So ya think ya need a stroker crank eh?

[wistech]

Heres the quiet core /spark arrester fmf (red) vrs the open straight through fmf (blue)

[claas900]

A Few years ago when WWE was into it I had a stock stroke with just a 98mm piston,stock head. I thought it ran perty good for just a piston. If i ever built just another motor i think id go with just a 98 piston.

[wistech]

Now the bad news. As CWR has proven you cannot hardweld a cam and run it that way without hardening it. The intake was a stocker that was hardened and coated. The prototype was just hardwelded and ground to new specs. After 20 minutes of breakin the exhaust already had wear and galling started on one lobe. I decided to go for max power right away and break it in on the dyno before we started to lose lift. It must not have worn much because power continued to climb right up until the last run.

We also had an issue with a crack in the headpipe affecting afr at low rpm. I installed a new air tube all the way up the headpipe past the crack just a few inches from exhaust port and that solved that issue.

I was also not allowed to use straight u4 fuel but had to mix it 50/50 with 110 . The compression on this piston is as high as my SAS . Tim would know for sure . I chambered the head more than usual to drop it down some. I was not fond of keeping the rev limiter down below 11,000 either. But there again Tim is such a worry wart.

The charging system was not used . As we have learned from the last dyno day at least 1/3 hp can be gained without the stator hooked up. The quad ran off the battery .

This engine also warmed up slower than most and cooled down faster than most. After richening up the map trying to fix the afr with the leaky we ended up going back the other way and leaned it out in many spots especially around the 5000 to 6000 rpm area.




Now for the entertainment section of our program.

In the graph below is a chart of a dual chambered Fleet Farm tractor muffler on the fmf headpipe(red) 46hp

The green line is a straight through Fleet Farm tractor muffler . It actually sounded good. Hey Steve looks like the tractor muffler beat out my gutted toaster,your TC muffler, and your BlackWidow . 52 hp for $19 not bad. LOL

The blue line is the FMF system.

[cannondale27]

You know looking at some comparisons there is a reason to get a stroker unless all you are going for is peak hp.

[wistech]

Ah yes the man behind the curtain.

[wistech]

This engine was a design study to see if the 30ft pound barrier could be broken. Something no stock crank or falicon has been able to doon a regular basis . At 34 it pretty much smashed through. Id say this pretty much proved big torque and over 50 hp is possible without having to stroke the engine. Albeit it takes more rpm to do the same job than the bigger engines. Just wait till we apply this setup to a 495 or 505. Ill bet 65hp will be within reach shortly.

[ANIMALSCANNIBAL]

QUOTE (wistech @ Nov 18 2006, 09:20 PM) <{POST_SNAPBACK}>

Ill bet 65hp will be within reach shortly.

Ah, the game is ON.lol

[cannondale27]

Yeah can you imagine that setup in a big motor!

[wanablaze]

Hey Wistech,
Stock stroke, you should be able to run 12,500rpm rev limiter. (I wouldn't).

I'm hoping that the prototype cam is what made the power peak higher than previous stroker motors.

[ANIMALSCANNIBAL]

Wistech quote "This engine was a design study to see if the 30ft pound barrier could be broken. Something no stock crank or falicon has been able to do."

stock ported 432cc 12 hr race motor.Red open box & not tuned.Blue stock box tuned.
cr 12:1