Is the engine in the pp 140xr better than dhz 140?

[edzy]

whats better?
engine in the pp 140xr better than dhz 140?

 

[pmc.21]

unless im wrong, im pretty sure there the same, unless the DHZ has the 55, but i no the 140XR has the 56

 

[Le|Garage]

They have the same big valve head (27/23). and same 5 plate clutch. But the dhz engine makes the displacement with the 59mm stroke. You can add 56mm bore to it and make a potentially bigger displace engine. The other engine (56mm bore) can't go as big without an offset pin stroker crank.

The one with the 56mm bore should rev higher but be short on a little torque.

 

[Cactus Jack]

Here's what the seller of 1P56FMJ engines told me they are ..........

Question:

Hi , can you guarantee that these engines have a 59 mm stroked crank and how tall is the cylinder measured in mm ? Also , do they have a standard type flywheel or on inner rotor type ? Thanks - John .

The sellers reply :

hey john. i dont know or have the technical specifications of the engine so i cannot confirm the sizes you are asking about.all i can tell you is the engine has the model no 1p56fmj stamped on on the case. i do know lifan make a lot of differant engines with the same base model numbers but differant specs. i can see that the engine uses a standard flywheel setup though

Follow up reply from the seller :

Dear John, just getting back to you with further information about the 1P56FMJ engine. The engine is assembled by YX Motorsports and it built from a combination of Lifan, Jialing and YX parts. This is the same manufacture that GPX branded engines come from in the USA. We order the engines with standard flywheel due to quality issues with the chinese IRK's. From a reliablity standpoint they are superior to the Lifan 140cc 1P55 engine as they do not have the kick starter gear issues. A race cam fitted. The bore is 55mm and the stroke is 59mm, therefore it is definately a genuine 140cc. We are happy to sell the engine with a money back guarantee. If you require additional information, please do not hesitate to ask.

Further follow up by the seller :

Hey mate, sorry I made an error with my previous message. The engine has a 56mm bore and 57mm stroke, making them 140.39cc. Therefore, no they do not have a 59mm stroked crank. Let me know if this is the engine you are after.

 

[Cactus Jack]

Here is where the confusion lies with this seller :

He says that this engine with a short alloy cylinder is the 1P56FMJ and claims it is better than a Lifan 140 even though he's listed it as a Lifan 140 .

http://i12.ebayimg.com/03/i/000/c6/10/194f_12.JPG

http://i6.ebayimg.com/08/i/000/c6/10/18e1_12.JPG

Then there's the Pit Pro 140XR which they say has a 1P56FMJ Lifan 140 in it . The real question is ...... does the 140XR have the above alloy cylindered type of engine .

Or this type which DHZ sells :

http://home.exetel.com.au/miumiuxuxu1/DB/140enginenew1.jpg

The Lifan 1P55FMJ has 10.0 to 1 compression ........

Big Bore 140cc LIFAN Oil Cooled Engine
Model: 1P55FMJ
Type - 4 Stroke Single Cylinder
Compression Ratio - 10:1

The Pit pro engine ONLY has 9.0 to 1 compression so it's easy for the seller to "claim" the kick start gears have been "strengthened" . They have less chance of breaking purely because they are under less strain due to the lower compression ..

Engine Specifications
Engine Model Genuine 1P56FMJ 140cc Lifan Big Bore Factory Race Engine
Engine Type Single cylinder, 4 stroke, oil cooled, horizontal cylinder
Brand Lifan
Compression Ratio 9.0:1

 

[pb performance]

hmmm, So this confirms the info that I didn't want to talk about in the poll thread about which is better !!!!

That these motors (56) are not made by Lifan !!

I was told by someone that has a good contact at Lifan and they said they dont make a motor with a PN of 1P56FMJ !!

 

[Cactus Jack]

For those people who imagine alloy cylinders to be superior to iron cylinders .... THINK again ! Chevrolet's top of the line "maximum" effort competition blocks are tall deck IRON blocks ........

And Honda seems to agree also ....... just check out what they use on their stock CRF50's , CT110 posty bikes etc ........ they KNOW that these engines will get used for long hours in summer heat and that kids will rev them relentlessly at low speeds in low gears for hours on end ....... iron is more heat stable than alloy . Alloy engines stall all the time when they get hot ...... that would piss a posty off ..... the engine gets started in the morning and runs just about all day long for millions of miles ........ RELIABLY ....... You'll also find that Lifan has used an iron cylinder for the very same reasons .... Incidentally , most aircraft ALSO use iron cylinders for safety and reliability reasons ...... despite the weight factor .....

Read the specs on the Bowtie iron block and the Rocket block ......

GMP SBC Block

Air-Cooled Cylinders 3

 

[MasterSpoon]

ok went and had a look at my engine this arvo
my bike is from the first lot of the pitpro xr140's and has the 1p56fmj motor and the IRK. It is not the alloy cylinder (magnet sticks to it),it has a alloy head, oil cooler is fed from a plate on the head just infront of the spark plug, could not spot the lifan logo or anything on it but I may be going blind....
I took some photo's but won't have time to upload them to tomorrow arvo.

On a side not it has some of the fins on the cylinder trimmed down from factory for clearance for the carbie.

 

[MasterSpoon]

ok not sure if these pics will be of any help
http://thompson.homedns.org/wayne/pitbike/engine pics/1.jpg
http://thompson.homedns.org/wayne/pitbike/engine pics/2.jpg
http://thompson.homedns.org/wayne/pitbike/engine pics/3.jpg
http://thompson.homedns.org/wayne/pitbike/engine pics/4.jpg
http://thompson.homedns.org/wayne/pitbike/engine pics/5.jpg
http://thompson.homedns.org/wayne/pitbike/engine pics/6.jpg
http://thompson.homedns.org/wayne/pitbike/engine pics/7.jpg
http://thompson.homedns.org/wayne/pitbike/engine pics/8.jpg
http://thompson.homedns.org/wayne/pitbike/engine pics/9.jpg

does that help you at all cactus jack?

 

[RYNNO]

the 08 xr has the 56 the 07 xr has the 55
the dhz has a 55.
the 56 are not exactly lifans, they are jailing motors as i was told at the moto expo and theirs been alot of talk about the lifans listing their 56 as a lifan where as it is a jailing.
the 56 are the same motors running in motovert, and im pretty sure moto vert are runing jailings!
the 56 is just that tad more reliable in starting gears!

 

[themountain]

the 56mm is from yx...has nothing to do neither with Lifan nor with Jialing...they have bigvalve heads , a better cam and a different gearbox then the others!!

 

[Cactus Jack]

Yes rynno and mountain are correct ..... just by looking at that engine and comparing it to a new Lifan 140 ..... although his cylinder IS iron , it's totally different to the Lifan 140 .... which has a notch cut out of every top fin near the crank cases and has 140 cm3 cast on the right hand side ..... the head isn't even a Lifan BVH ....... The sticker doesn't have NEAR enough numbers on it ..... the intake manifold isn't a Lifan 56-2 DC and the carb looks like it doesn't line up properly with the manifold flange ... it's definitely NOT a Lifan 140 ....... and to top it off .. IF his cylinder isn't 78 mm tall ...... then it most certainly doesn't have a 59 mm crank .....

They may be a good motor ..... only the actual owners will know that ......

But .... as they say ....... Forgery is the best form of flattery .........

 

[MITTZ]

but isnt a jailing motor better than lifan? thats what your saying isnt it, that its a jailing not a lifan?

 

[Cactus Jack]

LOL ... The sellers of Jialing would like to have you believe they're better than Lifan ...... Lifan is the biggest selling engine from China so the others are after a slice of the pie ..... Lifan had the 140 in it's popular form first .... now others are copying ..... work it out mate !!!!

Go to Planet Minis and see all the problems they have with Jialings bored to 140 and up ..... even Hondas bust kick starter gears if they're kicked roughly when they're bored and stroked to 140 ....... even TT500 Yamahas had a viewing glass so you knew when their cranks were in the right position to kick them over .....

The 56 has 9 to 1 compression ...... the 55 has 10 to 1 and probably a 2 mm longer stroke ...... so of course it needs to be kicked over properly ...... even a cam with longer duration lets some of the compression escape at cranking speeds and will make things easier on the kick start gears .....

 

[MITTZ]

so all this hype about the 08 pitpro xr40 having a better engine that my mso is crap! woop woop

 

[motoXXX]

abit of topic but how should u kick start your engine i get mine ot top dead centre or wateva it feels hard then give it a big kick mostly start first time when warm but about 2-3 if its cold

 

[MasterSpoon]

from what I can tell so far the motor in mine seems quite good.
Has enough power and runs good
thats good enough for me, just means if I wanna build a race motor I'll get a lifan 55 140 and do it up, personally I wouldn't be put off getting a XR140 simply because its a XY donk

 

[MITTZ]

take that goose!!!! lol

 

[pb performance]

once you have the piston just passed TDC on the compression stroke and you let the kick starter come back up, make sure you slowly lower the kick starter back down till you feel the starter gears engage !! Then push through the rest of the cycle with a firm solid kick !!

If it don't start, which normally they do hot or cold (if cold use choke) then start from the top of this walk through again !!

Don't just start kicking it like its a warn out old smokey 2 stroke !!!! or them starter gears wont last long at all !!!

 

[Cactus Jack]

abit of topic but how should u kick start your engine i get mine ot top dead centre or wateva it feels hard then give it a big kick mostly start first time when warm but about 2-3 if its cold

That's PRECISELY the quickest way to bust your kick starter gears and cases ....

What you should do is feel for TDC on the compression stroke (the hardest part) then slowly get it just past that point ....... THEN give a hard , full range kick . It's quick short stabbing at the kick starter that busts gears and things .......

The reasons why you want to get the piston past TDC on the compression stroke and kick fast and hard are :

1) the engine CAN'T kick back for nearly another 2 crank turns (700 degrees) since the plug has already fired . THINK about it ..... combustion is powerful enough to drive the bike ...... when the engine kicks back , you are trying to compress exploding and expanding gasses so you are putting the kick mechanism thru huge stress for which NO kick starter on the planet is designed to handle . IRK's are notorious for causing kick back ..... so if you've ever broken a kickstarter with an IRK fitted ..... then you now know why ......

2) the reason why you need to give a good hard , full range kick after TDC .... is so that the kick start mechanism is rotating FAST .... thereby giving an attempted kick back less time for the gasses to expand and overload the parts . When gears are turning fast , the shock of the load is passed over multiple gear teeth thru far greater mechanical turning moments (degrees of rotation) . So no gear tooth in particular bears the brunt of the load long enough for the stress to concentrate and cause it to fail . Also , when the hard part in the cranking hits , the lever will be trying to push the kick gears and shaft forward into the strong part of the cases rather than downwards or rearwards .

The only options are .... to lower the compression and accept less power ....... fit a decompression device ........ clutch start the engine ......OR adhere rigidly to the starting method outlined above .......