved.

My machinist now things that the grooves are not getting enough oil and bleeding off, which caused the original cam failure. I don't think it caused the original cam failure as it happened like someone threw a switch when I got finished screwing with the crank. He suggests I make a high pressure oil pump.

I think that I have a faulty oil pump to begin with and I will be replacing it regardless. One question is if the grooved lifter bores are in fact causing the loss of oil, would a high pressure or high volume combat this? I'm thinking high volume because I still have pressure above the minimum stock.

I don't like the idea of a HV pump, but if my engine needs, so be it. But a HV or HP pump? I won't be running heavy oil either.. more like 10w30 for now then switch to a lighter synthetic. Also, with 160 mile son teh engine would I have done any damage to the lifters or cam running it with not enough oil pressure or volume?

[Muad'Dib]

Id say go fo it .. but thats really all opinion and not based off anything sound or technical.

I mean really what can it hurt... Especially with the grooved lifter bores. The extra volume should / will equal to more pressure. Plus, now that cam break in is completed, i dont think you will have anything to worry about.

Either way you should be covered.

Dont go high pressure btw .. only high volume.

[YJason]

My HV gives me 20-25 psi hot idling and 35-40 psi hot anything above idle. At least that is what my factory guage is telling me.

BTW: The guy at the machine shop told me to run 7 min up to 8 qts of oil. I measured 7 1/2 qts setting level brings the oil level just below the baffles. I'm planning on running 8 qts and see how it goes. He suggested the extra qts because my brgs showed signs of running low on oil.

[SilverXJ]

I doubt too the the lifters not being pumped caused any damage now or prior. That is how Rhoads lifters work. And that is actually how my lifters are behaving.

YJason, I heard that a high volume pump could cause the sump to run dry and starve the bearings. Are you running a Melling HV or Hesco/Melling pump? Also, what is a negative on running the oil level higher in the sump? The only thing I could think of is when the engine is at an angle then the crank can become submerged in oil. I was also thinking of having a box welded on the right side and maybe left side of the pan to increase volume.

[YJason]

Melling HV

The only real neg I can think of is when taking off hard, or steep inclines I will get oil up in the rotating crank. I welded a baffle across the back of the pan to help when I'm climbing steep hills or hard acceleration

I'm going to try 8 qts, if I get a little blue smoke or I feel my oil is getting whipped up by the crank I'll back off to 7 1/2 qts.

[gmakra]

I was told by both Clifford Performance and my machinist that built my engine not to go with the high volume oil pump. He would not warranty the engine the reason given that under certain circumstances you can run the sump dry and starve the engine for oil.

[Bodo]

HV pump. If you've got alot of clearance, it's the way to go.

[SilverXJ]

I was told by both Clifford Performance and my machinist that built my engine not to go with the high volume oil pump. He would not warranty the engine the reason given that under certain circumstances you can run the sump dry and starve the engine for oil.

That is why I am probably going to enlarge the oil pan. Maybe add an extra 1-2 quarts capacity.

The other issue I may need to address is the oil pump drive gear oiling. Maybe add a squirter for that.. don't know

[gmakra]

Oh and I forgot one other thing that was mentioned is that they do put a lot more stress on the cam and distributor gear.

[SilverXJ]

Oh and I forgot one other thing that was mentioned is that they do put a lot more stress on the cam and distributor gear.

I know. I'll carry an extra cam sensor drive with gear (had one fail a while ago, but its an issue with the shaft seizing in the housing). Also, run the gear oiler maybe and definitely run low weight synthetic in the winter.. like 0w-30

[lafrad]

I'm looking at running 360 oiling (grooved main bearing shell on top and bottom.. rods get oil pressure for the entire cycle), HV pump, and work out a "squirter" for the distributor gear.

the oiling should encourage a bit more oil to be slung at the cam, and also pressure oil the rod bearings for ALL aspects of the otto cycle...

I was staring at the block the other day, and saw that it looks like the oil pump housing is directly next to the cam gear... aside from "unfiltered oil" being used, what would be a downside of drilling a small diameter hole between the oil filter passage pointing directly at the cam gear? In my mind, its splash oiled anyway, so unfiltered oil is on that thing as is... at least that way it will have a constant flow of oil for lubrication and cooling....

[SilverXJ]

I haven't confirmed this, but according to info on Hesco's forum there is a hole in the head that drips down on to the cam gear, so not 100% splash oiled.

Also, found this post on Hesco's about oiling the gear like you suggested. http://www.hesco.us/forum/forum_posts.a ... PN=0&TPN=2

[SilverXJ]

Should the pressure be too high on the HV pump, how is this reduced? Cutting the pressure dump valve spring?

Another consideration is when does the bypass valve on the oil filter open up?

[lafrad]

oil filter bypass only really cares about the pressure drop ACROSS the oil filter.... not the total pressure in the engine. it shouldn't significantly affect engine oiling performance.

The bypass spring just opens at a specific pressure... so if its 60 psi, it will open at 60psi, no matter what RPM. if you want that lowered, you fiddle with the spring. unfortunately, if you are wearing stuff out with oil pressures LESS than 60 psi, (or whatever the bypass is set for), then you must lower the bypass pressure... I don't know if thats a great idea, however. the bypass really is there to bleed off pressure when the oil is cold... you dont want to be bumping into it on a warmed up engine, ever.

[lafrad]

thinking about it a little more...

if the oil pressure is "too high" on a high volume pump, and you aren't against the relief spring, the only way to lower pressure is to dump oil volume somewhere, from the high pressure side. So, in theory, one could "dial in" the pressure they want by routing a "bypass/needle" valve from the high pressure side of the oiling system somewhere, back into the crankcase. then just adjust the size of the valve to get the pressure that you desire.