Lifan Performance Cam

[Meko]

Hey guys, I noticed this on Ebay - what do ya rekon?
eBay Australia: CRF50 140cc RACE CAM 7mm LIFT THUMPSTAR PITBIKE (item 120123627946, end time 29-May-07 13:59:58 AEST)

 

[mr_sikma]

could be interesting

 

[tubes380]

would have to try it out to see what happens

 

[themountain]

I guess they are Akunar Cams.....and they are crap!!...Quality is expensive!!
look under akunar cam in Planetminis!!

 

[themountain]

would have to try it out to see what happens

...you don´t want to joke around with a cam......that can cause seeeerious damage!!!!

 

[Le|Garage]

Hey there, yes i think most of the items in his store are akunar items..what i have read so far about akunar cams are they are garbage...

with a cam with 7mm lift, i would think you'd need stronger valve springs...

 

[epod]

Don't rubbish Akunar.

Hey fella's, ranuka from akunar is a great mechanic and great bloke. I use his 7mm cam and high comp piston. And they work amzingly. So don't be a ****** who is only into name brands. Marketing cost as much as manufacturing these days, hance the rediculaious prices some companies ask. The old saying you get what you pay for just does not apply to everything these days. A smart consummer can always find a better deal. Akuna run a 176cc pitty that would blow anything in oz the the weeds, so don't rubbish those guys, you'll just damage the industry.

 

[Meko]

Hey Epod, what motor you running mate? I agree that not everything out of Asia is crap and its just a matter of sussing things out, thats why I started this thread. Thanks everyone for voicing your opinion, its what makes this forum great - Anyone else using Akunar gear?

 

[Mack]

Yes you need race springs for 7mm lift. There is a lot to cams. Lift is nothing. There are a ton of cams out there with 6.9-7mm lift, but they all perform completely differently depending on the lobe profile and centres. Also the durations and retard/advance of the cam in the engine.
Little real development has gone into cams for these engines IMO. It has been a case of adapting already existing profiles from other engines.The best performers so far are aftermarket Honda cams which have been adapted to suit. You'll find most of these other sellers have had China copy these Honda cams and had cheaper quality ones made. Another thing which has been done is to grind the base circle off a stock cam which increases the lift and duration to a small degree, but is a very unsatisfactory way of altering a cam. The thing about using cams well designed for Honda's, is that the 50 Honda head and engine is really a completely different machine than something like the Lifan with a BVH. The bore/stroke/rod ratio is completely different and changes the cam requirements completely. Why do you think a built 124 Honda makes so much power compared to a built 125 China? Its simple, the Honda has been developed properly. A 125 Lifan can be developed to the same level, but it won't be done using a Honda cam.
Cams sold to the general public are made also so that anyone can drop one in without degreeing the cam properly and get away with the cam being out by a fair amount without risk of things colliding.
Having taken note of all that, you will still see a good improvement in your power output by carefully picking out available cams you have heard are good for the type of output you want. If you know what your on about, and have a specific cam requirement, PM me.

BTW- that guy has 2 neutral's and 2 negative feedbacks out of only a small amount of sales. That is always a warning sign for me.

 

[Le|Garage]

wasn't supposed to sound like i was bagging akuna, i personally have dealed with ranunka and run their high compression piston 28/24 valves.and they are great.

But i spoke from what i've heard about the cam from them. Mack, can you get z40 cam's and valve springs to suit? cheers

 

[Mack]

I have my own grinds. I can do similar to z40 except bigger and meaner. Springs are a must for nearly any cam run in these heads with over 6.5mm lift because the stock springs are close to binding after this.

EDIT- I can put any lobe centre alterations and advance/retard on the cam, also increase or decrease the exhaust/inlet ratio. If you deck the head or machine the barrel I can also set the cam to the degree your out after machining. No slotting sprockets.

 

[andy600rr]

From memory Rovaza can supply a Z40 & springs to suit the 140 Lifan.

 

[dhz138]

hey people

yeh, dont knock AKUNAR.. Im just about to get my new cylinder, high comp piston and 7mm lift cam, 28/24 valves as well as my head port & polished and bored out.

Ranuka does seem like a great bloke, and has great customer service..

EDIT - is it worth buying the 7mm lift cam from AKUNAR ? or should i go else where ?

 

[daimojay]

mack, if i sent a stock lifan BVH cam, can u re profile it?

 

[WyldOne]

Tryed looking at the ebay link but didn't work. Anyone got a pick of these cams and would it be worth buying one?

 

[numroe]

EDIT - is it worth buying the 7mm lift cam from AKUNAR ? or should i go else where ?

The head on my 140 has an Akunar A1 bottom end 6.7mm lift cam. Akunar valves and springs too. It all did wonders to the performance. As did the carb setup and inlet port matching. I generally ride it pretty hard until I feel the both the engine and shock starting to fade due to heat build up, but after about 15hrs the head is running fine. I use Rimula-X oil and change it ever ride (per 2 hrs). Note I did crack the 140 engine casing on the clutch shaft. Most likely due to kickback issues upon incorrect starting.

On the Lifan 140, the inlet valve needed more clearance on the piston crown. The updated engine output was ample, so I'd suggest 6.7mm is enough lift for MX tracks. The modified head worked so well, that I plan to put it on my Lifan 150. My goal is to beef up the bottom end torque and spread out the usable torque rpm range in the 150. I am pretty sure it will work nicely. The stock 150 cam has a very noticeable mid range rpm "hit" which for my needs is slow. I'll test it ASAP, but I am not home much this winter so not sure when.