Big Bore Kit...

[Crazy Beetle]

well im not asking would it be more powerfull than a stock, i am asking how much more???


confusion........mg:

its much more powerful.
FG says the engines in their models give about 3,9 HP. Zenoah tells you yhat the same engine gives 2,9 HP.
i belive that Zenoah gives the right numbers for the engines.
You wount finde any numbers on the HP in an OBR engine. but a 27,2 Reed engien make about 6 HP with the RN tuning pipe and a litlle less with a FG or Jetpro pipe.

i will probobly blow you mind when you get the engine in the car and tued right.

if you have bougt a top end kit take your time and port the crank case så it matches with the top, dotn take mutch juste round out the edges and open up som that the case and sylinder matches. that will give you som exstra power. it will work just fien with the stock crank case to but you wount get that litle exstra. if you have bought a race ported kit take the extra time and martch the insulator yo yhe topp anf the cartb. do the same on the exhaust side of the engine.

 

[dc2 man]

its much more powerful.
FG says the engines in their models give about 3,9 HP. Zenoah tells you yhat the same engine gives 2,9 HP.
i belive that Zenoah gives the right numbers for the engines.
You wount finde any numbers on the HP in an OBR engine. but a 27,2 Reed engien make about 6 HP with the RN tuning pipe and a litlle less with a FG or Jetpro pipe.

i will probobly blow you mind when you get the engine in the car and tued right.

if you have bougt a top end kit take your time and port the crank case så it matches with the top, dotn take mutch juste round out the edges and open up som that the case and sylinder matches. that will give you som exstra power. it will work just fien with the stock crank case to but you wount get that litle exstra. if you have bought a race ported kit take the extra time and martch the insulator yo yhe topp anf the cartb. do the same on the exhaust side of the engine.

yes it is a race ported kit crazy beetle,and thanks for the info,very good info as usual.
i got the race ported kit with 2mm crank,o neill says he ships all the nessary gaskets with this kit so no stacking them either.

i need to get the rn pipe,has your friend any right now??
maybe i could buy that from your friens as i didnt buy the engine,you see ££ was my reason for buying the cheaper head kit solution.

do you know something crazy beetle,the jetpro is a crap fitting pipe,the rn looks a lot better in build quality,i am taking the jetpro to garage everyday almost to get it welded,it keeps braking up,the mounting position on the gearplate is a disaster...i drilled new hole and everything but it is just not a good pipe fitment wise. but it performs great and looks great,all said and done i agree with you crazy beetle the rn tuning pipe is gorgeous

 

[CALIC]

Am thinking of getting the the bore kit wid reed but if i fit the reed in would the stock air filter touch the jetpro pipe from the back?

And will it make big diffrence if i get a reed or not?

 

[Ducky]

Am thinking of getting the the bore kit wid reed but if i fit the reed in would the stock air filter touch the jetpro pipe from the back?

And will it make big diffrence if i get a reed or not?

From what I've seen unless you go for something like the TS reed cases which have been designed for reed use from the start, I don't think you will see much gain from using the carb reed kit.

 

[mooman007uk]

i got a oneills 28.5 reed ported and a 28.5 race ported and there is a difference in the 2, the reed has a broader spread of power and more bottom end...i don't think the top end power is any different though from my personal experience. The TS is the best option for reed though as it's crankcase induction which is the best set up
Shame there isn't a zen/cy based powervalve engine...wow wouldn't that be nicemg:

 

[dc2 man]

i got a oneills 28.5 reed ported and a 28.5 race ported and there is a difference in the 2, the reed has a broader spread of power and more bottom end...i don't think the top end power is any different though from my personal experience. The TS is the best option for reed though as it's crankcase induction which is the best set up
Shame there isn't a zen/cy based powervalve engine...wow wouldn't that be nicemg:

god yes mooman wouldnt that be class...
be like hitting vtec :lol:

i suppose the reason they cant is because these small two stroke engines are much higher revving than a normal bike sized like say 125 or 250 cc,put it to you this way,the bike engines need the powervalve to get them going its just like an extra shot of fuel really where the small 26cc or likewise is already in the power from the off and much higher revving an in turn would not benefit from a powervalve,wouldnt even be noticed if fitted to an engine of such a high revving nature.

bike say example 125cc two stroke powervalve-max revs 11500
zenoah 26cc max revs- 22000rpm

hope this much needed information helped :lol:

 

[mooman007uk]

The powervalve on the old Yam RD250/350 altered the exhaust port timing, it was crankcase induction with the powervalve...made huge power over the older rd aircooled..i rode both...i reckon a small powervalve motor could be made and offer big power increase but would cost some, it was a mecanical valve...before the time of ecu's..so could be done with patience, the knowledge and access to the right tools

 

[Crazy Beetle]

The Reed engien give more low and mid range power. the topp end is the same on the race ported and reed ported. the difference iss that tha race ported revs a little higher.
a race ported can reach 22000 rpm. the reed engones top out at about 20000 rpm. at stock 26cc zen tops out betwen 16500-18000 rpm.

OBR milles the combustion chamber so that it accepts the 2 mm longer stroke.
the tek oyu about 0,75mm to make rom for the piston thats moves 1 mm longer in the sylinder, and at the same time the alter th compresion rate in the engine. this means that you don't have to stack gaskets to get enough
clerance and the right compresin rate.

Rc-RAcign hav e the monster fat power in stock. the last time i was in his shop he only had the RN tuning pipe for FG´s monster models
ite a great pipe specialy with the race ported engiens. this pipe give a bit more low end grunt than the RN pipe made for the marder.
check otu www.rc-racing.no ore give him a call and you will get the help you need

 

[Bknate]

I just put a (CAD Power 27cc Race Engine) in my Baja with the Two Speed and RN Tuning Fat Power Pipe on it, and I can't even control it. I had it clocked at 74mph and we taped it also, as soon as I get the video from my friend I'm going to upload it for you guys.

 

[CALIC]

Crazy B how much is that pipe in USD or GBP?

 

[mooman007uk]

I just put a (CAD Power 27cc Race Engine) in my Baja with the Two Speed and RN Tuning Fat Power Pipe on it, and I can't even control it. I had it clocked at 74mph and we taped it also, as soon as I get the video from my friend I'm going to upload it for you guys.

you got a picture? i want to see how much of the body you had to trim, if it don't look to bad I'll get the 6012

 

[dc2 man]

hello lads hope i am not changing your conversation here,i just want to find out if there was anything else i could do to my big bore kit when it arrives,as in match up ports or enlarge them,some people have reccomended this to me,but tbh i wouldnt have a clue what to do,like crazy beetle told me to match the isolator block aka intake manifold to the new port on the head kit...and he also suggested to do the same with the exhaust port.

i presumed all this should be done already to this kit...

just to remind the kit is a race ported o neills 27.2 with 2mm stuffed stroker crank,zenoah.

should i let it as is?

any ideas?

 

[Bigger the Better]

https://www.largescaleforums.com/forum/showthread.php?t=1769

Thats the insulator.

Not sure on the rest.:no:

 

[dred69]

inquire

:dots:

The Reed engien give more low and mid range power. the topp end is the same on the race ported and reed ported. the difference iss that tha race ported revs a little higher.
a race ported can reach 22000 rpm. the reed engones top out at about 20000 rpm. at stock 26cc zen tops out betwen 16500-18000 rpm.

OBR milles the combustion chamber so that it accepts the 2 mm longer stroke.
the tek oyu about 0,75mm to make rom for the piston thats moves 1 mm longer in the sylinder, and at the same time the alter th compresion rate in the engine. this means that you don't have to stack gaskets to get enough
clerance and the right compresin rate.

Rc-RAcign hav e the monster fat power in stock. the last time i was in his shop he only had the RN tuning pipe for FG´s monster models
ite a great pipe specialy with the race ported engiens. this pipe give a bit more low end grunt than the RN pipe made for the marder.
check otu www.rc-racing.no ore give him a call and you will get the help you need

i need the phone number,to your friend shop ive been trying to get this pipe forever no luck ive gave up. i would love to have that pipe for my monster mt

 

[mooman007uk]

first pic you'll see at the 4 corners of the inside of the case are machined and ground a little to match the size of the ported head at the transfers in the second pic...just rounding out the corners so there are no steps between the case and head. The cy case has this done already...i just had to open the one corner out a bit more(the rougher one)
the plastic insulator block or intake manifold you'll want to shape to match the intake port again so it's smooth and no steps or ridges between the two. Real easy to do with a dremel and cutting bit....just take your time and remove small amounts of material at a time..

 

[dc2 man]

did you do that mooman,very nice man

what kit is that?
listen any chance you could post up pics or something of what needs to be done to intake manifold please as i am getting my kit early next week awaiting shipping now,i just want to know what i need to do to it before i bolt it on.

i am using the cy bottom with new fast eddy bearings..

 

[dc2 man]

https://www.largescaleforums.com/forum/showthread.php?t=1769

Thats the insulator.

Not sure on the rest.:no:

cheers btb for that link,just saw that now.

so how do i do this without a dremel......mmmmmm?

 

[Clubin]

cheers btb for that link,just saw that now.

so how do i do this without a dremel......mmmmmm?

Dremel is cheap, and will last forever. I prefer the cy intake over the Zenoah one the brass threaded inserts pull out of the Zenoah ones. , the only thing I have done with the cy ones is I screw a couple screws into the manifold and full the area where the nuts are with JB weld, let it set unscrew the bolts drill them through, tap the holes and sand the insulator flat on some wet/dry sandpaper till flat, it gives the gasket a bigger area to seat on. I still prefer the Aluminum manifolds, but the cy manifolds with that mod are a close second.

 

[mooman007uk]

I didn't port the head just cleaned and smoothed up a bit under the intake where the transfers are cut out (I'm a bit too fussy) , it's an oneills 28.5 race ported head. the case is cy and I only removed material from the rougher looking corner, didn't have the right cutter so used a cone abrasive bit.
I'm using the cy intake manifold opened out to match the intake in the head....

 

[dc2 man]

do you know something there is a whole host of problems to be encountered with these machines on the way to building a reliable machine.
i think everybody gets trouble with the carb bracket that holds it in place on the intake manifold,my one on the zenoah became pure worn and loose and as you said them small brass fitting were not fitting great anymore so i had to use a new one..

annoying to say the least because my old engine was prob sucking in air at the point where the k&n is mounted on.

you see its the weight of the carb/airfilter/jubilee clips with pressure on the carb and combine that with all the vibrations of the car when driving and thats where our problems start lol