lol cheers for your concern Miguel, but the 2.5mm overbore is pretty much run of the mill over here, and as long as you look after it by running it in properly, regular oil changes etc, it pretty much takes everything that you can throw at it, as for the 5mm overbore, well to be honest, if I see that Wossner makes a piston that size, and specifically for a DT, then obviously I'm going to have a go at fitting it into an engine, and seeing as how I've researched all the places to on how to engineer it, by replacing the liner for an alloy one then nicosil plating it, I'm going to do that, and if it all works and I get a 145cc bike that runs like Jack ****, then other people will obviously want to have a go, and do the same with their bikes, have a look at some of the other projects in here a couple of lads are doing at the minute, one lad is putting a 200 barrell onto a 125 bottom end, how crazy is that, but looking at what hes done, I reckon it's a goer, another lad is changing his swingarm and suspension from a bike you'd never think would go into a DT, but again hes having a go, if it works it works, if not then its just a case of changing to a different set up. Cost wise I'm already quids in, as the price I paid for a Belgarda 4dl2 engine, plus 38mm Keihin carb, and barrell and head come to just over £100 pounds, you'll need to convert to Euros I know, but I reckon total cost will be about £375 to have the work done that I need doing, making it a total price of say £475-£490, about £50 pounds more than just buying a £440 quid 150cc kit from Germany, and remember I have the full stage 3 Belgarda engine, and a carb for £475, so like I say I'm on to a winner, providing it doesn't all blow up on me I know, but then again I could buy a 150cc kit from Germany and within 2-3 months have that blow up on me too, if say it was starved of 2t oil from the pump.
-- Edited by NEV on Monday 8th of October 2012 03:18:23 PM
But im not concern about the cc's you have, because the engine might run very good aswell. A friend of mine has a dtr 200cc cylinder, those from brasil, i dont know if you are familiar with it!! But you cant just take the cylinder and put it without changing nothing more. but he also needed other cranckshaft, some adjusts on the electrical, ypvs not working(locked), an exhaust made for that cylinder and crankshatf, it has a 38mm keihin too.
the thing that im not understanding is that if your going to re design your cylinder to an allow liner and then nicasil on it, why not make it 56mm(standart measure) and then you.ll have a 125cc that runs as fast as the 145cc or more fast even!! You choose the measure of the cylinder right? Cc's are not everything, and i think that a 5mm oversize piston is to big and heavy for the original cranckshaft. But im thrilled to see that bike running. that engine has a lot of potencial. and it was a pretty good deal mate!!!! here they are very rare and expensive.
im going to talk to you about many situations that happen here in portugal. are you familiar with big bore athena kit 170cc? here he have lots of that, and most people think that you just fit the kit and you'll have a 170cc bike that's overpowerful but that's not that simple!! you'll need to change some stuff to make that run like A 170CC.
go to videos section, i posted there a vid, check it out :)
^^^ wossner do a forged conrod for the dt, thats prob the only other thing to go wrong? last thing anywon needs is a rod through the cases at 12000 rpm lol
Nah not doing owt with the crank, as of yet anyroad, going with the 4mm Wossner piston now instead of the 5mm, mainly so as to be able to use the servo for the powervalve, with the 5mm I would have had to have the powervalve pinned open, due to too much meat being taken off it to suit the overbore, btw Cream, on the Black/Green bike I'm on a 2.5mm overbore and cranks fine on that, and the cylinder volume works out to 135cc , with a 4mm piston it works out to 141cc.
never had a clue what the holes in the back of the pistons were about lol some standard pistons have them,aftermarket don't? need some close-ups of the scoops... wossner don't do nuffin for nothing... if they're on the top of the piston its to open the exhaust port quicker though
looking well! those dimples and hole are to keep the bridges/edges of the port cool with fresh cool mixture to stop seizures? that things gonna be a beast
Game on !! Have managed to get a frame +v5 with the added bonus of it being a 92 frame, plus I didn't have to pay the daft inflated prices I've seen on Ebay or Gumtree, need to get it sent off for powdercoating, and then possibly off elsewhere for another £200 for stuff to be done to it, I'll not say too much at the minute, but all will be revealed in the coming weeks. Deffinately going to go to town on this bike.
Dunno to be honest Calum, I got the bottom end minus the barrel and head, the 4DL cylinder that is meant to be with it, is basically an aggressively ported and gas flowed 3MB one with a circular groove, on the outside of the bore, cut out to take an 'O' ring that sits under the head gasket, the head that goes with the barrel is showing a 4dl head in the parts list, I'm unsure of the difference between the 4dl head and the 3mb one, but will be shoving a 3mb head on anyway and see how that goes, I'll need to be taking some off the inside of the head as the barrel has been re-lined to take the 4mm oversize Wossner piston, and the cylindrical volume will be needed to be changed accordingly with the re-bore. All this is being done as we speak, and should be ready for weekend.
The nicosil plated barrels dissipate heat better than steel lined ones, therefore are used for Endurance/distance, whereas the steel lined were for speed
Been getting all stuff ready for powdercoating, took bearings out of swingarm and wheels yesterday, just trying to find who's best and cheapest to take it all to, engine is all done and waiting to go back in, working on white bike next week to get ready for MOT, Black bike sailed through its MOT so that's on road, awaiting you and your trusty steed to get ready for bike night, you gonna be ready for May? I think that's when it starts
Woow can't believe I'm only seeing this now!! really REALLY interesting project here nev mate!! Loving the engine, looks absolutely mint!! Can't wait to see this all put together!!
Cheers Skint, engine is pretty much there, barring a 4dl reed valve intake, that I'm keeping my eyes open for, I can doctor a normal sized one to fit, but the 4dl is much bigger as it takes a much bigger carb than the standard TZR one does, and possibly looking at putting a KTM V-force reed block on it too, dropping off stuff next week for powdercoating, so that'll be another job out of the way. but am toying with the idea of gusseting the frame before I do, as the extra power may need some added strength on the frame.