Author Topic: Camshaft construction, characteristic angles  (Read 307 times)

Offline paolo1959

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Camshaft construction, characteristic angles
« on: July 18, 2021, 09:41:10 AM »
Ciao a tutti
Sto costruendo un motore a quattro tempi.
Vorrei avere consigli sulla costruzione del albero a cam.
In particolare voi quale angolo usate fra le due cam .
Io farei la cam di aspirazione poi mi sposto di 110 gradi all indietro ( gradi negativi ) e faccio la cam di scarico.
Aspetto i vostri graditi consigli.
Hello everybody
I'm building a four-stroke engine.
I would like to have advice on building the camshaft.
In particular, what angle do you use between the two cams.
I would do the intake cam then move 110 degrees backwards (negative degrees) and do the exhaust cam.
I await your welcome advice. :cartwheel:
live to save lives

Offline stevehuckss396

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Re: Camshaft construction, characteristic angles
« Reply #1 on: July 18, 2021, 12:02:39 PM »
I always use 110 degrees lobe centers and 240-300 degrees duration. The exhaust lobe always leads the intake lobe.
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Offline gbritnell

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Re: Camshaft construction, characteristic angles
« Reply #2 on: July 18, 2021, 03:54:05 PM »
There's a little bit more to cam design than just the lobe separation angle. You would have to first decide what timing characteristics you want for your cam, inlet opening, closing and exhaust opening and closing. You will then have to make a sketch of the cam shape, base diameter, lift etc. Once you have the basics done this will give you a better idea of the lobe separation. When designing a cam also take into account the clearance you will be using. On a small engine no more than .005 (.127mm) This will change your timing numbers, not by much but somewhat.
gbritnell
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Offline paolo1959

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Re: Camshaft construction, characteristic angles
« Reply #3 on: July 18, 2021, 04:32:18 PM »
GRAZIE per consigli !!!!
Il motore ha queste caratteristiche di base, diametro pistone 30 mm (1.18 pollice ) corsa pistone 36 mm (1.41 pollice )
diametro valvola 10 mm (0.39 pollice )
per l apertura valvola pensavo 3 mm ( 0.11 pollice ) e su questo dato accetto consigli .
Di questo motore non ho fatto disegni perche mi piace costruire cosi i miei motori ( sia a vapore che motore a scoppio)
Mi piace costruire partendo da un idea che ho in testa e poi piano piano mentre la costruzione avanza risolvo i problemi che incontro .
questo e il primo motore 4 tempi che costruisco gli altri 3 che ho costruito sono con sistema hit & mis :cartwheel:
THANKS for advice !!!!
The engine has these basic characteristics, piston diameter 30 mm (1.18 inch) piston stroke 36 mm (1.41 inch)
valve diameter 10 mm (0.39 inch)
for the valve opening I thought 3 mm (0.11 inch) and on this data I accept advice.
I have not made drawings of this engine because I like to build my engines like this (both steam and internal combustion engine)
I like to build starting from an idea in my head and then slowly as the construction progresses I solve the problems I encounter.
this is the first 4 stroke engine that i build the other 3 i built are with hit & mis system. :cartwheel:
live to save lives

Offline gbritnell

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Re: Camshaft construction, characteristic angles
« Reply #4 on: July 19, 2021, 05:54:44 PM »
Here's a drawing I did for a friend who is building a 6 cylinder engine but this will give you an idea of cam timing and construction.
Talent unshared is talent wasted.

Offline paolo1959

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Re: Camshaft construction, characteristic angles
« Reply #5 on: July 19, 2021, 09:26:04 PM »
grazie a tutti per consigli !!!!!!
thanks everyone for advice !!!!!!
 :cartwheel:
live to save lives