Head Identification

[hayleyl]

Hello all again - I need help identifying some heads I have. I have 3 pairs. One set has extra casting on the 'back' of the head or let's say the inlet side. The other heads are more 'open'. Here are the numbers and they vary in how they are displayed.
Set one - 11684-52 (has a 'one' 1 underneath) and 11682-52 have the numbers embossed and the casting is what I'm calling 'open' on the back of the heads (I'll attach a pic)
Set two - 11684-52 (followed by an 'E' in a circle) and 11682-52 (followed by an 'E' in a circle) have raised or letters in relief and 'open' casting
Set three - 11684-52 (followed by an 'E' in a circle) and 11682-52 (followed by an 'E' in a circle) have raised or letters in relief and extra' casting in the heads.
Cheers Hayley. (also I'll attached pic of engine number for site).

[EKHKHK56]

52-53 K heads have stamped in part #s. 54 and up have raised cast part #s. Difference besides the fins is more relief in the combustion chamber for bigger intake valves in 54 and even more relief above valves for higher lift KHK cams and head. Erik K

[hayleyl]

Thanks EK, it all makes perfect sense now. Thank you for your insight. Also I have a set of new, never fired a shot or assembled crank cases (no trap door). These cases have no numbers at all, no numbers on engine ID plate or belly. Obviously these have been replacement cases at some stage. I lucked onto these at a Yamaha dealer in rural Victoria (Australia). The business has been a motorcycle dealership for ever and probably has had a few different franchises. These cases were kicking around on a shelf in the back of the shop for years. Would I be right in assuming these are K only? or maybe KK? or is there some way of identifying them by cast part numbers? Cheers Hayley.

[EKHKHK56]

OK being non trap door door dates them 54 or so latest for stock application. Those cases would be 52-53 K & KK replacement if there are no stroker KH slots cut out of the deck. If cut out they were meant for 54 KH KHK. And other small changes. The H-D change to Trap Door happened "midstream" 1954. Erik K

[hayleyl]

Thanks again Erik, attached are pics of 'nude' cases. Cheers Hayley

[EKHKHK56]

Hmm no belly numbers. Usually means new replacement case. However perhaps it was numbered on the pad at some point as the pad has been milled down. Could have heen a poor number job on replacement cases later erased. The primary part of the pad sits taller than the circular machined round spot where the 1/4" case stud nut sits. I see it does have the late style quick release case retaining zip ties for fast transmission gear repairs and updates! Erik

[EKHKHK56]

Like your 52K pad shown above which has the correct unmodified pad with circular portion lower than the rest.

[hayleyl]

Thanks Erik, yes figured they were K replacements. Cast pads where belly numbers should be are still the cast finish, there is no indication of parent material removal? Another mystery perhaps? Yes - quick release function is so i can change ratios just as I'm leaving turn 2....Thanks so much for sharing knowledge. Cheers Hayley.

[hayleyl]

Sorry Erik - yes engine ID pad is flat but still doesn't look like it's been machined or altered, has casting pits etc. still. Maybe these case were never finished properly?
Best be checking all oil holes etc. Cheers Hayley

[thefrenchowl]

Hi,

Your serial cast pad has deffo been milled down then shot blasted again... I bet you there was a serial there once...

The round part for the bolt washer is milled down with a spot face tool at the factory, so should be shinny, unlike the blasted parts...

So, no mystery there then ; - )

Patrick