LT1 aftermarket pistons
 

Does anyone make a 4032 piston for the 6.2? All I’m seeing are 2618. I need a 4.060 bore 11.5cr piston for a stock rod and L8t crank in 4032 for a mild na 6.6 build.

I used the Diamond Pistons 11533-R2-8 Chevy LT1 LT4 Gen V Dome and they are almost what your looking for. They are 4.065 and 11.5 compression.

I don’t see what you are looking for. Correct if I am wrong but that size your looking for I have seen in Mopar products not GM builds.

Thanks.

My bad, I did mean 4.065 bore. It looks like diamonds entire lt catalog is 2618 though.

Straight off my box. These are the ones you want for a NA build. I did manley rods, reinforce your heads big time and really go with a bigger cam if your doing these.

i plan on using a dome piston. je, wiseco & diamond all offer domes w/ .200 reliefs that bump compression to 12.3 with a factory cc head. i'm hoping to be around 13:1 with aftermarket heads and thinner gasket. otherwise there's no point in swapping pistons for an na build, imho.

The swap is needed in my case for pistons because of the Nitrous load. Ring gap on LT1 are not the greatest for power additives.

The fact that reduce weight, and improve strength, durability and ring sealing will help any build with better quality pistons. There’s nothing wrong with someone adding quality pistons to NA build to make it bullet proof and down the road to add a power additive. It’s a costly move but if anyone has the money to do that then I say go for it.

What benefit are you looking for in the 4032 grade? I thought most "regular" type automotive pistons were high silicone?

But what about all the extra costs and balancing? I can't remember now but I thought the GEN V stuff is also fracture split rod ends so even more machining, or maybe I am thinking of something different. I thought I remember seeing rod bolts in question, but then you hear about all these supposedly extreme RPM stock bottom end stuff.

You’re right. Fracture split has both advantages and disadvantages.

https://m.youtube.com/watch?v=5Nm5hNbtfoY

https://www.holley.com/blog/post/eve...n_v_lt_engine/

That’s true, most automotive pistons are high silicon, the OEM hyper eutectics for example. There are two main alloys used in forged pistons. 2618 and 4032.

2618 is low silicon. This makes the material more resistant to fractures, but also is softer and requires more bore clearance due to its higher coefficient of expansion. The softness is somewhat alleviated with skirt coatings and ring land anodizing, but they still rattle at cold start and won’t last.

4032 is high silicon, and is more brittle than 2618, but wears better and expands less.

2618 is typically used in power adder applications and 4032 in na. The trade offs for the “toughness” of 2618 are not worth it for what I want to do. A hyper eutectic cast piston like the OEM would work for me.

I did the Manley Forged Pistons and Rods. I did their blower setup with 10.0 compression.

you might look into what it takes to hang a stock rod on an aftermarket piston, it may be cheaper or within a couple hundred bucks to use an aftermarket rod, as well. arp fastener requires big end resizing and possibly the wrist pin needs bored.

why are you wanting a forged piston for a "mild" na build? i don't see any aftermarket stuff outperforming a stock piston in that instance. esp if you are planning on keeping the compression so low.

id be looking to see what it takes to use a stock LT1 piston in your case.

Stock piston won’t work with the L8t crank, but you are correct that a cast hyper piston would suffice for what I want to do.

There are plenty of 4032 offerings from mahle and others for the 3.780 bore engines that use the stock rod. The stock rods are stronger than most people give them credit for.

Not sure how 11.5 is low comp, but then again I remember when 9.5 was the top end for a pump gas build.

So is there any improvements we can make by going to a piston with a high expansion coefficient to get better properties to resist cylinder pressure and/or mass reduction? I would think there would be more custom designed alloys for engine piston use but maybe these are. I would sacrifice cold start piston slap noise for better properties.