Lifan 2.5 in a Cranny

HOLY CARP THAT IS A MONSTER. The price is certainly right on it. I was thinking the harbor friend for the next build but I'm going to look into that one.
 
Wow, thats a unique installation. What kind of top speed are you getting? Any idea as to engine rpms? When I factored in my ratios I used 4k. Im sure it will turn more, just being conserative. Does it run pretty smooth?
 
I'm running a 9:1 ratio (confirmed by turning the drive wheel one complete revolution & the clutch drum turning just a hair over 9X's).
With the governor bypassed, it gets a bit more rpm's but I'm not sure how many.
I've seen advertising for these engines & they say it runs 4250 rpm's governed.
I've got a bike speedo calibrated correctly (by rollout) & it shows I am just hitting 50 mph on the flats in a full aero tuck position. I can cruise at 35-40 at half throttle sitting up.
This engine is great, & has torque everywhere from a dead stop on up to redline.
I highly recommend this Lifan (even has a cast iron sleeve).
The bike is a Downhill MTB & made for going down nasty mountain terrain fast.
I dropped the fork tubes a few inches in the triple clamps for better road geometry & still get the full 7" of travel both front & rear.
Handling is very motorcycle like & the extra weight of the engine out front actually aids the balance & handling at high speed.
-Lowracer-
 
What can you say, but thats just killer! I can see my next project now, I have a full suspension MTB gathering dust in the garage. Not anything exotic like that one, but a good start. What was the problem with the stock exhaust? I wanted to use it on the Cranny but it interfered with the belt. Looks like it would clear on your bike, a deflector would keep it off ya. My goal was to use the engine out of the box.
 
cannonball2 said:
What can you say, but thats just killer! I can see my next project now, I have a full suspension MTB gathering dust in the garage. Not anything exotic like that one, but a good start. What was the problem with the stock exhaust? I wanted to use it on the Cranny but it interfered with the belt. Looks like it would clear on your bike, a deflector would keep it off ya. My goal was to use the engine out of the box.
Click to expand...

cannonball2,
I tried the stock exhaust when I 1st built it & the exhaust blew right onto me & my clothes...Yuck!
I thought about a deflector, but once moving the air would blow it straight back again onto me?
I bought some flex pipe from a mobile pressure washing co. online, cut some extra tubing off my seatpost & cut a poo-poo pipe for the header. Then a $6 sausage muffler from the local ACE Hardware store to cap things off. Found some Profile aerobar clamps & another old bicycle stem to clamp everything together with Permatex gasket goo at the seams. It works real well & sounds good too. Has a Thumper 4 stroke dirtbike sound to it now. I also like the exhaust down low towards the ground & as far away from my clothes as possible...lol
-Lowracer-
 
Kinda what I figured on the deflector idea. Was just looking at my MTB, looks like it is feasible to mount the engine on the rear. How is your rim/sheeve attatched to the wheel? Just what I need to start lining up another project before the Cranny is finished, but hey thats the way I roll. I am really amazed the little engine pulls a 9:1 ratio so well, should climb hills, which we have a lot of, well with my 13.9:1 then.
 
If I could do another sheave build up, I'd definitely go for some Velocity Deep V MTB rims to make the drilling thru & bolting together that much simpler. I'd even space the two rims apart with some aluminum stock providing fork or rear stay clearance would allow to allow a wider tire (increases belt to tire clearance).
-lowracer-
 
I found the motor online at home depot. There were none on ebay. Too bad they won't do free shipping to the store.
 
Cannonball2,
I'd like to see close up pics of your engine mount.
Did you retain the Lifan engine mounting plate or remove it to reduce height & use the bolt holes for engine mount holes?
In-frame could be on my list of future projects & I'd definitely use another Lifan 2.5
-Lowracer-
 
That shipping is a handful. That brings the price eight up to the Harbor Freight Greyhound of the same size. I think I might go with it next time it's on sale. I like the idea of walking in and picking it up. Also having a place to return it if the things goes sideways.

But thanks for the information guys. You know i need to check the weight of the motors one might be significantly lighter.
 
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deacon,
I think the HF Greyhound is a 79cc engine & the Lifan 152F is 98cc. Probably some difference in torque though both engines are rated at 2.5 HP
-lowracer-
 
I just checked and found that yes and the greyhound is actually a tiny bit heavier for some reason. less than a pound for sure. I am running a 3hp 2 cycle now and it is a little bigger than either but I find the torgue is excellent at all speeds. The max rpms are a little low on mine I think. It came from a snow blower. Since it is on a direct friction drive, I am going to try a larger roller, but not too much since the roller is welded on. I can go up a hair in size but I wont be able to come back down.

I'm thinking with that torque, it should handle a little more roller size no sweat. I would like to get the max roller size figured out before I go to the better engine.

I do have a question, does the four stroke have better torque than the two or is that just an illusion. I know that the four stroke engines in the friction kits have less cc than the two stroke.
 
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lowracer said:
Cannonball2,
I'd like to see close up pics of your engine mount.
Did you retain the Lifan engine mounting plate or remove it to reduce height & use the bolt holes for engine mount holes?
In-frame could be on my list of future projects & I'd definitely use another Lifan 2.5
-Lowracer-
Click to expand...

The real trick was flipping the steel mount around to get the offset I needed, hole sawing a 1/14" hole which was then opened up with a band saw to allow the mount to fit around the front frame tube. I could have run the engine bolting it directly but it would require the use of wider angle to mount it and the bolts on the left side may have not cleared the angle vertical, so I just modded the stock mount. This engine is so compact that height is not an issue in a standard cruiser frame if the mount is modded like mine.
 

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Cannonball2,
Wow, you really got that thing in there just perfect.
I dont think I would be able to do that!
I really like it.
If you went real wide on the bottom bracket axle, do u think you could get the pedal option too?
-Lowracer-
 
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lowracer said:
Cannonball2,
Wow, you really got that thing in there just perfect.
I dont think I would be able to do that!
I really like it.
If you went real wide on the bottom bracket axle, do u think you could get the pedal option too?
-Lowracer-
Click to expand...

It was possible to have pedals, this is a loose interpretation of the Popular Mechanics power bike from the 50s. Floor boards were part of its charm. The Grubee pedal set for the G4 kit from Kings would have had plenty of width. The Lifan is actually narrower than the HS/G4 engine/trans. Should be no problem to juggle things around a bit for the pedals. I have a G4 set up on another bike with the above pedal set, they are the widest I have seen.
 
cannonball2,
Now I gotta go check out the Kings website...lol
Always a project waiting in the wings.
I've done a few rear rack & front rack MB's now, but have yet to tackle the in-frame.
I think for weight distribution & center of gravity, the in-frame is the best of both worlds, but I've always been a pedaler & never wanted to go China-girl kit. This could be the ticket...
Thanks!
-Lowracer-
 
No problem. This little engine is so compact, in my frame there was room to move it higher if necessary. Not having pedals I dropped as low as possible, modding the mount is the key. What type bike is next?
 
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