Desean Strickland

I’ll be running 98 since there’s no e85 where I live and my power goal is around 450hp

Cast pistons have a lot higher silicone content, 2618 has less than 1% silicone content and 4032 forged is somewhere in between. You wouldn’t use 4032 in a 1000hp engine since the extra silicone makes it more brittle but for my application, wanting a strong piston that will run close to factory piston to wall clearance running probably under 20psi boost it’s perfect. and the need to go forged is more to do with needing a 86.5mm or 87mm piston since I probably won’t be able to keep the stock 86mm bore size. And even if I could it probably wouldn’t be a great idea to put 30 year old scored stock pistons back in it. as for going with a 25/30, it gives a lot more low end torque and power, hits full boost about 1-2k rpms earlier and should make a lot better street car than a 25det would, the downside being it won’t rev as high which dosnt really matter for a street car.

Hey so I’m building a rb25/30 and I’m after some 4032 forged pistons but I’m struggling to find any. Has anyone here used 4032 forged pistons for a 25/30? If so where did u order them from Second question is people who went with 2618 forged pistons, have u had any piston slap on cold starts or anything like that? Iv been told it’s a possibility when using 2618. It’s not gonna be a track car and I wana run tighter pistons to wall clearance to suit a daily driver which is why I’m after 4032 pistons but keen to hear people experiences with both types of forged pistons.

Hey so i am trying to choose what pistons to use, the goal is 300kw but i would be happy with around 270-280kw, just whatever it makes on a safe amount of boost. i am fairly sure i wont be able to use my stock pistons as the bore will probably need oversizing and i'm not too keen on spending $2k on forged pistons for a power level that many people claim is safe for the stock pistons. the idea of using aftermarket cast pistons came from this post: He used Hypatec cast pistons with no issue. However hypatec now only seem to make the std size 86mm pistons for the rb30, as the oversized pistons have been out of stock everywhere that sells them for a while. Another brand of cast pistons i found was Endurotec: https://www.precisionintl.com/products/pnirb3060203e?variant=40555792498883 on the ebay page for Endurotec pistons it doesn't say where they are made, only "Endurotec® pistons are sourced from various world class suppliers. Make no mistake, these pistons are not seconds or factory rejects and are all manufactured from quality eutectic alloys with T5 heat treatment that are basically the same as many other premium brands". which doesn't exactly inspire confidence when they are saying their own pistons are "basically the same quality" as other brands. The only other brand of cast pistons that i cant really find any information on is ACL. However i cant find where to get them. I can find ACL pistons for other engines for sale, just not the 6MKRY2799 set needed for the rb30e. Has anyone used ACL pistons? are they good quality? i thought since they made good engine bearings they would also make good quality pistons? if i have to buy forged then i will, but i just wanted to get opinions on the aftermarket cast pistons first. cheers

Alright thanks

will the rb30 flywheel work with a clutch that is meant for an rb25 flywheel? I know they bolt up but are they the same?

is the stock rb30e flywheel the same as a stock rb25det flywheel? im doing a 25/30 swap in my r33 and dont have a stock rb25 flywheel because the car had a twin plate in it which im not re-using. i do have an rb30e flywheel that came with the rb30 block that i got tho. would it work? from what i can see from pics online they look identical. yes i know theres already a thread on this but there was a lot of conflicting answers, i just want a yes or no from someone who has actually held both and knows what they are talking about. cheers

I have a brand new g3 21u high flow that I can’t use any more due to going 25/30 selling it for $750 cost me $1000 brand new never installed or used comes with stock wastegate actuator in WA but can post it delete if not allowed

Hey Tao I bought a 21U g3 highflow a few months back, was planning to put it on my rb25det. long story short i discovered i had to rebuild my engine. i have gone down the 25/30 route, what would happen if i just used my internally gated 21u g3 highflow on it? my power goal is 300kw. what other turbo could you recommend? also if i did go with a bigger turbo could i still stay internally gated? cheers

Hey guys For people with a built rb25, how much did u pay for the machine shop side of things like balancing and prepping crank, testing and resurfacing the block, cylinders bored out piston and bearing clearence measured etc. I’m assembling the engine myself and using my local machine shop but just wana make sure I’m not getting ripped off, Not parts cost just the actual service. Cheers

yeah im guessing the piston rings are fine coz it has 150-155 compression it was stock fuel pump which iv just replaced with a walbro 460, have done the wiring relay mod as well, it had a haltech platnum pro already installed and tuned by C-red and basically just made stock power, iv also got a hypergear g3 highflow and the 980cc injector kit from Efi to put in.

Yeah iv thought of doing it myself but if I did I would probably rather go with some 86.0mm forged pistons and just spend the extra 1.3k while I’m in there and just re use my stock rods how did u hone the cylinders? Did u send it to a machine shop or did u just do it yourself? im in WA, about 2.5 hours away from Perth so my options are kinda limited. and yeah after I finished cleaning all the pistons today it’s more like 5 of the pistons have detonation damage. either way it’s gonna get re-tuned when I’m done. The stock turbo seals blew causing it to slowly burn oil for a while so that could have been the cause.

True, I never thought of that. Iv seen u in other threads and u seem to know a lot, so roughly how much do u reccon it would cost me to get the engine rebuilt if I’m pulling the engine and just dropping the short motor off to the engine builder? Obviously I would have to get forged pistons Cus those ones are ruined, probably an mls head gasket and arp studs and just the rest close to stock? Assuming my block and crank are reusable. I know that’s a question for an engine builder and I’ll try and get some quotes on Monday but just from either your own experience or from what you’ve heard from others, how much u reccon it will cost me if I’m pulling the motor and all they have to do it just rebuild it?

Yeah cams are still in, the silver look on the pistons in the first 2 photos is because I cleaned them to see if it was just carbon buildup, which it isn’t. Engine has 200,000kms and it is 3 pistons which has notable wear around the edges

Iv already cleaned the piston in the first pic and it looks exactly the same, it definitely isn’t just carbon buildup. And the engine has 200,000kms and was burning heaps of oil from the turbo seal failing prior to pulling it apart, it didn’t run for long while burning oil.