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Offline mkramer1121

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Head Markings
« on: December 18, 2007, 09:03:40 PM »
Ok, here's an odd one for you.  I purchased a head from Dragman with a number of other parts, and after some examination, it seems someone had done some modifying to the head, no big deal.  There is a marking of IPO on the top of the head in the recess by where the cam chain runs.  Its raised, looks like someone hand wrote it on w/ a bead of weld maybe?  I didn't remember seeing anything similar to this when I put my stock engine back together. 

Well, since I wanted a pro (MRieck) to have a go at it sometime towards the spring, I purchased another head off of eBay.  Figured give him a new ball of clay.  Well, this one too has a similar marking, however it is an SJ.  The ports also look like someone has been in them.  Hmmm...

My question is, was this common practice to put the guys initials that modified the head in that location?  It seems to be in the same spot on each, though not on my K8 head....  Its located in the circled part of the attached pic, just not on this K4 head either....

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Offline 754

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Re: Head Markings
« Reply #1 on: December 19, 2007, 09:25:21 AM »
Bump, look at the front cam cavity headbolt.
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Offline mkramer1121

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Re: Head Markings
« Reply #2 on: December 19, 2007, 08:49:46 PM »
Well here are some pics.  I'm guessing they are both early heads.  The SJ could be a mirrored 27 casting mark and the IPO could be a mirroed 160 casting mark.  If it is an early head, I have never seen one prior to a K4 so pardon my confusion...Could also mean that these heads aren't modified, just early heads w/ bigger ports:

Newly purchased head:


Old Head:
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Offline 754

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Re: Head Markings
« Reply #3 on: December 19, 2007, 09:25:25 PM »
Top head is 73 and up.

Markings have no meaning to me.

Front edge of top fin angles off  smoothly to the sides.
(should have 3 rectangle bars between fins, viewed from the side)

Rocker shafts have the extra little bolts between the rockers

The second head, if it has no bolt hole in front of the cam cavity is  from sandcast to#1026,149.. should have 4 or more round bars between fins viewed from the side
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Maker of the WELDLESS 750 Frame Kit
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Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline mkramer1121

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Re: Head Markings
« Reply #4 on: December 19, 2007, 09:39:32 PM »
Yup, no bolt hole on the second head....So it is a sandcast head?  Cool, means I CAN finance my engine project...There's some chipped fins, but....

Thanks for the info, should give me something to go on now.
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Offline Terry in Australia

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Re: Head Markings
« Reply #5 on: December 20, 2007, 04:06:10 AM »
Not so fast Mike, the "Sandcast" tag is being bandied around a little too much here, the diecast K0 head has no front bolt hole either.

Even if it was sandcast, it's not a "must have" part, like sidecovers, airboxes, seats etc. Don't spend your dough until you've sold it, or you might be disappointed! Cheers, Terry. ;D
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Offline mkramer1121

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Re: Head Markings
« Reply #6 on: December 20, 2007, 04:57:48 AM »
Awww shucks..... ::)  I was really just kidding, but I can probably use it for somethin'.
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Offline KB02

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Re: Head Markings
« Reply #7 on: December 20, 2007, 05:24:33 AM »
Quote from: mkramer1121 on December 19, 2007, 08:49:46 PM
The SJ could be a mirrored 27 casting mark and the IPO could be a mirroed 160 casting mark.

I think this is the key right here. My K8 head has marking of the same kind, but in different locations. If you reverse them they read, "10,25" and "14-A." Most likely a simply casting mark.
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Offline Terry in Australia

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Re: Head Markings
« Reply #8 on: December 20, 2007, 04:25:08 PM »
Quote from: mkramer1121 on December 20, 2007, 04:57:48 AM
Awww shucks..... ::)  I was really just kidding, but I can probably use it for somethin'.

Ha ha, sorry Mike, I wasn't trying to burst your bubble, and you could always send it to me, I'd be happy with (another) spare K0 head!

The other head is more interesting, the stamped marks near the intake valves are (I'm pretty sure) made by an engineering shop to denote that it's been "reconditioned". My K2 head has the same marks, but none of my other heads have these marks.

I know that the K2 engine had a major rebuild by the PO, (1 new cam tower, new OEM cam, new .025mm over pistons in new bores, etc) and I can see where the gasket surface has been milled, so I presumed at the time that it was done here in Oz, but as the marks are pretty much identical to yours, maybe there was a company in the US that provided "reconditioned " heads worldwide? Fascinating! ;D
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I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline 754

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Re: Head Markings
« Reply #9 on: December 20, 2007, 09:46:32 PM »
Kramer, I figired out how they made those marks!! The funny ones.

They simply took a  pick or scribe and scratched them into the sand core, so they would be viewed backwards on the head.
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Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline Terry in Australia

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Re: Head Markings
« Reply #10 on: December 20, 2007, 11:34:06 PM »
Possibly, if that's a "sandcast" head, but what about the similar markings on the K4 head? Surely they were "diecast"?  ;D
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I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline mkramer1121

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Re: Head Markings
« Reply #11 on: December 21, 2007, 05:24:02 AM »
Well, it makes both head then sandcast, when 1 has the extra cam chain tunnel bolt, and the other does not....
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Offline KB02

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Re: Head Markings
« Reply #12 on: December 21, 2007, 05:27:49 AM »
Quote from: 754 on December 20, 2007, 09:46:32 PM
Kramer, I figired out how they made those marks!! The funny ones.

They simply took a  pick or scribe and scratched them into the sand core, so they would be viewed backwards on the head.

Through the magic of Photo Impressions I have managed to turn them around to be read properly. The original pics are on the bottom and the reversed ones are on top. The first one is still open to a little debate. I think it says 160, but I could have reversed it the wrong way. It all depends on which way is "Up." The second one is pretty straight forward. 27.


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Offline 754

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Re: Head Markings
« Reply #13 on: December 21, 2007, 08:07:59 AM »
All the heads are sandcast, better cores used on later ones.

But only one head for the "sandcast" model, and it overlapped into K0.
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Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline malcolmgb

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Re: Head Markings
« Reply #14 on: December 21, 2007, 08:53:47 AM »
I'm no expert but if I had to guess I would say each mould that is used would have a code number engraved in it, then if a problem is ever found in castings they would know which mould to look at.

I worked in the testing lab of a foundry for 6 months, testing the metal quality with a spectrograph machine, if the sample failed that particular batch had to be isolated for further testing. This foundry only did sand and shell castings in relatively small quantities.
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Head Markings
« Reply #15 on: December 21, 2007, 09:41:26 AM »
Looks like Japanese writing done with some type of welding equipment to me. I haven't seen anything stock like that. Looks like someone went to a lot of trouble just to specially label one head?! Let's see some pictures of the other side and the ports. What are the valve size measurements? 
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Offline mkramer1121

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Re: Head Markings
« Reply #16 on: December 21, 2007, 10:56:37 AM »
Valves are stock.  Here's some pics of the head marked IPO/160....The port shots turned out blurry....




And here's the 27:
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Offline Terry in Australia

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Re: Head Markings
« Reply #17 on: December 21, 2007, 04:45:09 PM »
Have you got a "Macro" setting on your camera for closeups Mike? Those pics make me feel drunker than I was last night! ;D
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I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline mkramer1121

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Re: Head Markings
« Reply #18 on: December 21, 2007, 05:55:28 PM »
yup probably....I'll figure it out...
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Offline Terry in Australia

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Re: Head Markings
« Reply #19 on: December 22, 2007, 02:52:48 AM »
It's the little icon that looks like a flower Mike! ;D
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I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline mkramer1121

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Re: Head Markings
« Reply #20 on: December 22, 2007, 12:46:20 PM »
Heres some better pics...

160 head:








27 head


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Offline Terry in Australia

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Re: Head Markings
« Reply #21 on: December 22, 2007, 03:55:17 PM »
Geez I can't believe how rough those castings on the 160 head are? I can see that someone has cleaned up the ports on the 27 head, (and the combustion chambers?) so I know which one I'd be using! Cheers, Terry. ;D
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I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Head Markings
« Reply #22 on: December 22, 2007, 05:41:25 PM »
I can't determine if someone has either tried to build up that area or done some butchering with a grinding tool.
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Offline Terry in Australia

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Re: Head Markings
« Reply #23 on: December 22, 2007, 05:51:29 PM »
Yeah, I thought that too Jerry, could it be an "unfinished" casting?  ;D
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I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline mkramer1121

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Re: Head Markings
« Reply #24 on: December 22, 2007, 05:58:51 PM »
hmmm...the set of cylinder i had bored doesn't have the extra hole in it for the "27" head.  Since this is a better head, can I still use it?  Do I need to plug the extra hole?
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Offline Terry in Australia

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Re: Head Markings
« Reply #25 on: December 22, 2007, 06:09:09 PM »
G'Day Mike, I take it you bought the "160" head and cylinder block from the same seller? Looks like you got the top end off a K0 mate? I can't see why you can't the cylinder block with the later head, (can you drill and tap a hole there?) but I think the extra 6mm screw was to reduce oil leaks, (not that my K0 leaks oil) so I'd suggest that you replace the original cylinder studs with heavy duty APE studs, particularly since you're gonna be revving the pisss out of that 836? Cheers, Terry. ;D   
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I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline mkramer1121

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Re: Head Markings
« Reply #26 on: December 22, 2007, 06:42:51 PM »
Yup, already got the APE studs.  That and the Ti Retainers, and the Kibblewhite HD springs.  Also a Webcam 63a....

The cleaned up combustion chambers were on the 160 head, however, I just took my trusty steam cleaner and a stiff nylon brush to the 27 head and it came out looking pretty good.  This head is going to MRieck anyway, maybe I should ask him about the extra bolt...
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