mikko k wrote:They have done a great job!! I do respect that. BUT, Why a 12 valve heads? Porsche has done 4 valves heads for years! Why don't develop a 5 valve cylinder head with twin spark and douple OHC heads?? No rockers, no mass, more revs, ect.??
4 valve aircooled heads are prone to have cooling issues at the exhaust valves. Even Porsche used water cooling on the 4 valve heads. The cylinderheads we are working on were designed long ago by a great engineer. That's the main reason we stick to this concept.
Even we have wild dreams of DOHC but hey, we're working on finishing a part of history here and we are not complaining
And I do believe we will not stop after this
Very very good!! I really don't complain, just go further!!
I really like how the central valve cover turned out. Very solid. I hope Roberto can CNC it out of an alu block very soon
Also very cool how you managed to improve the original heads(molds) design with the 'slight' modifications you incorporated into them.
It sure looks to turn out even better than Herr Apfelbeck ever would have dreamed of
Thanks Ronald!
Groeten,
Walter
T4T: 2,4ltr Type 4 Turbo engine, 10.58 1/4 mi in a streetlegal 1303
"Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
A week ago we gave a presentation of our Apfelbeck Project at an Autodesk Inventor User Group meeting. For this event we played with the new Inventor Studio to create a new movie. Needles to say that movie can be found on our site www.apfelbeck.nl
The heads probably wouldn't be the limiter anymore.
With Pneumatic valve springs, 15K would probably be reasonable ;-)
(Why doesn't somebody make "generic" pneumatic valve springs?
Too many racing classes outlaw them?)
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
Haha, that sounds funny!
Well, we won't know for sure either of course, but we have selected the valve train components for the first prototyp ( 2 liter) engine to accomodate indeed somewhere around 9000 rpm with some reserve build in iirc. But if it still is making more power at 8000 rpm and peaking at 8500, I would be very happy
Being able to rev 8500 rpm or making max power there are two entirely different things mind you.
Since we will be using a small stroke counterweighted crank (66 mm) and some other (semi-common) tricks in the oiling department, the rotating masses should be ok for that rpm as well...
T4T: 2,4ltr Type 4 Turbo engine, 10.58 1/4 mi in a streetlegal 1303
"Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
Just outta curiousity... I was wondering how the cam/vavle train was going to recieve any oiling. Sense you moved the cam out to the heads now it is nessicary to have a decent oiling system to reach the cam bearings, and all the high friction areas. And seems like before with the pushrods, there was adaquet oiling to the heads. But sense with your motor there is going to be no use for them, and you probably welded up the original pushrod tube holes on the case itself, does this limit your heads to a 2 stage oiling system with a dry sump? Again I'm just curious as to how this is gonna work out. I can see the use of a belt drivin 2 stage dry sump. They heads are sort of like split heads, in that it's a head per a cylinder, with a porsche like cam running through 2 of them, or am I seeing this all wrong?
BAVWCJoel wrote:Just outta curiousity... I was wondering how the cam/vavle train was going to recieve any oiling. Sense you moved the cam out to the heads now it is nessicary to have a decent oiling system to reach the cam bearings, and all the high friction areas. And seems like before with the pushrods, there was adaquet oiling to the heads. But sense with your motor there is going to be no use for them, and you probably welded up the original pushrod tube holes on the case itself, does this limit your heads to a 2 stage oiling system with a dry sump? Again I'm just curious as to how this is gonna work out. I can see the use of a belt drivin 2 stage dry sump. They heads are sort of like split heads, in that it's a head per a cylinder, with a porsche like cam running through 2 of them, or am I seeing this all wrong?
Thanks.
Joel
The heads will recieve the oil trough the Cam. That way we can reach every bearing and other places we need oil. Oiling systems like this have been used succesfully in racing and in road going cars.
You're right about the dry sump pump an again right on the Porsche like cam trough the seperate heads. Porsche has a seperate single cam housing however joining the heads on each bank.
