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yea , i agree on the difference in pressure per motors,,i even swapped the gauages..same thing...

good question,,the starbd engine is running little hotter than port engine...
stbd is running about 160ish and if a am running 4 to 5 thousand the oil temp will get up 250 260
then when back off to 3500 300 oil emp comes back to 230 240

port mtor runs 120ish never seen oil temp above 230 running hard on that motor..

i am thinking the impeller in my gleenwood cam driven pump is going bad..
think i am going to switch back to normset up

Quote:

Originally Posted by compedgemarine (Post 4650768)

I have had plenty of motors that only had 40-50 psi wide open and lived forever. the big concern to me is that you have two supposedly similar motors but way different results. if they were indeed built the same with the same pumps, etc they should not be more than a few pounds apart from each other.

motor are totally same parts,,,i would say there is about a 15 psi difference running 3 to 4 thou....

Both engines plumbed the same? Hoses, fittings, etc? What gen blocks are they? I feel for you and your frustration. You may have mentioned but did you change oil and filters. Also what is the condition of your coolers and what size are they? Did you upsize with more power? Both oil coolers cleaned and inspected prior to installing with new builds. I only mention that cause I experienced a similar situation years ago. PITA but a cooler swap might possibly tell you something. Always fresh water coolers? If you do do by chance decide to upsize I have 2 nice shape fresh water 3 x 18's.

I wouldn't rule out the pumps either regardless if there thecsame part numbers. Lot of pot heads in production lines now a days. Springs, clearance. Never know. Doubtful but thought I'd mention if all else checks out. Btw yes I would want to get to the bottom of it but I ran 50 pds at 5,700 5,800 for years never an issues regardless the rule of thumb.

Just throwing some things out there.. good luck and keep us posted.

are these gen 5 or 6 blocks.

Quote:

Originally Posted by getrdunn (Post 4650926)

motors are plumped the same,,everything the same .........motors are mark4 bow tie blocks 4.50 bore.
i havent changed oil yet this year, only put 6-7 hours n motors this year, but will chanaged before winter. i run peen brad 20/50
i took the oil cooler to rad shop had the boiled out when i rebuilt these motors.
this boat was completely redone back in early 90's new motors etc...so these motors were 510"s...4,50 bore 4 inch stroke..so boat has had these coolers in there for years.
i guess i added maybe,,maybe another 100 hp
my coolers dont know size....https://cimg3.ibsrv.net/gimg/www.off...5f74e7f1fd.jpg

Quote:

Originally Posted by kvogt (Post 4650927)

are these gen 5 or 6 blocks.

mark 4 bow tie blocks

might be lifter to bore clearance different on the engines.

Different bearing clearance, maybe a plug was left out somewhere or is leaking.

No water pressure gauges? if this has always been an issue since rebuilds (18 hrs) I would think a bad impeller woulda let go long ago but good point though. Housing possibly worn and or combination of the two. Just for a piece of mind without spending much money a couple mechanical water pressure gauges would be helpful. Even if there just temporary for time being. That difference in oil temp is quite a bit. I've never used a cam driven pump but like a fuel pump I could see where one could wear internally. You ever do a comparison with engines cold. Up to at least 2,500 anyway. One other thing is if you ever did have an impeller grenade that you had to replace. They can go in some mysterious places. You running t-stats?