2.3L ('83-'97) Forged Pistons vs Cast Pistons

[ThomasT56]

Hello everyone, this is my first post on the fourm and I have a question. I have a 1993 2.3 5spd Ranger that I'm looking to turbo swap. I just picked up what I thought was a factory 2.3T motor, but after further investigation it looks like this motor was a NA motor that someone has turboed. It has compression, seems to have been used and run before, but I have no knowledge of the history on the motor. I just gotta know if the pistons are cast or forged. I got the oil pan off to look for the casting lines, to be met with what seems to be 2 casting lines per piston that might just be part of the design, not sure. They say ford on them, with 2 part numbers. One is f37e-ac and the other is 3384-g. I search for this on Google and find absolutely nothing. I can get a video of the pistons too if needed. Any help GREATLY appreciated. I got the motor for 500, and it has 250 dollar injectors on it, an aftermarket clutch, and a turbo already installed, so in parts I've at least made my money back if these are cast. Just need to know if I have to replace these pistons. Thanks for any help!

 

[franklin2]

They say the cast pistons look rough on the underside except where they are machined while forged look smooth all over.

If you are building a engine with serious boost, you had better tear it down and really make sure what you have. The turbo engines had a lower compression ratio also. I want to say the SVO engines had a hypereutectic piston, which is a good compromise for strength and normal piston to bore clearance. Forged pistons require a larger clearance in the piston bore, but are the strongest. If you do not plan much boost, you could just run the cast pistons if that is what you have.

 

[ThomasT56]

Thank you, the more I look at them the more I think they are cast. What type of pistons did the thunderbirds 2.3T run? People on the fourms say "forged" when referring to the 2.3T . Is the bore of the 2.3T and the NA 2.3 blocks different? I'm not looking for something crazy powerful all the time, but I want something reliable that I can turn up a bit if I want. If hypereutectic pistons are the cheapest and easiest way I'll go with them.

 

[scotts90ranger]

The stock forged pistons are 8:1 instead of the stock N/A pistons at 9.2:1, I took a picture but hopefully a description helps, I'll post the pic later... the N/A cast pistons just have crescent valve reliefs in the face, the forged turbo pistons have a D shaped "dish" covering like 3/4 of the face about 1/8" deep.

Blocks are the same turbo and N/A aside from the oil drainback port on the passenger side a couple inches above the oil pain rail.

People say the stock cast pistons can handle about 5psi before things get iffy, more than that and you risk damage with detonation. Turbo pistons are hard to find and expensive, when I was looking like 5 years ago it was over $100 each for the cheapest option...

 

[ekrampitzjr]

Rule of thumb: assume pistons are cast unless you know otherwise. Forged pistons are rare.

 

[ThomasT56]

Thanks guys, mine are definitely cast then. I'll look around for some pistons, now since I'm taking it apart we'll see how far I go, but I definitely want to run more than 5psi, thanks for the help.

 

[ThomasT56]

Found these on rock Auto, I see they say 20 thousandths oversized, I would have to bore the block for these to work, correct?

 

[Blmpkn]

Found these on rock Auto, I see they say 20 thousandths oversized, I would have to bore the block for these to work, correct?

Probably, you'd have to get in there and measure the bores. If it hasn't been bored already and measures out with decent tolerances you'd be better off just finding stock size pistons. If you DO need to bore it out.. it's generally reccomended to bore as little as possible to make it happy.. Unless the bores are completely smoked than 10 thou would likely do it and would be a better plan.


But then you gotta ask yourself... is all that work worth cast pistons? What's the weakest link in one of those motors that's had an n/a-t swap done on it? Pistons? Rods? Crank? If the crank and rods are stronger than the pistons by a healthy amount (which isn't uncommon).. then I definitely wouldn't be happy having that much work done without upgrading to the forged slugs.

If you want to run more than 5psi to start, with room to turn it up when your feeling froggy... dishing out the money on forged pistons would probably be advantageous.

 

[ThomasT56]

Probably, you'd have to get in there and measure the bores. If it hasn't been bored already and measures out with decent tolerances you'd be better off just finding stock size pistons. If you DO need to bore it out.. it's generally reccomended to bore as little as possible to make it happy.. Unless the bores are completely smoked than 10 thou would likely do it and would be a better plan.


But then you gotta ask yourself... is all that work worth cast pistons? What's the weakest link in one of those motors that's had an n/a-t swap done on it? Pistons? Rods? Crank? If the crank and rods are stronger than the pistons by a healthy amount (which isn't uncommon).. then I definitely wouldn't be happy having that much work done without upgrading to the forged slugs.

If you want to run more than 5psi to start, with room to turn it up when your feeling froggy... dishing out the money on forged pistons would probably be advantageous.

Thanks, the rods and crank can handle 350whp no issue, and I don't even want to go that high, I already have a my racecar, this is my daily. However I do want to run more than 5psi if I want (because we all know how addictive boost is). I have to tear the motor down, take measurements, and see if it need to go to the machine shop anyway. If all is good, I will try harder to find stock size pistons. If it needs to go to the machine shop anyway, I guess I'll bore it out. I appreciate the input!

 

[ekrampitzjr]

Here's a little perspective, though I'll probably get flamed for it.

In the real world on the street, anything much above 200 hp in something like a Ranger is solely for bragging rights. The stock SOHC 4.0 in my Ranger has about 200 hp and plenty of power. Bumping up the power isn't going to increase the payload or tow ratings without big changes to the rest of the truck. Also, will the transmission and drivetrain handle a big bump in engine power?

I had a '98 Taurus wagon with the 3.0 DOHC V-6, which had 200 hp. That car could move and haul. I never wished I had another 100 hp.

 

[scotts90ranger]

I have an estimated 225hp on my '90, it's a hoot to drive and a good balance, an M5OD is just fine with it, I doubt me putting the power to it is what took out the output shaft bearing, probably not changing the fluid... he just said the bottom end (minus pistons) can handle 350hp, not that that is his goal... If the goal is about what I'm putting out (15ish psi with a ported head) then it'll do that all day long with the stock forged pistons, don't know about the hyper's as I haven't looked into it... it would be awful tempting, I'd be more tempted to be nicer to the pistons for that price though like actually buying all premium gas instead of whatever I feel like like I've been doing for years , I've had mine apart a few times, it doesn't seem to care about some pinging... not recommended but it's not my only vehicle...

 

[ThomasT56]

I'm looking for around 200hp, something in that area. I don't need it to be crazy fast, and most of the time I'll probably have the boost turned down for gas mileage, but if I want to push it a bit I would like to knowing I have room to turn it up. Just want something reliable that I can maybe learn to do some tuning on myself, and cast pistons would not allow any room for error. I'll slap some pistons in it. 15psi of boost sounds perfect for the top end of what I'm doing. She has 98bhp right now, 150-200 wheel would feel like a rocket ship. I'm on the interstate every day, so when I see a gradual Incline I would like to be able to maintain my speed!

 

[Blmpkn]

Size the turbo correctly and you won't need to turn the boost down for mpg. If you pick one that'll start to spool around 2-2500 that would be pretty nice.. be able to putt around most of the day on vacuum getting mid 20s, until you want to step on it and go weeeeeeeeeeee! right down to 4mpg.

 

[19Walt93]

If the piston ID started with F3, that means 93 so it wasn't a factory turbo piston. We sold a bunch of Turbo Coupes to people who drove them 12 months of the year. They were good in snow because the lower compression and delayed boost made them doggy at low revs. I would go smaller on the turbo sizing to get the boost lower in the RPM range as a second choice. My first choice would be to ditch the turbo, shave the head to get more compression, get an RV type cam, port the head, and get some small tube headers. If you stay with the turbo forged pistons are worth the investment- keeping in mind that they're heavier than cast so balancing would be a good idea, and that they need more clearance. Either way, deeper(higher numerical) rear end gears would help a lot.

 

[Blmpkn]

Walt has a point.. bump that compression.. 8k+rpm cam.. mmmmmm. It would sound and go wild at full song and be plenty efficient.