big (huge) valve stock xr 80 head

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storminnorman07

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like most of my ideas either GDFP whispers sweet nothings in my ear or chit talking with buddies. this idea was chit talking with buddies. two of my buddies have takie heads for their xr's. after a few adult beverages the fun began. "chad, i love how you have to do a special motor so you make sure your motor is faster than ours i'm going to laugh when we all go to the dyno and our takie xrs out dyno your mutant" after this statement from one buddy i blurted out oh yeah ill take a stock tail dragging 80 head and make it beat the snot out ur high dollar takie head now what ya gotta say about that. after alot of chit talking back and forth i decided i wanted to try it and at the time my mutant was pissing me off so i went for it.

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stock seats and valve sizing worked combustion

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i didnt want the big clunky 5.5mm stems so i made my own guides for 4.5mm stems

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after seats where installed no cutting

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anyone need their horse bathed?

after some roughing work

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gives you a idea just how big the intake is. thats a 25mm valve vs the stock xr's 24mm and the bowls havent been opened up yet
 
did a lil weighing in tonight see what difference there is between the oversized valves vs the stockers. not great but not bad still have to shorten stems to get proper valve protrustion and installed height so i should lose a lil more. if i end up going ti valves should prolly be in the neighborhood of 18-19grams on intake and 14-15 grams exhaust. did see some nice weight savings on the springs though ;-)

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oversized intake
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oversized exhaust
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stock xr 80 intake
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stock xr 80 exhaust
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new valve springs for os valves
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Head gasket area doesn't look as bad as I feared. You moved the bore center-line forward a couple mm?
 
I think there's a 35.6mm APE 50 crank here for the taking, but it doesn't work for the 125. Might do a 110-class asphalt build, next? Lifan BVH with a filled floor?
 
so this what im thinking about doing with my bv head. what do you think terry? those are the only bearings i had and i wanted to see what it would look like so i hacked up a cam. but i would ultimately use the bearings you and i discussed when i first got on this bearing trip turn the cam down like the below pics and line bore head and cam take a couple ths off the cap for a nice huge on the bearings. for cam gear i havent decided. im really digging the idea of keywaying the cam and cam sprocket holder drill and tapping cam and bolting it on. other option would be press fit with a lil stich here and there.
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I think you're on to some thing, Chad. I like it. Obvious bearing sizing aside, it sure would free up some juices for lobe lube. Saving a trashed head, especially one with some work in to it or fancy Japanese writing cast on the side, is a swell side effect. Keying it would be trickier, unless you went broach shopping. I know your tooling budget exceeds the GNP of most 3rd World nations;)
 
I think you're on to some thing, Chad. I like it. Obvious bearing sizing aside, it sure would free up some juices for lobe lube. Saving a trashed head, especially one with some work in to it or fancy Japanese writing cast on the side, is a swell side effect. Keying it would be trickier, unless you went broach shopping. I know your tooling budget exceeds the GNP of most 3rd World nations;)

Lol I can't help im addicted to buying tooling. I go to meetings on a regular basis. Hello my name ia chad and I have addiction to buying tooling just don't seem to be working....lol all the pin talk and grinding I may or may not of placed a bid or two on a dumore tool post grinder. That cutting is overrated on that hard ****
 
Great work Chad, you and Terry remind me of Burt Munro in the fastest indian ... I'm assuming you both saw the movie in your formative years lol
 
Step 1: We have come to realize that we powerless over sharp, shiny things. Our tool crib had become unmanageable.

Yeah, modding the stroker pins to destroke for my 125cc National kids made me want some more aggressive cutting tools, but my little Jet 9" doesn't have the arse to hang that much bit out there any way. Slow and steady, similar to my riding. Except the steady part. I did three KLX flywheels last night after dinner and was cursing not going with a 14. Dunno where I'd put it, or how I'd afford it, but still. It sure would be cooler to have some fat blue curlers searing in to my left wrist instead of a bunch more little ones leaving their dots:mad:



Dready, I was 39 when the movie came out. Pretty much in my current form by then. Round and cranky:)
Super cool early engineering, though, and an inspiration for my own LSR efforts. Still want to see yer dreads flapping in the breeze at over the ton. Maybe we can do a Rollie Free-like set of pics, too. The magazine editor that's sponsoring just got a new giant lens.
 
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I even have a similar carnage shelf. Not as extensive or well-documented, but there are some beauties on it. Chad's starting to get a tidy collection of "Well, THAT didn't work" artworks.

I suppose I should start some photo documentation of my attempt. Without further buggering Igor's thread;)
 
Step 1: We have come to realize that we powerless over sharp, shiny things. Our tool crib had become unmanageable.

Yeah, modding the stroker pins to destroke for my 125cc National kids made me want some more aggressive cutting tools, but my little Jet 9" doesn't have the arse to hang that much bit out there any way. Slow and steady, similar to my riding. Except the steady part. I did three KLX flywheels last night after dinner and was cursing not going with a 14. Dunno where I'd put it, or how I'd afford it, but still. It sure would be cooler to have some fat blue curlers searing in to my left wrist instead of a bunch more little ones leaving their dots:mad:



Dready, I was 39 when the movie came out. Pretty much in my current form by then. Round and cranky:)
Super cool early engineering, though, and an inspiration for my own LSR efforts. Still want to see yer dreads flapping in the breeze at over the ton. Maybe we can do a Rollie Free-like set of pics, too. The magazine editor that's sponsoring just got a new giant lens.

ha ha i know what you mean would of loved to have a dedicated lathe and mill but simply do not have the room. since we are dreaming make them both cnced ;-) lol slow n steady never worked out for me i'm more the fast and out of control type of guy. with any luck i'll win this bid on the tool post grinder to help aid in my fast and out of control ways.
 
I even have a similar carnage shelf. Not as extensive or well-documented, but there are some beauties on it. Chad's starting to get a tidy collection of "Well, THAT didn't work" artworks.

I suppose I should start some photo documentation of my attempt. Without further buggering Igor's thread;)

aagh yes in deed not to found of that art gallery of mine. bad art if you ask me..lol but hey cant push limits if you dont fock up a couple a things on the way. lots of well that work out like chit and the few now thats purdy are well worth it in the end :)
 
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