CX500 PartII

so tell me, it looks like you have two different kinds of inlets there. little rubber bits, and nice long metal ones. whats going on there?

Steve F said:

So going for some more performance, ordered some Mikuni VM34 carbs and the custom intakes etc. Should be here in a week or two.

While I'm waiting for the carbs I pulled a set of heads off of one of my spare engines. Valves are coming out for new valve seals and a good clean. Then I'll lap the valves and port match the heads to the new inlet stubs from the carbs. With this fairly simple work I should get 20% more power out of the CX (with the pods and freeflowing exhaust) as the stock carbs dont like pods at all and very rarely do they produce more power with pods. Torque will be up quite a bit as well and I'll end up with a CX that will wheelie off the throttle

Also ordered an electric fan off a Ducati so I can take the mechanical fan off as it runs on the end of the camshaft and slows throttle response and saps more HP. Basically I'm trying to put the Racer in Cafe Racer

Cheers
Steve

Click to expand...

Those vacuum carbs are a bitch to tune, but they can be made to work with pods. The thing is that the jetting goes down in size instead of up when pods are added. Yeah, I know most will disagree with that, but I did it on my BMW and it picked up 12 mph on top end along with gas mileage going up. According to what I read, the pods produce some sort of suction effect which pulses and makes the main jet produce two shots of gas per intake stroke making the bike run rich with the stock jets. On my bike I had to go down several sizes. Some of you might want to try this on your CX's if you are having carb problems with your pods.

Your fairing is truly awesome and I love the phone/gps mount. I've been wanting to do something similar to mine for awhile. Great build!

Re: Re: CX500 PartII

ProSimex said:

so tell me, it looks like you have two different kinds of inlets there. little rubber bits, and nice long metal ones. whats going on there?

Click to expand...

The rubber mount is to isolate the carb from the metal intake it bolts between the carb and metal intake.

Cheers
Steve

Sent from my GT-I9300 using Tapatalk 2

I am a fan!

Years ago I worked on a CX650 turbo that was going to run on the salt, never made it (project lost funding) but the engine ended up making almost 140hp on methanol and 20psi if I remember. Kanticoy ended up with the intake manifolds I made for that bike reworked for his rad 360 Gretta.

There is great gains to be had by doing a little port work. Along with your port matching, blend the bowls to the seat and cut back/radius the small side just a little. You don't need to hog it out huge, just clean it up. You can also either blend the valve guide protrusion or since it's not likely to spin more than what...9000rpm, you could probably get away with grinding most of the protrusion away completely. If you're feeling froggy, you could probably have some high ratio rocker arms made (more lift at the valve), may be able to source from something else?)....

I love this build, some people want to hate on the CX but I like an underdog story and yours is looking sharp indeed!

this is damn cool

Swagger said:

I am a fan!

Years ago I worked on a CX650 turbo that was going to run on the salt, never made it (project lost funding) but the engine ended up making almost 140hp on methanol and 20psi if I remember. Kanticoy ended up with the intake manifolds I made for that bike reworked for his rad 360 Gretta.

There is great gains to be had by doing a little port work. Along with your port matching, blend the bowls to the seat and cut back/radius the small side just a little. You don't need to hog it out huge, just clean it up. You can also either blend the valve guide protrusion or since it's not likely to spin more than what...9000rpm, you could probably get away with grinding most of the protrusion away completely. If you're feeling froggy, you could probably have some high ratio rocker arms made (more lift at the valve), may be able to source from something else?)....

I love this build, some people want to hate on the CX but I like an underdog story and yours is looking sharp indeed!

Click to expand...

There comes a point where the money spent doesn't really give me any proportionate gaine Hopefully with that simple head work, the carbs, exhaust and pods I'll hit the 60-65hp mark, in saying that I'll have a better look at the heads and do some of those tweaks you mentioned When it comes down to it people do love to hate the CX but I reckon with a few mods and some time they can look great and for a 32yr old 500 go pretty hard too, especially when compared to other 500's of the era. And of course the water cooling and shaft drive make it a great daily rider as well.

I'm hoping to surprise a few people when it's all finished and have this old girl lifting the front wheel without having to beat on it to get it too

Cheers
Steve

My valve spring compressor turned up today so pulled one of the spare heads down this afternoon, the spring compressor made the job real easy with it taking a minute or two each valve. The head I pulled apart looks pretty good with no sideways movement of the valves in the guides and minimal carbon buildup. Anyway, got the dremel out with the wire brush attachment and gave the valves a quick run over, a couple of minutes each and they come up nice and clean.

The one on the right is untouched.



The one on the left is untouched in this pic, you can see it's not too bad at all



Next is to do the othe head and then port match the inlets and get the carbon off the exhaust ports. Hopefully the new valve stem seals will be here mid next week and I'll be close to putting it back together.

Cheers
Steve

Steve, if you don't mind, how do you "port match" the inlets? Is that as simple as having the rubber boots on, and making sure that no metal is showing to "block" air? I'm JUST about to do some headwork on my bike, and was told the cb500 ports were known to be off quite a bit. Looking great so far!

I'm not Steve but I play him on TV......

I have however ported loads of heads, your comment above leads me to think perhaps you haven't done this before..... my recommendation is don't, beyond port matching.
You have it right (on the intake side) though, check to see if there are protrusions into the port at the boot/manifold and clean those up. On the exhaust side don't be surprised if there's a bit of a lip all the way around, it's almost always there for a reason beyond sloppy, production-line foundry work. It's there to cut the return shockwave that slows the exhaust velocity and robs you of power in a street engine.

Obviously if you see some giant wad of casting flash in a port carefully knock that down but don't enlarge or radically change the ports without doing due diligence.
If you're interested though, a great layman's book on basic head work is called 'Practical gas flow by John Dalton'
http://www.amazon.com/Practical-Gas-Flow-John-Dalton/dp/1855205645
Worth the money and it will put you WELL beyond the average garage engine builder in terms of tuning and understanding of flow. Do it. DOOOO IT!

Read up and do the work Mr.Dalton lays out (all of it) and gain "free horsepower". That $20 is the cheapest horsepower you'll ever make!

Thanks Steve,err Swagger

I wasn't going to mess with exhaust side, I'll leave that to Steve! Thanks for the info, I'll check that book out.

You'll love it!

(sorry for the highjack Steve....carry on haha)

Postie brought me some fun stuff today

A pair of these, the inlet manifolds, throttle cable and numerous bits and pieces to mount it all up.



One of these to replace the mechanical fan on te end of the camshaft with. It's of a Duc but luckily made in Japan so will work all the time



Also brought me some of the stuff I need for the RFID ignition system to get rid of the key, spent some time sorting out a wiring diagram, it'll work fine on the CX and probably any other Honda that grounds the kill switch wire to cut power to the CDI.



Now to start pulling things apart and replacing bits

Cheers
Steve

I looked at the company but couldn't figure out what parts you were using for your RFID ignition....can you clue me in?
Thanks mate...

Sure, bits are off of ebay.

One of these

RFID Reader

and one of these

Programmable solid state relay

And some of these

RFID Wristband

Hopefully that'll help

Cheers
Steve

Thanks mate, that's perfect....what a great idea!

Swagger said:

Thanks mate, that's perfect....what a great idea!

Click to expand...

No problem....

Bare inlet manifold flange bolted on to one of the heads and what do I then notice, someone has been there before me on this pair and they have already had the inlet ports matched to a pair of carb mounts That's a job I dont need to do now and may explain why the valve guides are nice and tight with no obvious wear. Looks like this set of heads are a good'un.





Cheers
Steve

Sweet! If you've got the valves out turn the stems down at the tulip just a little and you'll gain a bit too.

Got the RIFD ignition switching sorted.

This video just shows the gauges going on, and then off, with a swip of the RFID. If you watch the Acewell guage it's more obvious (switch to HD)

http://www.youtube.com/watch?v=KIMvBhrcFlE

This one shows the LED I mounted in the numberplate. It comes on when the RFID detects a key, when you move the key away it triggers the latching relay (on/off). The next swipe swiches the latching relay to what ever the other state is (off/on). You can here the mini relay clicking when the LED light goes off.

http://www.youtube.com/watch?v=PRwhxxpeQ3Y

And here is my new harness to the plug that went to the ignition switch originally



I got an auto socket from jaycar, it's an eight pin but the stock socket plugs into it still. I'm going to leave it like this (it's tucked away under the tank now) until I'm confident in the RFID setup as if it fails now I can just plug it back into the ignition barrel. Once I'm happy I'll either switch the stock plug to a new one to match the eight pin or try and find a pair of 6 pins as the stock plug is falling apart.



Cheers
Steve

Steve that's a nice touch on the led in the rego plate. Did you just mount the existing light there or did you wire up another one?

I was going to wire that LED feed into my illuminated button up front which incidentally will also turn the ignition off so you don't have to get the key fob back out.

Great work mate!