2618 or 4032? Tips for Choosing the Best Piston Alloy for Your Performance Engine from RaceTec

[@SummitRacing]

Thanks for watching everyone! What other piston related tech would you like to see us cover?

[@mikef-gi2dg]

I have been an engine nut for a very long time. That was an excellent description of piston alloys.

[@boosted2.4_sky]

I chose 4032 years ago.. 4 cylinder, turbocharger build, rod piston, making ~500 rwhp , street driven..NO PROBLEM dumping 28-32 psi and getting down...tuning is key to any engine build regardless of the piston alloy... In my opinion, if it isn't a dedicated race car there's no reason not to choose 4032..they'll last longer and handle anything you've got in your street/strip car..

[@Alss383]

@boosted2.4_sky what air fuel ratio did you tune for on this engine?

[@a807511]

Unfortunately it seems a lot of manufacturers tend to forget putting the alloy in their specs. I've been looking at pistons for a while now, from my last LS build, to the big block coming. And it's way harder than it should be to find that spec.

[@Dirtyrpide4life]

So true!! Unfortunately most do that on purpose to have blended materials non disclosed via cost per manufacture:(.

[@Alss383]

I heard of story where a guy got a Chevy 383 for the price of a 355 because the shop had a short block lying around. Unfortunately they didn't tell him it had 2618 pistons and he was shocked by the noise on startup.

[@williamchandler6151]

Guys. There is zero SiliCONE in pistons. There are however various amounts of SiliCON. SiliCONE is used to caulk your windows and is man made. SiliCON is an element sometime used for alloying.

[@davidreed6070]

I remember another material..ms77 that worked pretty.

[@FenzoMac]

@RobbyLayton brought me here. Thank you @SummitRacing for supporting @RobbyLayton. love the content here at @SummitRacing.

[@SummitRacing]

Thanks for watching !

[@ericwilson2585]

Thank you, that was very informative.

[@SummitRacing]

Glad it was helpful!

[@ardennielsen3761]

aluminum... was looking around and found, cast iron and cast steel piston options mentioned in a few things... one would be heavier then the aluminum but the cast steel from ford was said somewhere to be 128'000psi tensile. but as far as it goes the one engine was 185hp one year then at the end of a production quote was 265hp... cant get clear information from anyone tho in thought it seems like, they just switched from cast steel to compressed nitrogen/argon forged aluminum. tho that 128ksi steel would be nice for a mild tune up as the OEM aluminum almost looks like there to be intentionally softer not for a hard "working engine" just lighter for those EPA measurements of 185hp 4.6L w/steel pistons and 265hp 4.6L w/aluminum pistons being for the EPA one uses 48% less fuel over "#.../mileage" models made. like seeing 15mpg and not 21mpg, one is 128ksi cast steel the other is 78ksi cast forged aluminum? or so i read somewhere the one might be a tempered 4140/4340 chromoly steel piston. but anyways, whatever pistons are in it, it allegedly snapped off a 28 spline 8.8 with 400'000km on the dash, even tho i have other suspicions as to it only having 85'000km ... something the other was paying to get stuff done to 20 years ago with no carfax report info logged other then a transmission kit with a very faded reman sticker on it... and a low power note in the fax... it broke the axle's after a fuel pump and pressure reference fuel regulator was put on it. 440gph @ 0psi... pump... gallon per hour. those pistons all have numbers on them so if ya borescope it, they can be traced back right, by reading the piston face print numbers? got a 325lbft number as by the shaft ratting and braking from a motor specified as 265lbft as a stall torque from 4800rpm to 0rpm in "seconds of time" equaling the factory advertised 265lbft... +325lbft as the axle shaft broke, just from a regulator and pump swap... odd? 400'000km is a lot of fuel for 15mpg. wrecker paint numbers here and their...

[@Dirtyrpide4life]

Loved the content!!!!!!!! 👊🏻👊🏻🇺🇸🇺🇸

[@SummitRacing]

Thank you!

[@autumnjeserich2689]

Would the 4032 be good in a daily driver truck application? I had planned to go with Hypereutectic pistons for my LQ4 thats getting a 4 inch stroke but I haven't found any hypereutectic pistons for a stroker motor

[@Alss383]

@@autumnjeserich2689 absolutely 4032 will last in street application.

[@nonamebleach]

What about 7000 series alloy? Ever seen that being used?

[@user-Dr.]

I've been building long stroke 383 gen 2 LT1's, for road racing, yet keeping them street drivable, I build them for maximum torque, I've been using JE sportsman racing pistons, last fall for the third time a piston broke in half right along the wrist pin center line, never any other damage, throw new pistons in and go, this time I switched to Ross pistons, a lot lighter wrist pin, heavier piston, same over all weight with a little touchup, nobody can tell why this is happening, can it be cured, any suggestions, this build is making over 600 lb-ft of torque, on the engine dyno.

[@SummitRacing]

Thank you for your question. That’s great torque out of a 383! 4032 Alloy lacks the fracture toughness of 2618. Meaning once a crack starts, it shoots through the forging like a lightning bolt from silicon particle to particle and you end up with a pile of shrapnel in the oil pan. 2618 Alloy is ductile and lacks the silicone particles so a crack may start but travels to a low stress area and often stops on its own. 4032 can make a little more power than 2618 and often wears better too if a skirt profile isn’t super-developed, but it has its limitations. Circle track pistons are an interesting case. .150 deck pistons are lightest but usually split over time and it may not be catastrophic because the engine builder notes the blowby occurring and swaps out pistons before bad things happen. Going to .180 is a noticeable improvement. .200 is better and rarely fails. .225 is often used in endurance applications. Racers love to throw in the thinnest wall (.080 to .105 range) and lightest pins they can get. The problem is thin pins flex. When they do, the pin towers flex with them. Pin tower flex causes cracked decks. Having a forging that narrows the unsupported span between the piston and rod small-end to .050 puts the pin in shear and makes ANY wall pin stronger than it would be versus “hanging out in the wind.” This is a problem because the piston AND the rod manufacturer’s want to sell you the lightest part and the clearance here grows further away from each other. Optimized pistons/rods like Summit’s Pro LS series complement each other in this way. For your issue, keep a close eye on pin bore wear and use it as a guide to when the pins are too thin. Lastly, ceramic heat barriers from Polydyn, Calico or Line-2-Line keep the deck from annealing as quickly and this can extend piston life as well.

[@user-Dr.]

@@SummitRacing Thank you very much.

[@user-Dr.]

@@SummitRacing Thank you very much for that information, I've been reading it over and I think it may be a huge help in solving my problem, I really appreciate it, both engines are running perfectly at this time, and I will run till a failure, at that time I will put this info to good use, I'm going down to the pole barn right now to look at the old pistons and see what I can with the wristpin bores and the like.

[@babaoreally8220]

Silicon not silicone.

[@andyreiwitch8845]

Silicone...🤦‍♂️