kadabra

Hello guys
I'm about to start shopping for my nex season build and i want to find out if the stock pistons on X are forged or not? And where can i find all the information about X engine internals. I've seen some pics and i cant remeber where.

Regards, kadabra

DRAG

iTrader: (3)

I have responded twice and keep getting errors with the site. That is happening a lot lately...so I'll try one more time and gonna keep it short.


They are a forged piston but they are not like a 2618 alloy that Wiseco, JE (je/srp have some high silicon pistons), CP, etc use. Those are low silicon pistons that are softer and expand about 15% more than the higher silicon 4032 alloy. The 2618 absorbs more shock and resists detonation better, but it also requires more piston to wall clearance because of this expansion. So basically what that means is that on cold startup you have to wait for the piston to get some heat in it before it is at your "running" piston to wall clearance.

I believe the OEM X pistons are Mahle 4032 alloy and what the high silicon does is it makes for a piston that is more brittle and expands less. So OEM mfgs use it so that they can keep the piston to wall clearance tighter for emmissions and to keep engine noise down. If you are daily driving the car, especially in the winter and where you will kinda "jump in and go" instead of waiting for the motor to get up to operating temp (oil temp, not water temp), then the 4032 is probably a better option. They are certainly stronger than a cast piston and probably good to 700hp or more, but not as forgiving as the 2618.

I think the real weakness of the OEM motor is the rod. It is cast and scrawny. I murdered mine, but it took a decent amount of power to do it.

kadabra

Wow thanks alot
What ammount of power you blew you stock pistons with? Can they handle ~380-400 whp on weekend trackdays for a season or two?

Thanks for being helpful and posting despite site errors, they are pretty **

UT_EvoX

OK, that's some detailed info but it's not at all accurate.

The pistons may be forged, yes, but I was under the impression they were gravity cast. I do know they are manufactured by Mahle, so who knows.

Actually see that dot pattern on the bottom side of the piston crown? That's from casting, not forging, I'm almost positive.

However, you're completely wrong about the rods. They are most definitely forged. I can tell by just looking at them. The last time Mitsubishi used cast connecting rods in their engines was in the 90's. Actually probably not even then. The 6G72 has had forged rods for the past 2 decades, so has the 4G63 and 4G64. Rods in US-spec Evo's have never been cast for certain. Turn one of those rods over and look for a casting line; you won't see one, instead you'll see a very wide forging separation line that has been ground down.

Your stock rods may have snapped (because of a MASSIVE amount of detonation or pre-ignition), but they are most certainly forged. It does not mean they are as strong as any aftermarket performance forged rod, however

Ruff Ryda

iTrader: (13)

^^^ Those were from a 200shot of the juice.

DRAG

iTrader: (3)

380-400 is no issue at all. I don't put my car on the dyno, but my Data Log Lab showed around 430 on turbo which was enough to run 11.7 at 3700+lbs. Then I sprayed a 200 shot on top of that (minus 7 degrees of timing of course) and that is what broke them. I don't know what kind of power it was making at that point. It held 100, 125 and one bottle at 150 just fine.

UT_EvoX

You threw a 200 shot on a 4 banger without direct port injection. That's why your engine blew the **** up! lmao, please don't listen to this guy's anecdotal evidence unless you want to end up with a pile of scrap metal for a 4B11.

4B11's have forged pistons yet cast rods. That's some logic right there.

DRAG

iTrader: (3)

You can talk all the smack you want...the only thing you know about my car is what I have posted, so don't act like you have any knowledge of what I did beyond the few details I shared. Apparently just because I broke some parts, that automatically discredits anything I say I guess the solution to that is to not share anything at all. I have already disproved the theory that I got more nitrous in cyl 1 and 2 from the single injection point on my SF1020 and all cylinders looked happy fuel wise based on the plugs. There is one cylinder that would have received more than the others, but it wasn't either of the ones I broke. Thanks for your brilliant analysis of why I

UT_EvoX

You're the one who cannot tell the difference between a forged rod and a cast rod Sorry, thanks for your brilliant input, I'll continue building engines and cars that turn heads rather than throw rods.

Stop being so defensive and don't argue with somebody who knows more about engines than you do. Moral of the story.

I'm done here, to the OP, just PLEASE do not listen to this guy, he hasn't a single clue about the 4B11T.

DRAG

iTrader: (3)

I never claimed to know more than anyone about engines and I certainly do not have first hand experience with forging connecting rods. If that is indeed forged, then it isn't the best example of a forging and I retract my statement about it being a machined casting. I have no shame in admitting being in the wrong, but to be attacked for it instead of corrected is juvenile.

I didn't get defensive; you are hostile and if you wanted to pat yourself on the back about your engine building abilities then go pick on someone else. I didn't break an engine that I put together, I broke a stock motor. I don't need to rub myself off for satisfaction in here to impress others. My car runs hard on and off the bottle and I'm content with that.

UT_EvoX

You were first politely corrected and then you were "attacked" after you continued giving stupid anecdotal evidence about your 200 shot "build." Stop. Giving. Bad. Advice.

#1 you were blatantly wrong, #2 you are retarded. Have a nice day

The 4B11T has (quality) cast pistons and forged rods. /discussion

flyboytb

well girls this discussion is not helping the OP at all.... get on topic....

there are people well over 400whp on the stock internals running track days (in drag, circuit, auto x etc.) for example Ryan Gates car is making big HP on a stock block and his x is a dedicated track car.

so if your looking for around 400whp for your x and reliability the stock block will do just fine.

DRAG

iTrader: (3)

You need to go back and read before you act like a *****. I never disagreed in your correcting me on how they are made, nor did I even reference it, so I don't see why you are so angry and surely don't see where you get off calling me a retard. I am here to learn just like everyone else and with oil and carbon all over my **** that was my observation before I threw them in the trash. I guess I should have looked more closely and I stand corrected. I never looked at the bottom of the piston to see the webbing even when I snapped that picture so I think you made it clear that it is a casting.

EVOFreak27

Actually I believe that the pistons are forged. I am not claiming to be a know it all engine builder but you should check out this link.

http://www.turbomagazine.com/tech/08..._oil_pump.html

UT_EvoX

The article is probably wrong, check out the photo of the pistons:

http://image.turbomagazine.com/f/982...le_pistons.jpg

Note the rough surface on the non-machined sides of the pistons. Indicative of a casting. Also, look at the Mitsubishi and other stamp on the left piston. Those would not be present on a forging and would likely have to be machined in.

This info is completely relevant if the OP actually cares how "strong" the 4B11T is, on a quantitative basis. That said, not all cast pistons are weak, and not all forged pistons are strong. I've had some very nice quality 2618 forged slugs fail on me multiple times because of a terrible design. Looking at the design of the 4B11T's pistons, it seems very robust. I've yet to hold one myself, but I'll make a first-hand assessment once I get the chance.