2005 stroker questions

[flint250trx]

Wll just found out my crank in junk so i got a steal on a +3 mil stroker crank for the 05 450r. I was wondering what pistion and compression you guys recomend with this crank. I will be doing mainly MX racing at the local track. I would like to stay away from a full race fuel bike 50/50 wouldnt be bad. Any input you guys have would be great. I am also sending the head out to ken oconnor racing for porting and valve work.

Any input would be great

Thanks

[deathman53]

correct me if I am wrong......but a stroker in a 4 stroke shouldn't make any difference in timing, compression or power delivery, as it would in a 2 stroke greatly. So you should be able to stick with a 12:1 piston and you will have more displacement and not mess with anything else. Longer strokes tend to have more torque and not rev as fast, thats as I understand it.

[lightning_2000]

Originally posted by deathman53
correct me if I am wrong......but a stroker in a 4 stroke shouldn't make any difference in timing, compression or power delivery, as it would in a 2 stroke greatly. So you should be able to stick with a 12:1 piston and you will have more displacement and not mess with anything else. Longer strokes tend to have more torque and not rev as fast, thats as I understand it.

Piston speed. People tellin me same stuff. I don't get it. 393 in my truck makes killer power. But I've read on a 450r u will have low end power. But not as good a top end

[deathman53]

now think about it, who really makes the most of their bike to use ALL of the top end power. Most of the time we spend in 1/4-3/4 throttle. How often are we banging on the rev limiter when riding??

[01boneless]

not sure on your other questions but make sure you send that to crankworks to be ballenced other wise you will have mad vibiration and the bearings could go bad fast some have got away without it but i wouldent chance it.

[flint250trx]

Ya i will be sending it to crank works for sure to have it balances and possible lightned. Waiting to hear back from a few people on head might go with a different builder not quite sure yet.

[D Bergstrom]

The +3 crank will add a bit to your compression ratio, around half a point or so. Taking more volume, an extra +3 mm of stroke and compressing it into the same area as before.

As far as balancing, I don't feel it is required. Sure, if you have the extra money/time do it, but as far as I am concerned, you won't have a time bomb if you don't. For sure use OEM crank main bearings though, I wouldn't trust the Hot Rods bearings.

I installed a +3 crank in my 2005 450R back in 2007, didn't do anything to it, just took it out of the box and installed it. Quad has more hours on it then I want to think about, thing runs strong. Yes, is has had a feew top ends over the years, but the crank has not been touched. Desert, dunes, and sometimes a race, just can't kill it. The quad has a little more vibration then before, but not much. the only reason I notice it is because my other 450R has a stock crank, so switching back and forth it is noticeable, but its not bad. I would install another without it being balanced and sleep just fine at night.

Doug