Dart big M regular or HV oil pump
06-29-2017, 05:44 AM
#11
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Location: Olmsted Falls,Ohio Marblehead,Oh
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I had the hv hp pump out of 540 bulldogs in my 572 darts last year. Oil pressure was PEGGED. I have one engine is out. Took pump apart. They use a high pressure spring with 2. 1/16 thick washers behind it. So 1/8 behind a 70 lbs spring. It's TO MUCH. I'm going to quality standard volume pump, maybe with 70 lbs spring with no shims. I'm putting port engine back in soon and running the starboard as is until end of season when I can pull it to change the pump. Even with a cordless drill and 0-20 oil cold I got 60 psi with mechanical gage at top of block behind lifter Valley. God I wish these things had external oil pumps. Dart does not recommend hv. Maybe it would be ok with 60 lbs spring. That would give good idle pressure and stop at 60. Rule of thumb 10 psi for every 1000 rpm. I like to see 65 or so. I am going to run bulldog pump with 60 spring with my drill. Before I seal up pan. Just going to keep pan up with a few bolts and a few qts of 0-20 oil. If I see more say 40-50 psi with cordless drill I'm using standard pump which I already have waiting on the bench.
as far as distributor gears, I never had any issues there either if things are meshing peoperly.
06-29-2017, 06:50 AM
#12
Clearances are.. 001 per inch on all bearings. Mains are about. 003. The block and manifold dictate location of drive gear. All you can do is shim distance on distributor to center drive gear on cam gear. It isn't like a rear end gear. I was running well over 80. Don't know what the oil pressure really was because the gage was always pegged. It dropped some once warmed up and idling but still way up at idle with 20 wieghts oil. I will let you know what I find out when I experiment with Springs. Running mercruiser bulldog 12 qt pans. HV with HP spring will pump the pan low if you use lower capacity pan. Don't forget it's a dart MIV style block with priority oiling. They also don't have the large drain back hole at front of block like the factory Chevy has. I would like to stick with the original pump because of the pickup but if the pump is just regurgitation the oil then it's just making heat.
06-29-2017, 07:15 AM
#13
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I had 100 psi too with melling hv pump on dart block mk4 w
.028 rods and .003 to .0033 on mains, went to anti cav pump and honed lifter bores slightly looser last time. Now i have more like 80 cold and 60-80 hot running. Cam gear had quite a bit of wear at 100 hours, msd distributer w bottom oring off, ground oil slot in dist body to force oil cam gear last time, went to .060 or so front block feed hole to timing gear thrust torrington
.028 rods and .003 to .0033 on mains, went to anti cav pump and honed lifter bores slightly looser last time. Now i have more like 80 cold and 60-80 hot running. Cam gear had quite a bit of wear at 100 hours, msd distributer w bottom oring off, ground oil slot in dist body to force oil cam gear last time, went to .060 or so front block feed hole to timing gear thrust torrington
06-29-2017, 07:30 AM
#14
Yeah cam gear and drive gear should not wear much at all, if any at all. Don't bring engine up to speed unless it's warmed up. I did just hone my lifter bores. They were very tight. Much better now. But I don't think it will bring psi down without reducing spring pressure. I have 60 and 70 psi Springs I'm going to try with HV pump before I make a decision on whether to use HV or standard. You know the old mopar and hemi engines have external pumps bolted right to block. That may have been a good idea. Right lol
06-29-2017, 05:18 PM
#15
Just talked to dart. They said they use restrictors in there blocks and the hv hp pump will run the pan dry. I do have 12 qt pans but he was stead fast on standard volume melling. So what am I going to do?. Move my pick up to standard pump and use 60-70 lbs spring. Leaning toward 70. Not even going to try the hv pump because they were already in there last year. My bearings looked fine when I tore it apart but cam and dist gears were getting chewed. 4hrs on engines last year. If an idea makes you feel happy it still doesn't make right.
