Honda CB750 Sandcast

Oil Pan, Oil Filter Cover - Painted?

vnz00 · 27 · 13548

kp

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I presume KPis observations were actually about sandcast rather than K0 pans, and if so I agree in full.

As to "linishing" -  a common term here in the Uk. In fact at work we have a "linisher", this being a floor mounted continuous abrasive belt machine used for clean up on flat metal surfaces, taking burrs off edges / corners, etc.

cheers - Chris R.
Yep, correct Chris. I should have said sandcast. As for the clear painted oil pan I saw, this item was on eBay so could have been clear coated by the seller
Yabba Dabba KP


vnz00

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Hi folks, Thanks for all the discussion! Great that we have it all here for future reference.

Yes linishing is a common term here, especially for a light clean up of crank journals. They are not machine cut, but retrued back to a flat surface by linishing. It just removes light wear marks.  In reference to removing casting flash, the belt sander Chris described would be used.  I couldnt see it being polished off with a mop and compound, and a disc sander wouldn't have enough 'give' and would result in flattened edges on the rounded cover.

Well painting again on the weekend, hope to get some finished pics up there..,



markb

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My two cents worth, all the breather covers i've seen clearly have a gloss painted finish, silvery grey color, which appears (to me) very different than the aluminum color on cases.
Sorry to dredge up an old post but are you saying that the color is lighter or darker than the cases?  Anyone have a paint spec for a close match?
Mark
Mark B
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)


vnz00

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Mark, slightly darker gloss finish to the engine cases which are a bright alu finish.
Ill post a pic of what I painted mine which I colour matched to original.

I believe the cam chain tensioner housing is the same colour.

Regards,
Steven.


Marcello Tha

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This is the finish of a NOS sandcast cylinder head breather cover (12321-300-010), it was in an original Honda closed package. I think that the cam chain tensioner has the same finish.

Marcello


markb

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Thanks for the feedback guys.  However, it's really hard from the photos to tell the shade. 

Steven, just to make sure, you are saying the breather cap is lighter/brighter than the cases?  I have several caps that are different (lighter and darker).  I guess the key thing here is what was the color on early covers.  I've been holding off on painting the cover (and the cam chain tensioner too) until I could sort this out.  I have to dig out my caps this week.  I hope I have the #97 cap labeled. 

I'll have to take a closer look at my cam chain tensioner too.  I always thought they matched the cases.  I'm not doubting anyone's observation but it does seems odd to me that Honda would have two different colors for engine parts although it would make more sense that the breather cap was different. 
Mark B
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)


vnz00

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Hi Mark, sorry I didn't word my response very well:
The breather cover and cam tensioner housing are a slightly darker silver, gloss finish, to the rest of the engine which is a bright alu finish.

Ill post pics of 1853 which is what I used as my reference later.


Steve Swan

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Hi Mark, sorry I didn't word my response very well:
The breather cover and cam tensioner housing are a slightly darker silver, gloss finish, to the rest of the engine which is a bright alu finish.

Ill post pics of 1853 which is what I used as my reference later.

Agreed with Steven.  The cam cover breather covers i've seen that came with engines, clearly appear to have a painted finish.  Light grey.  Not silver or aluminum.  Finish is not a high gloss, but certainly every bit of a semi-gloss+.  imho, one cannot use a later production part as an example of what one would think the finish or appearance would have looked like on a part used on the assembly line.


Marcello Tha

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Dear Steve, I agree that a late production part cannot be used as an example, but the NOS head breather cover (12321-300-010) above was superceded by (12321-300-020) after serial number 10.338, an non longer produced from October 1969. Couldn’t a glossy paint from 1969 become a semi glossy at 2014?

Marcello


Steve Swan

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Dear Steve, I agree that a late production part cannot be used as an example, but the NOS head breather cover (12321-300-010) above was superceded by (12321-300-020) after serial number 10.338, an non longer produced from October 1969. Couldn’t a glossy paint from 1969 become a semi glossy at 2014?

Marcello


Hi Marcello, So i understand what you are saying... :) 

1.  That new breather cover is high gloss finish?

2.  After 45 years, gloss finish degrades to semi-gloss ?


Marcello Tha

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Steve, my NOS cam breather cover has a gloss finish, more a clearcoat with a little bit of silver paint.
I supose that due the time and usage a gloss part from a 69 bike today has today a semi-gloss finish.

Marcello