big (huge) valve stock xr 80 head

[storminnorman07]

well boys the bv xr 80 is all done. now time to start putting the thing together ;-)

valves in

ports

springs installed

comparison stock vs mod

 

[The_GDFP]

Beautiful work, Chad. Again

Tak has a forged 61mm to match a 41.4 6v crank, and a 59.4 to max out a stock 12v 45mm stroke. Clayton and The Mile both are tougher on head gaskets than a couple of chubby dirt-draggers.

If an idea strikes on getting that 50mm Tak wide enough to fill the cases, 56 bore still has ring flutter up over 14k. Minimum bore size, while keeping some meat outside the pockets? Where do you see the BV floating, if at all?

Have you & the guys got a St3 or +R that's not on a motor, to flow, compared to the BV? Oh, and we're building a flowbench next. If you're getting tired of digging holes and filling them back up..

I just got word that Clay's motor is being hand-delivered from Peoria shortly, and pops is taking the FPM crew to dinner. That state champ trophy has him pretty pumped:first: He won every race this year, but the first two, and those were the first rides after last year's double-arm-break. But, the ****y little bugger is gonna race against the 2-strokes next year on his conversion, so I gotta find him some more up top. Big britches, for a 10 year old. He didn't tell me that until after mentioning steak.

 

[storminnorman07]

ill let you decide bore x stroke since you have been dealing w/ clay for a while and have a good understanding what he likes. keep in mind head has been decked 0.171"/4.35mm. when i first got on this xr kick you was saying these lil puppies can twist 14g's with very lil work so i sprung for 14grand. if it needs to ring a lil heigher thats possible with ti valves. heres what the weights of everything are

stock valve train
IN- 23g
EX- 19g
valve spring with retainer- 44g

new valve train
IN- 26g
EX- 19g
valve spring with retainer- 32g
overall weight savings from stock- 21g
potential rpm increase from reduction- 735-840rpm

if TI valve were used

IN- 15.6g
EX- 11.4g
overall weight savings from stock- 39g
potential rpm increse from reduction- 1365-1400rpms

no both the ST3 and R head are on the boys bikes and they are hell bent to get to the dyno with my mutant when its done. so i dont see either one letting me yank one down for flow numbers. *knock on wood* luckily all the holes i have dug havent needed filled all showed gains on the dyno and felt those gains trackside. lol see if i owned a flowbench and a dyno no one would ever see me again i'd constantly trying new things. everytime i go get something dynoes i tell myself 3-6 passes and your done nothing else. well mike from lukesracing is cool as hell. we get to talking then it ends up sounding like one of our convos well what if you do this? hell i dont lets try it. and before i know it i have been there 6 hours trying off the wall chit.

thats awesome! do they do any indoor stuff during the off season? lol the ole man and the kid knew how to get ya. get you side tracked with a nice steak dinner then sneak in the Ooo by the way we are going to butt heads with the 2 smokes next year.

 

[Cactus Jack]

Excellent work ! ...

 

[The_GDFP]

14 is plenty. Use what ever works out, run with it, Igor. He's got a proven combo for points races

I'd like to see if he's able to make a right turn, and get him on the indoor kart track, if mom isn't afraid of cement. Speeds are way down compared to the 1/2 mile, though. WAY down, for me. lol

 

[storminnorman07]

and who says you cant put oversized valves in a 80/100 head and have sufficient valve to valve clearance on over lap with web 68/69 ;-) not 100% yet but im pretty sure i can cram web cams big boy cam or a takegawa grind in it.

 

[storminnorman07]

heres what im working with now terry.

dancing around that exhaust stud worked out idea. now the chain just fits with the 100 cam sprockets. so ill prolly take another .005 out of it for a lil chain slack

completely stock 100 crank piston sits 2mm in the hole. but thats with the 13mm pin so it will lose 1/2mm

 

[The_GDFP]

Awesome. Wanna do a Tak Twin-Spark-type tube in the other side for a decomp? You're making it too easy on yourself with this one, so I'll try to toss a curve in 63 bore should go 51 stroke, to stay under 160cc, tooo. BaaaHaaa!

 

[storminnorman07]

Awesome. Wanna do a Tak Twin-Spark-type tube in the other side for a decomp? You're making it too easy on yourself with this one, so I'll try to toss a curve in 63 bore should go 51 stroke, to stay under 160cc, tooo. BaaaHaaa!

Lol this one is pretty simple huh. Still hell bent on the decomp? 51 stroke prolly wouldn't be bad to do either. Make two bushings 26mm od X 25mm id press in 100 crank the press pin add 94mm rod from yx 57mm slingless crank and presto no spacer plate no fighting with chain plus one hell of a sleeper motor. I used a haggered looking jug so when someone looks at it they will think of its stock can't make that much power ;-)

 

[The_GDFP]

Haaa. OK, so maybe this one's not TOO easy Just gotta keep you on your toes.
I'm sure I have a stock 100 crank and a 26/25/26x3 pin and plenty of 94mm rods. YX needs narrowed up. Got a few around, though. Decomp? Yeah, my knees are ragged, and Clay hasn't broke 40kg.

 

[The_GDFP]

Sending a care package, today

 

[storminnorman07]

Sending a care package, today

sweet! full of extra brains a limbs and hearts to give life to this bv stocker? lol

 

[The_GDFP]

Yep. Hadda find a bigger box, though.
The usual medium flat-rate wasn't gonna do, this time
Searching for the other half of the bearing. Don't wanna make you work too hard on this one. Other stuff is pressing. *insert maniacal laughter*

 

[storminnorman07]

o the decisions the decisions keep it fair playin field of the two takie headed xrs or go big ;-)

 

[The_GDFP]

Well... If you wanna be like that, the parts in the box can be redistributed to provide 201cc:rockon:
63x65 does sound fun. It's 5AM, so I'm not doing the rod/chain math on that, right now... lol