please help, 379 hot rods stroker

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Stroker Crankshafts

Description:

Heavy Duty (+4mm stroke) makes 379cc. Important: Must use Vertex Stroker piston 23616A



Vertex-
PERFORMANCE PISTON KIT
Description:
Stroker Performance piston kit; +1mm makes 381cc. Must be used with Hot Rods stroker crankshaft 4143. Kit includes: Piston, rings, pin, clips
Part Number: 23616A
Distributor Part Number(s):
Parts Unlimited #: 0910-2637
For Models:
2004 - 2011 Yamaha RAPTOR 350, 1987 - 2004 Yamaha WARRIOR 350
Status:
Out Of Stock
Technical Specifications:
Compression Ratio (x:y):
9.2:1
Cylinder Diameter (mm):
84.00
Displacement (cc):
381.00
Piston Diameter (mm):
83.94
SizeOverStandard:
1.00

Last time I talked to hotrods they said this is the new piston there using.
 
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Well that blows. Dropping the base gasket from the picture and running a thinner head gasket can get it up to 10:1. Decking the head no more the .015" will get it to 10.5:1 easily.
 
Gen1Pat said:
Well that blows. Dropping the base gasket from the picture and running a thinner head gasket can get it up to 10:1. Decking the head no more the .015" will get it to 10.5:1 easily.
Click to expand...

9.2:1 has a total combustion chamber volume 46.3cc at 84mm bore and +4mm stroke
10.5:1 "" 40cc
Droping the base gasket will gain you around .015". Even better taking out the stock head gasket of around .060" and going for a custom thin head gasket of .005" and then decking the head like you say will get up closer to the 10.2-.5 compression. Just droping out the base gasket alone isn't going to get you there..

Really having the cylinder decked (milled down) to 0 deck would be great and get you where you will make the most out of this setup with the vertex piston but then if you are going to do that maybe just using say the wiesco or je is a better way to do this and again have a spacer plate made.. either way your looking at needing a adjustable cam gear to get the cam back in time...
 
BTW: it looks like all the stroker stuff for the warrior has been discontined.
Stage 2 cam
Stroker crank
Stroker piston
 
Yea but you can still easily buy it. And i could still use the hot rods piston over the vertex, right?
 
i go with the +4 crank , diggerzmound's kodiak 400 jug (mill it down to the right deck hight), deadlast's 11:1 je 60 over, and a hotcams s1 or s2...
 
jasonp said:
9.2:1 has a total combustion chamber volume 46.3cc at 84mm bore and +4mm stroke
10.5:1 "" 40cc
Droping the base gasket will gain you around .015". Even better taking out the stock head gasket of around .060" and going for a custom thin head gasket of .005" and then decking the head like you say will get up closer to the 10.2-.5 compression. Just droping out the base gasket alone isn't going to get you there..

Really having the cylinder decked (milled down) to 0 deck would be great and get you where you will make the most out of this setup with the vertex piston but then if you are going to do that maybe just using say the wiesco or je is a better way to do this and again have a spacer plate made.. either way your looking at needing a adjustable cam gear to get the cam back in time...
Click to expand...


I was mearly guestimating on the CR. Don't know what the volume is for these bikes. I haven't measured the base gasket in a while. For some reason I thought it was closer to .020". The Cometic EST head gasket is on average .007" thinner then stock.
 
Gen1Pat said:
I was mearly guestimating on the CR. Don't know what the volume is for these bikes. I haven't measured the base gasket in a while. For some reason I thought it was closer to .020". The Cometic EST head gasket is on average .007" thinner then stock.
Click to expand...

For the base gasket from what I've found is around .020" before torqued and ends up around .015" after. The est gasket can be ordered in a wide range of thickness. It all depends on what your measured deck height is. Then you can decide what type and thickness to go with.
 
Yeah I've only ever ordered the est kit off ebay. Never went to cometic's website or called them directly. I'm really not all too concerned about it. Dropping the base gasket and running a thinner head gasket isn't going to require race gas or E85 with a 10.5:1 piston. Not like this is rocket science. Just have to make sure that there is no valve to piston interference.
 
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Yeah if your not concerned about getting max squish from .030-.040" no matter what the compression ratio comes out to be then don't worry about head gasket/base gasket/head volume. You will just loose performance.
 
Hello everyone. I have received my crank and piston. I need to replace some of the bearings that are inside the case. I have no clue how to remove these bearings seeing as how you can only access most of them from one side. Is there a special tool to pull the bearings out or how do you go about doing this?
 
tchester55 said:
Hello everyone. I have received my crank and piston. I need to replace some of the bearings that are inside the case. I have no clue how to remove these bearings seeing as how you can only access most of them from one side. Is there a special tool to pull the bearings out or how do you go about doing this?
Click to expand...
Yea it called a socket and hammer LOL thats how I take them out and to put them in put your cases in the fridge or freezer let them get nice cold and should slide right in! Or buy a bearing puller tool!
 
You will need a small slap hammer type bearing puller. You can get a kit from a parts store or Sears. It should come with a few adapter for different bearins. You'll need the one that spreads apart to grab the i.d. of the bearing. These bearings are not pressed in super tight like wheel and axle bearings. All you really need to install them is some spray lube and a good rubber mallet, or small dead blow hammer. Just spray some lube(silicone spray, wd40, or even smear some engine oil on the bearing), and tap them in with the hammer/mallet. Just make sure the bearing is square in the bore before you start tapping them in.
 
Gen1Pat said:
You will need a small slap hammer type bearing puller. You can get a kit from a parts store or Sears. It should come with a few adapter for different bearins. You'll need the one that spreads apart to grab the i.d. of the bearing. These bearings are not pressed in super tight like wheel and axle bearings. All you really need to install them is some spray lube and a good rubber mallet, or small dead blow hammer. Just spray some lube(silicone spray, wd40, or even smear some engine oil on the bearing), and tap them in with the hammer/mallet. Just make sure the bearing is square in the bore before you start tapping them in.
Click to expand...

i agree with removal but for the install all you need to do is throw the bearings in the freezer 30-60 min and cases in the oven @ 300* for 20-30 min then and its just a matter of doping the bearings in it
 
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