help, oil pressure problems,, GQ 351 v8

[gq351]

hey guys,, ive got a gq with a 351 cleveland,& i have went though 3 engines now due 2 running out of oil pressure under revs when 4wding, its running a reversed sump with a high volume oil pump,the pressure always sat around 65-70 on the gauge until sunday da engine was only 2 weeks old, just wondering if there is anyone out there with the same set up 2 chat 2,, coz im sick of it ,, cheers

[MPRZIV]

get rid off the 351

[MPRZIV]

Go dry sump big oil tank with oil cooler and big pump.

whats it doing burning the oil or running out due to inclines you tackle

[tj81]

Sounds like its out of oil.

Dry sump would fix it, very expensive though.

Baffled sump also may be worth trying, as if your on a few knarly angles, the oil can be moving away from the pickup.

[gq351]

its fine on inclines either way ,it holds 9 litres of oil, & doesnt burn any, its only with revs 4-5000 rpm that i have had trouble, it sounds like a deisel now haha

[tj81]

id say toss it and throw in a 350 chev, but they also have well documented oil pickup issues !

[MPRZIV]

oil pump obviously cant keep up with the revs your giving it if your losing oil pressure maybe just try baffled sump first to keep oil at the pump if not you aint got many choices really.

Less revs mate get a real motor.
Like a diesel. lol or a 13b in your gq would be good that way you can rev it. lol

[gq351]

da sump is baffeled, with 2 step ups, & i like my revs otherwise i would of left da 6 in it, its mainly in bog holes it should be able 2 take it

[MPRZIV]

what are you building the motor to do high end or bottom end you need more torque down low so you don't have to rev the guts out of it nice torque curve from 1500 to 3000 should drag you through just about anything in an8 instead of producing all your power up at 4-5000 then running out of steam of course its going to cook itself sitting at 5000 for a while with no oil not getting anywhere. I would say look at what you want it to do for you then build your motor to that.

[mikesmith]

what problems do the chevs have with oil pickup problems?? should i look at high volume oil pump and baffled sump on the chev going into my patrol??

[Hoonz]

have you been using the same oil pump ... i'd be inclined to say you have a dodgy one ...

the clevo i had in the xy would do 6500rpm all day long with no issues


get onto www.fordforums.com.au and ask a question in the performance clevo section plenty of gurus there to ask

[gq351]

3 differeny oil pumps, i had one in an xe with no probs either, its got me stuffed but like i said da engine was only 2 weeks old what a waste of money

[Harb]

mmmmmm, a real can of worms.
Has the sump got a windage tray in it?
I would say the pump is pulling air under 4wd conditions.
If the sump doesn't have a windage tray the oil can be swept up by the crank and away from the pickup.
this is an ongoing problem with many conversions using road based motors under extreme conditions.
I would look at the pickup where it is situated and the sumps ability to direct the oil to it and the posiblity of the crank sweeping the oil.
is the bowl at the front or rear of the sump?
does the problem happen going up or down slopes?

Dry sumps are a problem is you intend to run an external pump as the belts very quickly get clogged with mud and get sput of.........

cheers
Harb

[tj81]

hmmm.

I was going to say oil pump too , but hoonz beat me too it.

i cant see it being anything else other than oil pickup, id be very surprised if it was anything else.

[gq351]

[hey thanks 4 da info, the bottom of the sump is about 10 inches lower than the block & the pick is sucking closer 2 the front of the car, its fine on steep hills either way, its only the bogholes that seem 2 stuff it up under revs, i thought maybe the block could have a crack somewhere & sucking air at high revs, could this be posible??

[marko]

sounds like the rocker covers are filling up with oil under high rpm and not draining fast enough.Wat grade oil is used? I would stay away from a high volume pumps and stick with the standard one.
Try to get the pick up at the rear of the sump
You say its a new eng. Did you build it or did you buy it

[gq351]

could be something that simple maybe,, i built the engine myself & had all the machining done, every thing is brand new, i normally run 8 litres of penrite 25w-50, i runs a small version of the of the Z9 oil filter coz there is no room for a bigger one..... maybe that could be bad 2 ??

[marko]

so actually happens to the eng. Does is spin mains/bigs bearing

[gq351]

it only happened yesterday up mt dissa,, so i havent pulled it down yet, it just sounds really bad & rattely like a deisel & the oil pressure has dropped from 60-70 down to 10-15, but the other engines diddnt spin any bearings , they were just all {gold} instead of silver, big ends & mains

[bogged]

i have went though 3 engines now due 2 running out of oil pressure under revs when 4wding,

and you havent changed your mind and gone with something proven for want of a better word?

[mattsluxtruck]

sounds like the rocker covers are filling up with oil under high rpm and not draining fast enough.Wat grade oil is used? I would stay away from a high volume pumps and stick with the standard one.
Try to get the pick up at the rear of the sump
You say its a new eng. Did you build it or did you buy it

Thats is the problem. High volume pumps sucks the big one. Mellings are the worst for it. Look for a high pressure standard volume unit.

[PGS 4WD]

marko is on the ball, high volume oil pumps create issues. They take more to drive and have been known to break the oil pump drive, spin the drive in the distributor shaft and shear the roll pin in the drive gear on the distributor. If you build the engine right you will have ample oil pressure. Check the main tunnel for straight. As he mentioned they can fill the rocker covers at high rpm and spit oil out breathers. Clevo's do have big end oiling issues as they feed the oil galleries to one side then the valve train/camshaft and then the other side big ends, there are restrictor kits available for use with mechanical camshafts, love or hate them.
Could the bottom of the sump be pressing against the pick up sealing it off when sitting in bog holes?? Perhaps you need to make it such that the pick up is further from the bottom or weld something to the sump to stop the pickup sucking to the bottom of the sump if something is pressed up against it.

Joel

[Hoonz]

hey guys,, ive got a gq with a 351 cleveland,& i have went though 3 engines now due 2 running out of oil pressure under revs when 4wding, its running a reversed sump with a high volume oil pump,the pressure always sat around 65-70 on the gauge until sunday da engine was only 2 weeks old, just wondering if there is anyone out there with the same set up 2 chat 2,, coz im sick of it ,, cheers

is there any metal in the oil? run a magnet over it
how are you breaking in the cam?
if it isn't done right you can chew the cam up and it'll basically destroy your engine ...

[gq351]

thanks alot guys for all your info , im going to check it out this week sometime, & ill lets yous know what i find, jess

[cooki_monsta]

id have to agree there go back to a std pump the high pressure ones are just shit

[gq351]

when i build or repair the next engine i would like to go a starndard oil pump, but coz i had so much trouble with oil pressure in the last engines, i wanted to be sure, maybe a big mistake, does any one know if you can get a restrictor kit done with a hydrolic cam ??

[90Mav]

Could be wrong, but im sure i've heard of restrictor kits in hydraulic cam clevos.. ( go the clevo dont put a bloody chev in )

[demo2]

I had a 351 in my MQ and never had any issues offroad at all, always maintained good oil pressure. It ran a standard pump, i now have a GQ wiv a 350 chev in it that has a high volume pump but havent had it off road yet 2 c have that goes.

[gq351]

hey mate, just curious, did your MQ have a standard sump or was it reversed with the pick up at the back ?? , maybe the rear pick up has 2 suck to far in mine , but a standard sump nearly sits on the diff so i have choice,, thanks

[PGS 4WD]

I have fitted a restrictor kit to a Hydraulic cammed engine, it was a 351 4V in a ZD Fairlane, it was a customers and it had no issues for 2 years until it was pulled down to have a larger mechanical cam and head work done. The tappets were rattly, in this case we weren't concerned as they were set with minimal pre load as the engine pulled 7200 rpm. It's not recommended and really shouldn't be necessary with what you are doing, we were trying to stop all the oil ending up in the rocker covers.

Joel