409 Oil Pan

[TheProphet]

I've heard that you cannot use a 348 oil pan on a 409 because the 348 pan isn't wide enough.

My question is: Where is it not wide enough?

They both have the same bolt pattern on the same outer flange. At the Deep End where the pan is the lowest, the sides on both pans are straight down, not tapered, so you could not widen it there.

On the slanted downward towards drain shallow end, it appears that the 409 sides go down straight first for about 1.5 inches, then taper in. On the 348, the shallow end sides taper in right away. Is this the area that is too narrow?

It would seem that you could cut lengthwise at both sides of the shallow end, straighten the sides to match a 409 pan, add a 1/2 inch strip, then weld it back together to match the 409 original pan contour.

If you are wondering why, I have a 1956 Chevy with a 409. To install the 409 in the '56, you have to modify the deep end of the pan on the forward face to clear the steering linkage. This I've already done by cutting out and welding in a new sheetmetal piece. I've also already relocated and welded in the dipstick set up to the opposite side. Fits great, but it's a 348 Oil Pan.

Second hand 409 Oil Pans are rare, and a new one costs like $400 bucks. Plus... I'd still have to cut the new 409 pan to make it fit. 348 pans are readily available, and less expensive. Help!

 

[Don Jacks]

The problem area is at the front counter weight.I've heard that a little hammer work is all that is required,cutting and welding is not required.

 

[TheProphet]

The problem area is at the front counter weight.I've heard that a little hammer work is all that is required,cutting and welding is not required.

Thanks Don, I hope that's all it is. It would be at the "shallow end" of the pan, right in front. I'll put the pan back on with just 4 bolts, and turn the engine over by hand to see where it hits. Sure will save a lot of messing around.

Thanks for the tip.

Bob

 

[Carmine]

Can't help with the oil pan issue, but I put a 348 in my '56 straight axle gasser. When you fit the motor, make sure you have valve cover clearance at the firewall. I didn't use stock exhaust manifolds. Headers instead. Had an issue with the header and stock steering box. Just sharing a few experiences with you, Carmine.

 

[TheProphet]

Can't help with the oil pan issue, but I put a 348 in my '56 straight axle gasser. When you fit the motor, make sure you have valve cover clearance at the firewall. I didn't use stock exhaust manifolds. Headers instead. Had an issue with the header and stock steering box. Just sharing a few experiences with you, Carmine.

Thanks Carmine. I already have the engine in my '56. I drilled new motor mount holes exactly in between the 6 cyl. and 8 cyl. holes on the frame, and used the V8 stock mounts. Fits perfect, and valve covers have about 1.5" clearance in the rear. Everything else lined up as well. I had to fabricate 6 spacers made from thick 1/2" flat washers - 3 on each side - for the mounts, which raised the engine up an additional 1/4", which then provided clearance between the exhaust manifold and steering box.

Downside to this is that you have to modify the oil pan, as the front face of the deep sump portion will rub against the steering linkage. A lot of guys take a hammer to it, but I cut a section out, then welded an 18 ga. sheetmetal piece in, giving me additional 1 1/8" clearance. I also had to move the Drain Plug from the front of the deep sump to the bottom center for the same clearance issue. I didn't want to ruin a good, original 409 oil pan, because apparently they are more valuable than their weight in gold! Picked up the 348 pan for $45.00 on local Craigslist. Had a few dents and dings, but they were easy to hammer and dolly out.

 

[models916]

I did a 348 pan on 348 block and 409 crank long ago. Placed the pan on couple of beach towels folded up and used a hard rubber mallet to make it fit. 348 pan holds much less oil.

 

[Carmine]

Sounds like you're coming along nicely on that build Prophet. It's always something with these cars. I insisted on using the stock steering box and what a nightmare I created. Had a case of death wobble that had death wobble. Received some friendly, well meant advice, some of which mentioned to drill the oil pan to be able to connect the center link and idler arm. I said no thank you. That wouldn't work for me. Then I fabricated a pitman arm that was about 12" long. I was told the car would steer like a Mack truck and they didn't lie. Finally gave in and used a Vega steering box. Fond memories LOL, Carmine.

 

[k9hotrodder409]

I used a "Hurst " front motor mount in the 348 in my ;57. I used the stock motor mount pins in the 6 cylinder holes and it seems to work just fine. I had the 348 pan notched at the front to clear the drag link then I decided to use a 3 " dropped drag link to clear the pan AFTER I notched the pan
NEVER DO THAT AGAIN !!! My engine clears the upper control arms JUST BARELY ! I have stock manifolds on the engine . I too have about 1 1/2 " at the firewall also. I am now looking for a tri-five Rack & Pinion cradle that does,not cost an arm and a leg to revise the steering.

 

[Carmine]

Just wondering, do you have that motor bolted in at 3 different places; front mounts, frame horn and rear transmission mount?? Thanks, Carmine.

 

[k9hotrodder409]

Carmine , I have that engine mounted in the front , at the rear of the block and at the transmission cross member .
I'm still looking for a rack & Pinion mounting cradle .

 

[Carmine]

Thanks Butch. I put a blown 406 sbc in my '57 Belair and also bolted it in at those 3 locations. Pretty strong. Never had any problems with twisting, Carmine.

 

[Randy]

Yep, all that you mentioned has to happen. In my 56 with the 409, I have the stock exhaust manifolds, and they are really, really close to the steering box. It is mounted as you mentioned and I have about 1 1/2 inches of clearance also.
I have been trying to to get more capacity for the oil, because you lose some with the pan being modified. Haven't figured that out yet, but it seems to be ok in the mean time. The exhaust pipe was another problem with the centerlink. Just replaced all the old bushings in the control arms, new ball joints, rebuild the centerlink and rebuilt the I
Idler arm with bearings. Had to modify the pipe to give me more clearance to it.
Good luck on your project.

 

[DonSSDD]

Maybe use the stock canister filter to get more oil in the system than you will with a screw on filter?

 

[Randy]

Don, how did you know I had a spin on filter? I guess that would give me a little bit more if I put on the canister filter, how much, no idea, but I bet it would be very small increase.

 

[Don Jacks]

The difference wouldn't be a half of cup when comparing the "long" spin-on to the canister type.If you're using the"short" filter,you're losing about a cup as compared to the long one.

 

[DonSSDD]

Most people use the spin on for convenience Randy. Don, I would have thought it was more that a cup but I have no idea what the difference is.

Don

 

[models916]

You need the extra oil in the bottom of the pan.

 

[oldskydog]

Here's one way……not pretty but I might try it in my 55 or 57.

 

[Randy]

You know I thought about a pan like that, but wouldn't that interfer with the starter. You most defiantly wouldn't want it on the other side, your oil filter is there. I for one wouldn't want to drop my oil pan to service the starter. Just thinking...

 

[Carmine]

Not trying to steal this thread, but I'd like to ask a question about a dented oil pan. I believe I have read it here and also elsewhere, that some have taken a hammer and dolly to a dented oil pan and removed most of the dents. How does that work?? Aren't you still left with small dents?? Do you smooth things out with bondo?? Thanks, Carmine.