4 valve 911 heads??

[BURN-BROS]

This a little bit of a pie in the sky thing, but I'll post. The 959 was 2.8 liter(?). You have a cylinder head stud spacing issue to deal with. Stupid expensive. Added weight. custom pistons for N/A on an on. If you must choose 4 valve heads, grab 996 heads and check the spec on it. I think the gt3 and turbo still use the air cooled case.

[KobaltBlau]

Sherwood, I really don't believe that there is anything significant about a 4 valve combustion chamber that makes the engine produce more heat. In my mind, it is purely an issue of heat dissipation, essentially there isn't enough room for fins and airflow with DOHC 4v + air cooled. Now, honda does SOHC 4v, which might give you a little more space.

Feel free to try, folks, but a complete GT3 engine (or 996 turbo engine converted to NA) is IMHO the easiest/cheapest way to get an NA 4valve motor in an older car. If you are going to go to water cooled heads, what is the big deal about avoiding water cooled cylinders? Most of the heat comes out through the heads anyhow. You have to deal with a water cooling system either way.

Is a 4v engine technically superior to a 2v? Usually. Is a multilink rear suspension technically superior to a semi-trailing arm? Sure. Are modern transmissions technically superior to the 915? probably. Does that make me want a new 325i or an old 911 with a 2.5 and 'mod S' cams? take a guess.

[jluetjen]

Does that make me want a new 325i or an old 911 with a 2.5 and 'mod S' cams? take a guess.

I agree completely Andy. At some point, this re-engineering "because it's there" mindset just seems to be a huge waste of time. If you really want 4 valves per cylinder back there, it's most likely easier to just drop in a Suburu motor!






... Did I just say that???

[Porschekid962]

yes the subie engine would be fun, I have some friends at school that have the new WRX and have about 350 hp at the wheels with huge turbos and what not. I am just suprised no one has adopted the 959 water cooled heads to a different engine. We see centerlock hubs, RSR dizzy caps, 935 suspension and what not but no 959 water cooled heads. Just thought it would be awsome to build a 3.6 litre twin turbo, air cooled, water cooled heads engine for a 911.

[JasonAndreas]

So who wants to go first?

959-104-013-01 cylinder head with valves ready for installation
or
959-104-033-01 cylinder head without valves

[Wayne 962]

Originally posted by Porschekid962
the porsche 959 was air cooled and had 4 valve heads. why not adapt those?

Nope, the 959 had water cooled heads...

-Wayne

[Wayne 962]

Originally posted by Porschekid962
thats even better!!! just like the 935 and 936 that made gobs of power, now we need to find a set of 959 heads and cam towers oh the craziness!

Ironically, I just looked up the price on these yesterday (I was bored). $35,000 each - still available from Porsche.

A 959 engine case is about $8K.

-Wayne

[JasonAndreas]

Is that retail or dealer/your cost?

[911pcars]

Jason,
If Wayne gave you a 15% discount, you would only have to forward him $178,500. If you're a resident of CA, add $14,726.25 sales tax. Add a few bucks for delivery and don't forget the insurance.

Sherwood

[JasonAndreas]

$178.5k??? You only need two per engine!

[al lkosmal]

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33617&item=7923939883&rd=1

[Porschekid962]

WOW, that guy has some awesome other stuff for sale, I wish I could get a loan!

[snowman]

Please note that Porsche had some Very advanced heads for its 356 carrera. Twin overhead cams no less. And that was in 195? I don't remember if it was 2 or 4 valve. It did have twin plugs.

[al lkosmal]

The guy that has those for sale used to have a nice Pcar shop/engine rebuilding business in Seattle. He obviously still has some cool stuff in the garage.