Sonic by Selvy?

[disco]

The Jug you bolt onto your bottom end to turn your 250 to a 500? Thoughts? Do they work? What piston does it use? Anyone ever run one? Is there a downside?

[Duner]

The Jug you bolt onto your bottom end to turn your 250 to a 500? Thoughts? Do they work? What piston does it use? Anyone ever run one? Is there a downside?


The jug you bolt onto? You referring to a Sabertooth cylinder?

[bryan raffa]

he's gotta be referring to that..raced many lost tons of times,, but I also didn't have to pick my tranny up off the track ...Twice in one season...:thmbsdwn:

[disco]

Doesn't say anything about Sabertooth on it. Was told it bolted right up to an 85-86 lower end. What's the word? The bottom won't live?

[Duner]

Doesn't say anything about Sabertooth on it. Was told it bolted right up to an 85-86 lower end. What's the word? The bottom won't live?


How about being a little more clear on what your asking...there is no 500 that bolts up a 250 bottom end unless its a Sabertooth....

[NOS_350X]

Well Cory, a Sabertooth, and ProX arnt the only big bore kits around. It woudnt suprize me if Slevys made there own, (or had them made) They did it for the 200cc bikes why not a big bore. Also i know PSI had a +400cc kit with the "dial a dome" head. Who knows whats lost in the ages. Brian, You can call me, ill try and help ya out. Really though, need some pics, bore sizes, stuff like that.

[Duner]

Well Cory, a Sabertooth, and ProX arnt the only big bore kits around..


I agree. He did say "250 to 500" though...and only the Saber can achieve that right now.

[Mr. Kasey]

just because he used the word selvey leads me to believe he is hiding something,,,

ok brian spill the beans,,, selvey did alot of things 25 years ago.. so you have a rare piece? since you said selvy sonic i believe its engraved in the side of something you have to show us.

AND yes they were garbage!!! so if you want to just toss it in a box i will take it off your hands :lmao: :lmao: :lmao:

[NOS_350X]

Without doing a stroker crank, a saber cant. Take a look at this 425cc with a stock stroke
http://www.psipowerinc.com/425cc.htm

[disco]

All I have have is a description and a claim that it's a Sonic Selvey. It supposedly bolts up to a 250 bottom end, and turns it into a 500. Was wondering if it was a road I wanted to go down. My father and I have been talking about doing a 500cc, but this would obviously be MUCH cheaper. I didn't realize it was a rare piece. I figured I'd pop on here and find out a little about it. Didn't realize I'd be the brunt of jokes due to ignorance. If it doesn't exist, and someone is trying to get over on me, so be it. Just thought I'd try and find out a little about it.

[bryan raffa]

I would like to see the micrometer reading...right there it will tell you..heck it could be a 200 kit.. like kasey said they did to alot over the years.

[Mr. Kasey]

all joking aside brian, if in fact the description is true and the piece does exist... you might have run into a VERY rare piece .. selvy were out of the box thinkers i have never heard of a big bore from them BUT they might infact have done something in a small way to get an open class racer too .. very much worth a look and a trip if possible to seek the truth.

[ridetrikes250R]

i wouldnt be suprised if selvy's made a big bore, I bet the case has to be cleared, on the back side, I bet you could sell this rare peice and finance your 500

[NOS_350X]

Brian, Whatever it is, i think it worth getting, (of course depending on the price) Sending it up here and ill make you a screaming bike :)

If it is a bolt on 500 cyl i cant see it staying togeter. Not for the way you ride and such. A cr500 conversion would much better suit what you want IMO.

[Duner]

Without doing a stroker crank, a saber cant. Take a look at this 425cc with a stock stroke
http://www.psipowerinc.com/425cc.htm


PSI motors are not very impressive. Buddy of mine has one in Longview, and it's nothing to write home about..My ESR 370 pulled harder and longer then his 425

Sabers come in 460, 496, 510 and 539 kits depending on the stroke you choose..


Trannys can hold up to the tq, but you need to maintain them, AND, a Saber is not a play motor, they will overheat if not on alky. I have seen 2 sabers built for the purpose of duning, and they overheat within minutes on gas.

[ridetrikes250R]

what you mean overheaded? you mean overheated?

[Duner]

what you mean overheaded? you mean overheated?


yes, thank you...

[NINJA]

If it says SELVYS and SONIC on the cylinder, it is not a 200 kit. The 200 kit is very distinct in it's appearance and only had SELVY engraved on the left side of the cylinder. When Selvys would port a cylinder, they would engrave SONIC into it's side. I have never seen, heard, or read about any 500 cylinder from Selvys. Hell, it's not even dimensionally possible to have a "bolt on" 500 cylinder. Chances are it's a Selvys Sonic ported 250 jug and the guy doesn't know what he has. Either way, I'd snag it. Selvys did fantastic work and the parts are very very rare as they were extremely pricey for their day.

[cbx1170]

I went and got this cylinder if this the CL ad in SO CAL. NOT 500 cc he was just braggin tryin to sell it. Eveybody sez they have a cyl ported and has the power of a 300 or 350 or 500 etc etc. 4 phone calls to nail exactly what he had confirmed this. i just wanted to see it and did buy it just to have. gave me another cylinder also. Selvy's has 68.5mm bore way crazy porting, very pretty. Mike PHX

[Mr. Kasey]

welcome to the board.. you going to post up some pictures? would like to see it .

[TLR-Online]

welcome to the board.. you going to post up some pictures? would like to see it .

+1 :D

[cbx1170]

I could slip a couple std pics on here but if somebody would give me a quick tutorial on getting a larger pic(s) that would do more good i'll get right on it. I've seen big pics on CL, EBAY and everywhere else i have just not taken the time to get it done. thanks Mike

[dcreel]

Get a www.photobucket.com account and download your pictures to there. You can then use your IMG code (cut and paste) to paste it straight into your post.

[cbx1170]

http://i785.photobucket.com/albums/yy131/cbx1170/selvy%20cyl/DSC09764.jpg
http://i785.photobucket.com/albums/yy131/cbx1170/selvy%20cyl/DSC09793.jpg
http://i785.photobucket.com/albums/yy131/cbx1170/selvy%20cyl/DSC09787.jpg
http://i785.photobucket.com/albums/yy131/cbx1170/selvy%20cyl/DSC09777.jpg
http://i785.photobucket.com/albums/yy131/cbx1170/selvy%20cyl/DSC09769.jpg
You likey? best i could do with setting sunlight Mike

[cbx1170]

I forgot to add. Appears to be Grey 86 casting. ATC or TRX I don't kow this guy was 4 whl racing TRX style. He had no clue what cyl was set up for 3/4 whls. He just knew it made a 250 into a 500!! LOL By comparing to other cyl he gave me whick looks untouched anywhere Grey 86 looking. 3mm total removed from alum cyl casting. Its shorter height wise. 2mm from base gasket surface. 1mm from head gasket surface. 1.5mm remove from bottom of steel cyl liner that sticks into crank area. Pics do no justice to transfer port work. some taken of on inside face of vertical wall up to actual transfer ports in liner .4mm, but more taken off of outer vertical wall up to transfer port in liner 1.5mm. Head gasket surface to top edge ex port 3mm shorter. Ex port eyebrowed to above transfer port, total width at top is 3.5mm per side for 7mm total. Ex bridge is narrower also ~2mm. Mike

[Mr. Kasey]

so thats probably a 200cc cylinder.. with all the height shaved off of it,,, i would like to see a port map in degrees would be interesting

[cbx1170]

68.5mm bore Mike

[Mr. Kasey]

if they shaved 3mm off then it must have a 69mm stroke ? maybe

[mymint87]

you freaking wrench heads are funny:chuckle:

I tossed the CL ad link on that cylinder up in classifieds over 3 months ago:doh:

and you guys are still GAWking over it:loser: :duck:

[Mr. Kasey]

you freaking wrench heads are funny:chuckle:

I tossed the CL ad link on that cylinder up in classifieds over 3 months ago:doh:

and you guys are still GAWking over it:loser: :duck:

the invasion is only 10 months away ,,,don't you have something to get ready????:lmao: :lmao: :lmao: :lmao: :lmao:

[NINJA]

That is not a 200 cylinder. Much more decking and modification would be required. It would have to be decked .470" Sweet score nonetheless!