Piston Notching : Cutting Or Modifying Valve Reliefs

[@stevenn8449]

Making your own cutting tool from an old valve is freaking brilliant! You just saved me a lot of money, sir

[@BobMatthews]

The tip about marking through the valve guide onto the piston crown - is an absolute gem.

[@doddielagervall3871]

I don't even have a scooter,but if reckon love watching and learning fron your vids. Thank you for making them and please keep making them!

[@49ccscoot]

Thank you!

[@VinnyMartello]

These are some darn clever little ideas!!! 90% of good mechanics is cheap tricks. The other 10% is a socket set.

[@sunilg.sharma3931]

Awesome idea 💡

[@alexkinnane5831]

Very smart 👌

[@TPVPRO]

I liked the video nice work!

[@49ccscoot]

Thanks!

[@AmrinderSingh-zx9hr]

Great

[@yeanlingsoda359vortexcars8]

We're doing this to my vortec 350 for clearance

[@8bit711]

Dope.

[@dreionnaellegardbatalla3676]

nice tools

[@jovenshollowblockconcretep8091]

What the name of tools or long rod that you use to extend the drilling tools?

[@49ccscoot]

Drill bit extension. Here's one like mine (affiliate link) : amzn.to/3fulm7e

[@jacquesevans1023]

How thin can you get away with on the piston crown where the relief is on a small engine like this? Thank you

[@49ccscoot]

It depends on the exact design and use, but I was never able to nail down a concrete answer. I would try to stay 0.100" or thicker, but I did one about 0.065" after reliefs and it didn't come apart. Probably pushing it.

[@jacquesevans1023]

@@49ccscoot Thank you

[@AdammP]

cutting it freehand might work but in the long run the piston balance is going to be off causing a throw effect in the cylinder over a period of time , hence causing wear on the bore in a sideward manner.. and resulting in a loss of compression. pistons are things to be machined and are perfectly tuned to cause minimal engine wear from this situation.

[@bryanroupe8646]

You would never remove enough material to make a difference. I have been sitting pistons for 12 years.

[@chriswest5360]

Steven L who’s wrong? The op, or the guy that said it wouldn’t be enough material to matter?

[@civilianspaceagency7106]

@@chriswest5360 Its going to be way off balance a few grams goes along ways in longevity especially to a single cylinder Tiny Bore like this .... This is No Way to Do Anything ... Order the Correct Piston Or have it Machined an Correctly Balanced the Rotating Assembly

[@michaeldavis2585]

Way cool ideas ordered 100cc block for my 50cc mopad what should I go with rollers or the flats

[@49ccscoot]

I prefer sliders. Use them in every one of my scoots.

[@chappiechappman7330]

How many hours did you spend working on this ? please reply just needed from my mods project :)

[@49ccscoot]

It's been a long time so I don't really remember.

[@SylviaBwalya-go6jq]

Wat happened if u just grind a bit of 0.3mm to the engine pistons?

[@49ccscoot]

You mean the entire crown? You'll lower compression a lot more than just making a smaller recess.

[@SylviaBwalya-go6jq]

@@49ccscoot thanks for the answer.

[@F0R3V3RD3AD]

Hey in the past when you did the piston to valve clearance videos on the 139qmb, was that scrappy's 52mm piston that you had in there? Also was it on a stock crank or a stroker?

[@49ccscoot]

+Korey Eberhart I haven't done a P2V vid with the 139QMB. My recent vids about this have all been a GY6 150, mostly showing a domed 58.5mm piston from an eBay seller.

[@chriswest5360]

How does this effect the balance of the rotating assembly?

[@49ccscoot]

If you had everything balanced, then it prob wouldn't be wise to then cut material out of the piston. In that case, mock up and cut then balance. Otherwise, it's likely a minimal change unless you've really got to cut a lot. Beats the alternative of smacking a valve into the piston still.

[@civilianspaceagency7106]

@@49ccscoot Everything was balanced from the Factory ... its not a minimal change either a couple grams is tremendous to this little fine built Machines Balance ... Its also a big deal to take everything apart an have it rebalanced . What Beats the Alternative of smacking a valve into the piston these engines Very Rarely if Ever have that issue ... The loss in compression is going to effect performance negatively .. Unless you added a hot cam which would necessitate this modification an a piston replacement an rebalance ... Shade tree at best

[@49ccscoot]

@@civilianspaceagency7106 Apparently you've never installed a big bore kit. Remember that this video was made about a scooter. The big bore pistons can be quite a lot heavier than stock. If anything, you'd be putting it closer to original balance by notching in this case.

[@bumblebob5979]

Scoot, I have a racing cam im going to install on 50cc bt49. It has 1mm more lift and much more duration? Should I be prepared for piston strike you think?

[@49ccscoot]

It would be a good idea to check. I have vids about checking piston to valve clearance a couple of ways. The absolute minimum effort check is to turn the engine over by hand before it's ever started and make sure there is no contact. That won't tell you if clearances are technically sufficient, but at least maybe the piston won't hit the valve and ruin it as soon as it fires up.

[@kevinstearns4198]

what about 2 stroke pistons ive seen windows cut out on the intake side and holes drilled in the exhaust side.whats your take on this?

[@49ccscoot]

Not at all related to this topic. Dimples or even holes on the exhaust side are usually for oiling/cooling and must be done so that they don't align with any ports. I'm not sure that windows on the intake side do much of anything on the case-reed inducted engines that scoots I'm used to have.

[@kevinstearns4198]

thanks im not putting any holes in it.

[@1121mdcity]

where in md are u from i noticed one of ur videos i seen md state trooper car in a drive way lol..im from college park md..

[@49ccscoot]

+1121mdcity jiggy Other side of the bridge.

[@Halterofilador]

What is puston notching for?

[@49ccscoot]

+Luis Lucas-Tzun It is a way to gain clearance between the piston and valves. Here's a video about piston to valve clearance that may help to explain it : kzbin.info/www/bejne/pYvKmYp_pdakq8U

[@bryanroupe8646]

Many different scenarios

[@compagato5086]

hey some help please I have a 2014 TaoTao and I over twist the spark plug and now it's not engaging any tips for that or what's that kit that I need to replace appreciate the help

[@49ccscoot]

+Oscar Navarrete It sounds like you stripped the threads in the head. It could be re-threaded, but with the cost of a new head, it makes a lot more sense just to replace it. There are heads with 64mm or 69mm valves. For the TaoTao, you should need the 69mm version.

[@luismardones2554]

HAITIAN TECHNOLOGIES.... xD