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Tim Robinson 06-10-2005 03:40 PM

Titanium Components
Apart from cost, why aren't people using Ti con rods,valve springs,suspension springs and valves etc etc. What are the draw backs to using these components. We talk about Ti retainers but the valve itself would be a huge weight saving and together with con rods would have to increase the rev limit and thottle response considerably. There are so many cost no isue engines out there but ..... All the literature says these components out last every thing else and the Honda NSX , Ferrari and others use them so why not in the 911???

kenikh 06-10-2005 03:55 PM

I have heard rumors that titanium rods tend to go oblong more quickly than steel. That's kinda tough to rationalize for anything but a race motor. Considering you can build a short stroke 2.8, 3.0 on a 66mm crank and conventional components that will rev to 8800RPM, this kind of cost for weight saving on the rotational mass seems wasteful.

Tim Robinson 06-10-2005 05:54 PM

short stroke
Hadn't heard about that rod problem,but these problems are exactly what I am looking for. As for the short stroke thing,I used to sprint a Alfa v6,2.5lit crank with 3 liter pistons giving a great revy 2.8 but I still was slower than a straight 3liter. I'm thinking more about this stuff in a 3.6 but having the revability of say a 3 liter. Personally I am all for low displacement high rev engines but If you don't have to fit into a size class then bigger is better even if it sounds a bit duller.

Bill Verburg 06-11-2005 06:06 AM

You do realize that the stock 993 rods are already ~200g lighter than the rods used on the so called rev meister 2.7RS?

Stock 993 vrams will rev like crazy(when they are not pulling a bloated 993 chassis around), the tach can not keep up w/ the engine

ps just kidding about the bloated 993 chassis I do love them;)

Shuie 06-11-2005 06:38 AM

Search this forum for 'titanium rods'. there is a lot of info here.

jluetjen 06-11-2005 01:39 PM

Aren't the 993 rods designed for a 76.4 mm stroke? I wonder how much of the 993 rod's "weight loss" is due to the fact that they are shorter then the 2.7's? In other words it may not be a meaningful comparision since you wouldn't be able to simply replace the rods in a 2.7 (with it's 70.4 mm stroke) with the 993 rods.

Bill Verburg 06-11-2005 02:57 PM

He's been asking about 3.6s in general and 993 in particular

I was not suggesting that 993 rods be used in an earlier engine, they are not compatible. Though the 964 rods are.

The 993 rod is .8mm shorter than a 2.4/2.7/3.0/3.2/3.3/3.6(964) rod.

For an all out race motor Pauters, Carillios or even the reinforced 993 are used.

It would be interesting to see if the Ti 996 pieces could be used, but they are certainly not needed.

Tim Robinson 06-11-2005 04:17 PM

Bill is right ,I have been thinking about the 3.6 v ram. I don't even have a car yet , just want to make sure I buy the right stuff first time around and not put money where its not needed. Getting a long wish list together. Basically I want a 70's look road car that i can enter road rallys and super sprints with. I like the idea of a bit of a sleeper so no tails or huge flares , oh except for a raceing stripe!! Definatly want perfect engineering and presentation. This forum has an amazing wealth of knowlege and I totally appreciate all of you advice. I would say I have about 12 months before getting out my cheque book.
Regards Tim

Bill Verburg 06-11-2005 04:33 PM

If the 102mm p/c are out, I would still rec. RS valves(both I/E) and Cup or RS cam, 964 cam drive, stock hyd lifter for street use, solids for track, Arp or Raceware rod bolts, 993tt head studs. Custom chip, burned on a dyno.

pretty much everything else can stay stock. Valve springs retainers etc are nice but not needed for street use.

BReyes 06-16-2005 06:23 PM

Not neccessary for street use. Race motors yes. So it depends on what you are going to do with the car.


304065 06-17-2005 08:07 AM

My thoughts:

Jim Newton built a car for one of his customers that has kicked serious butt in every race it's been in, using "S" rods.

While Ti is certainly cool factor, the cost of the rods is several thousand dollars more than steel rods. The galling limtations of Ti, and ovality after a few hours, are also drawbacks.

If you are setting a world record (911R) or trying to win Le Mans (935) and competing with world class drivers and factory teams, every little bit counts. If you are just trying to beat some dentist you can save the money.

michel richard 06-17-2005 02:59 PM


Originally posted by kenikh
. . . Considering you can build a short stroke 2.8, 3.0 on a 66mm crank and conventional components that will rev to 8800RPM, . . .
I'm considering rebuilding/hotrodding my engine and the thing that I'm most interested in is high revs. I'm curious as regards the 8,800 rpm figure. Is there a source for that figure, and a recipe ?
All info will be appreciated.
Michel Richard

TimT 06-17-2005 05:19 PM

center drill the crank,

have the throws ground and use Clevite NASCAR bearings.

We can shift at 8500, and with the other mods to the valve train, the crank guy and cam guy say we are safe shifting at 8500

Tim Robinson 06-17-2005 07:57 PM

Iteresting reading, obviously all the Ti maufacturers say there product out lasts any thing on the planet so its interesting to read how rods go out of shape and I bet the coil springs sag to. The oposite of what they say. The mix of 98% road to 2% track leads me to another Question. All about making my investment last and also be fun to use.

If you were driving in the sydney to london rally , via some of europes race tracks,and you needed to drive home again , how would you build your engine?? Because this is what most of us want out of our engines isn't it?

andrew15 06-18-2005 06:28 AM

I think a lot has to do with public misperception and the particular alloy used.
A couple of examples of the difference of opinion:

From another thread - 'Ti cracks easily and shouldn't be used in stressed applications', but the Russians use Ti as the pressure hull material for their attack submarines (a bit of a stressed application).

- Even the con rod issue seems to have totally different sides - some say the rods don't last longer than a race rebuild, but Porsche is currently using them in their current GT-3 customer road car.

Andrew M

Steve@Rennsport 06-18-2005 02:53 PM


Considering you can build a short stroke 2.8, 3.0 on a 66mm crank and conventional components that will rev to 8800RPM,
Giving all due respect for whomever told you that or gave you that impression:................Not For Long. :) :)

Without going into details, extended, RELIABLE operation at or above 8000 RPM requires some special parts and a LOT of extra preparation.

Engine component stresses build logarithmically with RPM. Its not a linear relationship as I've discovered over the past 30 years of racing 911-based engines.

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