Topic: Did anyone see this? -- Honda CB750 16 Valve Twin Cam Head. Piper

[MessnerMoto]

I sourced springs for dumper and dimensions from R1 bike. Springs are really big.

I like the idea of hanging idler at the back on damper shaft. I can do that with my design. Do you think if that is possible that in front, existing primary bolt and 6mm hole, can be used.... without additional bolting?

[Captain]

 MessnerMoto, you appear to not understood what I said in my last post so please re-read it carefully.   The load is “upwards”  and  the exsisting primary bolt and 6mm hole are woefully inadequate.
Do not underestimate the loads and the dynamics of all this or you will have a pile of broken or at best very damaged parts in short order.

 Captain

[MessnerMoto]

MessnerMoto, you appear to not understood what I said in my last post so please re-read it carefully.   The load is “upwards”  and  the exsisting primary bolt and 6mm hole are woefully inadequate.
Do not underestimate the loads and the dynamics of all this or you will have a pile of broken or at best very damaged parts in short order.

 Captain

Mirko is the name

thanks Brent... I am asking then if I secure idler around primary shaft where should I put bolts and how many... approximately.

[kmb69]

Mirko, Brent uses a bearing mounted in the idler bracket at the primary shaft and 4 bolts - 2 through the bottom and 2 through the sides. His front bolt is mounted quit substantially and is a 7/16" bolt. Brent's bracket essentially becomes "one with the cases" when installed. I agree with Brent, even mounted to the primary, the 6mm bolt will not get the job done and it requires side mounting to prevent any flexing.

[MessnerMoto]

...Still dont see where to make holes in engine case for all of the bolts... still thinking ...

I can reuse front primary bolt/hole and enlarge them.... and the other thing is to use side walls of primary "tunnel" but walls of that tunnel are thin?

Brent, I can attache idler to primary shaft in my design, like you did. But it is then getting really complicated etc.. Is that really necessary in sohc engine? I know you are making 200hp in dohc engines... I dont want to over engineer, but I only have your advice as a guid

[Ken Rutledge]

I owned this Curtis / Piper Honda back in the 80's!
Saw it in the window of an auto parts supply store in North Vancouver and was smitten. Memory is a bit vague now but ended up purchasing from Jim Brokensha without really understanding what I was getting into. Had some fun riding around greater Vancouver and entered in a few show & shines. I remember it ran really hot, probably because of oil reservoirs under the seat. . . A couple of memories: baffle in megaphone was held in by (a single?) alen bolt. Drove it once around UBC perimeter road with baffle removed. What a sound! But unfortunately attracted the attention of an RCMP. They let me go with a warning. Another time was taking it for one last ride of the season and was wide open on a 4-lane road also in UBC. Coming up on some traffic I realized the car at the head of the line was an RCMP cruiser (same guy maybe?). I went past them hard on the brakes with the front end diving. Looked across and made eye contact and, not surprisingly, they waved me over. The officer was fascinated by the bike and I seem to remember discussing for a long time. Explained that it was the last ride of the season and was again let off with a warning. Sold the bike at some point but have no memory of who to. Great to see the Cycle World article on this forum. Pic attached of the 'Killer Honda'. Thanks for the memories! 

[754]

Very cool that you owned that  bike, it was a sandcast..
 I met Jim once over at Dave Banks place..

[Sam Green Racing]

I owned this Curtis / Piper Honda back in the 80's!
Saw it in the window of an auto parts supply store in North Vancouver and was smitten. Memory is a bit vague now but ended up purchasing from Jim Brokensha without really understanding what I was getting into. Had some fun riding around greater Vancouver and entered in a few show & shines. I remember it ran really hot, probably because of oil reservoirs under the seat. . . A couple of memories: baffle in megaphone was held in by (a single?) alen bolt. Drove it once around UBC perimeter road with baffle removed. What a sound! But unfortunately attracted the attention of an RCMP. They let me go with a warning. Another time was taking it for one last ride of the season and was wide open on a 4-lane road also in UBC. Coming up on some traffic I realized the car at the head of the line was an RCMP cruiser (same guy maybe?). I went past them hard on the brakes with the front end diving. Looked across and made eye contact and, not surprisingly, they waved me over. The officer was fascinated by the bike and I seem to remember discussing for a long time. Explained that it was the last ride of the season and was again let off with a warning. Sold the bike at some point but have no memory of who to. Great to see the Cycle World article on this forum. Pic attached of the 'Killer Honda'. Thanks for the memories!

Ken, if you look back through this thread, I did some research on this head. I contacted Piper and they couldn't remember it, OK, I probably spoke to the wrong People.
They also did a similar conversion for the British BMC Austin Mini and they couldn't remember that one either and I only remember seeing one in a local Mini specialist.
Anyway, I did find a couple of pics of one, if I can find them in my pics. Here goes.

OK, I found 2.

Sam.

[Ken Rutledge]

Great stuff. Thanks Sam!
Your info twigged a few more memories of the bike. Head was supplied by MTC and came with 1000cc kit.
Tried to find some closeups of the head but no luck. Found one picture taken outside the shop I used to work in, but when you zoom in you'll see a rag where the cams should be. . . Had to adjust valves by adding / changing shims in buckets as I recall. Of course no shims available so had them mfr'd by a local 'wiz' machinist. Wot fun! 

Note the bikes in the shop window. A Mike Hailwood Replica and Rickman Triumph. With a Nourish (Weslake) 8-valve head! We had it bad in those days. . .

Happy New Year!

[Ken Rutledge]

More pics of the 'Killer' Honda.

[754]

Which shop was it ? I knew Mick King after he moved up to Kelowna... he had Superformance on the North Shore ....I believe that is where it was located.

[turboguzzi]

very special moto! love the psychedelic shapes and paintwork, oh-so-70's!

you got to wonder where it is today...

[Tintop]

I remember speaking to Denis Curtis about theses, and him mentioning all the machining issues.  Is that not the bike that was built in his shop in BC?

Edit - found this about the HRD that Jay Leno now owns, & the Piper head > http://www.curtisracingframes.com/street-bikes.html

[Ken Rutledge]

Which shop was it ? I knew Mick King after he moved up to Kelowna... he had Superformance on the North Shore ....I believe that is where it was located.

The bike was in the window of an automotive parts supply store in North Van. I think it was either 'British' or 'British-Italian' Imports, or similar. I'll dig around tonight and see if I can find any more clues.

[Ken Rutledge]

I remember speaking to Denis Curtis about theses, and him mentioning all the machining issues.  Is that not the bike that was built in his shop in BC?

Edit - found this about the HRD that Jay Leno now owns, & the Piper head > http://www.curtisracingframes.com/street-bikes.html

Yep. This is the BC bike. Thanks for the links to Curtis custom street machines page page.