Estoril Length- WOW MUCH POWER!!!!!!

Pipe masters, I need some advice, Ive read on here about all the Estoril Pipe lengthening and shortening.

I just bought a nice MLM header for the M1 and was wondering how short to go to increase a little top end, dont need much as I am in the high 40mphs already.

The ID is much bigger than what is already on there.

Ive also heard from 2 stroke stuffing on youtube to restrict the stinger for a little more compression, just wanting to see what everyone thinks about increasing the performance of an Estoril.

Im running the non restricted one on a Gila kit with a Polini 19 on an M1

Re: Estoril Length- WOW MUCH POWER!!!!!!

Shorter header = more rpms

worth putting it on then considering altering the header length i dont know much about m1 engines

but ive been with puch's 1 inch of header alters the rpms by 300-500rpm at the top end

Re: Estoril Length- WOW MUCH POWER!!!!!!

Dirty30 Dillon /

Adams rpm numbers are pretty accurate.

The stinger restriction is correct although it doesnt boost your cylinder compression, it allows you to pack the pipe, giving a better pulse for better response.

Re: Estoril Length- WOW MUCH POWER!!!!!!

Overpriced Parts /

They need to make adjustable length header/chamber pipe so you could just squeeze a lever when your rpm is maxed out then move it in closer 1-2 inch and then gain 500-1,000 rpm

Re: Estoril Length- WOW MUCH POWER!!!!!!

Keep in mind the smaller the stinger diameter, the hotter the gasses. The underside of the piston crown heats up from the inside, and blows the top off.

Re: Estoril Length- WOW MUCH POWER!!!!!!

The tomos estoril is a totally different pipe, it's got a shorter stepped header and pulls way harder.

The blowdown on the cylinder 'powers' the pipe, essentially you are giving up trapping the energy in the cylinder to push the piston down, and blowing out that energy to get the gasses moving.

The header diameter will determine how efficiently the pipe uses that energy. If you have a small dia header the gasses will keep the velocity high and you don't need as much gas energy to light up the pipe, but it will choke on the top end. If you have a big header it will breathe up top but it will never hit on a cylinder with no blow down.

You can always cut it shorter but you can't cut it longer, so plan on using a radiator hose coupler (yes it will burn up but it's ok for tuning) and cutting the header back until you're happy.

Re: Estoril Length- WOW MUCH POWER!!!!!!

Dave Thacker /

I'm aching for a Karting like setup with a removable section that can be replaced. In kart racing 2 strokes does it this way so you can turn the engine for higher or lower ranges depending on the track. You have a section that fits on the end of the header, the pipe fits on the end of the changeable section. It's all head together with some very tight springs. Then you could tune it. Later easily make it longer if you went to ride someplace with hills for example.

Re: Estoril Length- WOW MUCH POWER!!!!!!

Top secret tip, the Vespa estoril is best for hacking

Re: Estoril Length- WOW MUCH POWER!!!!!!

> Daniel '' Wrote:

> -------------------------------------------------------

> Top secret tip, the Vespa estoril is best for hacking

Mind blown. I always forget that thing even exists, I always buy the tomos one

Re: Estoril Length- WOW MUCH POWER!!!!!!

> Graham Motzing Wrote:

> -------------------------------------------------------

> > Daniel '' Wrote:

>

> > -------------------------------------------------------

>

> > Top secret tip, the Vespa estoril is best for hacking

>

> Mind blown. I always forget that thing even exists, I always buy the

> tomos one

Thats what I hacked on the M1, a Tomos a3 Estoril.

So what youre saying Graham is if the header is too wide, the pipe will "Hit" later if it does?

Has anyone seen the 2 stroke stuffing videos? He has a super narrow exhaust hole to increase velocity on his new build, then opens up to a wide header. I wonder if this can be done. Im gonna look into it.

Re: Estoril Length- WOW MUCH POWER!!!!!!

Dirty30 Dillon /

Look up "exhaust port nozzling"

A lot of high power scooter kits do this, that's what Alex Degnes is emulating in a way

Re: Estoril Length- WOW MUCH POWER!!!!!!

ah yeah its not that it 'hits' later, its the whole diameter of the pipe needs more energy coming out of the port during blowdown to reach the same amount of pressure in the compression of the wave.

you can think of the compression wave pressure like amplitude or height of a wave on the beach. in very broad terms the length determines the timing of the pulse bouncing back and returning to the port, the diameter of the pipe determines how much energy it is capable of returning and bouncing back. a bigger header takes a bigger 'gulp' of air and can reach higher supercharge pressure, which is why french pipes have massive headers, but they need a lot of the energy from the exhaust/power stroke to be blown down and fed into them in order to create the energy in the wave they need to power them.

a bigger pipe diameter needs more blowdown energy to reach the pressure that it needs to function at peak efficiency. A smaller exhaust header keeps the pressure high in the pipe so the compression wave has energy when it comes back to the port to provide the supercharging effect, but at high energy it limits the volume that the pipe can suck out and return to the cylinder.

I dunno if i'm explaining this very well, i'm really tired and pretty drunk and its like next level thermodynamics type shit here so i'm probably not making much sense, but my general rule of thumb is:

small (diameter) header- small blowdown, big header- big blowdown

longer pipe- low rpm, shorter pipe- high rpm

sharp expansion of cones- hard hitting/narrow powerband, gradual expansion of cones - wide powerband/ less 'hit'

the modded estoril should be a perfect pipe for your setup, like i said i designed the head but Blake/Dos did all the testing and i'm not sure who out there in ATL ran it or what their setup was but i've gotta say 40 sounds miserable since i know some stock M1's that run solid mid 40's. i don't think the pipe is your problem. I also know that chad burke has run some different kits on M1's and might be someone to talk to. unfortunately he doesn't post much on here anymore but you can probably message him.

Re: Estoril Length- WOW MUCH POWER!!!!!!

Ok yeah I see what you mean regarding the header.

I’ll experiment with some different lengthA and see what works.

Thanks for that write up.

I’m not complaining about my speed. I’m getting 49mphs consistently.

Re: Estoril Length- WOW MUCH POWER!!!!!!

That’s cool. I didn’t know Alex was on MA at one point. I watch all his vids and they def helped on my tuning.

I don’t have much left to do on the SS, I’ll eventually do a disc brake set up to feel comfortable going 50+

Re: Estoril Length- WOW MUCH POWER!!!!!!

> . Chudas. Wrote:

> -------------------------------------------------------

>

> I’m not complaining about my speed. I’m getting 49mphs consistently.

I thought you said at one point it was only doing 40 in the thread about it running really cool CHT. Sorry, 49 is awesome and probably makes great torque getting there. You might pick up a little speed by shortening the header but the tomos estoril pulls clear to 10k out of the box. On cylinders with a lot of blowdown it can make power out to 11.

Re: Estoril Length- WOW MUCH POWER!!!!!!

> Daniel '' Wrote:

> -------------------------------------------------------

> Top secret tip, the Vespa estoril is best for hacking

Why the Vespa one?

Re: Estoril Length- WOW MUCH POWER!!!!!!

> Overpriced Parts Wrote:

> -------------------------------------------------------

> They need to make adjustable length header/chamber pipe so you could

> just squeeze a lever when your rpm is maxed out then move it in closer

> 1-2 inch and then gain 500-1,000 rpm

French bikes got that, sliding header so as it variates you're also changing the header length. raddd

Imagine instead though if you had the port timing change, pulling the exhaust valve open more with RPM

oh yea, they did that too... SICK

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