Going 2.5L..

[iTurbo]

I finally brought my TIII shortblock down to the machine shop today. To my surprise, the shop manager immediately started to disassemble it as soon as I brought it in. I had already stripped down the shortblock and removed the balance shafts before I brought it down to his shop. I measured crankshaft endplay (crankwalk) at approximately .050". The machinist removed the #3 main cap and according to him the original 2.2L TIII crank is indeed trashed..

So I'm thinking about getting a 2.5L crank instead, and some Venolia forged pistons since this is going into a heavy car and will mostly be street driven. Will the block/main caps require a line bore or does the crank just bolt right in with some new bearings?

And to those of you that have a 2.5L TIII, was it worth it or would you stay 2.2L?

[turbovanman²]

Common block crank will drop right in. Check Cliff's site, with a 50 trim t3/t4 he made something like 400/400 easily.

I can't compare back to back but its going to be fun. Scotmon has a 2.5L TIII.

[mcsvt]

Should bolt right in. Just check the clearances of course. Sounds like a good idea to me

[ShelbyZD]

I don't especially see the point of a 2.5 T3... its hard enough to get traction with a relatively stock one.

[iTurbo]

Really? I have a '91 Spirit R/T with a few mods and it is absolutely gutless below 3000 RPM, even with the stock turbo. The TIII I'm building up now (2.5L) is going into my Shelby Lancer. I guess I see a 2.5L TIII as having the best of both worlds; lots of streetable torque and a very wide power band.

[turbovanman²]

I don't especially see the point of a 2.5 T3... its hard enough to get traction with a relatively stock one.

Maybe for a lighter car but with a 2.5, you can stay out of boost or run lower boost to get the same effect.

Really? I have a '91 Spirit R/T with a few mods and it is absolutely gutless below 3000 RPM, even with the stock turbo. The TIII I'm building up now (2.5L) is going into my Shelby Lancer. I guess I see a 2.5L TIII as having the best of both worlds; lots of streetable torque and a very wide power band.

Thats my idea and with your elevation, it should help you out.

[Scottmon]

The 2.5 TIII in my IROC R/T is really torquey down low. I don't really have that much in the way of traction problems, 'cause it's a heavy car. If I plan to get on it hard I'll most likely be at the track with slicks on. It has *WAY* more power below 3K than my Spirit R/T. Matter of fact, it'll STOMP my Spirit R/T.

One thing to remember if you decide to keep the balance shafts. You'll need to find some 2.5 shafts to have it balance correctly.

Biggest (kinda) worry would be piston speed. Stock redline/fuel cutoff on a 2.5 8V is 6200, and with Venolias mine's seen 6500 on the stock 2.2 TIII cal. But if you go with another cal (like from Cindy) that raises the redline be careful of overrevving.

You can run +20 injectors on the stock cal and it'll run great. Just don't push the stock cal past 14 lbs. WAY too much advance for a 2.5 if you really start to mod it, and I'm running a Cometic for insurance. If I get more serious, it'll get a different cal.

[turbovanman²]

Thats the problem Cliff had, too much advance and blowing out head gaskets.

I do have BS's,

[Scottmon]

Something else to think about. The No. 3 bearing is the thrust bearing. Seems to me if the crank is OK that you'd be able to get the correct (thicker) bearing to get your thrust clearance back.

[turbovanman²]

Something else to think about. The No. 3 bearing is the thrust bearing. Seems to me if the crank is OK that you'd be able to get the correct (thicker) bearing to get your thrust clearance back.

I don't think I've seen a thicker thrust bearing. Usually the reason it gets larger is due to the crank being messed up, like Jeremey's.

[iTurbo]

Thanks for all the input guys. Several years ago back when I bought my R/T, I remember reading abuot Cliff's K-wagon and thinking a 2.5L TIII would be the ultimate for a street car (or van!).

When I was at the shop, the machinist pulled the #3 main cap. He looked at the thrust surface on the crank itself and said it was bad. He conferred with another guy about the possiblity of welding it but they both decided a new crank was required. He never said anything about an oversize thrust bearing.

I asked about the block and caps and he said they should be fine, although he had not yet disassembled any further. Would excessive crankwalk put undue stress on the cylinder bores, rods, or pistons? Can I expect any more bad news outta this?

At any rate, I still need to find a good 2.5L crankshaft. I've noticed that Venolia and Wiseco both make forged TIII pistons in a 2.5L version. Any idea what would be better? Everybody I've read about doing this has used Venolia. Also looking into Eagle or K1 rods.

[turbovanman²]

At any rate, I still need to find a good 2.5L crankshaft. I've noticed that Venolia and Wiseco both make forged TIII pistons in a 2.5L version. Any idea what would be better? Everybody I've read about doing this has used Venolia. Also looking into Eagle or K1 rods.

I have one,

Wiseco, give it up, I waited 6 months, now running Venolia's but if I had more time, I would get some lighter wrist pins. I would also use lighter rods, aka Eagles, K1 etc to help keep the 2.5 together.

[iTurbo]

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