CR500 Cafe project

100hp honda · Post by **100hp honda** » March 5th, 2011, 9:30 am

we know for certain the 450/480 were same base gaskets, parts fish tells us that. if you compare photos of 480/500 jugs on ebay they look the same as far as studs are concearned. the whole base mating surface looks almost the same to me. i do see some slight shape differences mainly at the boost ports but i dont see that to be a problem at all. we are only concearned with wether 450/480 jug goes on the 500 cases and i do believe they do. one thing that stands out to me is the 500 transfer port area seems to bow outward more than the 480, maybe its just camera illusions. might take some grinding to get everything matched up perfect. welding may even be involved, hell i really dont know for sure.

Pony · Post by **Pony** » March 5th, 2011, 4:14 pm

This is all interesting stuff! I orderd the cylinder, so I will post photos and pull the jug on the 85 and get some photos of that. We will find out soon enough! I'm pumped to document some "new ground" even if it has been done.

100hp honda · Post by **100hp honda** » March 5th, 2011, 7:12 pm

sweet. what cylinder ?

Pony · Post by **Pony** » March 5th, 2011, 8:03 pm

I got the 83 480 cylinder to match the head. I'm sure y'all are
tired of these little mock up pics but I got my new tank in. It's smaller, narrower and shorter. Looks a lot better I think.

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » March 8th, 2011, 7:25 am

so ya, i brought down the 450 today, Its different, by a ways.

The gasket surface at the base of the transfers will contact a watercooled crankcase by 1.5-2mm with that finned cylinder hanging inside the wet cases, and even the 500 fin cases. The studs are a long ways off, 12 and 11mm. It would have been alot easier to have gone with the '84 500 parts, theres some serious hours or welding and machine work to get that cylinder adapted to the cases, nevermind the pipe flange not working, the reed being small and no doubt there isnt a boot that will work proper.

This is another post based on nothing but bullshit and theory confirming yes Clyde you're a douche and you talked this guy into parts he wont be able to make fit.

Pony · Post by **Pony** » March 8th, 2011, 8:44 am

Ha dang, no love lost around here huh?

Roosty, I have researched a lot of your tech stuff and know you know your shit so I dont want you to take my questions as me questioning your knowledge, just me trying the what when were and why. I looked into this swap a bunch of different places and didnt find much. So if anything my mistakes and ya'lls collective knowledge might document what works, what wont and why it wont.

Anyways simple question first. The exhaust flange shouldnt be a problem. I would use the 480 flange and I am going to build a custom pipe since this is being built for the street. Probably an old downpipe style.

Same thing with the boot. I figure the 480 reed cage, with the 480 intake boot, with a PWK, and a Pod filter feeding it no airbox.

Now comparing the 480 to the fin 500 there are still major differences? I pulled my 85 motor from storage and my cylinder should come in around fri and I can post some pics and see more of what you are talking about.

Does it look like the 500 fin to wet cases would be a pretty involved feat as well? If it starts getting into the really expensive high end machine work kind of thing I might just sell some stuff and try and get in the market for a 500 fin complete motor.

pstoffers · Post by **pstoffers** » March 8th, 2011, 8:58 am

The 84 500 cylinder will bolt right on your 85. Get a 84 cylinder and head. Roosty you got any pics of Jeff Thomas's twin it is watercooled finer

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » March 8th, 2011, 9:04 am

alrite that all sounds good, you've got ambition. now i dont want to kill it for you but you're also going to put a cylinder with port timing meant for 76mm stroke on a 79mm stroke bottomend. You'll need a deck spacer forsure, which might help in the blending of the transfer port area (which is extremely bad right now) but you're going to have issues with the port timing.

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » March 8th, 2011, 9:07 am

pstoffers wrote:The 84 500 cylinder will bolt right on your 85. Get a 84 cylinder and head. Roosty you got any pics of Jeff Thomas's twin it is watercooled finer

I suspected it, but hadnt tried it. I knew the other stuff was a long ways off.
Thanks Paul

Pony · Post by **Pony** » March 8th, 2011, 9:09 am

pstoffers wrote:The 84 500 cylinder will bolt right on your 85. Get a 84 cylinder and head. Roosty you got any pics of Jeff Thomas's twin it is watercooled finer

If this is correct (no offence) Then I will have a 480 cylinder and head in the classified section for a good price if anyone is looking.

I didnt think the 84 would bolt right up. If so then I probably lost a bit of money but still have the majority of the parts for the project in hand

Pony · Post by **Pony** » March 8th, 2011, 9:14 am

Roostius_Maximus wrote:alrite that all sounds good, you've got ambition. now i dont want to kill it for you but you're also going to put a cylinder with port timing meant for 76mm stroke on a 79mm stroke bottomend. You'll need a deck spacer forsure, which might help in the blending of the transfer port area (which is extremely bad right now) but you're going to have issues with the port timing.

I was looking for the bore x stroke on the internet and couldnt find it! I knew that if the bores were the same the stroke had to be shorter or the displacment wouldnt be the same (duh).

I can see all this is dumb if the 500 fin is way close and the 480 is way off. So I guess the first step of this swap has been nailed down.

step #1. Get a 500 finner cylinder. lol

pstoffers · Post by **pstoffers** » March 8th, 2011, 9:23 am

The 84 is the same crank, rod and piston as 85-88

Pony · Post by **Pony** » March 8th, 2011, 9:51 am

pstoffers wrote:The 84 is the same crank, rod and piston as 85-88

and since it is the same displacement that be why port timing would be the same, correct?

Base gasket would probably be the LAST parts I should have been comparing. It's making a lot more sense now.

britincali · Post by **britincali** » March 8th, 2011, 11:02 am

pstoffers wrote:The 84 is the same crank, rod and piston as 85-88

How can the rod length be that same when they changed in 87?

pstoffers · Post by **pstoffers** » March 8th, 2011, 3:49 pm

britincali wrote:
pstoffers wrote:The 84 is the same crank, rod and piston as 85-88
How can the rod length be that same when they changed in 87?

My bad 84-86 ROD same crank - rod length 84-01

is that better Brit?

britincali · Post by **britincali** » March 8th, 2011, 6:25 pm

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » March 8th, 2011, 6:55 pm

its stil wrong

84-86 short rod
87-01 long rod

Pony · Post by **Pony** » March 8th, 2011, 7:14 pm

Ok not trying to keep mixing parts but I have a 480 head sitting on my bench. Do y'all know if it would work on the 84 jug? From what I understand the bores are the same. I was anticipating having to do some head work to remedy the pinging problem.

pstoffers · Post by **pstoffers** » March 8th, 2011, 9:35 pm

Roostius_Maximus wrote:its stil wrong
84-86 short rod
87-01 long rod

Thats what I said same crank - the rod lenght

Pony · Post by **Pony** » April 15th, 2011, 6:25 am

I figured this project is getting kicked to the side because now Im wanting to use this motor in an AF. Unfortunatly I had already orderd and 84 topend complete with slightly used piston. Might be a running topend, might not Im going to post pics of the bore and see what ya'll think. Anyways the motor had been sitting for 12 years and I was unpleasantly suprised that in the very small amount of time it had been run the piston damged the cylinder. So I will be making another thread adressing the motor because I have some questions.

Anyway since the jug was off and the piston was junk I went ahead and tried out the fin cylinder. Just like pstoffers siad, it bolted right up

So since I didnt want to do maintance on my 250, I was curious to see if the now larger motor would fit into my frame. Sure enough it does. I think this bike looks way mean and has the potential to be cooler than Roland Sands CR5.

I do not know what the immediate future holds for this bike. Any money I am putting into 500 stufff will be for the motor to run it in the AF or into a roller itself. But If I have all the parts rounded up and it just take some metal work and shit to make this thing good enough for a little ripping around to see what its like then I might do it.

Worse case scenario it will get put in the corner and when I come across a tired short rod motor it might get some money thrown at it.

Rhino89523 · Post by **Rhino89523** » April 15th, 2011, 7:35 am

I dig the look, I think it would blow away the look of Rolands bike, I like the way the tank and front end sit, Rolands bike looks way more modern.

Gmbond · Post by **Gmbond** » April 15th, 2011, 10:54 am

I love the look too!

Just imagine a great big downpipe tucking under the frame and I like it even more!

Post by **AlisoBob** » April 15th, 2011, 11:24 am

Gmbond wrote:I love the look too!

Just imagine a great big downpipe tucking under the frame and I like it even more!

X2

Pony · Post by **Pony** » April 15th, 2011, 12:05 pm

Gmbond wrote:I love the look too!

Just imagine a great big downpipe tucking under the frame and I like it even more!

Thanks guys. My watercooled cylinder is roached. I have no idea what I want to do. I want an AF bike really bad, but am financially way closer to having a cool bike to thrash around on back roads with. Who knows.

My main hurdle that would not carry over to an AF is going to be building a bitchin downpipe for this thing. I have read all kinds of info on pipe building and am kinda intimidated by it, but I kind of want to tackle this because I cant afford to have one built.

I purchased a program called "2 stroke wizard pro 3" and it is supposed to compute a pipe design based off of motor, desired power characteristics, port size ect. My plan was to have this program design my expansion chamber, build it in CAD, then print templates to cut my sheet metal with. Once that was done tack it together on on the bike make sure it fits then take it to a welder to finish it off so I dont warp it and pull it all over the place with heat.

Anyone have any experince with pipe building or using this program? would this be how to tackle it?

Nodge · Post by **Nodge** » April 15th, 2011, 1:06 pm

I would bet a good welder could modify an old high style factory pipe to go under the frame.
Cheap and effective. The old style stock pipes always ran the best in my experience.

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CR500 Cafe project