Oil filter cover

[chrisnoel]

I saw an oil filter cover sale on E-bay. The claim was that all sandcasts came with a no fins filter cover that was recalled and replaced during dealer service calls. I was thinking that my finned filter cover was original because my sandcast is not an early one.

He also claimed that his cover was previously an early finned cover with no internal reinforcing, but he had machined off the fins to make it look identicle to a no fins cover. Is this possible?

The two motors I have have differnt size bolts for the filter cover. Is the 14mm original? Or is the 17mm one original.

Thanks. Chris.

[Steve Swan]

Chris,

The owner of the cover you are referring to is a fellow member "736cc". If you are interested in his cover, I suggest you contact him.

General knowledge seems to indicate fin-less covers were phased out somewhere in the VIN range of 25xx to 35xx.

I know for a fact the fin-less cover was used beyond VIN 35xx. I distinctly remember my 4779, which I purchased new, Sept. 1969, having a fin-less cover. I remember the fin-less cover on that bike for two reasons. 1. I remember that cover being HOT to handle during oil changes. 2. My college buddy, Norm Mathis, bought a brand new Ruby Red K1, May 1971. I remember he & I, comparing the two bikes, side by side. I can remember three things about his machine, how I wished my bike was red, how much more I liked his side covers AND how cool I thought his oil filter cover with fins looked, compared to my 'smooth' cover. I ALSO remember how my 4779, could whup up on Norms machine, every time we had rolling start drags. No matter whether he or I was riding each others bikes, 4779 would ALWAYS beat him by 1/2 to 3/4 bike lengths. I suspect the reason for this was 4779 had nearly 20k miles and his bike was still quite new. Heh, heh.  Norm, where are ye now ? 

[chrisnoel]

Ok. Well my frame # is 5640. If any body knows of the finless cover coming on any later #'S let me know. One of my finned covers has a broken fin and would be a good cadidate for making a forgerie.

I would not like it to have a machined look. Rather I would like to make it appear original. I have some metal smithing skills, and could easily emboss a sand cast finish on it. I have already embossed away some ss#s that were scratched into my motor. I would first need to know if simply removing the fins is all that would need to be done.

How about the bolt. One of mine is 14mm. and the other is 17mm. Were they both used? Or is only one original?

[elisent]

Hi Chris, 14MM would be correct I believe. They switched to 12mm to stop overtightening and cracking of the filter cover. I think that change was part of the dealer fix when they replaced the smoothe covers. I'm not familiar with the 17mm bolt. By emboss do you mean bead blast it?

[chrisnoel]

embossing is normally a pattern that is rolled onto a flat piece of metal with anything that will fit between the metal and another piece of backing metal while it is sent through the rollers. If I wanted to make a flat piece of metal look sand cast I could just put a piece of sand paper on it and roll it right in.

When I embossed off the ss#'s from my engine I simply used some 80 grit sand paper and tapped it with a hammer untill the engravings were blended away.

Were the finless covers sand cast as well? I don't think tapping the entire surface of the cover would get me very far, but I could find a way to emboss the whole surface if need be I'm sure.

[Steve Swan]

Post by Frampton "Guest"

Just curious...why would you emboss off the serial numbers of the motor???

[736cc]

The orig smoothies were sandcast, painted silver and are presently extremely rare. Try turning a finned cover on a lathe, sandblast it, then paint it dull aluminun. Top it off w/ a 14mm bolt. Since you're going to all the trouble to make it look right, you should machine an early type w/o strengthening internal ribs. Otherwise, every time you change the oil filter, you will see the ribs and be bummed-out for not having your bike being as correct as possible. 
And to give it just the right patina, use the cover on your daily-rider CB750 so it gets kinda grungy.

[chrisnoel]

I never altered the engine #. A previous owner had engraved a social security # in a few places on the engine case and head. The method I used to blend out the engraving worked very well.

[chrisnoel]

Both my covers are the early type non reinforced fin type covers. One has a broken fin so that is the one I have begun to hack up. I like to use my hand tools, so I have already cut the fins off by hand with my 4" coping saw. Next I am smothing it down then wet sanding it. Then its off to the sandblaster.

Steve. I here that our K0's have a hotter cam than later years. Might be why you were abble to lay down the law when racing your friend.

[kp]

Chris. May I make a suggestion. No matter how adept a fellow you are you will never work this to the finish a lathe will accomplish. Please, take this filter cover to a machine shop and have a professional spin it for you. Have it wet bead blasted rather than dry as this produces a more realistic cast finish. You will be much happier with the result and I will sleep better knowing you did that KP 

[chrisnoel]

I've made a few things out of metal. Cutting stuff off and making it look like it was never there is part of just about every project that I have done. I have two of the fins gone to the point that they may as well have never been there. These were the outside fins, and the most dificult. Its all down hill from here.

The side wall of this cover is taipered. I don't think a machine will preserve that taiper as much as I can by doing it by hand. I also dont want to take off that flat lip under the bolt.

My assotment off files don't like the aluminum so I have to clean them often to avoid gouging.

thanks for the wet bead blasing Idea. That does sound better than just letting the local blasting shop have a crack at it.

[736cc]

Chris, if that finned cover gives you any problems, just use a bigger hammer. 

[chrisnoel]

That is my plan if I mess it up.

[chrisnoel]

Well I have removed the fins. I did have to chock it up in an arbor that fit my drill. Once I had the fins cut and filed down enough I spun it and sanded/trued it with 230 paper in a rubber block. It still has 4 little remnant indents that show it is a die cast cover. I will have to fill them with metal filler after I get it blasted and before I paint it.

I'm still glad I didn't machine lathe it. I don't think it is balanced enough to avoid removing too much material from one side with a lathe. My drill arbor fit perfectly and the thing stll was not balanced when I spun it. + had I let someone lathe it they might have kept going till even those indents were gone. Then they would have messed up the taipered angle of the side wall.

[kp]

Chris, I've done a dozen (12) or more filter covers with a lathe and have had absolutely no problems. The finish is superb and 2nd to none. I'm glad yours has turned out OK KP