stefan

Sorry Maximo, but that's bull§hit.

When you raise the liner ALL port timings are increased the same, because they are all linear.

0.1mm under the sleeve will increase the timing of all port by approx. 1.45 degrees.

Maximo

iTrader: (11)

Careful of what you say Big Shooter....!!!! .1 mm does not increase timing equaly FYI..it takes more to raise the exhaust 5 degrees then it does to raise the transfers and boost !

for example on a Go 21 7 port it takes .69 mm to add 10 degrees to exhaust, whereas it takes only .54 mm to add 10 degrees to transfer.......

stefan

Sorry small shooter, wrong again.

It takes a certain angle of the crank to move your piston a certain way and this is the same angle for all ports, period.

Why don't you just try it and come back with your results?

Maximo

iTrader: (11)

I have timing software, these results are checked and confirmed.... moving the sleeve up does not add equal timing across all the ports, the further the spread between stock intake and exhaust timings the more dramatic the differences will be.....When I re-time motors I must always cut more on exhaust to get 10 degrees then I have to on intake ports...I do this every day of the week and I do have good timing software....Maybe if you check it yourself on your own software you will see what I mean....and if you dont own software Edwards site has mini timing program you can use....... so go see for yourself before you start insulting me !

stefan

Maybe Edward or MXwrench will come here and talk some sense into you.

I don't use timing software, I use a timing wheel and when I put shims under my sleeves, all ports change by the same amount.
If you had a basic understanding of physics and engines in particular, you would not spread crap like this.

Btw, here is a quote from Edward from May 2006 on this board:
"The easiest way to get more power you will need to alter induction timings to the following 35 to open ABDC and 62 to close ATDC, then alter exhaust and transfer timing by adding-6-7 degree to total ##. Esiest way is to add shims under the sleeve. Here is general rull-0.1 mm shimming under the sleeve add about 1.45 degree to transfer and exhaust timings"

But I am sure we are all stupid and you got it right!!

M7H

Stefan, just 1 tiny little thing to think about.

Let suppose the piston is at BDC, rotating the crank back and forward for... lets say 10° will give the piston a certain movement, but if you put the piston in the middle between BDC and TDC, this 10° rotation of the crank will give the piston a bigger movement.
So, rotation of the crank and piston movement are NOT lineair to each other......

If all ports were on the same height... but the exhaust is higher then the intake....

RayJ

I have to check this on my own, but what Maximo says makes sense to me if I think of the length of piston travel versus crank rotation. Raising the liner does raise the liner equally on the exhaust and intake ports, but the intake and exhaust ports close at different times during piston. The piston travel is not linear in relation to the different points of crank rotation. When the piston reaches top dead center, the crank has to turn alot more degrees to move the piston in comparison to the beginning of the stroke. If all three intake ports and the exhaust port were located on the exact same location on the sleeve the timing changes would be equal. I haven't verified this yet, but it's another way of looking at it.

RayJ

LOL......M7H beat me to the explanation.

M7H

Maximo

iTrader: (11)

dude your talking way over your head...shut up now before you make even more of an ass of yourself....

Maximo

iTrader: (11)

This is exactly how it works.... its not rocket science and for someone who's as self proclaimed as Stefan I am surprised he doesn't understand such a simple concept.......But I guess he'd rather start shooting insults before he checks his facts.....

Riketsu

iTrader: (34)

Come on guys... stop with the insults. This is not a forum to prove whose better than who or who knows more than who. It is to share information and experience for everyone to learn. I for one am thankful for all the information about raising port timing or lowering it because I had never heard of it outside of rctech. Maximo... can you please tell me where to get a port timing software???

Maximo

iTrader: (11)

I would rather not argue as well...I would rather politely disagree then launch and all out assault... But everyone has different manners and ways to deal with situations like this.....

Anyways here is the software that I use..

http://www.prestwich.ndirect.co.uk/etp/

stefan

Now, if you go to the site you posted below and click on timing charts, you have it black on white, that the relation between crank rotaion and piston movement is linear, degree by degree.
http://www.prestwich.ndirect.co.uk/techtimingchts.htm

Maximo

iTrader: (11)

those charts must be wrong or misinterpreted...

here is an actual engine timing from the software..this is a p3 28 with stock timing, then 1 mm added to all ports....