Technical ground clearance for oil pan

When I did my first deuce 5 window it was about the 3rd or 4th 32 chassis I had built and for some unknown reason I mounted the SBC motor to low. On one of it's first drives I actually scraped the pan on the local railroad tracks as I was crossing them. I went back to the shop and devised a way to raise the motor a few inches which turned into a major job. Never made that mistake again. If anything I was guilty of mounting my motors a little high after that. Never had any customer complaints while I was building chassis.

 

There are road heaves that are taller than 3"

 

You want your oil pan clearance to be at least 1" taller than whatever you just ran over.

 

With a stock oil pump & pickup height , you can't use a shallower( less deep) oil pan .

 

As far as scrub line goes, The oil pan can be comfortably above the scrub line but what gets the pan is normally coming down on a speed bump when the suspension compresses after the front tires hit the speed bump and then the pan clips the speed bump. Go slow enough that you don't work the suspenson and you are ok. My T was built wit scrub line well in mind and could actually sit on the 4 15 inch rims on the shop floor and clear handily. The lowest spot was the brackets for the bones and looking back I had way too damned much caster in it but the wheels sure came back to center fast. That never hung up on anything but I left my mark on that speebump on the way into McClennan Community College's parking lot for as long as that bump was going to be there.

One of my buddies went out and measured that man hole cover when he heard I hit it and I think my front axle cleared it by about an inch or maybe more, They had raised it before they repaved the street. I wasn't the only one who caught one of those though.
Here is one of the few shots of the T that I have while I was building it showing the ground clearance o lack of it.

 

I'm willing to bet if Milodon sells a shallow pan they also sell a pick up to fit. I shortened my pan 3/4 of an inch and I am hoping that the pick up for a high volume pump will solve the problem.

 

Better plan on a windage tray / crank scraper or equivalent..?
Seems like it might be easier to just raise the engine or chassis or both ?

 

Yep.. https://www.competitionproducts.com/mobile/Chev-BB-Low-Profile-Oil-Pans/products/434/

 

Simply reverse the main leaf, and bear in mind that 16 inch wheels will buy you a mere 1/2". NOT an inch.
About that pretty 5" dropped axle: I ordered and chromed a 5" Super Bell axle, set it up on my '27 Highboy and promptly removed it. You could say it would've been a DRAG...
I had an 'in' with my chromer, so it wasn't too many $$$.
Luckily, a fellow shop owner (upholsterer) HAD to have that deep chrome plated tube, so I bought a Chassis Engineering steel 4" I-beam. Made up some nice 7/8" D.O.M. hairpins, too...

 

Hopefully the bump outs I made for the oil pan will take care of the oil level and capacity problems. I'm relying on having made good measurements and math. I will now have 5" of ground clearance.

Raising the chassis would destroy the aesthetic I worked so hard to get.

Raising the engine has two problems. The air cleaners would be above the hood line by 1/2" (see avatar) The second problem is foot room. This car is channeled 3". The bell housing would be further up in the passenger compartment. Right now I have just enough room for my left foot between the kick panel and the steering column. The position of my right foot is not uncomfortable on the gas pedal and I can easily get to the brake pedal. Also the brake pedal can go to the floor without my foot catching the gas pedal. (Not that I ever want it to.)

 

I know a guy who’s swapping out a 5” axle. They’re a better idea on paper.

 

How much clearance? More than this!

Chris

 

2x4 standing on edge just slides under front sump pan. Centerline of front axle is a bit lower,everything clears scrubline.

 

Yes! Had a cal custom pan on my 27, was so low it would contact the drain pan and unscrew it!… stock pan and 4” clearance is fine now

 

I will tell you that on the Produce truck I decided to put a deep pan on my 200 4R for cooling. Occasionally I pick the grass and mud out of the fins. I am constantly worried about it and it is coming off as soon as I get time. It makes for a miserable time in a parking lot full of speed bumps.

 

I've gotten away with 1/16.

 

Looking straight down the center of the vehicle, if the bottom of your front axle will clear the sewer cap or debris, then having your pan another 1" at least should allow it to clear as well. If the front axle doesn't clear, then you have a bigger worry than the oil pan to contend with.
As for the speed bumps, usually they are in an area where you are driving slow already and you have time to decide whether to turn around or to cross it.
If you have a trailer, you might try winching the rolling frame/body onto it and seeing how much you have to raise the engine to make it clear as it loads.

We can all speculate on an actual dimension, but your trailer may be different than others. I'd raise the engine as suggested above........then see how the engine looks locationwise once you have it off the trailer. One other thing. I have an off topic small truck with a modern V8 swapped in. It was an expensive complete crate engine. It sits a little lower than I want but cannot be raised without major mods. The oil pan that came on it justs sticks down somewhat below the front frame member. I welded a flat plate to the frame member that sticks down and hopefully keeps debris from contacting the oil pan. Kind of a little dam in front of the pan.

 

I've always found on any engine swap, if I keep the bottom of the sump/oil pan above the chassis rails I don't worry about speed humps and potholes.

Let the chassis take the hit and keep the sump up out of the way.

Works for me.

 

Skid plate. Build one put it on and never look back.

 

This. ^^^
I build oil pans with at least 1/16" thickness bottom plate to withstand trailer loading and most scuffing.

 

When I started doing customer chassis. I made it a point to mount the motor so the pan rail was even with the top of the frame rails. Always seemed to be about right.

 

I agree.

 

Timely thread for myself as I’m about to cut steel for the motor mounts in my speedster. I’ve designed everything around 5” clearance and would have liked it to be lower to allow more room for my size 13 shoes on each side of the trans tunnel, but felt 4” would be too low and 6” too high. Chassis rails are 6.25” above ground level. I also plan to dirt race the thing so that factors into the clearance as well.

 

Can you spacer the spring at the frame mount?

 

A speed concrete bump pluss an inch.

 

Years ago I was involved in street racing and one time the cops showed up so we all split, all of us meeting up at the coffee shop shortly after. On the way to the coffee shop a 427 Nova dinged his deep/oversize oil pan when crossing some railroad tracks and left a thin line of oil all the way from the tracks back to the coffee shop

I recently bought a ticket for a muscle car raffle and I spotted a deep pan in one of the pics. If I win, that will be one of the first things I change.

What's enough clearance? My answer would be "when crossing a speed bump, something else contacts/drags before the oil pan". Scrape the frame? Whatever. Scrape the exhaust? No worries. Rip a hole in the oil pan or smash the pan up against the pickup/knock the pickup off? No thank you.

 

My thought is that the farther from the front axle the engine is, the more ground clearance you need.

 

It is always the age old struggle of 'form or function', and some of those who chose form often learn a hard and very expensive lesson. They never make the same mistake twice.........

 

All it takes is one raised man hole cover on a dark night. Put a cow catcher on it & you'll be fine...

 

I like at least 3/16".