RC30 Rebuild

[shilka99]

The first parts have come together.



Its been 12 years since I last rebuilt this bike. I did dozens of track days on it, with an engine rebuild every year. Back then parts were hard to find so I had to improvise. It wasnt always pretty.
This time, thankfully, I have the machine tools to make what I need.

Once I have all the gaskets and seals, as well as assorted other bits and pieces it will be back up and running again.

[fireblade]

Please post more pics as you go, I'd like to see this thing come together.

[Blizzard_1708]

same here

[shilka99]

Its going to be a slow process. May not be any updates for a few months.

[sckego]

Aww, that's just cruel.

[shilka99]

My last major piece arrived today. Now that its here I can measure and order bearings, and once they arrive I can start the assembly process!





No telling how long it will take.
So far I have new wheels, bearings, gaskets, pistons, rings, 2 conrods, valves, seals, clutch, brake & clutch pistons and now the crank (the most expensive piece). All up - more than the price of a nice, track-ready GSX-R750. But this thing is more than just a track bike...

[U-Turn]

Are you going to do any machining on the crank or just go with it? Do motorcycle engines benefit much?

[Bailout]

Jealous...Ever since I moved out of Corinth I have lost my Machine shop and have been project free for two years....gettting antsy!!

Oh yeah your missing one side of the swing arm!! HAHA

[shilka99]

I've done knife-edge work on customer cranks but that was to make those engines accelerate faster. This engines strength is traction from the big bang firing order so making it accelerate faster could actually be considered detrimental. Even my damaged HRC race kit crank is not machined in that way. And the new stock piece is almost exactly the same weight.
The beauty of this bike is its low weight (under 360lbs with a full tank), good power (130hp at the rear wheel) and tractable torque (redline is at 14,000 but peak torque is around 10,000).

[milesmiles]

I would have never thought that bike would be so light

[Bailout]

That is the beauty of that bike!!

I had this bike back in 1991 as my first track bike ever and it was base on the RC31.....hell of a wheelie machine and track bike!!

250px-1988HondaHawkGT-02.jpg (15.81 KiB) Viewed 4900 times

[Jenson]

I have always wanted a hawk. Good examples are hard to find these days.

[shilka99]

Well I finally have some news on this project.
The crank shown above turned out to be the wrong piece. My motor is a factory special and apparently almost no stock parts will fit. I bought the crank on the recommendation of a shop who specializes in RC30's but this one is different. I was able to sell the stock crank then sent the race kit item to be repaired. It needs 2 journals welded and machined back to spec.
I also found out that the repaired connecting rods were destroyed when the shop bored out the little end for some unknown reason. This cant be repaired so I had to find replacements. Originals were made to order by HRC and needless to say they dont make them any more. A team racing the RC30 in Germany have had good results with steel rods so thats my best option.
The crank and rods might be finished and balanced by the end of this month. Maybe.

In other news, my new wheels look nice with the new Brembo rotors. I have to make new caliper mounts though as these rotors are 330mm in diameter instead of the kit rotors 310mm, but thats why I have a CNC mill.

And all of this will be so much easier with my new garage sale bargain bike lift.

[Rhino]

Just curious, how do you get the bike back down once it's built? Just heave-ho it off there?

Edit: Nevermind, I see the wheels on the triple tree stand. Is it an extra tall stand, or does it just look that way without rubber on the wheels?

[shilka99]

Having the stand on the lift, and no rubber on the wheel makes it look extra tall. But everything is retractable to a reasonable height.

[Grinner]

Hey Shaun....u might want to check with Blair @ SV650 racing. I think he makes adapters for 310 - 330 modding. Not sure if they will work if he does but figured it might save some trial and error time.

[shilka99]

Thanks G but I've already made the parts. I just copied the HRC 310mm adapters and moved the bolt holes 10mm. (even improved the design while i was at it). Free CNC machine time + existing aluminum plate = free parts. Couldn't be easier.
Now I'm designing new lower fairing mounts, radiator brackets and an ignition switch relocator.

[shilka99]

More parts arrived today:


These things cost more than my KTM!
The crank is currently with a company that repairs driveshafts for gas turbines. Falicon already said they couldnt repair it so I was lucky to find this place.
I have no idea how long it will take to get the rest of the parts I need, but there arent many left...

[DarcShadow]

Those are purdy.

[shilka99]

Just a small update...
My rim protectors arrived today. $75 each - not bad. 10 minutes to fit them and I can now roll the RC30 onto the work stand when I'm done with the KTM.



Voila

[U-Turn]

How many projects do you have going on?

[shilka99]

This one has been ongoing since it arrived here from Australia in 2010. The KTM is just a quick rebuild and would have been finished weeks ago if the parts had arrived when they were promised! I'll also have work do do on the RGV when it gets here, although not as much as on the RC. I've been promised that it will get here in time for the next track season opener...

[DemonDuck]

If something ever happens outside my warranty on my bike I know who I will come crawling to. LOL. "Shaun.... could you help me rebuild the S1k please?" "And by help me of course I mean you do the work and let me help you!"

[shilka99]

Anyone want to hear more RC30 drama?
The turbine repair shop said they cant do the journal repair on my crankshaft. Apparently they can only work on large shafts, not teeny weeny motorcycle crank journals. So my options are now to use the crank with the undersize journals and adapt to the stock size conrods by using custom made plain bearings. (the crank was repaired incorrectly back in 1998. the journals that support the conrods are 0.040" too small. As a result the standard bearings still available from Honda, for this and many other of their motors, are way too big on the inside diameter. The only solution is to make bearings smaller on the inside but with stock size outer diameter.)
I've spoken to 3 bearing makers so far but each said they only do orders over 1000 units. That would mean paying over $5000 for 8 bearing shells... how fun.

But then over christmas I was chatting with my uncle in Canberra who is an automotive engineer. He's been following my progress with this build since the engine detonated back in 1998. I told him the situation with the crank repair and the custom bearings and he mentioned he knows a guy who casts white metal bearings then machines them to any size...
I very calmly asked him to contact his guy and cc me...
If this option works and I can get these bearings made accurately I'll be able to begin assembly. The bearings inside the conrods are the most critical part of the entire build - the clearance between the crank journal and the bearing has to be between 0.0012" and 0.002". If the clearance is less than 1.2 thousandths of an inch the oil film is too thin and metal to metal contact will take place. If its over 2 thousandths of an inch the oil wont have enough pressure. the film will break down and we get, you guessed it, metal to metal contact.
I have no idea how long this last step will take but I sure look forward to putting this ordeal behind me. Once its running this bike will get a few outings a year and spend the rest of its life on display. If I could put it in the living room I would...

[nitzer]

White metal is pretty soft stuff...not sure why you would want a bearing made from the stuff. They cast model parts from white metal and figurines.