Performance Boats Forum banner

1 - 20 of 22 Posts

·
Glendale Arizona
Joined
·
2,368 Posts
Discussion Starter #1 (Edited)
O.K. had a little scare with the boat/motor Monday night. Was
getting all over it and stayed in it for a good bit of time, then
repeated several times. Following one of these runs, I noticed
my oil pressure drop to about 10 psi. Kinda freaked out and shut
it off coasting in to my trailer. I was right at the Big River ramp
when I noticed it so it only ran a few seconds (literally) before
getting shut down. I wasn't sure if I had sucked my pan dry (done
that a few times) by staying in it too long or what.

Didn't touch it after getting it out of the water. The next morning
I backed down to the ramp and disengaged the jetaway and fired
it off. Pressure was still low at about 10 psi at idle and 20 psi if
gassed. Shut it down right away and pulled it home.

Before tearing into anything I went and bought a mechanical pressure
gauge (normally run a Autometer Ultralite electric). I suspected/hoped
that maybe my sender took a shit on me and although it might still
be sending a signal, maybe not the proper signal.

Fired it one last time at home with the electric gauge and it still read a max
of 25 psi. Removed the sender and connected the mech gauge temporarily.
It seems to be better and reads 25 psi at idle and 50+ PSI when reved
up some. That's about what it's always been.

Here's my question.............never having run a mech gauge I see that
there is a lot of air in the capillary tubing (photo below). Is this normal
and am I getting an accurate reading with this thing?


Thanks for any help. Hoping like hell that it's just a gauge/sender problem.

The capillary tubing and mech gauge is just a temporary deal for trouble
shooting. No intention of leaving it that way.

Oh yeah, motor never made any weird/scary noises. Just the low oil
pressure reading.

Thanks for any and all input. Much as I want my stroker, I sorta need
this one to last the summer............fingers crossed



Filter pleats look o.k.

 

·
Registered
Joined
·
1,260 Posts
I had an electric and mechanical on my Olds. The mechanical always read higher than the electric. I think I would do a little tear down for piece of mind.

Also, you may get a new sending unit and see what it says.
 

·
Glendale Arizona
Joined
·
2,368 Posts
Discussion Starter #3
I had an electric and mechanical on my Olds. The mechanical always read higher than the electric. I think I would do a little tear down for piece of mind.

Also, you may get a new sending unit and see what it says.
Peace of mind tear downs will be limited to winter time only Tim.......:D
It is now officially the boating season.

My buddy TX-19 runs the same electric gauge in his sand car. He's offered to let me try his sender.

Reckon we'll see what happens.........

What about the air in the capillary tubing? Normal? Yes? No?
 

·
punk ass kid
Joined
·
524 Posts
I use a mechanical and the capillary all the way to the dash. The last time I had it allapart I "primed" the capillary befor conecting it to the dash. I dont think it really matters but thats what I did.

Now for oil press. issues, what do you have for an oil pump? Stock or a HV?? Your numbers sound right for a stock oil pump.

I had an oil filter collaps on me last year and it made the oil pressure different, not zero, but considerably less. Im pretty sure it happend after back to back to back passes last Oct. Pull the filter off and check it, its quick and easy.

Hope that helps :)hand
 

·
ATTA BOY
Joined
·
2,348 Posts
Dan my sender did this same thing 2 weeks ago. Freaked the shit out of me. Started the motor, 40 psi. By the time i had got to the channel at sag it was at 20 Turned out for the best. Im guessing your sender took a shit. Mine would hold for a bit the bleed off.
 

·
Registered
Joined
·
1,260 Posts
Air is normal. It hopefully is the sending unit. Cut the oil filter and check it.
 

·
AIR POWER
Joined
·
157 Posts
My electric gauge did the same thing last weekend except it started bouncing from 0 to 100 really fast then would go to 10 then back to 60. It was my sending unit that was my problem. For the mechanical pressure gauge, my 71 chevy truck has one and it has air in the line just like yours does.
 

·
Premium Member
Joined
·
4,704 Posts
Scary Dan! I had this happen in Yuma. Never heard any noise. Boat ran great. Just no oil pressure. Sat out the whole day at the sand bar. Headed to Farmer Johns to get a mechanical gauge hooked up. and there you go. I got Oil pressure. Go out Sunday. Boat runs great but the pressure was down just a bit from normal. Well now I know. If the pressure is different from the normal. Pull the motor. I had my crank crack at some point either there or here. The #2 & 3 bearings had spun. I had pressure but thought it was OK to run it. I did. The crank finally cracked to a point where the front snout did the wobble deal. Its guna cost me now. If I had just come home or hooked up with the wackas I may have saved some parts.

Prolly not your problem. For me I have a new respect for that OIL Pressure gauge,electrical or mechanical.

Good luck.

I heard you were looking to do a 540 anyways.
 

·
E-7 Sheepdog (ret)
Joined
·
6,834 Posts
There is nothing wrong with the air in teh line.

The gauge is pneumatic/hydrualic and oil @ 50psig reads the exact same as air @ 50psig.

Sometimes hard to believe air and fluids follow the exact same fluid flow and pressure dynamics laws, other than air being compressable.
 

·
21 Daytona
Joined
·
5,291 Posts
What pump drive are you running?

I have seen that hex drive on a 460 start rounding off
and would skip at high RPM/pressures. this was with a HV pump/stock shaft

might be worth pulling the distributor and checking
 

·
Registered
Joined
·
829 Posts
I used to use a plastic oil pressure line and for some reason it would always get crap stuck in it and give false readings. I now have 1/8 copper tubing, with a mech. gauge and everything is working fine at 60-70psi.
 

·
Seriously off center
Joined
·
2,439 Posts
O.K. had a little scare with the boat/motor Monday night. Was
getting all over it and stayed in it for a good bit of time, then
repeated several times. Following one of these runs, I noticed
my oil pressure drop to about 10 psi. Kinda freaked out and shut
it off coasting in to my trailer. I was right at the Big River ramp
when I noticed it so it only ran a few seconds (literally) before
getting shut down. I wasn't sure if I had sucked my pan dry (done
that a few times) by staying in it too long or what.

Didn't touch it after getting it out of the water. The next morning
I backed down to the ramp and disengaged the jetaway and fired
it off. Pressure was still low at about 10 psi at idle and 20 psi if
gassed. Shut it down right away and pulled it home.

Before tearing into anything I went and bought a mechanical pressure
gauge (normally run a Autometer Ultralite electric). I suspected/hoped
that maybe my sender took a shit on me and although it might still
be sending a signal, maybe not the proper signal.

Fired it one last time at home with the electric gauge and it still read a max
of 25 psi. Removed the sender and connected the mech gauge temporarily.
It seems to be better and reads 25 psi at idle and 50+ PSI when reved
up some. That's about what it's always been.

Here's my question.............never having run a mech gauge I see that
there is a lot of air in the capillary tubing (photo below). Is this normal
and am I getting an accurate reading with this thing?


Thanks for any help. Hoping like hell that it's just a gauge/sender problem.

The capillary tubing and mech gauge is just a temporary deal for trouble
shooting. No intention of leaving it that way.

Oh yeah, motor never made any weird/scary noises. Just the low oil
pressure reading.

Thanks for any and all input. Much as I want my stroker, I sorta need
this one to last the summer............fingers crossed

Put an T in the block and run both with the mechanical gauge on the T. There is pressure loss in extended lengths that make them react slower, and (in extremes) inaccurately. The mechanical gauge on the block will give the best reading possible. Compare the 2 gauges until you're comfortable with their readings. Watch them and enjoy the summer.
 

·
Living in a cage of fear
Joined
·
16,462 Posts
What pump drive are you running?

I have seen that hex drive on a 460 start rounding off
and would skip at high RPM/pressures. this was with a HV pump/stock shaft

might be worth pulling the distributor and checking
I have seen that also, to the point of completely rounding off.
 

·
Boat Nut
Joined
·
5,131 Posts
Air in the lines is no problem, it's just reading pressure... might see a little dampening thats all. If using copper lines be sure to loop the end before going to the gauge, this helps keep the copper from being over worked to the point of becoming brittle and breaking. Nothing worse than hot oil spraying all over the insides of you and your boat
 

·
Glendale Arizona
Joined
·
2,368 Posts
Discussion Starter #15
Put an T in the block and run both with the mechanical gauge on the T. There is pressure loss in extended lengths that make them react slower, and (in extremes) inaccurately. The mechanical gauge on the block will give the best reading possible. Compare the 2 gauges until you're comfortable with their readings. Watch them and enjoy the summer.
Thanks guys.

Mike that's the way I wanted to do it, and will. I need to pick up the proper fittings etc. The only reason I ran the capillary is because everything I needed was in the kit for a quick and easy diagnostics check. Also cut the tubing down to 2' (just long enough so I could put the gauge up front and watch it from the seat for the test.

Hopefully that's all it is and I can nurse another season out of it. I believe I'll try to rest my foot on the gas pedal just a bit lighter though........:D
 

·
Registered
Joined
·
387 Posts
Last weekend I ran mine, Always have 80 lbs. As I'm running I noticed my pressure dropping down to 40 lbs. Then down to 20 lbs. I get back to the beach and let it sit and cool off.
I then check the oil level, and it's all good, started it up in the evening and I have a steady 40 lbs, take it for a short run and it drops again, but at idle it is up between 40 and 50 lbs.
I get the boat home cut the filter and nothing, clean as can be, pump out the oil and thin as hell with fuel in the oil.
This happened while having carb issues. My motor builder said to put 50w
and run it, he said that he believes that with that much fuel in the oil and as thin as the oil was,He thinks that was the reason for the oil pressure drop.
I did think the sending unit went bad, so I took my pump pressure gage and plumed it to where the sending unit was and still had the same reading.

Still going to pull the motor and do a visual on the barrings. (Peace of mind)
 

·
Seriously off center
Joined
·
2,439 Posts
Thanks guys.

Mike that's the way I wanted to do it, and will. I need to pick up the proper fittings etc. The only reason I ran the capillary is because everything I needed was in the kit for a quick and easy diagnostics check. Also cut the tubing down to 2' (just long enough so I could put the gauge up front and watch it from the seat for the test.

Hopefully that's all it is and I can nurse another season out of it. I believe I'll try to rest my foot on the gas pedal just a bit lighter though........:D
Dan, the sender and line kit fittings should both be 1/8" NPT. I stock that kit if you need it, just give me a holler.
 

·
Registered
Joined
·
70 Posts
What weight of oil and what brand filter? Are you running a front sump pan?

I run Valvoline VR1 20/50. Run only Wix filters

466 BBF M84D Mellings stock truck pump. Idles 35-40 psi....65-70 psi @ 3000 rpm electric gage. 8QT full sump pan.

Also, Cut the filter open and check that before you do a teardown
 

·
Registered
Joined
·
387 Posts
I did run 10/40 castrol......Now I run kendall SAE 50 GT-1 High Performance.
Still have a few cases left. The good old green oil.
I run a wix filter.....51060R, Best filter that I have found, Constant flow, No blocker.

Dan Olson pan rear sump, custom cut for starter.
 

·
21 Daytona
Joined
·
5,291 Posts
I did run 10/40 castrol......Now I run kendall SAE 50 GT-1 High Performance.
Still have a few cases left. The good old green oil.
I run a wix filter.....51060R, Best filter that I have found, Constant flow, No blocker.

Dan Olson pan rear sump, custom cut for starter.
see post #10
 
1 - 20 of 22 Posts
Top