Hot Rodding ..... Modifying a Mark 4 BBC Oil Pan For a Gen V/VI BBC

Scott Danforth

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As part of my BBC build http://forums.iboats.com/forum/engin...ll-the-admiral I had picked up a mark 4 (1965-1990 454) 8-quart mercruiser cast aluminum oil pan. The problem is I picked up a Gen V/VI core motor for the project because I wanted a 1-piece oil seal and roller cam and valve train.

So after weeks of trying to sell the pan on CL and Ebay, I thought.... what the heck. Lets look up the dimensions, and see if we can get it to fit. Not to mention the admiral said I have an oil pan, so I cant buy another until I sell it or make it work.

After a bit of measuring, the mods are easier than I thought.

So in true hot rodding fashion, its time to make things work the way I grew up doing. Have the skills and access to the right equipment, so why not. I am posting this here because it is BBC related, and not brand specific. Also because there may be another boater trying to do the same thing. In the end I will have an 8-quart cast aluminum oil pan on my Gen 6 motor.

Here is a link to the photobucket folder, http://s1343.photobucket.com/user/sc...?sort=3&page=1

First step - see what hits. Front lip is too long, rear lip and seal surface is too small of a diameter.

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I laid the pans side by side, even went so far as transfer the dimensions onto a chunk of plywood.

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First mod to do is cut off the lip on the front of the oil pan. Both pans have the same dimension in length, and the radius for the front pan gasket to timing cover is the similar (had to put a bead of weld on it).

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Next mod - open the back side radius a bit (ok, a lot).

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After a bit of grinding and clearancing and material removal with a belt sander, it fits the block.

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Next mod - make a jig to re-drill the holes. I ended up indexing the oil pan aft about 1/4" to get the pan to sit properly. All the mounting holes will be welded shut and re-drilled.

I drew up the jig for the laser to burn out tomorrow. Will post more then.
 
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alldodge

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Sure is nice to have access to all the fancy tools. Great write up
 

Scott Danforth

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the tools used so far was a reciprocating saw (the jig saw was too slow), 4.5" angle grinder, roto-zip spiral saw and a belt sander.

one of the welders at work will weld up the holes tonight and fill in a bit of the flange.
 

Scott Danforth

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Thats because I am too lazy to transfer and layout the holes. so I made a drill jig.

the folks at Stef's use dowel pins with a point. place the pan over the gaskets, aligning to the gaskets, smack pan with dead blow hammer. the dowel pins imprint a dimple with the hole location. then drill mounting holes.
 

Scott Danforth

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Didnt get much done. tanker fire on the skyway meant I took the long way home with over 100,000 other people. traffic was a mess. took 3 hours to finally get home.

however did get my jig off the laser (some welding will be required for the checking feature I added). also got my most of my holes welded in the pan, as well as a few areas filled in.


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may get the welds dressed tonight after work.
 
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Scott Danforth

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Agreed, however they are only tools, and only as good as the creative mind behind them
 

Scott Danforth

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A bit of update. I finally got back to this project. Spent the weekend slowly removing material for a good fit. Drilled new mounting holes,

A bit of clearancing for the crank throws

Will get last of the old holes filled on monday
 

Scott Danforth

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Thought I would close this out. took a bit of time yesterday to finish the oil pan. I had all the welding done a while back. Clearance each bolt location. will be using polished stainless button heads

had two pin-holes in a weld along the flange, used some JB weld to fill those in and smooth out the welds.

hit the pan with some VHT self etching primer and then some VHT wrinkle finish.

here is the shot of the pan with the wrinkle finish being first applied, then dried



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