Thanks for the lead on the bike. I bought it to race in the production class at Bonneville. Since I am planning a complete rebuild, the $4000 I saved over most 650's will go to good use. Ed
There are Four reasonable performance mods that you can do to these bikes.
Mill the heads (a little).
Smooth the the Exhaust ports.
Run a Boost valve.
Run a Blow Off Valve.
If you want to make a drag bike, you could run Nitrous, but you will fuck up your engine.
Anything else you try will be a futile attempt, a very expensive attempt, and the only thing you will accomplish in the end is to fuck up a perfectly good bike.
Hi Ed, in what respect(s) do you consider the CXT's a "failed" design?
The production class at Bonneville is hardly a 1/4 mile dragstrip. Any bike is elevated in stature if it does well at Bonneville.
And exactly what is the difference between running at Bonneville and maybe throwing a rod or ?, and running a circular track and throwing a rod or ?. Or being parked and hit by a car, caching fire in a trailer or getting broadside on a public road, results the same. Six of one, half a dozen of another. At the price this thing sold for, most would have used it as a parts bike or parted it out, at least it'll cut through the wind again.
There are still a relatively large number of these bikes around vs production numbers, and few purists out there willing to pony up the $$$ it takes to keep them unmolested and stock.
If your work is going to result in the creation of replacement CP pistons and main bearings, go for it.
I'll support you 100%.
I do wonder, however, where you are going to get rings?
I have heard of an Audi oil ring being used to replace a bad oil ring, but no replacements for the main rings.
Tony GI think higher RPM's is the method for NA engines and 1/4 mile drag bikes. With a turbo charged engine I think some of those goals get discarded or minimized. Predetonation, timing, turbo mapping; head flow, boost level etc etc come into play equal to or greater importance than acheiving high RPM.
HP is just a mathematical function of measured torque. These 650's in stock trim made 80ft lbs from 4000-8000 RPM's. And that from a 40 cubic inch engine. That is where they got their acceleration rate. Not from being able to wind 50 ft lbs from 7000 to 12,000 and make bigger HP. A 650T will still accellerate with stock 600/750/900's crotch rockets of today, but top speed will be limited due partly to gearing.
Increasing torque by increasing boost while not inducing pre-detonation and altering gearing to allow that peak boost to get to the ground would be my personl goals. HP is just an RPM factor requiring lower gearing to maximize the torque available at that higher RPM.
I think the NA 500's and 650's are redlined for piston speed considerations and not neccessarily valve float. I think they also had some considerations for cam lobe configurations and cam ramp angle.
When they went to the 650 NA engine, they reduced the RPM due to the slightly longer stroke of the 650 which increased the piston speed.
You mentioned being afraid to ride your 12K bike and yet people ride 20-30K bikes on the road all the time. Thus your reluctance to ride your RG500 is not likely due to it's monetary value alone, but due to it's intrinsic value and rarity. But yet if you'd put another thousand in the 650 turbo bike as is, you'd end up with up to a 5 to 6k value (likely).
And it's likely as or more "rare" than your RG500.
The RG500's production numbers were approx 7500 in '85; 1500 in '86 and 500 in '87. Thus only if you have a '87 is your rarity greater than the 650 T that you have now.
From Wickipedia concerning the 650T
You can indeed do what you want with it; but it would be equally interesting and challanging to take a NA 650 engine and bike and install a turbo on it or modify it to it's maximum potential. You'd have to decide if the engine block and crank would take it. There are already several guys doing this with CX series bikes and thus you'd have company.
You stated that some of your goals would be to facilitate the fabrication of replacement and performance parts for the 650Turbo's. That and similar approaches have been found unmarketable and basically unwanted. Dan Topping discovered this perspective. There simply is not enough of the bikes manufactured and still remaining to mass market any type of performance upgrades. And most owners seem content with the performance for street riding as it is. If they wold want to spend 10,000 for performance upgrades AND for daily riding; they'd likely opt for a newer motorcycle also.
Many though would be appreciative though if stock replacement parts (such as sidecovers) wouild be sourced and manufactured. But even those are resellable to a very limited number of people.
Only a few of those cabaple of affording extreme parts to modify a 650 Turbo would actually have an interest in doing so. So your likely in a world of a very few modifiers such as Tim the dragracer and yourself.
Someone had even made a intercooler for the turbo, but couldnt' get it dialed in. That would be another performance upgrade that may net 20 HP.??
Just wondering if your reconsidering your racing project with the 650T due to our discussion.
In particular, wondering if you've changed your perspective of the rarity of the Gamma 500 in comparison with the 650T?
Tony,And there are several on the forum who find dislike for those who might purchase a rare bike and turn it into a racebike with likely no future possibiltiy of being returned to stock. Althouh not a speculator or trying to 'run the price up'; even those type are permitted to do with their bike what they desire.
There is likely a balance between those who dislike investors and 'stewards' of motorcycling history who keep them in riding or restorable order (even for someone else) and those who take such rare bikes and destroy them by racing them or parting them out.
The Harley phenomenon had little to do with rarity of bikes. Perhaps there were rare editions made, but even very few of these editions have collector value. It was done more on the status of owning a harley.
These are not peoples lives that we are talking about though and the importance of such material issues can sometimes get taken beyond its appropriate perspective.
I simply wished to expose to you the inconsistency of your felt value of your Gamma vs the 650T and correct you on your error of the rarity of the Gamma vs the 650T.
Thanks for the tip. It is about two hours away, but they have good BBQ there. I have to pass through there to pick up the bike in Illinois anyway. Price is a bit high, but like you said he may budge on it a bit. Shipping is about $200, plus crating costs, so local pickup is his best bet to try to sell it.Edh - Did you see this engine on craigslist? Engine is serial number RC16E-2001347. Possibly not far from you in the memphis...as I'm not sure where in Arkansas you are located. Price seems like it is a little high considering what it is missing and also that its true status is unknown. Its been for sale for a while though, so maybe you could check it out in person and then negotiate. Anywho, just though I'd pass along...