TIM LUTZ Posted July 26, 2010 Report Share Posted July 26, 2010 Thrashing my Shee for 8 years on Klotz and just now had to tear down the topend (hole in rad hose and ran her out of water) So I'm doing a mild build with new Wisecos, decent home port job and some 30mm OKO's. An honest 65HP motor when it's done. Any way, I was looking at the crank (still assembled) and I'm getting .019" and .023" on the rod sids and .065" and .070" small end arc. What do you guys think of these numbers? Skirts didn't break, didn't even seize just lost compression. Should I look for a tighter stock crank or a stock hot rod? Can't quite swing a 4mm at this time or I'd do it. Do these things give any warning (knocking) when they are ready to go? Quote Link to comment Share on other sites More sharing options...
jasons Posted July 26, 2010 Report Share Posted July 26, 2010 Thrashing my Shee for 8 years on Klotz and just now had to tear down the topend (hole in rad hose and ran her out of water) So I'm doing a mild build with new Wisecos, decent home port job and some 30mm OKO's. An honest 65HP motor when it's done. Any way, I was looking at the crank (still assembled) and I'm getting .019" and .023" on the rod sids and .065" and .070" small end arc. What do you guys think of these numbers? Skirts didn't break, didn't even seize just lost compression. Should I look for a tighter stock crank or a stock hot rod? Can't quite swing a 4mm at this time or I'd do it. Do these things give any warning (knocking) when they are ready to go? on a new crank the the connecting rod limits are between 0.25-0.75 doesnt say what the out of parameters are and the small end play is 2.0mm or 0.08in service limit so it seems to me you need to buck up and pay some money and get a 4mil crank. talk to alf or wildcard they should beable to hook you up on a nice price. Quote Link to comment Share on other sites More sharing options...
bansheesandrider Posted July 26, 2010 Report Share Posted July 26, 2010 From what I read in my Yamaha manual, you are outside the specs for a new unit but you are still within the factory service limits, meaning you can run the crank for awhile longer. But my expierence has been that a crank can let go at any time with no warning, based on that I would send the crank to Twister. They will rebuild it with new rods, thrust washers and all bearings and then true and weld it for around $350-$375. You will then have a good reliable crank that won't let you down. Quote Link to comment Share on other sites More sharing options...
prssantana Posted July 26, 2010 Report Share Posted July 26, 2010 Alf was talking about some new cranks he wanted people to try out. Said he would sell some for cheap. It posted somewhere on here i think sponsor spotlight. Quote Link to comment Share on other sites More sharing options...
TIM LUTZ Posted July 26, 2010 Author Report Share Posted July 26, 2010 Yea, the crank is within Yamaha service limits and looks fine but has a bunch of hours on it. That looks high for a rebuild. What dose a stock hot rod go for? Quote Link to comment Share on other sites More sharing options...
spurdy Posted July 26, 2010 Report Share Posted July 26, 2010 Yea, the crank is within Yamaha service limits and looks fine but has a bunch of hours on it. That looks high for a rebuild. What dose a stock hot rod go for? You can usually buy a new crank for the price of rebuilding one. The cost of a 4mm crank isn't much more than a stock stroke, however, there is more to it like porting, bigger carbs do to increased flow (30s maybe ok). To pull 65hp from a stock stroke everything is gonna have to be matched, all components complimenting each other. SP Quote Link to comment Share on other sites More sharing options...
bansheesandrider Posted July 26, 2010 Report Share Posted July 26, 2010 I can't find a better deal on a good crank that is trued and welded. Yes I can find new cranks that are less money, but they are not trued and welded so you have to have that done and around here that is $75-$100. Plus Twister is local to me and I don't have to pay shipping. I would rather have my crank rebuilt than buy some POS crank from China or Korea. Quote Link to comment Share on other sites More sharing options...
TIM LUTZ Posted July 26, 2010 Author Report Share Posted July 26, 2010 (edited) I checked out Twister crank's website. Wow they got some nice stuff but DAMN, I pay less for a big block chevy stroker crank. HaHa. Is the Hot Rod stuff any good? Anyone got a low hour stocker? Edited July 26, 2010 by TIM LUTZ Quote Link to comment Share on other sites More sharing options...
12 0 Clock P I M P Posted July 26, 2010 Report Share Posted July 26, 2010 I checked out Twister crank's website. Wow they got some nice stuff but DAMN, I pay less for a big block chevy stroker crank. HaHa. Is the Hot Rod stuff any good? Anyone got a low hour stocker? ha I got a low hour Hot Rods, but has bent rods haha...I have a stocker with 5 hours on it and I just up and bought new wiseco engine kit.......broken cranks are like boat anchors it seems time to work a few more hours for the 4 mil..... Quote Link to comment Share on other sites More sharing options...
AKheathen Posted July 26, 2010 Report Share Posted July 26, 2010 well, if you can't swing the 4mill, but want to in the future, then best thing is to check the play in the bearings, (rods and centers) and have yours trued/welded, then throw some new outters on there, which are dirt cheap when you buy from a manufacturer, not banshee vendor. vxb should be like $7 each. that thing should last untill you are ready for 4mill, and then some. they generally don't give you any warning before letting go, they just get sloppy, or separate, which you can get lucky and catch, but flaking can be felt by hand, wear play can be measured, and oil starvation can happen anytime, no matter the hours, or crank. trued/welded stock cranks are verry durable, and the stock center seal is the best i've seen, so far. Quote Link to comment Share on other sites More sharing options...
TIM LUTZ Posted July 26, 2010 Author Report Share Posted July 26, 2010 Thanks Akheathen. What is the deal with the 4mm? I know I need a 4mm base plate but what does that do to my porting? As you know I raised my exhaust and transfers this weekend (couple pictures on that "boost port height" post) Will I now need to lower the port floors 4mm if I go with that setup? Thanks Quote Link to comment Share on other sites More sharing options...
AKheathen Posted July 26, 2010 Report Share Posted July 26, 2010 Thanks Akheathen. What is the deal with the 4mm? I know I need a 4mm base plate but what does that do to my porting? As you know I raised my exhaust and transfers this weekend (couple pictures on that "boost port height" post) Will I now need to lower the port floors 4mm if I go with that setup? Thanks well, if you use the spacer plate, then it will be allot of topend, and real short blowdown. best thing to do is get some cut domes, and bring the exhaust back up to an appropriate time for decent blowdown, and that will set your miinimum rpm range on the porting. allot of times, you are stuck with near drag when you stroke an already ported motor, since there is too much cut from the transfers. either way, you will need to lower the port floors for better flow, since the piston will be dropping either 2, or 4mill further, creating a ridge Quote Link to comment Share on other sites More sharing options...
TIM LUTZ Posted July 28, 2010 Author Report Share Posted July 28, 2010 Well, I'm set as far as my bottom end goes. Just picked up a low hour 10 ball welded Hot Rod stock stroke for $200. Now I got a good excuse to match port my upper case. Quote Link to comment Share on other sites More sharing options...
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