tommyS

Have a question about the 4,5 L turbo ,and 4,5L-S . Are the cylinder heads
the same ????? Does anyone have info about this..
Thanks Tommy.

tommyS

I have an offer to buy a turbo Engine , and just wanted to use the heads on my -S .
Dont know if there is any Changes on the heads between the two.. I want just the heads for a port job
and then fit them to my -S on the same time ill do the plastic cooling pipes change to the aluminum..

touareg

I thought I read somewhere the the only difference was the pistons for lower compression when the engine is blown.

Don't quote me though.

tommyS

Yes thats my guess too but its hard to get the facts. .Thanks for your reply though.
Facts so far .. Bore *Stroke 93mm*83mm.
3,66in*3,27inch
Is the same for the two Engines.
But te compression is 9,5:1 Turbo
11:1 -S
1000 dollar question , is the diffrense in compression in the Head or the Pistones.
Tommy

bigbuzuki

Hope this helps.

The pistons for the naturally aspirated engines are cast.
Cayenne Turbo Piston are forged.

Cayenne Turbo Piston Cross Section
The pistons of the naturally aspirated engine have different combustion bowls than the turbocharged engine. The bowls in the pistons for the turbo engine are much deeper in order to reduce the compression ratio.

The cylinder head for the Cayenne S is designed in two pieces. It consists of the cylinder head and the camshaft housing with the lifter guides and the camshaft bearings. This multi-piece construction offers the best design for the use of high-heat resistant aluminum alloys to handle maximum specific loads. The exchange of gases is managed by 4 valves per cylinder, which are operated directly by hydraulic self-adjusting lifters. The two intake and two exhaust valves are arranged in a V, with a valve angle of 29.6o.

Cayenne Turbo Cylinder Head
The cylinder head design of the Cayenne Turbo is identical in principle to that of the Cayenne S, however, due to higher loading a special high-heat resistant aluminum alloy is used. The intake ports in the cylinder head have been reworked with respect to different gas velocities compared to the naturally aspirated engine.

Valves and Valve Springs
The valve stem diameter for the intake and exhaust valves on the Cayenne S and the Cayenne Turbo is 6 mm. The intake and exhaust valves are bi-metallic, this means different materials are used for the valve head and the lower part of the stem than for the upper part of the valve stem.
The exhaust valves for the Cayenne Turbo are sodium- filled. The diameter of the intake valve heads is 37.1 mm and that of the exhaust valve heads is 32.5 mm for both engine versions.
The intake and exhaust valve springs on the Cayenne S and the intake valve spring on the Turbo are single helical springs. To ensure proper closing of the exhaust valves even at higher pressures in the exhaust system, dual valve springs are installed on the exhaust side on the Cayenne Turbo.
The intake and exhaust camshafts for both engine versions have a base diameter of 38 mm. Intake valve lift is 10 mm. Exhaust valve lift for cylinders 1, 2, 6 and 8 is 8 mm, for cylinders 3, 4, 5 and 7 exhaust valve lift is 9.85 mm.

touareg

Sounds like it will fit, the ports for the intake valves are different. So tell us more about your project?

Flat6 Innovations

The Turbo also has Nikisil bores, instead of Lokasil in the S engine. I am looking for a Turbo long block to use for my 5.3 package for my Wife's CTT. If you need heads I have several sets of S heads and an entire S core engine that in fine shape.

tommyS

woo .. that was information enough to make your head spinaround,why the different lift heigts on just a couple of cyl...and yes there is a difference in the engine block barrel surface..A have heard the -S block problems with the Lokasil coating.But the Nikasil turbo coating seems to hold up great....Thanks for info ... My project is my cayenne -S 06 ...The change of the plasic cooling pipes is up, have no leaks but intend to do it before a dissaster ocurrs. At the same time the engine is half way tourn apart my intentions was to have a set of cylinderheads ported and ready for a swap.At the same time the exhaust manifolds is coming out of the engine bay as a bonus. And my intentions are to watercut a couple of exh flanges in stainless an build a few headders calculated for the -S engine....The only way to reach the exh-manifolds is either to lift the engine out or remove the heads...Think it is way to few things for the S engine performance upgrade....Look at the std exh manifolds. ..Dont want the 4,5 l turbo gas mileidge .In the S there is moore potential ,just have to work for it though.....Flowed heads,headders , 100 cell metallic cats.And a new software.B.c Racing suspension.....Why dont i just by an GTS??? well just for the hell of it i think ...... reg Tommy

tommyS

Well the motodyne.com http://motodyne.com/images/cayennev8blower.jpg has a tight supercharger for the 4,5 and 4,8L v8.
And vividracing.com http://www.vividracing.com/catalog/2...7-p-35154.html
stuff right over the counter with no effort like digging in to calculate your own headder and to make them fit in a very limited space in the Cayenne Engine bay. Maby i should Contact you
"Flat6 Innovations " and see if we can work something out with your -S heads you have laying around . tompasvan@hotmail.com
reg Tommy

mcbit

The Cayenne V8s are neither Nikasil nor Lokasil, there are no liners or coatings. All of the V8 blocks are monolithic castings of Alusil.

tommyS

HMMMM ... That was a new one .. I thought the barrel liner is treated in a chemical process etched . Just like a 2-stroke nikasil barrel..
hope im not wrong and i Think im not 4,5 -S Engine liner is 69% alu 31%silic.= Alusil as you mentioned. reg Tommy

seafeye

Here is the parts page for the heads. Can anyone decipher the model codes?

hahnmgh63

Wow, why are there different Turbo Cylinder heads for China? I wouldn't have thought China had any kind of restrictions.

mcbit

The Alusil used in the Cayenne V8 blocks is which is AlSi17Cu4Mg is 17% Silicon. Exposure is carried out after honing and is now done using a mechanical process rather than by etching.

tommyS

OK. But why is the turbos holding up better than the -S if it is the same... Here is where i would like to send a block http://www.928motorsports.com/services/uschrome.php .. Oh look the cylinder plating is 3 times thicker than the oem.
Tommy