New Member Big Bore Stroker Question By dirtrider1219 (Read 2,079 times)

[dirtrider1219]

Hello everyone I just joined and this is my first post  I am a huge scooter fanatic on the quest for more power The problem is I have a 1p52qmi. I know the 1p52's (125cc) and the 1p57's (150cc) are the same besides the cylinder. All the reading I've done says that the difference with the p is in the head. Well if I buy this kit, won't it work since it basically replaces everything from the bottom up?

www.ebay.com/itm/SCOOTER-150CC-GY6-HIGH-PERFORMANCE-HEAD-BIG-VALVE-STROKE-6MM-CYLINDER-63MM-/171969743962?hash=item280a320c5a:g:hsYAAOSwFTRTqXpj&vxp=mtr



Also, he says that it does not require a spacer. A +6mm stroke is alot to have no spacer no? Is all of that clearance cut out of the piston? The guy's feedback isn't too great so I'm a little weary

EDIT: Update on page 4. I have also learned that yes, the kit I linked above and other 200cc stroker kits WILL fit the p engines. As long as you replace the crank as well and the kit comes with it's own timing chain that's the right length. You could even use the stock crank, they are the same, but you need to split the cases anyway to install a shorter timing chain.

[Alleyoop]

That link does not show your kit.

[dirtrider1219]

Sorry, it's fixed

[jct842]

In big letters it says "(Cannot FIT IN ENGINES to 1P52QMI, or 1P57QMJ Engines.)" If there was a way the seller would say as I am sure he wants to sell as many as possible.

[Alleyoop]

That is a 63mm kit, you will probably need to have the case bored out for the jug to fit. What you should be concerned about is the STUD spacing on your current motor and then ask for the stud spacing on that kit.

Also I would ask about the DISCLAIMER that IT WILL NOT FIT THE 1P52 and 1P57 motor? Is he talking about the FREE CAM or the ENTIRE KIT.
Alleyoop

[dirtrider1219]

I know but I messaged him and his reply was "The 2 bolts 6mm att The haed and cylinder have difference measure. You can see in you tube, thanks". First of all the bolts are 8mm, and secondly I've never heard about the spacing on those side 2 bolts being any different. "The people who sell engines are not the same people who build them" great quote I read somewhere.

[dirtrider1219]

So I just went and measured mine and i have the 54mm spacing, so i should be good to go. What else could possibly stop this from fitting?

[czmdiver]

I'll touch on something here.
There cylinder is taller too accommodate the Stroke, so somebody attempted math anyhow.
I could Not see enough of the Piston supplied but have suspicions. They have done the Piston Mod for you.
I would want to See it.
At +6mm stroke with the Stock Rod length the Rod Stroke Ratio gets Worse with every increment. Harsh Rod Angle.
The Piston Needs its Skirt to Keep it Stable and the More Square in the bore (stable) the piston is kept Throughout the Stroke The Better the Ring seal. 
These Suppliers, Private Labelers, MFg's are Cutting off the Piston Skirt with a Cut off Saw With No Measurements. Unreal.
We have a Harsh Rod angle and they Cut off the Skirt.
Here is supposed be name brand Taiwanese quality snit NCY on the Left. the Chopped the Skirt off regardless if its in a stroker or not. JUNK

Her are two other Skirt shapes with some marking to point out difference.


The only thing that name brand quality NCY piston is good for

[czmdiver]

I pointed out the Bad, No good but did not show the Better or way it should be. My bad.
Here is a Skirt profile That will work Better in Any and Especially Any Stroker Combo.
The first Pistons I showed you were what's called a Full Rounded Skirt, is ok 
This is a Slipper Style Skirt, The Skirts are Only on the Thrust faces of the piston. Sides Scalloped 





Now this is supposed to be the Top of the Line Taiwanese all the snit Forging. Right? They Left out the Pin Oilers. Nice, No Instructions, No Warranty they Don't Even Cover there Workmanship.

[dirtrider1219]

Thank Diver great info!! I would imagine on that original kit that being such an extreme stroke with no spacer that the bottom of the piston is probably flat. Check out what I found though.

www.ebay.com/itm/321885825517?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649

It says "stroker ready piston", but I'm not too sure. So we agree that running even a thick cylinder spacer is better than messing with the piston right? Also if you got a piston like on your last picture, would you drill those oiling holes out or just leave them? Doesn't the piston move side to side where the wrist pin goes through the rod, so it's steel to steel, and not steel to aluminum? That could open up a potential wear point no?

[czmdiver]

Oct 25, 2015 8:19:23 GMT -6 dirtrider1219 said:

Thank Diver great info!! I would imagine on that original kit that being such an extreme stroke with no spacer that the bottom of the piston is probably flat. Check out what I found though.

www.ebay.com/itm/321885825517?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649

It says "stroker ready piston", but I'm not too sure. So we agree that running even a thick cylinder spacer is better than messing with the piston right? Also if you got a piston like on your last picture, would you drill those oiling holes out or just leave them? Doesn't the piston move side to side where the wrist pin goes through the rod, so it's steel to steel, and not steel to aluminum? That could open up a potential wear point no?

Lee explain, The Longer Stroke will take the Piston Out of the Top of the Bore. The First Kit Has a Taller than OE Cylinder to Replace the Spacer and have a Correct Zero-Deck.
Now the Piston Mod or just making a Correct Piston is on the Bottom of the Piston and has Nothing to do with Spacers or Cylinder height, As the Piston goes to BDC the Skirt's or Pin Boss Will Hit the Crank. 
Here is a +2.5mm Stroker with the correct Piston I showed you, See at BDC how Close this Piston is to Hitting the Crank.

And Yes the Pin oilers go in this and All my Pistons,, I see these with No pin oilers and the Wrist Pins All come out Fourteen Different Colors of the Rainbow.
No, the Piston doesn't move side to side only on its Thrust Faces, Don't need any sides on these Pistons

[cyborg]

i would only cut the piston as a very last resort,,,and minimally at that,,,i would think at +6 a cylinder base spacer is in order,,,and as our resident engine guru points out,,,with the severe rod angularity you need all the skirt you can get,,,oh it will start and run but longevity will be an issue big time,,,we used to call those "grenade builds",,,i've changed my mind over the years as far as strokers go,,,i now prefer as big of an oversquare as can be done within the crankcase design limits and spin it faster,,,keeping rod angularity down ,,these style builds last longer and make the kind of power i'm after

[czmdiver]

Oct 25, 2015 10:10:48 GMT -6 cyborg said:

i would only cut the piston as a very last resort,,,and minimally at that,,,i would think at +6 a cylinder base spacer is in order,,,and as our resident engine guru points out,,,with the severe rod angularity you need all the skirt you can get,,,oh it will start and run but longevity will be an issue big time,,,we used to call those "grenade builds",,,i've changed my mind over the years as far as strokers go,,,i now prefer as big of an oversquare as can be done within the crankcase design limits and spin it faster,,,keeping rod angularity down ,,these style builds last longer and make the kind of power i'm after

This is all correct.
I'll point out the fix.
I've hesitated to give this up cuz its a money maker for someone on the pipe.
Because of the Unfavorable Rod Angle/ Rod-Stroke Ratio. I do these Stokers with +Longer Rods.
This Not only Straightens out the Harsh Angle that So Hard on Piston Skirts and Ring Seal, the Piston will Dwell Longer at TDC and BDC. Piston Dwell Time. I may get more complete burn.
I build these with a +2.500 Stroke and a +.250 or +.375 Longer Rod. 
Pretty Unassuming Mouse Motor. Long Rod 385i Stroker will rock your world. yayaya, the Vacuum Advance was removed  and is mechanical.

This again Straightens out the Harsh Angle, Longer Piston Dwell time, And my Pin Height went from 1.550 (oe) to 1.250 Thats a .250 Shorter Piston and saved Bunch of Weight.
Long Rod, Short Stroke Ripper and all I need is a Ring Holder for a Piston.

[czmdiver]

Oct 25, 2015 10:10:48 GMT -6 cyborg said:

n

[cyborg]

To achieve zero deck you must be running special pistons with raised pin location and shave the crown too or you can get it with the piston?