Super Low Oil Pressure

[babeslx]

My 87 had a 5 liter 4V transplant recently and appeared to be running pretty good. I had a arcing problem with the ground and toasted a shifter cable in the process.

The motor has a pretty radical roller cam, roller rockers, and a big Edelbrock - 750. It's been on the road for a few months and the oil pressure was always really low - 3psi on idle!

The shop who fixed the electricals and shifter basically told me the motor was hosed. Only a matter of time before it packs it in - any opinions? :wazzup:

[babeslx]

thanks for all the feedback

[NoSlo5.0]

Well, the rule-o-thumb is 10psi per 1k rpm right? Did the builder perhaps use race clearances and then stick you with a standard oil pump instead of a high volume unit? Low oill pressure pretty much means there is too much clearance somewhere. Check the pan after the next oil change, cut the filter in half, see what's going on.

[babeslx]

Well, the rule-o-thumb is 10psi per 1k rpm right? Did the builder perhaps use race clearances and then stick you with a standard oil pump instead of a high volume unit? Low oill pressure pretty much means there is too much clearance somewhere. Check the pan after the next oil change, cut the filter in half, see what's going on.

I'm having the LSDiff installed this month, so I'll get my guy to drop the pan and check it out from the bottom up. :beerchug:

What's funny is while idling in Drive, the stock gauge drops to below the bottom but while idling in Neutral, it's back up to 20 psi or so. Does that sound normal? :silly:

[cobraspence]

Is your sending unit correct for the guage? Is this an aftermarket gauge or did you just hook up the 4v sender to the 87 dash?

[babeslx]

Is your sending unit correct for the guage? Is this an aftermarket gauge or did you just hook up the 4v sender to the 87 dash?
The 5 liter 4V was transplanted into my LX that used to have a four-banger and the gauge is stock. However, it was in the shop with the valve covers off and they put a manual gauge on it showing low pressure. :nailbite:

I think I'm going to get a new gauge hooked up when I check out the bottom end. :ugh2:

[babeslx]

I got the high-ouput oil pump (not installed yet) but I was talking to a 5-0 guy who said without a big sump oilpan, the pump may do more harm than good. Any suggestions?

[gasman]

if the guages are right then your bearings are probley hooped. If you are going to get a rebuild then you can go with a high pressure pump that will give more oil pressure and you can use the stock pan

[yosemiddysam]

Dont sound too good to me.