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Interesting 4 valve/cylinder type 1 style head.
bajachris88 - September 11th, 2012 at 07:47 AM

Saw this and thought it was a pretty interesting setup to share. You'd want to have a fat wallet at $4400 starting price per pair. But uses stock style performance cams, push rods, tubes, barrels, flat top pistons etc.

The volumetric efficiency benefit would be the saving grace for any super hypo engine i would assume.

here:

http://www.araoengineering.com/vwheads.htm 

http://www.araoengineering.com/_images/combus_1.jpg
http://www.araoengineering.com/_images/VALVES_1.jpg

reub - September 11th, 2012 at 09:59 AM

http://www.youtube.com/watch?v=3KERkb7SaH8

psimitar - September 11th, 2012 at 11:34 PM

That video is mentally funny :lol::crazy:

waveman1500 - September 12th, 2012 at 12:08 AM

What a hideous rocker arrangement for the second set of valves!

http://www.araoengineering.com/_images/rocker_side_1.jpg

Double the rockers, double the friction/wear points, double the mass. Those heads are huge chunks of metal too, and it doesn't look like they'd cool too well. Not for me thankyou. A very interesting exercise though, to try and cram four valves per cylinder into a pushrod engine.

vassy66T1 - September 12th, 2012 at 06:41 AM

I did notice revs did not go too far past 6K. Must be hell on pushrods
(unless my labrador is deceiving me)

vwo60 - September 12th, 2012 at 07:11 AM

It would be two cartons to do the tappet clearence, you would have to juggle two feeler gauges.

matberry - September 12th, 2012 at 08:08 AM

Interesting. Don't think I'd bother either. 2332 making 235

Now compare with a JPM 1915 making 248

http://www.youtube.com/watch?v=JtpzA0hd8Kg 

AND ONLY 2 VALVES per cylinder

psimitar - September 12th, 2012 at 01:52 PM

Quote:
Originally posted by matberry
Interesting. Don't think I'd bother either. 2332 making 235

Now compare with a JPM 1915 making 248

http://www.youtube.com/watch?v=JtpzA0hd8Kg 

AND ONLY 2 VALVES per cylinder


Ah but you would have to compare cam and gasflow specs to draw a better comparison.

Still that rocker arrangement is poorly designed. Could think of better solutions myself but any pushrod engine is hard to make 16v properly.

vlad01 - September 12th, 2012 at 02:48 PM

these heads= what a waste of time and effort.

tar76 - September 12th, 2012 at 04:25 PM

Quote:
Originally posted by matberry
Interesting. Don't think I'd bother either. 2332 making 235

Now compare with a JPM 1915 making 248

http://www.youtube.com/watch?v=JtpzA0hd8Kg 

AND ONLY 2 VALVES per cylinder


that JPM bug is a animal :cool:

Smiley - September 12th, 2012 at 06:50 PM

I'm not sure why they have gone with such a complicated rocker setup.

The engines we rebuild at work are 4 valves per cylinder pushrod engines. They simply have a small metal 'bridge' between both valves and the rocker arms pushes down on the middle of this opening both valves.
I'm not sure why you couldn't run a similar setup instead of all that extra crap.

The engines at work are low reving diesels though, they top out at around 2000rpm, and only make like 3500hp :D So this setup possibly can't cope with revs.



Smiley :)

ian.mezz - September 12th, 2012 at 07:24 PM

there are pictures of one in the Hot VW and dune buggy .

http://www.hotvws.com/issue_previewLrgContents.html 

there is also a video on their facebook page.

matberry - September 12th, 2012 at 07:34 PM

^^^That one is twin overhead cam, way better but mega work, interesting that it pulls 10500rpm also

bajachris88 - September 12th, 2012 at 07:48 PM

What i find exciting is simply the concept of the cross sectional area in total of the valves compared to 2 valve per cylinder. :yes:

You would hope the rockers were super light. Overhead cam would be fun for tuneability, i'd have to take a sticky beak :P