Hardcore Biker
You don't need grease or anything like it to be able to remove it afterwards. Just pour it in. (I am talking about the red vinamold, I don't know about the other colors)Originally Posted by peewee
hey i just ordered some also. hope to see it by friday. 2kg but maybe i only needed 1kg. oh well i guess ill have plenty of extra if i need it
since i never used vinamold before, what type of oil or grease do you apply to the duct wall so the vinamold can be removed easily ?
Forum whore
50+ hp Turbocharged 125, engine is still in Std trim.
Hardcore Biker
While on the subject...
500+hp two-stroke turbo ;-)
http://www.youtube.com/watch?v=X1Jfd7gGIYQ
Dyno:
http://www.youtube.com/watch?v=T44ZV...ature=youtu.be
Forum whore
While still on the subject...
500+hp two-stroke turbo
Forum whore
Was it revved to hard, to lean, over advanced or really out of a 150 4T? .....
Hardcore Biker
Got me there
I think the 1100cc triple wins in regard to power to weight though
Was it revved to hard, to lean, over advanced or really out of a 150 4T? .....
Forum whore
the wartsilla is flat out at 102 rpm maybe the 120 rpm big overrev killed it
Was it revved to hard, to lean, over advanced or really out of a 150 4T? .....
My neighbours diary says I have boundary issues
No8 Wire Extraordinaire
Is that Rich's FXR'150' again?
Don't you look at my accountant.
He's the only one I've got.
Anorak
KB longest running gag all set up but where is Mike?
Kinky is using a feather. Perverted is using the whole chicken
Forum whore
Good forks, worth a look.
Not forks but worth keeping handy.
Scooter boy
I expect that Wob knows the answer to this question already!
Whilst we now accept that the forward hook on the rearmost flank of "B" transfer ports is ideal where there is a fifth "C" port, but is the same applicable where there is no rear "C" port, as is the case in a lot of older piston port engines? I can perhaps see a situation for un-scavenged gas to lurk in this potentially stagnant area if the hook is in place?
Grateful thanks for any help here.
Trevor
Hardcore Biker
let me add something if you dont mind. jan and frits have both said those sharp hooks are no good. theres also other eveidence that suggests a hook is no good. if you look at the newer generation of ktm mx cylinders, they have eliminated all hooks. the rear wall of the B port still has a forward facing trajectory but its definatly not a sharp hook like what you would normally see years ago. i think your better off if you can make the duct wall change direction with out a 'kink' or sharp 'hook'. problem is, many cylinders have the studs in a bad location and simply dont have sufficient material thickness of the transfer ducts to properly shape the ducts walls, atleast not without welding and a bunch of other work
Forum whore
The so called "sharp " hooks where the angle is formed with a distinct corner were replaced quite a long time ago with a smooth radius.
This I saw for the first time in Harolds early KTM cylinder and then the SA cylinders on the Pulse engine.
Much later on when I finally managed to get a look into an RSA this was the first thing I saw.
The aiming point of 1/3 toward bore centre has been common for a long time.
I have described what the direction change actually does before - but here it is again.
The effect I saw on screen when I first saw the flow regime of a Roberts KR3 analysis on a Czech CNC anemometric flow tester.
The actual stream exiting the port is rotated axially and this clears out a dead area in front of the boost port that would normally be
unscavenged of residual Ex gas.
The rotating flow then attaches to the boost port stream and combined with the direct on collision effect this forms part of the tilted tower of Pisa
rising column Frits has so eloquently described.
You can easily see this axial rotation effect by simply having running water from a tap go down the duct - very easy to see, hard to describe.
As far as doing this without a boost port - no free lunch,as the only way you can get a decent scavenging flow regime with this sort of setup is to
have the B ports collide - head on, and use the backward pointing radial angle on the A ports to get the flow attached to the rear wall and form a loop.
Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.
Scooter boy
Many thanks Wob, more techno information than I could have hoped for, you were able to confirm what I had suspected but was unable to confirm.
Trevor
Hardcore Biker
yes, most, if not all of the more advanced engines have used a smooth radius on the back wall of B port for quit a number of years. however some people still fool around with older design engines that have sharp hooks. banshee for example , which has sharp hooks up until atleast 2012, maybe even to this very day , if theyre still being sold in some countries.
some people arent aware the sharp hook is no good. not knowing which engine trevor was dealing with, or his skill level, i was just offering some advice, in case he wasnt aware the advantage to a smooth radius on the B port back wall, and A port front wall. there was a time when i hardly knew anything, but thanx to jan and frits ive learned quit a bit
There are currently 74 users browsing this thread. (1 members and 73 guests)
Posting Permissions
Reply With Quote
Bookmarks