Oil injection! I'm gonna do it!

GoldenMotor.com

LS614

Active Member
Dec 22, 2009
1,236
3
36
CT and MA
Okay everyone! Here's my proposal. I have been researching my butt off the past few days and I decided it is perfectly possible to do an oil injection system on a bike so there is no more premix and you can fill up anywhere. Here's how I plan to do it. Basically an oil pump for a two stroke needs to be driven by the engine in some way so that the pump is actually moving oil. There is also a linkage that is operated at the same time you twist the throttle so that your engine is getting more oil at higher rpms and so it doesn't run dry on hills. The pump I plan to use is this one Oil Pump Assembly because I feel it will fit nicely under the engine in the place that I imagine. I picture cutting off some of the clutch housing so that I can take a small bevel gear like this </title> <base href="http://www.bicycle-engines.com/"> <meta name="description" content=" - 2-Stroke Engine Kits,4-Stroke Engine Kits,2-Stroke Parts,4-Stroke Parts,4-Stroke Engines,2-Stroke Engines,GT Series Bicycles," /> <meta name="keywords" conten with the exact same number of teeth as the other small bevel gear and put it on the shaft of the oil pump. I have figured out since the small bevel has 24 teeth and the big bevel has 80 or 82, that it would drive the pump at a ratio of 4:1 off the big bevel. This would however mean that it is actually turning the pump at an equal rpm to that of the crankshaft. I know that this is not an insane thing to do because the pumps on tomos mopeds are directly connected to the crankshaft, these pumps pump very little for the speed they are going. Most motorcycle autolube systems run at a ratio of 3:1 or more, so I know this will be fine :) The easiest way I have found to deliver the oil from the pump to the engine is to make a system just like this http://www.dansmc.com/yam_autolube4.JPG This is a very easy system where the oil is simply fed directly into the intake manifold and pulled in with the suction of the engine. I will install a checkvalve on the intake manifold to prevent blowback, as air bubbles in the lubrication system could prove detrimental to the engine internals. The picture below is a picture I did on pain with my laptop track pad so don't make fun of my drawing skills :D Also, the rusty clutch was the best pick I could find :( Hope you enjoy this thread!

 

LS614

Active Member
Dec 22, 2009
1,236
3
36
CT and MA
I'm surprised that so many people have looked but no one is saying anything. I know people have made claims before so is everyone just thinking "I'll see it when he does it"?
I'm buying parts this weekend and I'll start developing my system soon :)
 

BarelyAWake

New Member
Jul 21, 2009
7,194
21
0
Maine
Well, in my opinion - although perfectly valid and quite an innovative undertaking, in fact kudos to ya for striving to improve your motor to exactly what ya want...

It's... well, a touch dicey in that any oil injection system is (perhaps even just slightly) less trustworthy than simply premixing. Yes, they've been proven reliable - I'll admit to a bit of a grudge, I seized my beloved Honda MB5 (49cc 2 stroke motorcycle) due to a faulty injector.

I've never really forgiven oil injection systems lol :oops:

I'm sure there's some "I'll see it when he does it" and a touch of general skepticism regarding oil injection for this application - but don't underrate pageviews, while no doubt you'll get more and more comments as you make progress, pageviews are by no means less important - each and every view is someone interested, somebody that wants ta see jus' what yer up too ;)

Personally? I'm jus' as happy with pageviews as comments - sure I love the feedback & babble ofc, the feedback is very educational to say the least... but bear in mind the more you stray off the path of the known, the less advice & comments you'll get as you're the one doin' the experimentation, until you've a bit more to show what's goin' on - yer kinda on yer own a bit if ya know what I mean...
 

LS614

Active Member
Dec 22, 2009
1,236
3
36
CT and MA
Thanks Barely, you're right about that! Pageviews are also good :) As for oil injection systems, yeah, they die, and that really sucks. If it were a japanese bike that I was doing this for I would think myself crazy, but I really don't mind on the chinagirls because they are SOO cheap to replace that I can trash an engine through a failed experiment and try again on another the next week :D Developing a product may prove to be too daunting of a task, but I certainly think if I can get it to work it will be a really cool thing to talk about at rallies :D :D :D
 

matthurd

New Member
Dec 13, 2010
817
2
0
manchester NH
if i was worried about not mixing i'd have just gone with a 4 stroke :p

i wouldn't try it because getting the ratio to work just right could be a problem, or maybe the way the oil is going in wouldn't quite lubricate the whole area or something.

but you seem a bit less strapped for cash then me so good luck.
 

LS614

Active Member
Dec 22, 2009
1,236
3
36
CT and MA
I've researched this pretty seriously, there's no reason that I should be too afraid, and yeah, I'll get another engine if this one blows up. I consider it an experiment, I'm not afraid :)
 

LS614

Active Member
Dec 22, 2009
1,236
3
36
CT and MA
You're young still right, don't worry my friend, you still have A LOT of experimenting ahead of you! :D Happy building! You have more build skill than I did when I was your age
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
6,537
264
63
living the dream in southern california
whoops, clicked on this page by accident. there's another page view for ya...;)

just kidding

i have no probs pre-mixing, but the way i like to look at these engines is (and i'm nowhere close to rich) you can do all sorts of experiments on them, and throw them away and buy another if it blows up.

i mean, for the cost of 4 pizzas, or a coupla cartons of smokes, or a few cases of beers, you could buy another motor.

if it came down to it, i could probably recycle some cans and bum some change in front of 7-11 and have enough in a week. even less time if i bummed change in front of disneyland...:)

so go ahead and experiment. i'm interested to see what happens.
 

flybytaco

Metal Molding Madman
Oct 17, 2009
1,170
8
0
seekonk MASS
I'ts funny to see someone making an oil injection sytem. Every bike i had with it has been bypassed and removed. and switched to premix. good luck with that. it's fun messing with theese things
 

LS614

Active Member
Dec 22, 2009
1,236
3
36
CT and MA
Thanks guys, yeah this should be fun. I have read if you do it right there is no reason why you should bypass the injectors. They are your friends. Maybe rather than getting on for a 50cc engine and trying to get it to work for a 66cc, I'll play it safe and get one for like a 100cc dirtbike that is adjustable, make it over oily at first and then dial it down. We'll see.
 

Black_Moons

New Member
Oct 25, 2010
205
2
0
Canada, Bc
Fill up anywhere is nice. Iv allways wanted to go to the ONLY full service gas station around here, Toss the guy a quarter and go 'Fill it up!' :)

Might I recommend the CNS carb? It seems to have a hose barb that goes right into the center of the intake before the slide. Of course now that I think about it, you might want one after the slide so it has decent vacuum at idle. Of course then you get little vacuum at WOT, but you get little vacuum at WOT anyway.
 

matthurd

New Member
Dec 13, 2010
817
2
0
manchester NH
Fill up anywhere is nice. Iv allways wanted to go to the ONLY full service gas station around here, Toss the guy a quarter and go 'Fill it up!' :)

Might I recommend the CNS carb? It seems to have a hose barb that goes right into the center of the intake before the slide. Of course now that I think about it, you might want one after the slide so it has decent vacuum at idle. Of course then you get little vacuum at WOT, but you get little vacuum at WOT anyway.
do some math fill the tank half way with your oil+gas mix, but use 2x as much oil as you normally would for the amount of gas your tank holds.

then go to gas station, and have em fill half a tank. get the look on his face, ride down the street where he can't see you, give your bike a good shake.

do eeeeeeeeeeeettttt!!!
 

Black_Moons

New Member
Oct 25, 2010
205
2
0
Canada, Bc
Actualy, I have a 76ml bottle of oil in my backpack, with a 1.8 liter tank that gives me a 23:1 mix. 20:1 if I assume 1.5 liters of fuel in the tank. (Tiny bit left over, not filling the tank all the way, etc)
Once I open the seal on it and actualy use it, I plan to refill the bottle with only about 50ml of oil however... Or buy a bigger gas tank :) (or just not use the entire bottle) as 20:1 is a bit oil rich. 50ml/1.5L = 30:1
I could just toss the oil in before going to the pump.. Coast into the pump, hah.