5LikesNEW OS 21 XZ-B and Speed XZ-B
12-05-2012, 07:03 PM
#4111
12-05-2012, 07:05 PM
#4112
the main reason i was asking is that i had it running great, idling beautiful. then a *guru* adjusted it without me asking and now it won't idle properly.
i just needed to know if i had it right the first time. again thank u.
12-06-2012, 07:54 PM
#4114
yeah frank. that's what i do. racing sunday so i'll see how it goes. adjust as necessary.
12-07-2012, 12:46 PM
#4115
12-12-2012, 11:56 PM
#4116
most of the guys that would run the base vz-b would throw a speed vz-b rod in(oil hole in the rod) the base xz-b is probably the fastest engine i have ever owned. seemed like the longer you held the throttle open the more the rpm would climb. the top seemed endless. way more bottom than the speed also. the cranks are really soft though. theres no denying that. the bo2 crank seems to be the hot ticket out. i even think the vz-b base crank is harder! i only got three gallons out of my base xz-b before it generated way too much slop. i caught it before i threw the rod(when you start to burn out brand new glow plug after brand new glow plug, sure-tell sign) i basically had to scrap the engine because the head button, crank and rod were no good... so 5 to 10 gallons seems a bit optimistic for a stock, base xz-b crank. i break in all my engines the same way and that was my only experience with a 3 gallon crank. so get an base xz-b only if you have a b02 or speed crank laying around
+1
the old days the bo1 crank despite not having the tungsten weight, had more timing and could make more steam than the vzb speed....now OS decided Mugen isnt gonna have the upper hand and basically use a base blue head xzb crank with the DLC coat in the bo2 and the xzb speed crank has all the tweaks and more detailed machining..
I could tell my first Sidewinder xzb uncoated crank was already goin to $%it after only a gallon and half/close to 2 gallonsish...too much rod play as compared to the exact same rod on a old school bo1 or speed crank that im used to...when OS rods get a lil play in em, IMO its just a short time before you spin the lower bushing in the rod and the oil supply hole no longer lines up and ^$#@%$^...total loss if your not aware or inexperienced....ive also been playin with the xzb and xzb speed buttons a lil with the lathe, and after the very little bit of testing and comparison ive been able to do, I prefer the standard xzb button over the xzb speed button after it has been shaved 0.11mm and leaving the 0.10 copper shim out when reassembling...better idle, cooler temps (15 degrees), lil more bottom and when combined with a Ebmods powerplate backplate, youve got a balistic missle that finally will start making some fuel mileage...not like the vzb/b01, but noticably better than stock...just my 2 cents and also a very strong agree with tmth3 previous advice on upgrading the standard uncoated xzb cranks....
12-13-2012, 12:39 AM
#4118
I just wanted to put on here, I was forced into a rebuild after 4 gallons on my base XZ-B due to crankshaft slop. No big, was kind of expecting it. So anyway, had a friend with a nearly new speed rod and speed crankshaft, and I also grabbed a speed button from him. Rebuilt it, removing the .1mm copper shim with all the speed parts, and well I must say I am thoroughly impressed.
I have a reedy header with Nvision 2058 pipe, loud ass combo, in my rc8.2, and after all this I was able to go from 7:30 to a tank to 12min to a tank. Definitely doesn't have the insane torque anymore, but wow is it smooth. I think I finally found my perfect combo.
I have a reedy header with Nvision 2058 pipe, loud ass combo, in my rc8.2, and after all this I was able to go from 7:30 to a tank to 12min to a tank. Definitely doesn't have the insane torque anymore, but wow is it smooth. I think I finally found my perfect combo.
12-13-2012, 06:09 AM
#4119
you guys wearing out your crankpins so quickly what fuels are you using ?
12-13-2012, 07:14 AM
#4120
I just put a load of unfiltered dirt through an XZB and the crank spec'd 0.0003" off of stock spec.
12-13-2012, 11:55 AM
#4122
I have had speed cranks last well into the 14+ gallon mark on a couple engines. I usually dont replace the p/s/r, I will just retire the engine and break in a new engine, but the few times I have the crank pin has always been good through the p/s/r changed out at 8 gallons or so.
The VP fuel should be ok. My understanding is that it has the right oils in it.
The VP fuel should be ok. My understanding is that it has the right oils in it.
12-13-2012, 10:54 PM
#4124
if anyone really wants the skinny on fuel....ask somone like Neal, who does it everyday, on every brand, on every fuel, and on engines with much higher than stock stress and loads put on them after mod....its all there when actually private, random, lab tests are performed on all the major brands, every couple months.....I will definetely be reconsidering the fuel I run in 2013!! thanks Neal!!!
12-13-2012, 10:57 PM
#4125
I just wanted to put on here, I was forced into a rebuild after 4 gallons on my base XZ-B due to crankshaft slop. No big, was kind of expecting it. So anyway, had a friend with a nearly new speed rod and speed crankshaft, and I also grabbed a speed button from him. Rebuilt it, removing the .1mm copper shim with all the speed parts, and well I must say I am thoroughly impressed.
I have a reedy header with Nvision 2058 pipe, loud ass combo, in my rc8.2, and after all this I was able to go from 7:30 to a tank to 12min to a tank. Definitely doesn't have the insane torque anymore, but wow is it smooth. I think I finally found my perfect combo.
I have a reedy header with Nvision 2058 pipe, loud ass combo, in my rc8.2, and after all this I was able to go from 7:30 to a tank to 12min to a tank. Definitely doesn't have the insane torque anymore, but wow is it smooth. I think I finally found my perfect combo.
