Topic: 458 vs 466 cb400f

[rupaulpierce]

Been eyeing a cb400f parts lot with a 458 yoshi piston kit. What are the pros and cons of the 458 vs 466 mod?

Do I need a new cam and valve springs on a street only bike? Help give me an idea what I'd be getting myself into.

[robvangulik]

A 458 you can still rebore when worn or when something goes wrong.
Performance is hardly different, if compression ratio is about the same, you are tuning for more torque anyway with such a slight increase in cc's anyway, it is only 12 or 16 cc extra in a 100 cc cilinder. You don't NEED to do anything about valves, springs or cam, it 'll work fine, just don't expect to run circles around any standard cb500.

[Bodi]

The difference will be minimal, both kits increase displacement about 13% and the difference between them is not significant.
When I went to Yoshimura R&D to buy a kit, the guys there said they sold one 458 kit to each 10 or more 466 kits so I went with 466. If you do wear out a 458 you have to buy a new piston kit and pay for a rebore... used cylinder blocks are pretty cheap so the difference is not huge whether you rebore a 458 to 466 or start again with a used block.
You will notice a power difference with just the pistons but to wake the engine up and start running circles around stock 500s you want a hotter cam, springs to suit, heavy duty cam chain, a good header, and maybe bored carbs. The stock oval throat carbs are the main limiting factor in making big power at high RPM. A reasonable head porting is worthwhile if you want max performance. Remember this will still be a 70's bike and any modern sport bike will laugh at it.

[robvangulik]

The main, and fun, difference is that the sixth gear will be much more useable..

[rupaulpierce]

The Denoonsp site has info from OMT and their engine stages. Stage 1 is just the big bore kit and a cam.

Which cam specs would you recommend? Web-cam has quite a few options. Also open to other ideas.


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[Tracksnblades1]

Been eyeing a cb400f parts lot with a 458 yoshi piston kit. What are the pros and cons of the 458 vs 466 mod?

Do I need a new cam and valve springs on a street only bike? Help give me an idea what I'd be getting myself into.

I can only share but a few of what the late Great Smokey Yunick once may have said. There's no replacement for displacement. Go big, someone else will and you'll loose.

Only the Best on your project....👍

[ttr400]

The better piston to use is the Yoshimura 54mm 458cc kit if you can find rings for them. the CR is 10.5-1.

All of the 54.5mm 466cc kits i have used have the same CR as std at 9.4-1.

Or very rare now is the Yoshimura 2 ring 56mm, 492cc kit. also 10.5-1 CR. sold my last set a few years ago. have 15mm small end, so new rods and sleeves required to fit.

Kevin

[rupaulpierce]

There’s a 458 yoshi set near me, but the cruzin image set is so cheap! Looks like the yoshi set has rings, but not sure what else.


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[Bodi]

A full Yoshi set has pistons, rings, and head gasket.

[ttr400]

Yes i know what you mean on price, can't be beat.

Also for street use nothing wrong with the cruzin kits, i have used plenty of them. in fact also about to place an order for another kit.

As Bodi pointed out, kit will include rings, head gasket and the piston pins and clips.

Kevin

[rupaulpierce]

Still thinking about whether or not to go 466, and how far to go for a street bike.

Seems like there are three main paths:

1.) 466 alone
2.) 466, ported head by mreick
3.) 466, ported head, welded cam/rockers, HD valve springs and cam chain

Option 4 is obviously going even further, bored out carbs (missed a set on eBay, still having nightmares), whatever else. I suppose option 5 is enjoy the 400 for what it is and save up for something else.

Any of you with experience have a recommendation?



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[Mark1976]

   My personal perspective, I've done the 455, 30 plus years ago with the head work and cam header K&N's etc. When I was thirty years younger its was fine as long as you really enjoy rowing the gears and listening to the sound that this package makes coming together from the pipe. But I'm not 31 I'm 61 and while i enjoyed riding that version then, today not as much. I have a 77 now with a 1st o/s piston, very mild head work, web cam, dyna coils, high volume oil pump, oil cooler, Hondaman ignition, , Sudco header, etc... But the main difference now is retaining the stock air box. It does pull a little better down low and less on top but it was easier to jet and set up. Now in hindsight I'd drop the high volume oil pump, its pretty tough on the oil, the oil cooler is more important on this engine. Build a solid bottom end and break it in properly. When I built my 455 I spoke with kaz yoshima on several occasions during its build, he passed this info along to me, he said "the oil temp was a bigger issue than the oil pressure. Keep the temp at or below 235-240 degrees. When you build a 492 w/OS valves that screams to 11,500 rpms you need the pump."
   Throw on a bigger rear sprocket get a decent set of coils, Hondaman ignition, header, cam, good valve job and new springs, it'll go plenty fast. Your choice.
   Just my thoughts.

[rupaulpierce]

Thanks Mark. “Halfway” there with the header, coils, Charlie’s ignition and larger rear sprocket. Feel like I should take advantage of proximity to mreick for head work.

Have you put Cb400f stuff on Craigslist in the past? Can’t think of any other explanation for my association of Voorheesville with motorcycle parts.


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[Mark1976]

   I'm on craigslist every blue moon or so, last item I sold was 2 yrs ago, my dual disc front end, most of my cb400f parts stash is all gone. Thank god!!!
   Head work and a cam are the best bang for your buck. Invest in a degree wheel, a positive stop, a dial gauge and magnetic base. Helps in getting that cam installed properly. I'm busy these days collecting for my next project,  a cb500.

[Kevin]

I have a brand new in the box Webcam Grind 302 High Performance Street, Part #55-331 Hard Weld that I am not going to use.
I'll sell it for $350 shipped within the CONUS, no core required.
PM me if interested.

If you are planning on degreeing your cam you will need a slotted cam chain sprocket.

Kevin

[rupaulpierce]

   I'm on craigslist every blue moon or so, last item I sold was 2 yrs ago, my dual disc front end, most of my cb400f parts stash is all gone. Thank god!!!
   Head work and a cam are the best bang for your buck. Invest in a degree wheel, a positive stop, a dial gauge and magnetic base. Helps in getting that cam installed properly. I'm busy these days collecting for my next project,  a cb500.

Saw that! I remember now, blue frame?


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[rupaulpierce]

I have a brand new in the box Webcam Grind 302 High Performance Street, Part #55-331 Hard Weld that I am not going to use.
I'll sell it for $350 shipped within the CONUS, no core required.
PM me if interested.

If you are planning on degreeing your cam you will need a slotted cam chain sprocket.

Kevin

Kevin, I’m definitely interested. I’d need the hard welded rockers too if I go with the 302 cam, correct?


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[Kevin]

I have a brand new in the box Webcam Grind 302 High Performance Street, Part #55-331 Hard Weld that I am not going to use.
I'll sell it for $350 shipped within the CONUS, no core required.
PM me if interested.

If you are planning on degreeing your cam you will need a slotted cam chain sprocket.

Kevin

Kevin, I’m definitely interested. I’d need the hard welded rockers too if I go with the 302 cam, correct?


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No, you can use stock rockers as long as they are smooth. I usually install new OEM with a new cam, if you watch eBay you can pick them up for a good price.

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[Mark1976]

That blue frame was a guy in syacuse, i remember it. I highly recommend the transistor ingtion up grade. Get a decent dwell meter reinstall the points. Its not quite set it and forget it, but its darn close. My bike starts at the touch off the button every damn time.

[rupaulpierce]

I have a Hondaman I want to try, but spent so much damn time troubleshooting the Charlie’s unit I’m going to run with that for a while. Bike is running better than ever right now.

There was an interesting lot on Long Island with dual calipers and yoshimura 458’s but looks like it’s gone.


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[Mark1976]

The last time i saw that collection of parts, it was on ebay several months ago. What came of it i have no idea...

[rupaulpierce]

Seems like opinions go both ways about the rockers... if I remember correctly mreick advocates for the hard welds.

Has anyone run the 466 and ported head without the hot cam?


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[kyre]

I have a 466 (cruzin) with ported heads from mreick, bored carbs, Yoshima exhaust, heavy duty valve springs and cam chain, and oil cooler (highly recommended as this little engine gets hot). All with stock cam and rockers.

I was going to go with a hot street cam and hardened rockers (mreick's advice) but it was too expensive at the time with all the other work being done. Figured I'd go that route down the line sometime which would really open this motor up.

It's been about 5 years since I've done all this work and havent even thought about adding the cam/rockers. It's plenty fast/fun for what it is, and noticeably faster than stock.

If you have the $$, go for it all! but I'd think you'll be happy without the cam as well.

[rupaulpierce]

If you have the $$, go for it all! but I'd think you'll be happy without the cam as well.

I have the money for the cam... I don’t know if I have the WILL to also pay for the rockers. Thanks, this is exactly the kind of info I was looking for.


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[Mark1976]

As stated above, if your exsisting rockers are in good shape, get the cam and valve springs. Use an oil cooler and a high quality oil. l've reused nothing but the stock rockers in my builds, its a road bike not a roadrace bike.