New Rosten Pistons

[TDIsyncro]

There is a bit of a missunderstanding here. Mr Rosten is offering OEM Mahle pistons from a 8V PD 2.0L 136HP motor, not custom billet pistons.

 

[Ski in NC]

Um, am I missing something? Is the flywheel not BOLTED to the crank? How does a high friction plate in between the crank and flywheel do anything at all? Haha, I'm sure I'm just not picturing the right situation here.

The shim with diamond dust increases the friction between crank face and flywheel face. So at high output, there will be less chance of relative motion between the two. The clamping force from the bolts remains the same. If there is relative motion, faces will fret and also bolts may fatigue and fracture. The shim will make that less likely. If it even was likely.

 

[Scott_DeWitt]

.... it's the diameter of the piston. I.e. for different size cylinder bores.

What the heck is a flywheel friction shim ?!?

A crank scraper on a TDI? Man, things are beginning to progress with TDI tuning.

It's a very thin and hard steel shim with a Diamond like coating on it. It's purpose is to cut into the crankshaft (microns) and keep the flywheel from rocking back and forth. Audi also uses them on the front crank gears to prevent the timing pulley key from shearing.

 

[shizzler]

Ok, makes sense. But I can't see this doing much more than 6 (or 8?) flywheel bolts do already.

Thanks for the explanations.

 

[bussso]

hi guys,
I've seat ibiza cupra tdi 160 hp year 2004 with 258.2 hp 4100 rpm.
Which piston i can used for my engine?i wish 300 hp.
Thanks
Simone

 

[TDIsyncro]

hi guys,
I've seat ibiza cupra tdi 160 hp year 2004 with 258.2 hp 4100 rpm.
Which piston i can used for my engine?i wish 300 hp.
Thanks
Simone

Keep your OEM pistons, but drop the compression ratio a bit (17 t 17.5:1) for long term reliable power. You drop CR by machining the bowl volume a bit bigger, plus whatever you remove for extra valve clearancing.

 

[TDIMeister]

I agree with the above. With the PD160 you likely already have the very best OEM pistons available. For 300 HP you really need to focus all your attention on fueling and air flow, both intake and exhaust (including turbocharger and charge cooler).

 

[VW97JettaTDI]

So, stupid question. If im building a engine for rally and am looking for durability will i want a increased or decreased compression ratio. Im wondering because im looking at pistons and found Rostens to be very interesting. If im looking for a more durable, lower temp piston is there a better choice than a Nural piston. I dont think his pistons are HD either. I think coating the top could be a option for improvement as well?

 

[TDIsyncro]

So, stupid question. If im building a engine for rally and am looking for durability will i want a increased or decreased compression ratio. Im wondering because im looking at pistons and found Rostens to be very interesting. If im looking for a more durable, lower temp piston is there a better choice than a Nural piston. I dont think his pistons are HD either. I think coating the top could be a option for improvement as well?

As I already mentioned above, Rosten is not selling an aftermarket piston. It is an OEM Mahle 8V 2.0 PD piston.
Regarding your question..it really depends on what torque you want to be pulling. Reduced CR is a requirement related directly to torque..lower CR always make the engine more durable if pushed hard. Using the OEM piston that Rosten is selling is a good choice, Franko6 and a few others are offering an ASV piston, or buy OEM BHW if you want the best. The BHW is 18.5:1 factory and you can go all day at 170+hp/320tq and never have to worry. It also has a well positioned oil gallery so you can machine it out if you want lower compression. Shortysclimbin is one member that offers that service..perhaps MrChill is anouther, but I am not positive.

 

[Drive_Diesel]

For an ALH, does anyone know what the observed power limits are on the ASV, Mahle and BHW pistons?

 

[TdiRacing]

So, stupid question. If im building a engine for rally and am looking for durability will i want a increased or decreased compression ratio. Im wondering because im looking at pistons and found Rostens to be very interesting. If im looking for a more durable, lower temp piston is there a better choice than a Nural piston. I dont think his pistons are HD either. I think coating the top could be a option for improvement as well?

Stock pistons are fine for rally racing. We ran the same engine for 6 years. I made 225 Hp with them without issues. And that was on my 250K mile engine. Torque we ran about 399ft lbs. No use for that much TQ in rally thought as it just spins tires. Good rally set up is 150hp and 350ft tq. All super easy on stock engines(ALH). Basically bolt on stuff.

 

[dieselpower04]

If I upgrade my rods to Rostens, would I drop in new pistons as well?

 

[VW97JettaTDI]

wait i'm confused, The Nural pistons are stock for a different engine than the AHU vw. But i dont think their from a PD?? Can some one clarify the difference on ASV, BHW and Mahle pistons. I know ive been looking at the NURAL pistons due to a improved number of features compared to the stock crown. Some one please explain these mixing acronyms ..

What exactly is the best solution for pistons (available) at this time for performance vs. availability and cost? My understanding is quality of skirt thickness and coating, depth of crown well vs offsets of valve well, extra cooling of piston, geometric placement of cooling ports or wells in case of possible machining. Geometric position of combustion well in crown and ability to increase atomization of fuel to air with as little turbulent flow to concentrate combustion in concentrated area for best energy transfer into kinetic energy of piston vs. transfer to air resulting in increased egt's.

To cut it short. who sells the best piston, for what ever purpose . . Personally i thought the (Rosten:Nural) seemed the most likely though comments about difficulty to modify are hindering. It would be nice to have a low clearance piston with just the allotted space from head to crown to allow valve opening and closing without disrupting flow. then on top of that have the most concentrated well. Give me some reasoning. my blocks half apart and I wanted to have pistons years ago. Whats the current view?

PS: (Should i just make this a thread?)