2.2 to 2.5 with common block

Can just the pistons be switched over or do you need to do the crank too? Also is this an improvement? since from the factory the 2.2T had more HP than the 2.5T? Is torque where the 2.5 makes up for this?

[purevl]

crank and pistons need to be changed, rods are the same, the 2.2 came with a better turbo than the 2.5 and different electronics, hence the hp difference, but the parts are nterchangable, so a lot of guys use a T2 setup from a 2.2 on a 2.5 engine

what kind of increase am I looking at by swapping in 2.5 pistons and crank into my 89 TII Daytona?

also is the 2.5 crank forged? Any downsides?

[purevl]

i can't give you any hard numbers, because i haven't done it myself, but it should be substantial. no the crank is not forged, but the cast crank is extremely durable, and much lighter than the forged crank. the only 'downside' really, is that the 2.5 isn't as willing to make power in the upper rpm range, but this happens anytime you lengthen an engines stroke, which is why pro FWD drag teams often destroke their engines to make better power. think of hondas that make 150 hp a liter, but don't make enought torque to roll a baseball downhill. however, unless you are building an all-out drag car, the abundance of tire-roasting torque the 2.5 will give you will more than make up for any high-end deficiencies, especially on the street.

[macncheese]

i'll have to second that. i put a 2.5 in my charger, and with the mitsu turbo, that puppy will spool and drool...wait, that's not drool from the car--it's me peeing my pants. the only problem i had was third gear. broke two of them out of two different A-520s, with and without a chrome-molly bearing plate. if you're going to put it on a manual tranny, i'd suggest nothing weaker than a 555, as i broke my transmission at just 5psi. also, i have to note that you'll run out of gear, because the gears are just spaced too damn close. instead of making power from, say 3000 rpm to 6000 rpms (2.2) you'll get it from 2500 to 4800 or so, significantly narrower. SO it hurts a little more when you shift at 5000 rpms only to come back down to 4200. two solutions. A) automatic tranny B) a cliff special...555 gears with a 3.50 520 differential with bearing plate and posi. he just built one for me (check out the vendor feedback for a description of my experience with him) and i'm bumping 80mph at 5000 rpm in 3rd gear. i can't wait to get back to the track, as i'm expecting high thirteens on just 14psi and 8*ingition advance. aside from that, check out the numerous posts on 2.2 vs 2.5, but first grab a pepsi and some popcorn.
hope that helped a little
tony

[purevl]

here, you go, advice from someone who's done the swap, that's always helpful. as far as transmissions go, i would suggest you use an A-523, it's stronger than the 555, cheaper than the 568, and best of all you can find them in all sorts of cars, good luck, and keep us posted

thanks for the help guys, these boards are the frienliest I've been on (neon, RX-7, M3, Firebird, none compare)

[macncheese]

heck, i didn't know the 523 was stronger than the 555. i must've passed two of them when i was looking for my second 520. boo.
tony

[86Shelby]

I agree with macncheese. I did this swap this past fall. The power just isn't up in the rpm range. I was at the track last night and tried a few things which I honestly couldn't tell if they helped since it was my first time doing racing with something better than a stopwatch and a flagman. I went from running a 19.8(don't ask) to a 14.63 during the course of the night. I did notice that when I shifted before 5k that the next gear felt noticeably more powerful. In fact, my best time was shifting at 4500 and I ran through the lights consitantly at 5k in 4th. I feel like I'm driving a high-revving diesel when I'm racing, shifting so soon.

The 2.5 is great for around town driving. No shortage of torque. Heck I can shortshift and be at 1200 rpm in the next gear and the 2.5 just pulls through like a champ with no bogging or lugging whatsoever. This torque does have it's drawbacks on icy or frost-covered roads in the winter...

Another thing that I noticed is that the powerband of the engine changed significantly after I installed a larger exhaust. Before with the 100% original exhaust the engine pulled cleanly and hard to 6k. Afterwards there was more power down low, but it ran out of steam above 5k. I figure that I was just making less power across the board, but since it couldn't breathe well it was tough to tell where the power actually dropped off.

A 555/250 hybrid is in the plans for me. All I need is the '89 520 and I can get started. I want it simply for the highway mileage, though any benefit at the trakc is a welcome byproduct. Spinning nearly 3500 rpm at 75 mph is a bit much for me. If I can get 28 mpg now, I figure it should be at least a little better with the lower gearing.

[macncheese]

heh, if i can ever manage to keep my foot out of the carpet for half a tank, i'll report my mileage to ya, but don't hold your breath!!! you're gonna love the hybrid transmission, but DONT FORGET THE POSI!!! i really can't believe how much more fun the charger is now. i have to keep going out and driving it around the block.
later
tony

[glhsken]

Quote:

Originally posted by macncheese heck, i didn't know the 523 was stronger than the 555. i must've passed two of them when i was looking for my second 520. boo. tony

It's not....

[glhsken]

2.2 to 2.5 swap... Do a board search. The topic has come up MANY times and there are some great threads.

There are a lot of "mis-conceptions" in this thread, that those threads will clarify.

FYI, 2.5's do not usually make more hp than 2.2's in the same configuration. Torque yes. But then again these cars are about torque (even the 2.2). The 2.5 makes it's torque and meets the 2.2's torque curve usually around 44-4500 rpm. From that point on, the 2.2 is normally making more power.

[purevl]

well, i managed to get my foot in my mouth again, i must apologize to any which i have misled. i will defer to ken, because obviously he is much better informed than anyone i know. it seems that i have recieved some misinformation about our transmissions from some of the other board members, sorry again, i was just trying to be helpful

Is the A555 the strongest?

[glhsken]

A568 followed by the 555 then the 523 and 520. The Chrome moly bearing plate puts the 555 on about par with the 568, And the 520 with the 523