High performance engine tuning

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dannyrds

New Member
ive been looking thru the threads and cant find much on engine tuning, ie: port and polish, high compression, re ground cam shafts, dual plug heads, balanced and lightening internals/flywheels, etc...

i recently bought an 81 Honda CM400 and have a problem with leaving well enough alone. do people get into these kind of mods? what about superchargers?

discuss
 
You're better off with a turbo. There's plenty of info here about performance engine modifications. Its usually just included in the build threads so it can be a little tricky to find. Your best bet is to start a build thread (if you haven't yet) and tackle it there. You'll definitely get more specific responses.
 
I agree with the above post but think you are alot like me. I don't just do the open exhaust, pod install fine tune and done. There are a few individuals who want to go further with there motors and have done some trial and error testing. The biggest problem is lack of aftermarket support for all brands of older bikes. Trying to find the hardware is like a needle in a haystack search even with all the advancements in the internet. So if your wanting to go old school hot rodding your left with a couple choices. Make the parts yourself or contact manufacturers with custom one off requests. Check out APE race parts for machine work on cranks, rods, lightening balancing type services. I would contact http://www.cavanaughracing.com/index.html for porting and polishing cylinder head work. He mainly focuses on Kawasaki Suzuki brands but may do others. Arias pistons and a few other piston companies will make custom pistons. Web cams may be able to do custom cams or regrinds. Then of course you can always go the turbo route like suggested and I would look into Garrett turbos. The GT1241 they are making now is tailored to small displacement applications capable of enough airflow to support 50-130hp. Frozen boost dot com carries liquid to air intercoolers and accessories that are small enough for bikes. Its just a matter of how much you want to get involved and money! I'll probably end up with about $7000 in my KZ440 turbo cafe I'm building. Way more than the bike is worth but it is for my enjoyment so it doesn't matter to me. Hope these suggestions help. Good luck and happy hunting.
 
Thanks for the responses, I used to have a vw gti 16 valve that had a large set of cams In it and I fell in love with the lumpy idle, I have a mechanics ticket and an electrical ticket so getting down to business is the easy part. I would like to do almost all the work myself, I have friends in the machine shop world if on the odd chance I need parts made, I'm just not sure where to start or what direction to go, maybe I will go buy one of those performance engine building books from parts store.
 
First off, open exhaust and pod filters are not a performance mod on most bikes.

Most of the issue you will run into is the fact you are working with one of the least performance related motorcycle honda ever thought of building. Its like trying to fine HC pistons and race cams for a kia.

Play to bikes strength and dont force or shoehorn things together.
Sure you can get custom stuff made for anything, but why? At the end of the day you have a bike that may or may not be slightly faster then you started with. But still slow compared to most other things on the road.

Use the hawk for what its best at. Learn bikes, ride the wheels off it. Hell even play dress up with it like others have. But when you want to start making real improvements to a motor get something else. No reason in reinventing the wheel.

As for FI, have you checked what oil pressure a hawk makes?
 
Haha, didn't realize I would need a flame suit for this topic. Basically I have a good running bike with higher mileage, I wanted to open up the motor to replace bearings, gaskets, etc... So while the motor is apart I would clean up the ports, lighten and balance rods and pistons, curious as to what others had done
 
Flame suit? you sit and pee? this place is the happy go lucky place on the web.....

If its running then why open it up? Dont make work just for the sake of work.
if there is and issue its probably cheaper and easier to just swap in a running motor.
 
im not sure what the expected life span is on the motor, i plan on riding it 400km each way in the summer to my cabin. I want to make sure its reliable. i dont want the issue to be at 9 at night on a rural highway
 
I see what your driving at here danny. Unless your the original owner its hard to tell what the previous owner did in means of care and maintenance. I tried the whole if its running leave it alone aspect and sometimes it just doesnt apply. My GPZ1100 had some electrical issues when I bought it and after fixing those it developed a head gasket leak. Fixed that and then had a cam cap issue. Fixed that and then.... So I can tell where your comming from. If you have the means and opportunity to go through the motor and that is YOUR choice to do it then go for it. Removing sharp edges from rods, balancing the bottom end are all good things to do that will increase longevity of the final engine. As far as lightening the bottom end I would say only really necessary if your wanting all out performance and will use it as such. Remember the more power you create the more wear on the motor so it is a balancing act. What is applicable to a car engine is applicable to a motorcycle engine with a few exceptions. They are both fourstroke engines (two stroke bikes excluded) and operate on the same princepals. Gains wouldnt be as much as you would see in a car in hp to hp comparison but considering a bike weighs less it doesnt need to be huge. Cutting weight were you can will give the feel of more power without the actual need for more power. Think power to weight ratio. I've seen CB350's go from 26hp to 46hp without turbos/superchargers. Gear heads understand what you are trying to accomplish. Could you provide an idea of what your end goal would be. That maybe easier to help in suggestions. Good luck and like Von said start a build thread. Makes getting specific answers a little more tailored. Good luck and later.
 
You would be better off looking at the 3 valve Honda car motors for some information on port mod, cam timing etc.
Honda used the bike engine for R&D several years before the car motor came out.
If your coming from the car world, you'll find the bike engine is already 'stage 3' tuned
A lot of the intakes on the car motors are built for fuel injection but it's pretty easy to see what 'import tuners' have been up to
Researching this stuff can get quite expensive, I've bought a lot of books over the years, sometimes for a single page of relevant information (but the single page is worth it)
The cost involved is why you won't find too many people just 'giving away' information
 
> Its like trying to fine HC pistons and race cams for a kia.

and that's a quote
 
Go for it ...turbo that sweet thing and go all Burt Munro in your flame proof suit ;) have you seen the altar that Burt Built...they told him stuff wasn't available for his Indian that Indian had a top speed of what? the guy that sold me my Super 3 bought a turbo 5k for his triumph. He is sporting 160 bhp... totalsleeper Triumph made out of two wrecked bikes. He has 8 grand in the bike total...Tinkerers are inventors...my son and I plan on blowing stuff up!
 
Where would one even start looking for a turbo setup that would work with a cb200 lol... If it could be made reliable and safe I would definatley consider it
 
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