Block compatibility

[Shelbyz26]

I have an 88 Shelby Z TII 5 spd that I've had for the past ten years. After numerous rebuilds and abuse the block and crank basically are beyond salvaging at the machine shop. My question is how compatible would a later common block be with the '88 components I have now. Also, which later engine packages came with the forged crank and rods. 5 years ago I would probably have known this but I've been out of the game for too long and memories are escaping me now. Sorry if this is a bit of a newb question but I'd appreciate any input. Thanks

Matt

[Shelbyz26]

Ok so after doing what I should have done in the first place and looking through a few threads in this section....It looks like any turboed 2.5 has forged rods (crank?) and that I should be able to swap my existing TII topend onto a 2.5 block. Outside that I'll have to switch to a round tooth sprocket on the cam and my power steering pump will mount differently. I forgot to mention I had an underdrive pulley on my original setup, I'm assuming I won't be able to reuse this on a common block. Is what I'm saying here even remotely close to reality??...thanks in advance

["Top Fuel" Bender]

pretty much
'88 is its own bastard year
the head will swap over to earlier or later blocks
newer block will need the round tooth cam gear
the '88 underdrive pulley won't work on anything but '88

[Shelbyz26]

Alright well that makes me feel like less of an idiot. After reading over Donovans site on shortblocks am I right in saying that the 2.5 CBs arent going to have a forged crank but it really shouldn't matter? I'm not really looking to ever make over 300 hp as the tona is never going to be a racecar. Finally, will I need to mess with my ECU due to the bottom end swap? I have both a stock TII setup and one from FWD set up for +20s.

[tryingbe]

Power steer pump bracket will mount just fine.

You can find and use a 2.5L TI computer as-it or get a re-cal so you can use that +20 injectors.

[iTurbo]

Alright well that makes me feel like less of an idiot. After reading over Donovans site on shortblocks am I right in saying that the 2.5 CBs arent going to have a forged crank but it really shouldn't matter? I'm not really looking to ever make over 300 hp as the tona is never going to be a racecar. Finally, will I need to mess with my ECU due to the bottom end swap? I have both a stock TII setup and one from FWD set up for +20s.

I did the 2.5 TII thing in an Omni; you'll like it. The 2.5 is only available as a cast crank but hardly anybody breaks crankshafts so I wouldn't worry about it, especially for your goals. You should swap ECUs though. Since your car is an '88 it uses an SMEC computer. This is good news for you because all you need to do is get an '89 2.5 TI SMEC and it will plug right into your '88 Daytona with no wiring modification. The only 'gotcha' is that your engine will no longer use the charge temp sensor since the 2.5 TI motors didn't use them, the SMEC will ignore it unless you get a custom cal from Shelgame or another vendor.

[Shelbyz26]

Ok thanks

[turbovanman²]

You can't run a stock cal 2.5 on +20's, runs pig rich, so what I used to do was use an AFPR to turn down the base fuel pressure, worked fine, so do that, stock injectors or what others suggested, custom computer.

All 89+ turbo rods are good ones, so simply have them redone with ARP bolts. Cast cranks are tough,

Also, you'll have to notch your water pump housing to clear the oil pan or use the CB water pump setup. Oil pan is unique to the CB's also. You also have the option of running the balance shaft's or deleting them, choice is yours. For a DD, I prefer them.