How low is too low?

[andreas_kc]

Mounting a Cummins 4bt into a 51 frame with a Heidt's Mustang II front-end.. You can see the current altitude in the pic below... The oil pan is currently slightly lower than front crossmember... and slightly lower than control arms...

Running board brackets maybe slightly lower than the oil pan sump? Thoughts on the height before I start fabbing up mounts?





Also, have a build thread at (may have more related pics)

http://67-72chevytrucks.com/vboard/s...d.php?t=735623

[andreas_kc]

Most likely the fabbed mounts are going to end up on the top of the frame rails...

[mongocanfly]

I wouldn't want my oil pan to be one of the lowest parts of the truck...I'd raise it up a little..my 2cents

[joedoh]

Originally Posted by mongocanfly

I wouldn't want my oil pan to be one of the lowest parts of the truck...I'd raise it up a little..my 2cents

I would throw a dollar on that 2 cents. I have bottomed out on the front crossmember on enough lowered rides to be thoroughly scared of having an oil pan lower than it.

[andreas_kc]

Thanks for the $1.02, yea, after sleeping on it last night and feedback just gonna give a few more inches for bottom of pan to be higher than bottom of front crossmember.

Yesterday we were talkin in the shop about the running board brackets might be the lowest thing to hit the ground first.... but some flimsy running boards prob won't cut it or they are back far enough the angle on a bump could still nail the oil pan.

Going with stock or higher ride height, but still want a good daily-ish driver that I don't have to be too scared wackin a speed bump

[my56chevytruck]

I was going to offer another $1 or more and suggest you do what you can to increase the oil pan spacing. although I've never bottomed out on the oil pan, I know of some that have and it's not a pretty situation. good luck.

[Coupeguy2001]

If you can't enjoy it, it's too low

[mr48chev]

That crossmember is only going to be about 6 inches off the road when you are done unless you run some super tall tires.

I have busted an oil pan because the engine was too low in the chassis but it was on my T bucket and the back of the pan was sitting just right for it to bottom out on speed bumps if I hit one too fast.

The only other thing besides raising the engine that I can think of is maybe raising the bottom of the pan up to the same height of the crossmember and putting some race car style bubbles on the sides of it to get the capacity back. That would take some good welding though.

[joedoh]

isnt a MII 5" lower than stock? asking, I havent ever installed one.


I bought a bagged mazda once that hit a manhole cover that had been popped up by a car in front of it. it looked like the crossmember was smiling.

[andreas_kc]

Originally Posted by joedoh

isnt a MII 5" lower than stock? asking, I havent ever installed one.


I bought a bagged mazda once that hit a manhole cover that had been popped up by a car in front of it. it looked like the crossmember was smiling.

I do think a normal MII kit does lower your ride some and you can lower it even more with some drop-spindles which it seems most people do. I'm doing the not-most-people-build.

Once I get this engine mounted, going to start putting cab + fenders back on so I can start figuring out wheel sizes... likely going with some good sized tires.. will have to see thou...

[robertsjm711]

Mine is that low - 5.3 in a '53 - but I am going to fab up a skid plate. If i know myself it will be some ridiculously thisk plate that makes the front squat. But it will protect the pan...

[mongocanfly]

^^^^That's scary lookin^^^^...seeing that pan that low...you just about gonna need a bellypan off a bulldozer to protect that....you could swap pans and pickup tube though..would help tremendously robert

[robertsjm711]

Originally Posted by mongocanfly

^^^^That's scary lookin^^^^...seeing that pan that low...you just about gonna need a bellypan off a bulldozer to protect that....you could swap pans and pickup tube though..would help tremendously robert

I know it is low - and a new pan is on my list of changes needed. I've got a long way to go before it actually hits the road and this is just one of those "kinks" that needs worked out. I guess what I was saying is for my driving style a little drop and a good skid plate, equivalent to the cross member in strength, is acceptable.

[mongocanfly]

"before it actually hits the road*"...boooom!!!!!!!...there it is...budampbump...haha

[andreas_kc]

mmm. got me thinking even with lifting my engine up a bit, I may still fab in a bellypan for the old frame. The peeps over at 4btswaps are fairly questionable about an old 51 truck frame holding up an 800lb torque machine. A 10 or 12 gauge bellypan may go a long ways to keeping the rails together.

[Desert1957]

The term you need to understand is "Scrub Line"

Here is a link I think will help

http://www.streetrod101.com/scrub-line.html

[robertsjm711]

Originally Posted by Desert1957

The term you need to understand is "Scrub Line"

Here is a link I think will help

http://www.streetrod101.com/scrub-line.html

This is great, thanks for sharing.

[andreas_kc]

Originally Posted by Desert1957

The term you need to understand is "Scrub Line"

Here is a link I think will help

http://www.streetrod101.com/scrub-line.html

Seconded, great explanation! Don't need a flat tire that grinds my pan off!

[vintovka]

Done with low vehicles. Never want to see that tell-tale trail of fuel or oil in the rear view mirror again.

[Jesse Z]

How about a set of travel trailer rollers under the frame to keep the oil pan from hitting the pavement?

[mongocanfly]

^^^^not on mine^^^^...you could still destroy a oil pan by hitting something that them rollers never touch. ..plus I wouldn't want them on my truck anyway. .

[dsraven]

everybody has their own ideas and plans and that is fine. it is their vehicle and their idea as long as it is safe to be on the road with everybody else. but, personally, I am done replacing headers and broken engine parts due to that "holy ****" bump in the road that you never seen coming till it was too late. or that obscenely tall speed bump with all the grind marks on it from regular height vehicles hitting it. yes, flat tires or blow outs are another reason for ground off parts but in my experience it is a bump that does the most common damage. it usually happens because you have somebody else in the vehicle at the time and they are talking or whatever and you are distracted. it doesn't matter the reason but it sure puts a damper on your day and whoever else is riding with you gets that "why did you build it like that? that was dumb" look on their face.
just saying. think about what you're doing and weigh the consequences. maybe there is a different way to get the truck in the weeds if that is what you want. like mono says, the frame rail roller idea sounds good in theory but.... I think that the chances of the frame rails lining up with the road debris/object in question is pretty slim when you figure the width of the frame rails compared to the width of the road and that also sort of assumes the bump or whatever is straight across the lane.
I like the scrub line link, it explains it pretty well.

I think a combination of these is what you are after:
raise engine
swap the pan to a shorter version allowing more road clearance
don't drop the truck as much
line the underside with 1/2" armor plate
make buddies with as many tow operators and parts guys as you can and hope for the best
make a mount for your bike in the box so you have a ride home or walk home and pick bottles along the way for recycling return fees that can help pay for the new parts
keep a bag of absorbent in the box to pick up the oil slick before environmental guys show up

just my thoughts.
another question is do you have enough "stop" to overcome all your "go"? is your old frame gonna handle the torque?
your truck, do what you like, safely.

[dsraven]

oh ya, and keep a fire extinguisher in the truck, handy.
skid plate the fuel tank as well if it is underneath behind the engine in the shrapnel zone.

[vintovka]

Just a comment on low vehicles in general. Had a recent incident where a flat piece of wood damaged the fuel return line and left a trail of diesel for 12 miles and a 20 foot wide pool at the destination. Filed a claim with Geico and was denied. In the process the claims administrator said damage from road debris is at an all time high and they were considering denying coverage to vehicles w/o "adequate" clearance as approved by govt. I askesd what "adequate" meant and they alluded to 6 - 8 inches. ???????

[joedoh]

Originally Posted by dsraven

in my experience it is a bump that does the most common damage.

man before I moved 37 blocks north on the same street, I used to drive it to pick up my kids at school. I had a bagged 62 galaxie that rode best a couple inches off the ground and the first time I picked them up I "found" a frost heave or something similar in the curb lane, BAM lower control arm and drivers header collector both, left a big gouge. I warned my brother in law about it about a year later after we bought the house and he was helping us move, of course he forgot and BAM knocked everything over on the trailer