Need porting

[FlyYoDreams]

Hey guys I’m new to the forum. I’m looking for a way to port my “80”cc Imaycc. I have some mechanical abilities but I’m not sure I can do it (sounds complicated with all the software etc). Can anybody give me some hints, tips and resources? Does anyone in south Florida port small engines?

 

[ImpulseRocket]

There is some simple porting work you can do to help a little bit, such as cleaning and smoothing things out on the exhaust side, or roughing up the intake and transfer ports to create a boundary layer for better intake efficiency and atomization, and gasket/port matching. Setting a proper squish gap never hurts either.

That work won't get you an extra 10mph though.

Porting can be fun. I am no master at it, but I do some port work to my own engines. My usual method for this starts by buying a whole new cylinder to get the results I want, or replace the other one that I screwed up, because it happens lol.

If you really want to get started with it you will need a degree wheel and at least a small Dremel or a Wen rotary tool with the flex shaft (my favorite) along with some burrs and sand paper rolls and rums for said rotary tool. Which if you buy the wen you could get it all for probably 100 to 150 bucks. Sounds like a lot, but after that initial investment, it's cheap to keep porting other cylinders.

 

[FlyYoDreams]

Yes, the pipe came with it...It is entirely stock, except the air filter...lol...It has been up to 51 MPH with throttle to spare but I dislike cleaning the racing stripes out of my underwear, I don't need racing stripes...lol.

I just like cruising between 30 to 35 MPH at around 1/4 throttle, thats plenty on a bicycle...lol...The advantage of a powerful motor is NOT top speed but being able to cruise at a decent speed without having to be at wide open throttle...Motors last longer this way.

Hahaha that’s awesome and yes that’s exactly what I’m going for. Just want the strength to go a comfortable speed without it beating up the engine too bad. I’m not trying to race the cars!

I might have to get that kit next, I don’t have a lot of complaints about my current one (it’s given me almost 2000 good miles since I put it on but I’d rather avoid porting to get that power if I could.

About the air filter you have on, does it have better air flow than the NTs? When I had the stock NT air filter on my bike it was struggling (22 mph tops)

 

[FlyYoDreams]

There is some simple porting work you can do to help a little bit, such as cleaning and smoothing things out on the exhaust side, or roughing up the intake and transfer ports to create a boundary layer for better intake efficiency and atomization, and gasket/port matching. Setting a proper squish gap never hurts either.

That work won't get you an extra 10mph though.

Porting can be fun. I am no master at it, but I do some port work to my own engines. My usual method for this starts by buying a whole new cylinder to get the results I want, or replace the other one that I screwed up, because it happens lol.

If you really want to get started with it you will need a degree wheel and at least a small Dremel or a Wen rotary tool with the flex shaft (my favorite) along with some burrs and sand paper rolls and rums for said rotary tool. Which if you buy the wen you could get it all for probably 100 to 150 bucks. Sounds like a lot, but after that initial investment, it's cheap to keep porting other cylinders.

Awesome, thank you for the info!!

 

[DAMIEN1307]

About the air filter you have on, does it have better air flow than the NTs?

Yep...It gives ya a full 360* air flow...some people when putting this one on, have to readjust the needle valve in the carby by lowering the C clip on the needle by one notch so it raises the needle up to allow more fuel...Once using this air filter on both the NT, or the JRL BoFeng that comes with the P-85, (A much improved NT type of carby), I have seen no need to ever buy more expensive carby's because they now work so good when allowed to breathe properly.

 

[FlyYoDreams]

Well post a picture of your cylinder, intake side and exhaust side. The easiest to do and understand is port matching, that's when you file/grinds/cut the manifolds to be the same size as the ones on the cylinder. Then you can widen the ports for a bit more breath. If the inside of the ports are not beveled before you start, make sure you do that before you put it back together.

Okay cool, thank you. I’ll post a pic here of the cylinder soon.

 

[FlyYoDreams]

Yep...It gives ya a full 360* air flow...some people when putting this one on, have to readjust the needle valve in the carby by lowering the C clip on the needle by one notch so it raises the needle up to allow more fuel...Once using this air filter on both the NT, or the JRL BoFeng that comes with the P-85, (A much improved NT type of carby), I have seen no need to ever buy more expensive carby's because they now work so good when allowed to breathe properly.

I’m buying this right now. Thank you for the suggestion!

 

[DAMIEN1307]

I’m buying this right now. Thank you for the suggestion!

Watcha buying???...The air filter, the JRL BoFeng carby, or the P-85???...lol...lol.

 

[ImpulseRocket]

I’m buying this right now. Thank you for the suggestion!

I have the same filter and engine as Damien, and yes it flows better than, and filters better than, any of the stock carb "filters"

It is also a washable and reusable K&N style cotton filter.

 

[Street Ryderz]

There is a web site, https://lambretta-images.com/tuningh/port-timing-calculators/
this does not require a degree wheel just linear depth measurements using a veneer caliper.
Another online calculator for finding the equivalent dia of a square or rectangle is needed to properly port match!
Over widening and or altering port timings will not give the desired results if using a stock carb, the stock carbs are only 15mm at best with a few now being 16mm that claim to be 19mm, this is a problem since the port windows are 19mm equivalent dia and all ready over sized to a stock carb!
Port matching is taking the carb being used, lets say 18mm and then having a matched 18mm intake track and port window this includes the intake flange and track between it and the window so as not to change the velocity, the carb only meters for the flow through the body so being larger any where after it will just slow that flow down.
On the exhaust side a 19mm window is ok because at the flange is probably 20-21mm which allows for some expansion of the gasses into the head pipe.
Transfers are an issue in these engines as there is inadequate blow down period/duration and they are not shaped properly, so correcting the angles here is a big improvement along with increasing the blow down duration, keeping in mind that raising the exh port it still has to be the proper dimension, so this is what I look at first trying to get as close to 20 degrees of blow down and staying within that dimension.
The port timing calc is very accurate and allows you to play around and see what will work before hacking away at your cylinder saving you time and money and most of all not ending up with a dud!

 

[FlyYoDreams]

Watcha buying???...The air filter, the JRL BoFeng carby, or the P-85???...lol...lol.

Haha i got the filter but I’ve got my eye on that engine!