Author Topic: '73 500 - Subframe Fabrication (Read 142430 times)

SOHC4 Cafe Racer Fan · « **Reply #275 on:** February 12, 2015, 07:58:00 AM »

They should have peed into the empties. You don't buy beer. You rent it.

Restoration Fan · « **Reply #276 on:** February 12, 2015, 09:35:34 AM »

Quote from: calj737 on February 12, 2015, 05:42:40 AM

Road trip story time-

Outstanding story.
Looking forward to more pictures, cal. I LOVE the way those pistons look with that coating on them. Bike porn at its best.

calj737 · « **Reply #277 on:** March 25, 2015, 09:38:58 AM »

So after test fitting of the motor (numerous times) finally got the head/piston clearance dialed in. Required milling the valve reliefs on the intake side about 60 thousandths. Unfortunately, the cermet coating will be missing on the new pockets.

Now to assemble one more time and hopefully button this thing up for good!

70CB750 · « **Reply #278 on:** March 25, 2015, 09:56:40 AM »

Looking good!

SOHC4 Cafe Racer Fan · « **Reply #279 on:** March 25, 2015, 09:57:16 AM »

That was some precision milling. Looking forward to this coming together, Cal!

bwaller · « **Reply #280 on:** March 25, 2015, 04:06:56 PM »

So Cal did you end up with piston compression shoulder at "0" deck height after milling? 126-20 cam, 28.5mm valve needed that much extra intake VP depth and the exhaust was ok? Good thing you checked huh?

You'll feel a difference.

calj737 · « **Reply #281 on:** March 25, 2015, 05:23:51 PM »

Yes, Brent. Pistons were 0.032 short, so the block was decked to bring them level. Then head assembled and clay squished. I'm guessing it's a combo of the OS valves and lift on the cam. The pocket more needed to be "flattened" than deepened if that makes sense.

Glad I checked? Uh, yeah, I'm checking everything 3 times! I've got a friend who's a Pro double-checking everything and doing the more advanced stuff for me. Not taking any risks since the whole upper end is non-stock and a bit hotrod.

SOHC4 Cafe Racer Fan · « **Reply #282 on:** March 25, 2015, 05:34:36 PM »

Well that definitely makes me wary about any hotrod alterations involving oversized valves and larger pistons -- to check clearances with clay. Had you not decked the cylinder block, you probably would have had clearance but less compression.

calj737 · « **Reply #283 on:** March 25, 2015, 05:46:06 PM »

Not so, Don. I would have had the slightest biting of contact and still no gap (target being about 0.030).

I doubt this is that unusual for a lot of folks who build up motors. Some of it may have to do with the Wiseco pistons, the cam, and OS valves. It's a recipe that needed to be baked, checked, and double-checked. I knew all along I'd have to check, just hadn't expected the piston to be sitting so low in the block. When I saw that, I knew milling the relief was coming...

bwaller · « **Reply #284 on:** March 25, 2015, 06:18:57 PM »

Often see 0.020" or so below deck with stock pistons, so base gasket thickness & piston compression height makes a big difference.

Was the Wiseco intake valve relief angle wrong, then at what angle did you machine the relief? I'll go back for a look at your piston pre machining.

Bootsey · « **Reply #285 on:** March 25, 2015, 06:21:16 PM »

Looking great Cal, interesting thread. Keen to see it all come together!

calj737 · « **Reply #286 on:** March 25, 2015, 06:49:45 PM »

Thanks, Bootsey. But it will be a while longer still. Motor is first part to get done, front end is somewhat done, but frame mods and body work is off a ways...

Brent, if I had to describe it angles, stock Wiseco cut was about 23* and new relief is closer to 20* if I recall correctly. Stock piston below.

bwaller · « **Reply #287 on:** March 25, 2015, 07:15:53 PM »

Thanks. I believe at some point I saw a Honda engineers drawing showing the stock included angle at 47d (23.5 each valve). When I had pistons made my best measurement was less than that, but in fine tuning the crown & pockets later ended up at 40 degrees.

calj737 · « **Reply #288 on:** March 25, 2015, 07:23:53 PM »

It's all Mike's fault anyway; talked me into the high end treatment on my motor

MRieck · « **Reply #289 on:** March 26, 2015, 10:33:26 AM »

Quote from: calj737 on March 25, 2015, 07:23:53 PM

It's all Mike's fault anyway; talked me into the high end treatment on my motor

Now, now,now......we are creatures of free will.

calj737 · « **Reply #290 on:** March 26, 2015, 10:40:10 AM »

Not complaining, Chief. Just identifying my source of inspiration!

SOHC4 Cafe Racer Fan · « **Reply #291 on:** March 26, 2015, 12:47:21 PM »

Quote from: MRieck on March 26, 2015, 10:33:26 AM

Quote from: calj737 on March 25, 2015, 07:23:53 PM
It's all Mike's fault anyway; talked me into the high end treatment on my motor
Now, now,now......we are creatures of free will.

Retro Rocket · « **Reply #292 on:** March 26, 2015, 03:20:00 PM »

Quote from: MRieck on March 26, 2015, 10:33:26 AM

Quote from: calj737 on March 25, 2015, 07:23:53 PM
It's all Mike's fault anyway; talked me into the high end treatment on my motor
Now, now,now......we are creatures of free will.

Its more of a "self control" problem Mike...

calj737 · « **Reply #293 on:** March 26, 2015, 03:39:43 PM »

Tattletale!

Retro Rocket · « **Reply #294 on:** March 26, 2015, 03:42:35 PM »

Mornin Cal {evening there}

calj737 · « **Reply #295 on:** March 26, 2015, 03:46:19 PM »

Evening, Mick!

calj737 · « **Reply #296 on:** March 31, 2015, 02:43:58 PM »

Well, had what I thought to be the motor basically all buttoned up. Rocker cover all in place and torqued. Rotated the motor to verify proper operation and "clink". Turns out that the MegaCycle cam has so much lift and duration, that the love contacts the rocker arm after coming off the intake lobe.

Meager amount of grinding required to relieve the conflict.

Then I realized, I never ordered the oil pump O-rings, so those are on the way now. By chance, any 500/550 gurus out there, is the O-ring that sits below the plate the same as the O-ring on the gear side? The one below the plate is not available separately... $:-\$ Also have new stainless flat heads coming to replace the shredded JIS units from stock.

SOHC4 Cafe Racer Fan · « **Reply #297 on:** March 31, 2015, 04:49:40 PM »

Cal,

Did you start the modifications to the frame and construction of the swingarm?

bwaller · « **Reply #298 on:** March 31, 2015, 04:51:24 PM »

No the two O-rings are different sizes. Someone on here offered an o-ring kit in Viton but I found those two were rather oversize. Take both to a hydraulic shop and try to find replacements?

Did you check clearance between cam lobe & and the cam tunnel in the head as well?

calj737 · « **Reply #299 on:** March 31, 2015, 04:53:38 PM »

Not quite yet. Boy is sending the subframe template to me so I can start cutting. Here's a plan view of two shapes he's contemplating. Also supposed to be sending me a 3D foam seat section for guidance.

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Author Topic: '73 500 - Subframe Fabrication (Read 142430 times)