Short Stroke Engine Idea...

Message

thedeatons · #1 Post by **thedeatons** » Fri May 02, 2008 7:20 pm

Hey guys.... I don't know if this has been discussed before, but I was wondering your thoughts on a short stroke Dale engine with a 460 piston.

Essentially instead of moving the crank pin in the direction that would achieve a stroker, you would move it in the other direction. That in conjunction with a Nykasil CP (460 size, can't remember the mm) should equate to a quick revving little power monster... Correct?

Even if it still worked out to a 432 (or so), it would rev really quick and have great top end.

Any thoughts on this? Does the idea have potential?

claas900 · #2 Post by **claas900** » Fri May 02, 2008 9:27 pm

Do you have a reason for wanting to stay at 432cc? The 460 piston is a 98mm bore last that I knew Tim didn't offer a 98mm Nykasil CP,thats only on 97mm and I think 95mm kits 98mm is a steel liner. At one time I had a 98mm on a stock stroke it revved very nice I liked it a lot. How high are you wanting to rev it?

thedeatons · #3 Post by **thedeatons** » Fri May 02, 2008 9:49 pm

I don't really have any parameters for the idea as far as a rev ceiling or hp requirements. I am more concerned with whether it would work and whether anyone had tried it...

Tim has a 450CP and has offered a 460CP in Nykasil to me before, but said they are special order.

I don't care if it is a 432cc, perhaps you misunderstood... Basically the new "shorter stroke" and that size piston will work out to some cc value. Whatever that is doesn't matter.

I was just thinking:

1) Shorter stroke = quicker revs
2) Biggest Nykasil liner/piston = more power to make up for shorter stroke...

wistech · #4 Post by **wistech** » Fri May 02, 2008 10:42 pm

I reality the stroker cranked engines rev faster than the stock stroke. If you have run a 505 or just snap revved one you would clearly see it. They can hit the rev limiter before your thumb hits the throttle stop. The stock stroke cranks however can tolerate higher revs as we have proven 12,500 is doable without failure. All the strokers start exceeding maximum safe piston speeds around 11,000 rpm and almost all of the stroker maps are around 10,500 for safety . This would be a good project if you wanted to compete in the 400cc class. I could see getting 50plus hp out a downsized dale where trying to get that kind of power out of a z400,400ex would be near impossible. Then if going with the titanium valve train I would think a 13 to 14k engine would be a hoot. I wonder how radical the cam timing would have to be for that. I will never know since that type of project would be a lot of cash and time I dont have.

cannondale27 · #5 Post by **cannondale27** » Sat May 03, 2008 1:34 am

Timbo is building a Destroked crank for Wayne Schofield right now as far as I know.So we should find out how it works soon.

thedeatons · #6 Post by **thedeatons** » Sat May 03, 2008 2:01 am

AWESOME! Do you know what piston he is running?

cannondale27 · #7 Post by **cannondale27** » Sat May 03, 2008 2:35 am

I believe stock.He wants it for his boy.Attempt to tame it down.

jesshamner · #8 Post by **jesshamner** » Sat May 03, 2008 2:43 am

So could we get a motor that could compete in the gncc sport class with the new 400cc limit?

thedeatons · #9 Post by **thedeatons** » Sat May 03, 2008 4:14 pm

I'm guessing this means there is interest... LOL....

wayneschofield · #10 Post by **wayneschofield** » Tue May 06, 2008 11:00 pm

The intention was not really to build a short-stroke so my lad can rev the spuds off it and make lots of top end power, more a case of making it un-burstable. A lot of the 'dale problems are vibration related and reducing the stroke would reduce the piston speed and thus, the vibration. Add to that lower comp and less cc for easier cranking etc....

I was wanting to build a motor for him that will last well, despite his best efforts to break it. It will still be fast enough, he's only seven stone wet-through!