87 shelby z engine questions-have 4 bolt crank can i modify a 5 bolt?

[bigjon69420]

I got a 87 Daytona Shelby z, turbo 2, 2pc intake. I'm running 72# injectors,3 bar map, boostbutton cal 18# of boost 21# shutoff. My clutch was slipping when I got over 14# of boost so I ordered a cluch kit it's probably a factor original clutch in the car. 105k miles.

Anyways I've been monitoring my oil pressure with sunpro gauges and it is geat whe cold but gets very low at idle when hot. so I bought a oil pump. I have other goodies I was going to install when I do the clutch, ss oil and new coolant lines,new alternater, new water pump,huge intercooler,belts.

Well I was driving it about a month ago and it stalled (I knew I shouldn't have driven with low oil pressure-went down to 3psi at idle when hot- but 40-50 psi cold) . restarted it and it has no power and it's rapping! I did a compression test I got 90 120 120 60 I know the 60 and 90 is horrable don't know if its rings or what yet. originally got the car with a blow head gasket(heater bypass valve broke on previous owner and it overheated. I put a remanufactured cyclinder head on it. I could not get the thing to idle. I did a compression test and had 120psi on all cyclinders. the idle issue was traced down to being bad injecor harness and grounds. problem long sense solved. but I figured it was cool to list old compression readings

I know where I can get a good 89 2.5 block for dirt cheap. Money is super tight or I would buy a set of forged pistons and do a full rebuild. Is there a good factory block I can just put my top end on?? if so what year? is there any cheap upgrades I can do to the motor when I have it apart?? Just looking for some advice what would you guys do??? the head was a remanufactured unit I put in last summer. Or if anyone has a good block I can get for cheap within 2 hours of 16125 it would be greatly appreciated! I really wont know what damage I did till I get it apart but I think I heard that 87 t2 had just a normal t1 block. I'm not looking to build a race car rite now just something that will be loads of fun to drive, and smoke most Camaros!
** I found a 88 2.2 from a Plymouth reliant with compresson in 130-140 range, for $200.00.

I'm going to pull my motor and check it out, I can get rebuild kit just rings,bearings,gaskets for 115 shipped. its a good quality kit used the same supplier when I re ringed my old f150 straight 6. my dad has a valve grinder and valve seat grinder, so as long I don't have to get cyclinders and crank machined I will probably go the rebuild route. is there any common things to really check out on my current motor , when I pull apart? I'm thinking plastic gauge main and rod bearigs? cylinder walls ect?

Questions:
1,) can I make a 5 bolt crank non turbo 2.2 work in my car by just bolting my intake and exhaust on, if so what do I do about lack of non turbo lack of oil restrictor(will 2 pc t2 intake and exhaust bolt up) and just add oil retun and coolant return lines) ?
2) can I use the 89 2.5 block
3.)what would you guys do in my situation
4) I also found a 86 2.2 t1 with 525 trany from a Omni glh for 250 but its a 4 hour drive(figure if I do this I will try to resale the 525 because I'm not giving up my 555(will my 2pc t2 intake bolt up?
call message or text me 724-815-1906
thanks
Jon

[GLHNSLHT2]

Been there, done that. Take the 2.5 shortblock and bolt it under your 87 T2 top end. You'll need a 89+ round tooth turbo cam gear. (I have one if you can't find one) Then just have the cal re-programmed for the 2.5 setup and you'll be good. I did this when the original 2.2 went bad in my 87 ShelbyZ. It was one of the best things I ever did to that car. So much nicer to drive with a 2.5 in it. Faster too at less boost.

[4 l-bodies]

Jon,
The non-turbo 88 motor I would stay away from. The crank gear, crank pulley, are all odd 88 only. Besides being non-turbo it will have too high compression and has really wimpy pistons and rods. Forget that one.

The 2.5 assuming it is a turbo is the way to go. Like Jay told you ^^^. More bottom end grunt but runs out of breath by 5500 RPM in stock form. You very possibly could see a mileage improvement going with the 2.5 over the 2.2.

As far as rebuilding. There is no really good cast pistons available anymore. The Mahle factory pistons has been not available for some time now. You might be able to find a new std. bore set, but doubtful. Want to stay away from hypereutectic pistons in forced induction motors. They won't tolerate much detonation. Rattle it even a little and you could bust up ring lands. Much more prone to breaking ring lands than the factory cast Mahle pistons. If you decide to use the hypers. open up the top ring gap to .019-.021. That may help it live a little longer. I personally think that is one reason why people have such bad experiences with them.

The 86 block would be a decent second choice. Block is identical to your 87 TII. However pistons are press pin instead of your floating pin. The rods are substancially weaker on the 86 vs. your 87. The crank is cast in the 86 while your 87 has a steel (forged) crank. Not much else is different in the shortblock. Don't sell your 87 TII short. It is a very stout motor even though it has the early block. Unless you are shooting for the moon, the early block (with steel crank) will hold fine deep into the 11's.

Like you said, I too would pull the 87 TII apart first and see what damage it has. If you need pistons but the cylinders walls don't look bad, you might be able to find some used TII pistons. You may be able to just hone and throw in a new set of rings and bearings and put it back together. If your going to re-use your TII rods, check side clearance carefully, as excessive side clearance can be leading cause of oil low pressure. Of course wiped out bearings will do that too.

Good luck,
Todd

[GLHNSLHT2]

Jon,
The 2.5 assuming it is a turbo is the way to go. Like Jay told you ^^^. More bottom end grunt but runs out of breath by 5500 RPM in stock form. You very possibly could see a mileage improvement going with the 2.5 over the 2.2.
Good luck,
Todd

I ran the original 87 2.2 T2 in my SHelbyZ at the track and found it to like to be shifted at 5200rpms. After the 2.2 nuked itself due the previous owner using too much RTV on the oil pan I put a 2.5 shortblock under the 87 T2 top end. Back out at the track I started at 5000rpm shift points in belief that the 2.5 wasn't a revver. But she felt faster on the street so I started upping the shift points until she didn't go any faster. That put me at 5700 rpms. Only change was the 2.5 shortblock. Why it liked 500 more rpms before shifting I'm not sure but it did. So in my case the 2.5 gave more bottom end and more top end than the 2.2. The math says it shouldn't but it did.