Author Topic: Nitrous on 50cc engine (Read 12532 times)

frodef2 · « **on:** August 15, 2016, 01:16:31 PM »

Hi. Any nitrous gurus here?

A local motorcycle club are hosting a moped (50cc) dragrace next month, and i want to try to run N2O on my scoot.

I have sourced the smallest single cylinder kit from NX. (10 hp)

I have successfully installed the kit,

and have made a semi successful test run.

The piston gave up after 5ish seconds of nitrous.
The damage looks like ring bind.

I had filed the ring gap to double the stock gap before running.

Any idea what gap i should run on a 45mm cylinder?

Frode j

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Lostboy Steve · « **Reply #1 on:** August 15, 2016, 01:18:32 PM »

God damn. That thing must have been screaming for mercy.

frodef2 · « **Reply #2 on:** August 15, 2016, 02:08:18 PM »

Well. One the first test, i pulled out one of the 6mm studs that hold the thing together. Then i upgraded the studs to 8mm a4-70 bolts. Then the piston gave up.

I have 3 new pistons and extra rings in the mail. Just need to get the right gap.

10hp at 50cc is 200 hp pr liter. Might be too much.

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simon#42 · « **Reply #3 on:** August 15, 2016, 02:25:31 PM »

i would try a single ring piston with a narrower ring , it should be quite a bit stronger
i use one in a puch that now makes more than 10hp with no problems . dont have a clue about nitrous though im afraid .

madmtnmotors · « **Reply #4 on:** August 15, 2016, 05:34:42 PM »

Quote from: Lostboy Steve on August 15, 2016, 01:18:32 PM

God damn. That thing must have been screaming for mercy.

ROFLMAO!

Sounds like fun! As long as nobody gets hurt, this definitely looks like a "blast". Keep us posted with results just in case one of us other mad scientists decide to reproduce your experiment!

Lostboy Steve · « **Reply #5 on:** August 15, 2016, 05:50:19 PM »

Quote from: simon#42 on August 15, 2016, 02:25:31 PM

i would try a single ring piston with a narrower ring , it should be quite a bit stronger
i use one in a puch that now makes more than 10hp with no problems . dont have a clue about nitrous though im afraid .

Go on.... You got my attention.

Bankerdanny · « **Reply #6 on:** August 16, 2016, 10:37:34 AM »

a 10 hp boost must basically triple the output of that thing.

Powderman · « **Reply #7 on:** August 17, 2016, 03:30:19 PM »

Gap top ring- bore x .005, 2nd ring- bore x .055, oil ring mini. .015
hth

neal · « **Reply #8 on:** August 18, 2016, 02:42:07 AM »

You might want to contact the guy at: www.perkllc.com

strynboen · « **Reply #9 on:** August 18, 2016, 03:14:24 AM »

find some steel piston rings they are 2 mm thik..the problem is lube..you vask all 2 stroke oil aut ,,and the rings bite in the bore..think steel rings is better not to bite in the cast iron

simon#42 · « **Reply #10 on:** August 18, 2016, 11:14:48 AM »

looking at the rest of the piston i dont think its a lube problem more likely there is not enough strength in the crown for this power output

frodef2 · « **Reply #11 on:** August 20, 2016, 12:42:06 AM »

I have sourced some new pistons with the top ring further from the crown. But i have to reshape the combustionchamber because the piston top is different from the old one. The squish became a "pinch"

The old piston was from a much better brand: Meteor. And the new one is noname. The invoice even said: measure diameter before install, this is not wiseco.

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frodef2 · « **Reply #12 on:** August 22, 2016, 11:21:22 AM »

A small update on the state of the engine.

Here is a comparason of the old piston to the right, and the new piston to the left.

Here are the domes. Note the difference of the edge of the dome on the damaged piston, compared to the noname.

The final improvement is 2 liters of vp racing c14 fuel.

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grcamna2 · « **Reply #13 on:** August 22, 2016, 08:34:17 PM »

That's a Suzuki FA50 ? What oil are you running ?

frodef2 · « **Reply #14 on:** August 22, 2016, 09:14:41 PM »

Almost. Its a FZ50. I do think the engine of the FA is almost the same as the FZ. I am running ELF moto2 race two stroke oil as anpremix, as i have removed the pump. For the gearbox i am running a generic brand 10-40 motorcycle type oil.

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grcamna2 · « **Reply #15 on:** August 23, 2016, 03:10:22 AM »

That is a cute little thing,you can get that engine to push 10hp?

Terry in Australia · « **Reply #16 on:** August 23, 2016, 03:54:26 AM »

That is sweet! How much was that kit mate? I looked at the NX website and the smallest kit I saw was in the hundreds of dollars? I bought a couple of these eBay nitrous kits for my twin engined bicycle last year just before I moved away from home with my new job, so haven't had a chance to install them yet, but looking at one motorised bicycle forum, a lot of good things were said about them, and you can't beat the price. Cheers, Terry.

http://www.ebay.com.au/itm/Motorized-Bicycle-Gas-Bike-Motor-Engine-50-80-cc-NOS-Nitrous-Boost-Bottle-Kit-/252508368349?hash=item3acaabeddd:m:mNzelcb6o--e7koKiykUp0w

754 · « **Reply #17 on:** August 23, 2016, 04:46:29 PM »

That looks like a top notch cast piston...oh yeah...!!

Lostboy Steve · « **Reply #18 on:** August 23, 2016, 06:07:02 PM »

I think you need a secondary oil injection system to kick in with the nitrous.

frodef2 · « **Reply #19 on:** August 24, 2016, 10:51:17 AM »

I have removed the oil pump, and rely on premix for the lube.

The NOS kit i use is this one: http://www.nitrousexpress.com/61025-25p-single-cylinder-proton-system-w-25-lb-bottle.html

not the cheapest kit, but looks like good quality. i have also added a electronic pressure transducer and a gauge at the steering. the price came to 800ish plus freight.

It pulls quite strong, but we have a fuel starvation issue. The last pull dried out the fuelsupply and we got a bang.

Goimg to do a small pulldown on the engine to check for damage. Then the next mod is altering the fuel tap/system.

Frode j

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frodef2 · « **Reply #20 on:** August 24, 2016, 12:45:04 PM »

video in better quality

frodef2 · « **Reply #21 on:** August 26, 2016, 11:40:30 AM »

Just came back from the garage, and the top piston ring was damaged. It didnt look damaged at first, but when i took them off the piston, it was apparent that it had lost quite a bit of "springyness" the no load gap was half of the lower ring, so it must have been overheated.

I installed 2 new rings, with the top ring opened even more. The gap is now 0,95mm. Should be enough for a 45mm piston. (0.035 inches gap)

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Lostboy Steve · « **Reply #22 on:** August 26, 2016, 05:42:37 PM »

Yup. Screaming for mercy. Lol very cool though.

frodef2 · « **Reply #23 on:** August 27, 2016, 08:10:37 AM »

Small update with a picture of the two rings i took out of the engine.

As you can see, the top ring lost quite a bit of "spring"

It also started shedding its coating, no wonder the piston got slightly branded

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madmtnmotors · « **Reply #24 on:** August 27, 2016, 04:05:19 PM »

You don't know where the line is until you cross it!

Stay on it, yer gittin close!

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Author Topic: Nitrous on 50cc engine (Read 12532 times)