WTF! Any engine builders out there?

[Shopteach]

I've torn the NA engine down on my wife's '90 notch. The engine has been gone through before by someone. When measuring the mains I get a diameter of 2.183, the specs I have are for the minimum to be 2.3982, that's a difference of .2152 almost a quarter of an inch! The rods measure 2.018 with a spec of 2.0465. That's even worse at .447, close to a half inch! The strange part is I Plastigauged the clearance with the old bearing and got .004 clearance. Clearance should be .0008 - .0026 on the mains and .0008 - .0015 on the rods. Clearance is out of spec but not horribly bad. I've measured thses several times both with a Starrett mike and a digital caliper and gotten the same results. Has someone put a different crank in here? Did some other year 2.3 use a crank with specs close to these?

 

[Stinger]

Sounds like the crank has been reground and oversize bearings where installed...

 

[Shopteach]

Usually when they grind a crank it is .010, .020 or .030 under. This is nearly a 1/4 and a 1/2 inch. I thought maybe some earlier or later 2.3 might have used a crank with smaller journals.

 

[RustBucket]

The dual plug motors used smaller mains. I don't have the specs, but I think that's what you may have. Problem is I can't see that crank running in the large journal block without serious problems. I think it would be painfully obvious that the crank was wrong during assembly, let alone upon start up.

 

[Stinger]

Are their spacers under the bearings??? If so, you've got a dual plug crank in a older style block...

 

[Bogus SVO]

looks like you have a "small main " crank
2.2051 std main
.022 under on the mains and
and ya got a lil lost on your math on the rods

2.0465 std rod, your claming 2.018 a diffrence of .0285

so you have a small main crank ground under .020 main
bearing part # MS1743P.50mm

and Rod bearing part# CB984-.75mm

the small main was run in dual plug head engines from 89 up
so your 90 stang fits the bill

also did ya notice the 1/2 thrust bearing?

 

[RustBucket]

Dual plugs didn't show up in the Mustang until '91. The Ranger got em in '89. Were there small main journal, single plug engines? I can't see a manufacturer running two different castings of the same block concurrently, but stranger things have happened.

 

[Stinger]

How do you know your engine is the factory one? If it's been undercut, that means someone was in there for a rebuild at some point...sounds to me like they just used whatever parts they had from different vintage vehicles...

 

[Bogus SVO]

well some one has put a small main block in your stang, My 85 ranger had a small main block/crank with a carb'ed 4 plug head......

the info i posted came out of

Clevite77 engine bearings catalog
dated 1999 catalog2-200-99
page 206 block 8

 

[Shopteach]

It looks like someone has just swapped in a different engine block and crank. At least now I know what I'm working with.Now to order up the bearings and start the rebuild.

 

[TurboBeater]

Not that this has anything to do with the motor problem, but i thought it was fitting for the thread. When I went to buy my '86 capri, i was surprised to find that the valve cover said 2.3 Turbo on it. I figured maybe someone just swapped covers since at the time the car was a 2.3 carbed. Took it home to find an oil drain-back on the block. It said "85-Tbird" in faded marker on the timing cover too. Figured someone went through the trouble of swapping the whole motor out a TC but not the turbo setup. Turned out that it was just the turbo short block but the original NA head from the capri with the turbo valve cover on it. The 88 Tbird head from the one I was swapping in was damaged so i pulled the head from the capri motor thinking it was for a turbo motor but i was wrong. Slapped the NA head on the car anyway cause i couldn't wait any longer to drive it.