Motorrads Jeff Ward engine build series 2

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Out riding around today....

Didnt even feel like I was stringing her out... Still had more to offer!! evil

MUCH BETTER THAN BEFORE EH DOUG!?

Motorrads Jeff Wards Engine build round 2 9-99999-7.jpg (80.8 KiB) Viewed 7403 times

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Just drawing up a "spec" wish list at this point on a custom Wossner...

longer exh skirt.. so I can drop the exh floor.... window, light weight, fix transfer port area, debating on domed or flat top..

If I do do a run of them though.. it WILL BE 88mm.... as I want to pursue a 88x88 motor... I think it will solve many issues that are already in the K5 motor just by doing that..

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Just got back in town from Pre-running...

have been out since thursday night.. (its now sunday night)..

there is a race comming up here local in a week and a half (ish)..

Good things on the bike... Jetting is CLOSE CLOSE CLOSE... and she is making lots of POWER POWER POWER.. evil


The forks I are acting up a bit... like I didnt center them when I tossed my dirt wheels back in... (forks bound up)..

But besides that.... My K5 is still KING OF THE DESERT...

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Checked my notes doug (home now not eating a cheeseburger)....

178M 60P stock needle #4 slot..

It was cold and wet out.. so under normal conditions Ill probly end up at a 175...

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I used my awesome paint skillZ to get rid of the mis match wheels

Motorrads Jeff Wards Engine build round 2 9-99999-8.jpg (71.12 KiB) Viewed 7403 times

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AND NOW for tomarrows project while at work ... afro

reed stuffer from a 2004 kx250 layed ontop of a cut rad valve..

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Ran a bunch of math... and the stuffer is the same volume as 38MM hole (carb)..(SHOCK thats what the 2004 Kx250 came with carb size)... so Im going to take some off the edges to get it out to 39mm worth of volume... then BUILD UP a s**t TON of weld on the Rad valve... so I can make the RESTRICTIVE hole in it match the reed stuffer from the 2004 reeds... Blah Blah Blah....

Volume wise... SAME SIZE HOLE from carb mouth to reed tip...

should get Intake velocity up a BUNCH A MUNCH...

Even though the hole is a bunch smaller than stock Kx500... the 39mm Keihin will only flow so much CFM's so should the rest of the reed block etc, as its setup for the same size carb, and volume wise (I know not exactly always the best determining factor of CFM rate) its the same all the way through...

My only worries,

#1 Not being as wide, it may starve the boost ports. But many members used to run the kx250 Vforce with good results, so why not..

#2 volume loss due to narrow reed (crank case volume).. perhapse not a big issue on my bike with the stuffers, also the smaller intake trac may make up for it...

#3 If the reed setup shows promice I can machine some delrin "stuffers" to bolt to the cage to fill that extra volume...



am I missing anything here?

Oppinions? thoughts?

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I think KawRider may have hit it on the head back on page teen somthing..

KawRider yeah why do people think you need a 46mm hole for a 39mm carb.

Motorrad
Id be interested to hear your thoughts on the bored to 39mm rad valve up to the Kx250 reed cage Larry.. VS a stock Kx500 cage

I know that reed doesnt have the Face area that the K5 one does... but it may not be an issue for a Non Drag motor

Larry Wiechman

Locking the pipe parameters will limit tuning options.
Consider the effect of exhaust port duration (EO) on tuned pipe length (TL).
TL = EO*1700/RPM
42.5 = 200*1700/8000
41.4375 = 195*1700/8000
That's an increase of 1.0625 with only a 5? decrease in total duration. About .078 lower port.

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no one has any thoughts on this?

its way backwards from what everyone is doing... (big carb big this, big that)..

But My thoughts... if the transfer tunnles are already known to be too big... (they goofed).. then like Kawrider said... why do ya need a 46mm hole after a 39mm carb? I measured the reed tip area today on the 250 reed's... not much differant than the 500 ones.. due to less dividers.. I realize that this wont be making power at 9000RPM etc that everyone is fairy tail chasing (drag guys and hill climb guys I know.).. But in the desert if I can make more power at 1000RPM lower than everyone else without giving up too much up top...... Im faster..

Perhapse it wont work.. but I have to try it..

Same size hole from carb mouth to Reed Tip is good in my head...

The carb signal will be good, and there wont be all the dead space to pull before it starts sucking on the carb... so perhapse a more compleete fill...


I cant count the number of times in the Car world I have had to fix guys mistakes of over carb/intake motors...

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81cr450

Definitly some sound logic in not over carbing a motor ,but I would wonder about it with the thought that a 250 can run a 38mm & still be smooth. If a 500 only turned half the rpm then bingo thats the size. If you look at a banshee with a 175cc cylinder 36mm carbs are the sweet spot. I think Larry's coment on playing with the pipe might be more likely as to getting the tune set where you want it. I ran a low pipe on my kx525af build "cr500 gnarly" & it didnt seem near as good as down low the stock kx500 with a fmf gnarly. Like the 86 cr500 I'm riding now, part of their magic was room for a fuller length pipe. Thats why I'm trying a topend cr500 pipe for the af this go round. I do like the idea of keeping the intake tract the same diameter all the way down, but I'd still vote bigger. Maybe epoxy stuffing the transfers to get the pressure of the charge up, it will certainly help feed the lower end power.

Or bigger bore & stroke to help make the transfers the right size evil

Motorrad

Like I said before... I realize the pipe is an issue on the K5.... it always will be... and I have chosen to work within the perameteers of my pipe... being it was the last new one avail... EVER... and I love the Tank that goes with it, for desert race...

Mine are already stuffed (JB welded) (transfers)..

Going to play with Bigger Bore and stroke later on.. evil

But a 39mm hole has roughly
1194mm?

The 250 reed stuffer has roughly
1139?

So with MINIMAL massaging... it is the same size..


If you all know anything about V8 chevys... Ill take good intake velocitys over BIG CARB'S any day of the week...



if it shows good promice..

I will be testing this next.

http://www.cokerraceproducts.com/CRP-Di ... ngPdf1.pdf

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Oh... BTW... what does the inside of your wifes dishwasher look like?

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Changing Jugs... and Pistons..

Found the 2nd machining flaw in my wiseco piston.... (yep 2 in one piston)... not happy.. that was causing my ring seal issues..


Going 88MM steel sleved jug (what I got).. (was going to go with 90mm, but ended up with a 88mm piston, so... gunna use it since its already here on the bench.)

Have some porting ideas I want to try with a sleve first before I dork up a good alum CLY...


Just pulled it off the mill.... Ran a Flycutter over the top.. to go with a ZERO deck hight...

all transfers etc are now ported etc how I want.. now I need to focus on the exauhst..


ALso going to put this 88mm piston on a Diet.. its a PORKER... weighing it at 446g (WITH A WINDOW CUT IN IT!!!)

after that it goes off to swaintech for pc9 skirt coat and Gold coat ceramic top coat....


Not exactly the route I wanted to go... as I was honing in on a good setup with the 86mm and other jug...

But Going this route I wont have hardly anything in it as its all here on the bench already... vs buying another piston, etc etc... so $$ was the determining factor in the decision...