Outer Limits 4x4 Board

I was just wondering if anyone has had/heard of engine troubles arising becuase of use on steep grades. I'm not talking about carby trouble, i'm talking about more serious stuff like lubrication.

I suspect real 4WD engines would be designed to run on the angles the vehical is capable of, but when we start increasing our 4wd's climbing ability with lockers/tyres etc, could the angles reachable exceed the engines limitations?

Just after some peoples thoughts.

-Stu

Most solid axle 4wd have a rear sump to their oil pan which retains the oil when pointing the front of the vehicle in the air. A forward sump is of more concern.

My hilux (3RZ-FE motor) only runs out of oil on steep downhills.

As beebee said, most 4x4s have suitably designed sumps. Some also have a small reservoir (walled off area) surrounding the pickup which retains oil at the pickup on steep angles.

I have noticed in my older diesel landie that the oil light flickers when I stop on a VERY steep hill (or go down a very long very steep hill). But this is preferable to the light coming on when driving up a hill.

Becomes a problem when you start doing engine conversions with motors out of sedans and so on. My EFI 302 Windsor smokes a lot when it is sitting on a steep hill waiting for winch to be set up in winch challenges. somthing to do with oil building in the tappet covers as it already has a rear sump pickup. Motor is out of a F150 or similar.

LudaCris

So there is no reason to expect that a standard engine in a relatively standard car (take for example my troopy, see sig line) couldn't operate for extended periods on a steep uphill or downhill gradient (assuming the vehicle is still on it's wheels )?

Just wanting to clarify!

-Stu

Friends 60 series has trouble getting fuel on steep uphills

as stated above if its carby it may have a rough idle on steep inclines but otherwise all good engine oil wise.

i read that early rover v8s were tested on a jig to 45o in all directions at 4000rpm. or there abouts to see if thay ran out of oil. there sumps are baffled realy well to keep the oil around the pick up on change of direction. also the fuel tanks are baffeld to prevent fuel slosh on side slopes that could be enough to tip the thing over. i gather toyota and nissan do simlar. only the strombergs on the rover have never had problems on steep hills i have climbed.

"My EFI 302 Windsor smokes a lot when it is sitting on a steep hill waiting for winch to be set up in winch challenges. somthing to do with oil building in the tappet covers" thats to do with the style of valve guied seals used on the fords. i think thay still used rubber buckets on the winsors but i could be wrong. if not thay could simply be worn out or gone hard like plastic from heat.

i looked at the sump i put on the Holden engine i put in the patrol..... i had to put one out of a HQ..... the sump is shaped in a way that even on steep downhills, there should still be oil in the back of the sump....... up hills aren't a problem.... i was going to weld a windage tray in it, but ran out of time and energy..... it's an old sump, and will most likely be replaced soon anyhow. If it gives me any dramas, i'll get my hands on another sump and put a tray in it and maybe enlarge it somewhat. I was contemplating testing it by lifting the vehicle with a forklift until it runs out of oil and see what kind of angle it's on.

1HZ engines when flat out up hill can suffer from overpowering of the oil return which results in the oil being drawn into the air intake via the breather and the engine running on its own oil, you have to stall the engine to stop it or the engine will self destruct. Toyota have a mod but a catch can would help to separate and return the oil.

Sumps are designed for a bunch of things... to clear steering components, cross members etc... but alsot to ensure adequate oiling under acceleration, braking, cornering... and climbing etc on a 4wd.

Sumps have baffles, one way gates, etc to try and reduce oil surge when off camber, climbing or cornering... or under heavy acceleration. Drag cars have very trick sumps (when they run wet sumps) for this reason.

Many modern sumps also include wingage trays (deflectors) to make sure the oil in the pan abd spinning off the engine components doesn't impact on those same spinning engine components and reduce engine power.

That's one of the reasons race cars go to dry sumps - to reduce windage effects... the other is to ensure oiling under heavy accel abd braking/cornering.

This pic gives you some idea of the baffling in a sump, and the tray at the rear is the windage tray. Just changing the windage tray can improve power... running more oil in your engine will reduce power usually due to windage, unless you are running a very trick sump and a real good windage tray.



This is a camaro (or LS2 sump?) by the way... the aussie LS1's out of commodire's etc use a front bulge sump to clear the cross member.

S.

I'll probably dry sump the 350 for my Bundy. good insurance.

sudso wrote:I'll probably dry sump the 350 for my Bundy. good insurance.

That will definitely eliminate oiling problems, but is going to cost you some serious dollars.

...$5k ish for a decent dry sump system... must be a pretty special 350...