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Personally I use JE/Nitto

Your topic may start discussion but wont provide a unanimous outcome.

I'm not aware of a comparison across the range.

Consider your build holistically !

against your goals, your capabilities and the depth of your wallet

I just found this, I wonder if mahle are the same as cosworth material composition.

I believe all CP pistons are made from 2618 alloy and Cosworth's Subaru pistons from 4032. 4032 is a high silicon alloy and the high silicon content provides a more durable wear surface and reduced expansion rate. 2618 is a denser alloy with higher tensile strength and a higher heat transfer rate.

4032 is a better option for a street application where low wear, long life, and reduced noise is of primary importance.

2618 is a better option for a race-specific application between the piston crown will run a little cooler and the piston will withstand detonation a little bit better than 4032. But the piston has less wear resistance and actually less stiffness.

However, Cosworth pistons use a boxed bridge design developed in F1. If you look at the back of the piston the pin bosses are reinforced with additional cross-struts and the pin itself is quite short. The bending loads on the pin bosses are reduced and overall the piston, skirt, and crown have greater rigidity. I don't think the Cosworth piston gives up anything in terms of overall strength compared to CP.

Cosworth pistons use a pin offset for reduced piston slap noise. CP pistons have no pin offset which is why they are not directional. Another reason for a very low noise level from Cosworth pistons.

Cosworth pistons have a polished crown which supposedly reduces carbon build up over time....probably another plus for a street application.

Theres a piston thread in the RB30 section, I think the wiseco are a good choice cause of tighter clearances possible but depends on power goals etc.. I chose to go with stock unopened bottom end cause its a pain and expensive to stuff around with engine builders that might stuff it up anyway... have faith in the OEM lol... nearly 30year old but yeah haha

So much potential for awesomeness. But to take it seriously before it reaches its inevitable train wreck of a conclusion.... Nah.

Carillo rods cause a bloke called Fred someone once used them in a race car which crashed into a wall and won a race. Must be awesome then.

Pistons. Well actually who cares. The most important thing about the piston in an rb26 is the rings and gettting a good seal. The rest of it doesnt matter. So best piston is a stock Nissan one. Take the Nissan out and you get oil puke unless you are really picky with your selection and run in.

CSB.

On the topic of rods, the weak point on H beams is usually the bolts anyway. I had to cough up an extra few hundred to get the ARP 625+ rod bolts in my Evo stroker kit.

Pistons... Well my stock Nissan VQ pistons have taken 40psi at the track many times, so have the rods. All I did to the stock engine was bolt the heads down harder with L19's after they lifted. As long as you keep the combustion temps under control the stock pistons would do fine.

  • Like 2

Tomei? My Tomei's are slight on startup. No piston slap and no blow by.

Its more of the engineering job that will make the most difference.

Make sure you use a good/the best engineer you can and whatever forged piston you use should do the job.

Depends on what you intend to do, there is no 1 rod or piston that's best for all situations everything is a compromise in certain directions.

Pistons can vary depending on what the build is, you wont build a high revving drag engine with the heaviest pistons with long skirts and you wont get far building a daily or long distance race engine with the lightest short skirt pistons.

Same deal on the rods, pins, rings etc.

Many people overlook the design aspect of parts and just see a brand name, put focus on the build purpose and then look at a piston or rod design to suit the application.

Basics like assembly weight which you want to keep low in high revving applications or highish to allow longevity through support and material strength for longer lasting lower RPM builds as some other basics to consider.

Its like comparing a Mahle and JE piston, 2 totally different designs from many points of view.

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