Author Topic: CB750 finned starter cover (Read 5312 times)

wolf550 · « **Reply #25 on:** March 21, 2023, 04:06:09 PM »

getting back to work on the finned cover
made a few more of the bar stock grinding away and angled the ends

wolf550 · « **Reply #26 on:** March 21, 2023, 04:09:09 PM »

once glued I can round the edges to sink into the cover
also sand off any overcast in the fins before filling with putty the three pieces
after casting the excess will be grinded away where they connected making them one continuous piece

wolf550 · « **Reply #27 on:** March 21, 2023, 04:11:46 PM »

still trying to figure if the fins should go all the way to the edge, leave a small lip, or large lip like the 550 cover
going to make a couple of different with each option to see how they will look
im not sure about keeping the fins angled but instead keep them flat like the 550 cover

bert96 · « **Reply #28 on:** March 21, 2023, 04:15:39 PM »

My choice is made. The one on the left please 😁

Bert

Gurp · « **Reply #29 on:** March 29, 2023, 12:36:34 AM »

Great work as always.

wolf550 · « **Reply #30 on:** March 29, 2023, 05:22:14 PM »

Thanks gurp
took awhile to get all those cracks filled in
still have to sand between the fins more smooth. the sand molds still get stuck on some fins and on the inside cover

wolf550 · « **Reply #31 on:** March 30, 2023, 05:45:25 PM »

interesting this was on here awhile ago

wolf550 · « **Reply #32 on:** March 30, 2023, 05:46:03 PM »

saw it in a thread from 2009 from cyclexchange

wolf550 · « **Reply #33 on:** April 01, 2023, 06:26:52 PM »

a little more work today
got some sun to make a cast today and see how it holds up
as I was pouring the aluminum the mold started smoking from the back and it was flowing out
sprayed the outside to cool the aluminum fast to block the flow and see if the casting could be salvaged
not expecting much but it was cast enough to do some work on it
grinded the fins down to less an angle and more flat
burred through the fins to get that rounded look as the 550
once I got most of the casting marks sanded down it started to look alot better
I have been without a dremel since the last one took a dump on me so the sanding has been terrible by hand and the sander is too big
it is still not ready to make a casting yet. the inside still hooks on the mold breaking it and some fins need to be sanded down more for same reason
its come a long way from just a cover

wolf550 · « **Reply #34 on:** April 01, 2023, 06:28:20 PM »

a shot where the aluminum didnt get filled in

wolf550 · « **Reply #35 on:** April 01, 2023, 06:29:24 PM »

Quote from: wolf550 on March 30, 2023, 05:45:25 PM

interesting this was on here awhile ago

this one reminds me of the time I tried to make finned side covers with popsicle sticks
almost worked

Don R · « **Reply #36 on:** April 02, 2023, 10:31:54 AM »

I have a set of high dollar cylinder heads made by a well known pro stock engine builder. They are full of cracks and porosity. Just proof that casting aluminum is not as easy as it seems.
Their repair guy said the casting company needed to add an air vent to their mold.

wolf550 · « **Reply #37 on:** April 03, 2023, 04:55:08 PM »

once I get the sweet spot it should turn out fine.
been trying to make the sand moulds but each time I go to release the cover the sand keeps sticking to the fins due to small cavities from using burr bits
the putty will not stay in these shallow areas so Im going to get some jb weld to fill in the last 3 spots.
all the other areas are stable
this is where a 3d printer will come in handy in the near future

wolf550 · « **Reply #38 on:** April 04, 2023, 05:13:29 PM »

finally after so much filing and sanding I got a decent mould to come out
only had a couple of spots that needed filling in but doable
it got too late to do a burn and tomorrow I go to get some teeth fixed so maybe in the afternoon I will give this one a try

wolf550 · « **Reply #39 on:** April 04, 2023, 05:15:13 PM »

you can still see some pitting at the inside bottoms of the fins but as long as it works I am happy

wolf550 · « **Reply #40 on:** April 04, 2023, 05:16:40 PM »

while at the storage place I found a familiar piece
that SOHC cover that I made a groovy cover out of
I think Ill make another just for fun

bert96 · « **Reply #41 on:** April 05, 2023, 02:41:11 PM »

Quote from: wolf550 on April 04, 2023, 05:15:13 PM

you can still see some pitting at the inside bottoms of the fins but as long as it works I am happy

One world, wow!

Bert

wolf550 · « **Reply #42 on:** April 05, 2023, 04:58:56 PM »

Thanks bert
Its getting there
after this on I realized I forgot to build up the bottom
the area that wasnt cast was so thin Im surprised that area filled in at all
the area between the fins needs to be smoothed out all the way to get a smooth fill otherwise I will have to machine those areas and it looks way better with the casting still on it

wolf550 · « **Reply #43 on:** April 05, 2023, 05:03:37 PM »

placing on top of the original theres about a 16th inch around missing from the casting
I can build these up but I need to be sure first

wolf550 · « **Reply #44 on:** April 05, 2023, 05:06:10 PM »

the screw holes look good but again have to wait and see

wolf550 · « **Reply #45 on:** April 05, 2023, 05:09:09 PM »

I gotta go back and check the measurements
gotta get another starter cover

wolf550 · « **Reply #46 on:** April 06, 2023, 06:04:07 PM »

looks good
after building up the inside Ill see if it completes a cast

wolf550 · « **Reply #47 on:** April 06, 2023, 06:06:22 PM »

if this works and it fits in all the right places I want to go back and fix the right side where the back should have one more fin and take away the excess area of the large right fin and make that flat

wolf550 · « **Reply #48 on:** April 08, 2023, 04:50:36 PM »

finally got a break in the rain

wolf550 · « **Reply #49 on:** April 08, 2023, 04:51:51 PM »

needed to try it both ways and see if that spot was going to be a problem

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Author Topic: CB750 finned starter cover (Read 5312 times)