chevys104x4 Posted November 12, 2003 Report Share Posted November 12, 2003 my 95 yamaha banshee. rod bearing on crank side came apart. considering replacing crank with stroker. maybe stroker with long rod. what is needed besides the crank to make this work. like porting or cylinder spacers if using spaceers what size, what carbs, do the cases have to be modified, will stock head work. please list what is needed for both stroker crank 4mm and stroker crank with 5mm rods and any other items. i know this is a large request. any help is greatly appreicated. thanks. Quote Link to comment Share on other sites More sharing options...
PassionRE Posted November 12, 2003 Report Share Posted November 12, 2003 No case mods needed, definately porting needed if you have a taste for real horsepower. 795 series Wiseco pistons for the long rod motor, cylinder will have to be decked or head mods....I personally prefer decking. If your set-up properly 34 Keihin's with v-force reeds will give crisp throttle response and blistering top-end. Ditch the stock head and run a Noss Machine head.....save yourself problems in advance..Jim Quote Link to comment Share on other sites More sharing options...
Oilsmoke Posted November 12, 2003 Report Share Posted November 12, 2003 Hey Jim What is done to the cyclinders that are already ported and you plan on making it a 370. How do you correct this without a spacer plate And please get technical Quote Link to comment Share on other sites More sharing options...
PassionRE Posted November 12, 2003 Report Share Posted November 12, 2003 If you dont deck from the bottom, ported cylinders can be used even if the ex. ports have been raised considerably, but you will have to relieve the combustion chambers for adequate squish clearance with 795 series pistons. If you deck from the bottom approx. .070"-.080" depending on what squish clearance your shooting for, the distance from the top deck to the top of the ex. ports should not be less than 28.3mm. At this spec with a +4 long rod crank ,ex. duration will be 198 degrees. The max considered by most(although I have exceeded this point on certain occasions). Decking from the bottom at the .070-.080 spec advances transfer timing to roughly 114 degrees ATDC, not neccessarely a bad thing although it does affect idle quality. This idle situation is something I'm willing to live with in order to maintain the forced convection cooling characteristics of the piston head and combustion chamber by leaving the piston well within the protection of the bore instead of stuffing it into the combustion chamber with relieved heads..Jim Quote Link to comment Share on other sites More sharing options...
SDD Posted November 12, 2003 Report Share Posted November 12, 2003 I don't believe you can make a stroker crank without longer rods on it. The piston skirts will hit the crank web at BDC. Quote Link to comment Share on other sites More sharing options...
Oilsmoke Posted November 15, 2003 Report Share Posted November 15, 2003 Jim I am confused. I was thinking the reason the spacer plate on a 370 long rod stroker was to raise the port window to work with the higher piston. If this is true why would you cut the bottom of the cyclinders down, that would lower them even more? Quote Link to comment Share on other sites More sharing options...
fixitrod Posted November 15, 2003 Report Share Posted November 15, 2003 Oilsmoke, I was thinking the same thing unless he is talking about to correct an already ported motor. A 4mm stroker does not need long rods. Dan at patriot racing doesn't use long rods until 7mm. They do relieve some of the stress, but a 4mm with stock rod length may yeild a little more power. Quote Link to comment Share on other sites More sharing options...
PassionRE Posted November 15, 2003 Report Share Posted November 15, 2003 Oilsmoke, I think your thinking that decking means milling. When I say deck from the bottom, I mean to add the spacer on the bottom, not mill the surface. The 795 series pistons are 5mm shorter than the regular pro-lites, this is to compensate for the long rods, not the stroke. The additional crank pin off-set of 2mm of a +4 crank has to be compensated for, otherwise your pistons will protrude 2mm over the top surface of the cylinders and crash into the head...does that make sense?...Jim Quote Link to comment Share on other sites More sharing options...
fixitrod Posted November 15, 2003 Report Share Posted November 15, 2003 Cleared it up for me Quote Link to comment Share on other sites More sharing options...
Patriot Racing Posted November 20, 2003 Report Share Posted November 20, 2003 We use a regular rod (110mm) 4mm crank with custom cut domes. By running the added stroke out of the top of the cylinders, this can allow previously ported cylinders to be used (in some cases not always) as TDC to port hgt has been increased by that port hgt. Alter the porting to match the desired output of the motor and the little 4mm motors can fly!!! We can also cut the stock head to work with the stroker. The advantage is as above, but also you are removing a potential leak point if spacers are used. Additionally when we cut domes or cut the stock head- you gain the performance and safety of having the head design correctly set-up for your fuel and riding type. The rod to stroke ratio on a Banshee is pretty long to begin with. We've built many long rod motors and none of them ran any harder than a regular rod motor. Piston wear and stress were nearly the same. However the power delivery of the regular rod motors were more favorable for most riders. Quote Link to comment Share on other sites More sharing options...
JaysBanshee Posted November 20, 2003 Report Share Posted November 20, 2003 Dan What pistons do you use for the regular rod 4mm stroker? Are they the wiseco 795 series? Also what crank do you use? I am wanting to build a strong dune motor and I am not sure on wether to use a regular rod 4mm or go with the long rod 4mm. Quote Link to comment Share on other sites More sharing options...
fixitrod Posted November 20, 2003 Report Share Posted November 20, 2003 If you use a standard rod, you use a standard piston. Quote Link to comment Share on other sites More sharing options...
Oilsmoke Posted November 21, 2003 Report Share Posted November 21, 2003 I understand Jim. I have another question. What measurement is the piston to deck height.I think thats what you call it. On a Stock motor and Modifed for High performance motor. Oh Jim , Dan Thx for The Info I am learning alot. Quote Link to comment Share on other sites More sharing options...
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