90.5mm vertex new ring end gap .022

boostdoctor · Post by **boostdoctor** » July 3rd, 2009, 10:42 pm

So how long are you guys Vertex pistons lasting? My piston didn't last very long; but I think my machinist set the clearance at .004(the proper clearance for a 4stroke according to the literature that came with the piston) instead of .003. Plus I found out that my crank seal(oil side) was leakinng as well. There was a black oil film covering the inside of the motor. So I sassume that the nasty tranny oil accelerated the wear of my piston and cylinder. I just want your opinion before i try another one. I hate to spend the extra money for a Wiseco if its not necessary.

I'll also like to add that the final bore size plays a major role with ring end gap. A larger piston to wall clearance will make your eng gap larger. I know most of you know this; but I just thought i would mention it for the guys that don't know.

Post by **AlisoBob** » July 4th, 2009, 9:45 am

If you think a Wiesco is going to outlast a Vertex, your nuts.

iggys-amsoil · Post by **iggys-amsoil** » July 5th, 2009, 1:57 am

No such thing as a Wiesco, so I guess your right.

M.F.D.B. · Post by **M.F.D.B.** » July 12th, 2009, 7:38 pm

Ive only ever seen ONE Wiseco crack, i wont mention (dont need to) how many cast pistons crack...

Post by **AlisoBob** » July 12th, 2009, 8:31 pm

Wanna' count how many scored, siezed, scuffed, and otherwise mangled Wiesco's youve seen..... FIRSTHAND????

M.F.D.B. · Post by **M.F.D.B.** » July 12th, 2009, 8:35 pm

AlisoBob wrote:Wanna' count how many scored, siezed, scuffed, and otherwise mangled Wiesco's youve seen..... FIRSTHAND????

So you are saying improperly clearanced cast pistons dont "score, sieze, scuff, and otherwise get mangled"?

Post by **AlisoBob** » July 12th, 2009, 8:39 pm

Nope, they rattle around for months and finally crack.

M.F.D.B. · Post by **M.F.D.B.** » July 12th, 2009, 9:35 pm

In your opinion whats more damaging, frag or freeze?

Post by **AlisoBob** » July 12th, 2009, 9:58 pm

Dont be stupid enough to do either one.....

CR500R7 · Post by **CR500R7** » July 12th, 2009, 10:33 pm

I don't think anyone sets out to shag either piston, it is more a case of not having your eye on the ball, so to speak.

M.F.D.B. · Post by **M.F.D.B.** » July 12th, 2009, 10:54 pm

I can tell you this much, if you are not a machinist nor have a dial bore guage, you are at the mercy of whomever has done your machine work.

I personally would rather squeek a forged, with the slim possibility of getting it restarted after a cool down, than be 50 miles from the truck with a fragged piston and subsequent punched case/crank etc.

Just one highschool drop outs opinion, whatever thats worth?

CR500R7 · Post by **CR500R7** » July 12th, 2009, 11:04 pm

That is pretty well what I meant by not having your eye on the ball.
You should always take your gear to someone with a good rep, but there is still a possiblity of it being F@#KED up.
I do like the sound of not pushing a bike for 50 miles.

As far as I know Smokey Yunick did not have a full on education either, but I would not call him a drop out.
Probably one of the best mechanics / engineers there ever was.
Just because you left school early DOES NOT mean you are stupid, GET IT!

M.F.D.B. · Post by **M.F.D.B.** » July 13th, 2009, 7:53 am

CR500R7 wrote:That is pretty well what I meant by not having your eye on the ball.
You should always take your gear to someone with a good rep, but there is still a possiblity of it being F@#KED up.
I do like the sound of not pushing a bike for 50 miles.
As far as I know Smokey Yunick did not have a full on education either, but I would not call him a drop out.
Probably one of the best mechanics / engineers there ever was.
Just because you left school early DOES NOT mean you are stupid, GET IT!

glen howell · Post by **glen howell** » July 13th, 2009, 8:52 pm

In todays economy price enters into the picture, L.A. Sleeve Prices Wiseco larger than std. $212.00 Pro-X $156.00 Vertex $106.00 Vertex is a very good piston (cast or forged)For all out performance Wiseco is very good you will also get a little more compression out of wiseco ,also with a forged 1 ringer Vertex,Pro-X compression will be about the same as O.E.M Honda. For singletrack riding any cast piston is very good. For racing forged is recomended, either single or 2 ringers and give the forged racing pistons good clearence more than a cast piston. Get a good straight bore and a good final hone finish it's best with a torque plate ,for boring and honing jpg[/img]][/img]

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M.F.D.B. · Post by **M.F.D.B.** » July 13th, 2009, 9:07 pm

Good point about Single Track type riding and cast pistons. I'm one of those peeps that isnt convinced that kind of riding can get a forged piston up to temp, therefore, it will be too loose in the bore. If slow speed putting or single track riding is all you do a cast is prolly the best choice. For me, the 500 is 100% dune machine, not a good idea for cast. (ya ya, flame on about how I never ride it anymore)

britincali · Post by **britincali** » July 13th, 2009, 9:16 pm

This is my experience.......

In a stock bike properly machined a cast piston is bitchin, I rebuilt the 87 motor in my AF (that was on a bone stock piston and bore for 20 years) with all stock honda stuff, I think the local machinist machined the bore a little big as it never really had a ton of compression and got worse pretty quick, the bike still starts and runs good so I aint bothered, I do single track stuff and hammer the shit out of it at the dunes and dont have an issue.

On the dunes bike I run a wiseco (due to the spray) and wether it be glens machining or down to the piston the compression is unreal, just like it was the first time I started it. I have cracked one wiseco but I think that was operator error with the nitrous

. Ive run at least 30lb of juice through the new wiseco now with no issues or loss of compression, im now hitting it with a .033 nitrous jet that equates to a 50 shot

and so far shes handling it

Bear in mind that the last 3-4 dune trips Ive been chasing a cooling problem and have litrally cooked the hell out of the engine by hitting it with spray while there was no coolant in it (I know I know I should no better) and the piston hasnt stuck once. A cast would be a shattered/melted mess.

I overheated it so bad the motor quit and wouldnt restart until it cooled, the piston has NO scuff marks at all.

It probably helps running 927 castor oil.

IMO after seeing the abuse the forged can take there is no way im ever buying another cast piston.

Post by **AlisoBob** » July 13th, 2009, 9:25 pm

glen howell wrote:Get a good straight bore and a good final hone finish it's best with a torque plate

Yup..................

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » July 14th, 2009, 6:30 am

pro-x's engineering idiots have not made the piston shut the exhaust port so its JUNK even new in the box

Bean · Post by **Bean** » July 14th, 2009, 9:18 am

[quote="Roostius_Maximus"]pro-x's engineering idiots have not made the piston shut the exhaust port so its JUNK even new in the box

Bean and myself looked at our old pistons today
the pro x from his motor had the same prob exposed the transfer port to the exhaust

where as my wiseco just cold seized
take your pick

Post by **AlisoBob** » July 14th, 2009, 10:27 am

Vertex

south central hoon · Post by **south central hoon** » July 14th, 2009, 10:48 am

Roostius_Maximus wrote:pro-x's engineering idiots have not made the piston shut the exhaust port so its JUNK even new in the box

That is an outrage! I've never seen one that bad before....from the photo it looks like you could shove a dime through there

M.F.D.B. · Post by **M.F.D.B.** » July 14th, 2009, 4:50 pm

Roostius_Maximus wrote:pro-x's engineering idiots have not made the piston shut the exhaust port so its JUNK even new in the box

Looks like u had a lot of run time before you took those pics. What happened to make you realize the flaw?

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » July 15th, 2009, 6:55 am

Its probably only 6-8 hours on that = probably 2 rides, the coating basically washes off, its supposed to be some breakin junk im told

I'd had this jug with a vertex ( i took from dads personal spare inventory

) in it, some junk came out of the tank on the first ride i'd made with it and on the way home squeaked the piston lean from pluggin the carb with crud, next oversize and quickest was a prox (next day), i didnt even look at it on the bench, ran it the next night and had gone thru the carb and tank cleanup again.

so now it ran but i had odd jetting issues that i couldnt explain being caused by the cleaning, had me a witchhunt.
I finally pulled the head and was looking at it, then by had kicked it over fast and realized it didnt have the POP from the ports so i looked to see where the compression was going and eventually pulled the pipe off.

Thats an '88 jug, fits the same in 86-89s and only leaks 1/2 of that in the '91 and '99s i checked. I am running one in a re-sleeved 86 jug that was intentionally left narrow on the exhaust port to close that window

dannygraves · Post by **dannygraves** » July 15th, 2009, 7:43 am

%100 wiseco all the f-ing time! I only ever run wisecos, in my cars, in my bikes, whatever. w/ a good machinist a wiseco will last for ever. poor machining, poor tuning and tight clearences are what mess things up. In all my time running wisecos, I've seized 2. 1 was on a 125 that had 0 flow through the rads and it cooked to death (would have with any piston) and the other was my gen-1 when I recked w/ the throttle stuck WFO and the kill switch broke off... it screamed for like 5 minutes until the loss of compression shut it off. That was a 2 year old top end w/ MANY hours on it, a cast would have broken into a million peices.
Although I am running ross in my stealth now... but that was because I got a good deal

If the machining was done properly, anything that will kill a wiseco will also kill a cast piston.

dannygraves · Post by **dannygraves** » July 15th, 2009, 7:44 am

on and I got my last wiseco (2 weeks ago) for considerably less than glens listed price on a prox

BannedCR500Riders.com

90.5mm vertex new ring end gap .022

vertex piston life?