Older engines Vs. New?

boostdoctor · Post by **boostdoctor** » October 16th, 2009, 7:46 pm

Roostius_Maximus wrote:i'm going to say its way easier to ride the long rod engines, the short rod one in my '88 is so dammn rangy its hard to know where the power is coming in, but when its extended for on the hill its revvedup for clutch dump anyways. I know that if i want a good scare i get on the field with that bike and no extention. i might hate the short rod in an AF, but it should be tried, and then i can switch the 525 jug to a long rod + tall deck case if i need.

So, I'm assuming that a 525 is a 92mm bore. What piston and sleeve are you using?

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » October 16th, 2009, 8:10 pm

i'll get you a part # for the piston, its a wiseco made for a rotax aplication, have to modify the intake window + cut some off the skirt to clear the case windage, also to use a stock stroke the jug must be cut on the top + bottom to bennifit on port timing + correct for the pin height difference of 4mm, of course a guy could just add stroke + run it bigger but i dont want to get too much $ tied up in it. the piston is special order as qty of 8 from wiesco, so if i screw it up i want to just slam another stock spec jug on the cases + ride.

I didnt really give up on the 550, its just that i'm building that '81 cr450 to run in the 450cc class and that'll take up this winters build fund. going to run a 2002 seat,tank+shrouds, probably stock '02 250 pipe + silencer to try, the stock 81 stuff is shared with the 250 of that year aswell as the reed +carb.

The cuz is going to be arround for a few climbs, but i hardly rode my af, the '87 went out the lane and back a couple of times, the '88 got an early spring ride, the '00 an afternoon at the fordville climb, and the '99 3 rides. might aswell use up some spare honda stuff to finish this bike + do another to use up the extra engine before steppin into a ktoom

4Z · Post by 4Z » October 17th, 2009, 7:01 am

boostdoctor wrote:
Roostius_Maximus wrote:i'm going to say its way easier to ride the long rod engines, the short rod one in my '88 is so dammn rangy its hard to know where the power is coming in, but when its extended for on the hill its revvedup for clutch dump anyways. I know that if i want a good scare i get on the field with that bike and no extention. i might hate the short rod in an AF, but it should be tried, and then i can switch the 525 jug to a long rod + tall deck case if i need.
So, I'm assuming that a 525 is a 92mm bore. What piston and sleeve are you using?

Now there's the right question!

boostdoctor · Post by **boostdoctor** » October 17th, 2009, 10:08 pm

Roostius_Maximus wrote:i'll get you a part # for the piston, its a wiseco made for a rotax aplication, have to modify the intake window + cut some off the skirt to clear the case windage, also to use a stock stroke the jug must be cut on the top + bottom to bennifit on port timing + correct for the pin height difference of 4mm, of course a guy could just add stroke + run it bigger but i dont want to get too much $ tied up in it. the piston is special order as qty of 8 from wiesco, so if i screw it up i want to just slam another stock spec jug on the cases + ride.

I didnt really give up on the 550, its just that i'm building that '81 cr450 to run in the 450cc class and that'll take up this winters build fund. going to run a 2002 seat,tank+shrouds, probably stock '02 250 pipe + silencer to try, the stock 81 stuff is shared with the 250 of that year aswell as the reed +carb.

The cuz is going to be arround for a few climbs, but i hardly rode my af, the '87 went out the lane and back a couple of times, the '88 got an early spring ride, the '00 an afternoon at the fordville climb, and the '99 3 rides. might aswell use up some spare honda stuff to finish this bike + do another to use up the extra engine before steppin into a ktoom

So basically...the cylinder wouldn't need much machining if used with a long rod in a early case?

Nice projects. Keep us posted with your progress.

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » October 18th, 2009, 9:19 am

the rod wont effect the jug at all, the pistons pin height is the snag, going to have to cut the jug to sit the porting down lower and match where the piston is at the bottom of its stroke.
I'd like to make it rangy like unreal with a shortrod, but expect too much skirt load at that bore size, and the -4 pin height could easily get the piston in the way of the crankwheels with a shortrod, which i havent even looked at yet.

xtremeslide · Post by **xtremeslide** » October 20th, 2009, 9:22 pm

This is the kind of post i like keep on giving info

Mik329 · Post by **Mik329** » October 21st, 2009, 6:04 am

My 85's hurt me a few times with the sudden burst of power, I did just come off a 250 and was still riding the 500 like that though. lots or rear fenders and bars that year..lol my 86 was a little more tame and by the time I got to 88's, I was looking for more power.

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » October 21st, 2009, 6:06 am

525 piston on the right, pinned with a new style standard bore wiseco.
the 2 small piston ports will be opened larger + the intake window needs to be 1/2" taller yet too. its 484 grams un modified, will be about 6 grams lighter, maybee more if i get creative

dannygraves · Post by **dannygraves** » October 21st, 2009, 8:32 am

that window is in the perfect spot too, just open that bitch up!

100hp honda · Post by **100hp honda** » October 22nd, 2009, 2:23 pm

why only 525 brotha ? i can see the part of not wanting to invest too much money but you only live once. whats that saying- go BIG or go home

. i thought of something similar for mine a while back but i wasnt going to fool around with anything under about 540cc. eventually i said hell with that idea and got the ktm instead. either way good luck. sounds like it should work fine

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » October 22nd, 2009, 4:13 pm

It could deffinately be stroked, I have a crank that needs rebuilding too, and I wouldn't need to cut the jug but space it taller and I think it got to 560cc.
I have a set of cases that could be modified too, but then there's the $ end of things.

I'd have to build a pipe, bigger carb, different air intake, all that.

Here I'm recovering the use of a jug I have that otherwise needs a sleeve, if I scuff this piston that's special order in batches of 8, that's 1300$ for another to make that queer stroke deal work, if this combo that will run ok on a gnarly + bored carb, all I gotta do is thro another jug on the standard cases+ run it same day kinda thing

Post by **AlisoBob** » October 22nd, 2009, 4:16 pm

Your only going to get so much air through that single reed block.... at some point, adding cc's isnt going to matter.

Look at the flow area of the TWO Banshee reed blocks (feeding 350cc's), compared to the single 500 one....

Your hitting the wall....

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » October 22nd, 2009, 4:33 pm

That's right.
I have a big pair of rotax mikunis too + looked at modifying the jug to take the 1000 rotax intake that's a fair bit bigger.

dannygraves · Post by **dannygraves** » October 22nd, 2009, 7:15 pm

yeah, 500 intake and reeds are tiny by comparison only because the motor wasn't designed for high rpms

gregrobo · Post by **gregrobo** » October 22nd, 2009, 9:13 pm

not enought air flow you say has anyone done any flow bench work on a standard barrell to see how much they do flow can it be done i have no experiance with that sort of stuff so i dont know if a 2 stroke can be flowed

dannygraves · Post by **dannygraves** » October 22nd, 2009, 9:59 pm

glen says he flows them, everyone else says they cannot be flowed...
look at a cr250 reed block compared to the cr500... the 500 isn't much larger.

britincali · Post by **britincali** » October 22nd, 2009, 10:06 pm

You dont need huge intakes when running some kind of forced induction

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » October 23rd, 2009, 6:07 am

word is a new superflow SF-450 was loaded on a truck yesterday and is headed north

http://www.superflow.com/Flowbenches/sf450.html

dannygraves · Post by **dannygraves** » October 23rd, 2009, 8:08 am

britincali wrote:You dont need huge intakes when running some kind of forced induction

nmdesertrider · Post by **nmdesertrider** » October 27th, 2009, 10:30 pm

When you guys figure out how I can make more uncontrollable wheelspin let me know.

britincali · Post by **britincali** » October 27th, 2009, 11:42 pm

nmdesertrider wrote:When you guys figure out how I can make more uncontrollable wheelspin let me know.

Nitrous and a knobbie.

Simple as that.

Disturbed · Post by **Disturbed** » October 28th, 2009, 4:46 am

I think my 87 was faster then the 97, both in a conversion. Funny though, the 87 is for sale in great condition but people are hesitant to buy/use it in an AF because of the tight plumbing.....

dannygraves · Post by **dannygraves** » October 28th, 2009, 8:14 am

tight plumbing, carb boot, kicker, corroded waterpump housing and smaller rear bushings...

Disturbed · Post by **Disturbed** » October 28th, 2009, 8:35 am

My AF carb boot/fit swaps between the 87 and 97 no problemo, Kicker [Ccurrent model] hit peg at the bottom but the kicker on my 97 hits the break pivot bolt, water pump housing is good, motor was rebuilt last winter and the rear bushing has been enlarged for current steelie or conversion fit.

dannygraves · Post by **dannygraves** » October 28th, 2009, 8:52 am

and this motor is for sale?

BannedCR500Riders.com

Older engines Vs. New?