opening a thread descussing building a 3.0 turbo i'm looking at a second hand S motor to take the head from but stuggling to decide if i want to go that way .
if anyone starts up that the 968rs is the benchmark of what should be done forgett it. 968rs had to fit in a power to weight class it was made to have no more than 360hp and is an acident that it makes 400 plus unrestricted also a good exaple is the 944 gtr leman 450 hp twin cam 1982


so thing big question is what head is better for a 500 or so hp 3.0 turbo and yes i do have all the other 500 hp bits computer big squirters heaps of fabrication my self .

just trying to consider weather the twinn cam head is the way to go considering the following

my 951 head has some money invested port work cam this would be wasted if i go twin cam.

the 951 head takes some work to mate up to the later block

the the twin cam head must have at least a valve job and thers 16 them

the twin cam will hang together and make power with no mods beyond 7500 rpm

the single cam will make more torque 2800 - 4500

the single cam can be configured with standard 951 parts when i have to present the car for various legal inspections to have it on the road


it is not curruntly road registered not sure if it will be again





as i outlined if you believe that the turbo head with ceramic liners is some kind of egineering marvel that can't be bettered please don't post

 

Get a 2.7 NA head if you don't want to sink big bucks into the 16v head.

Simple as that.

George

 

I'm assuming that you are using a 3.0 block and not a machined 2.5 with sleeves. Don't forget that you will need the 2.7 manifold as well.

G

 

hey the 2.7 head is rarer and more expensive again also the twinca head is with manifold and would fabricate it to clear the turbo please explain sinkinking mony into twin cam head perhaps as konstantien did it and did it well you think its the only way to go ?

 

the 2.7 head is extinct it is desired by a class of racers here in oz as it flows best of all and can be used in the atmo 944 challenge also everyone wants them for an easy 3.0 turbo set up

 

Ideally the twin cam setup would be most capable. Twin cam Cost will be significantly higher.

If you are not an experienced tuner or are not working with one I would suggest starting there. The baddest twin cam setup in the world won't run for **** without a good tune.

A solid lifter single cam head will go high rpm - think stock you are only good to 7500. Don't know that you will flow well that high without mega head work though (larger valves, etc)

 

from were i sit solid lifter set up will cost me more than the 16 valve and yeh i always figurd that i would not spin the 8 valve past 7500

 

the only cost i see inolved with the 16 valve is a basic freshen up all accounts say its so much bigger that no porting is worth doing other than the outlay for the head with i think i can get for around 500

 

I see a long road ahead for you, my friend.

 

yeh thats a good call in the past i've come unstuck for getting carried away and i've started to say
" i'd rather have 400hp tomorrow than 600hp in peices for 3 years"

 

from what i can see the twin cam will screw together esier than the 8 valve
but with numbers like above from the 8 valve who knows.

so super tooner on the long road to the big numbers what was the most painful and what you you maybe do different ?

 

8v heads = Archaic, restrictive, inexpensive, can be made to work but would take a decent amount of mods to get you there

16v heads = A heck of a lot more efficient and modern, a heck of a lot more expensive, not a huge aftermarket for them so mods will be a bit tougher and more expensive, will allow you to make the power that much easier which is always a good thing


The way I see it, dumping a ton of money into a custom 944/951/968 motor like that, the 16v heads are "worthy" of such a project. The 8v heads are trash. Do they work? Yeah, plenty of people have made them work just fine. They sure would simplify things quite a bit. However, IMO that's kind of like spending tons of money on a motor, then compromising and buying some cheap Taiwanese $100 knock off turbo that will fall apart next week. From a financial standpoint, the 16v is definitely quite a bit more expensive but, if you can afford it, it's worth it IMO.

 

Since you asked...
I will be shortly maxing out my 951 head. I have a full T4 and 100s of other modifications.
The 8 valve becomes impossible at close to six hundred wheel HP.
My next engine is a 968 head, 3 liter block, but with the 2.5 crank.
After this, I won't use the 8 valve head as an excuse, and I will make the folklore "dooooooooooooooom" car look like a one-legged man in an ***-kicking contest.

 

every one goes on about the expense of the 16 valve dare i ask how much is invested in the 8 valve head of the supatoonar above ? by the way a standard 16 valve standard will flow more than the 8 after you have spent a bomb on the 8
the turbo i have is rated to be max flow of 55lbs per minute so will i be able to max out that with a modest 8v that i have
i'm only after 450 or so at the wheels you are getting gready

 

gues i'm a bit taken back by people posting pretty big numbers with apparenly stock or mild 8v heads