christaylor

I just picked up a used 12A block to toss in my racecar. The PO said he thinks it's an 83, but he's not sure. He also said you had to use the same flywheel, otherwise the engine will be out of balance. I've got two questions.
1. If it is an 83, do I have to use an 83 flywheel?
2. How do I tell what year it is?

I was optimistic there would be some sort of serial number on the housings that would tell you what year it was, but I don't see anything of the sort.

Any help is greatly appreciated,
Chris

rhinor61

Flywheel need to match the engine year grouping, this site should have everthing you need to know.

flywheel reference




John

christaylor

John - Any idea if there's a site like that to help me identify what year the engine is? The problem is the engine has no flywheel, and I'm not exactly sure what year the engine is. If it's an 83, I've got an 83 flywheel to pop on there.

I may have to just set it up on the runstand and start it up and see if it wobbles.

rhinor61

Well I can tell by looking at them, do you have a few pictures you could post. If its a '83-85 is has the 't' fitting for the heater outlet, other years had the single.

How much of the engine did you get, meaning was a short block?

John

deeman111

so if i have a lightened flywheel.. am i supposed to get lightened counterweights aswell???

-James

rhinor61

If you have a lighten flywheel, you need the automatic transmission rear counter weight from a car that is the same year as your engine.


John

christaylor

John - here are some pics. Let me know if I need to take anything specific.






There's an auto counterweight on there, which I'll be taking off since I have to use the stock flywheel.

rhinor61

Hmm.
If you have the automatic rear counter weight, remove it and list the part numbers on it.

Also, the water port under the oil pressure sender, take of the rubber cap and let me see the end. Might be cut or if its a 1 hose (flared end).

John

christaylor

Won't be taking the big-*** nut off until I get the engine in the garage (it's much safer in the van than in the shop....), but I snapped a picture of the water line. It's been cut (it looks like), and may have been done for storage. The PO did a really good job of making sure nothing took up shop inside the motor.

rhinor61

OK, the only reason to cut that 'fitting' would be if it was rotted or a tee. I would guess that it a '83-85 engine, but the counter weight will verify the engine year.

Note: Reason for the 't' was because those 12a engines had the water-to-oil cooler.


John

christaylor

Would a 79-82 engine even have that fitting there? Hopefully I'll have the counter weight off within an hour...

christaylor

To answer my own question: yes.

Next question: My 79/80 rear housing has R5 stamped above the eccentric shaft hole. The mystery engine and an 83 have Y stamped in the same location. Does that mean its an 83-85 engine?

rhinor61

I think you are missing my point, the pre-83 engines have a single stub fitting, no reason for it to be cut off. The '83-85 have a 't' fitting and a person usually cuts it off cause they are afraid to cap the unuse oulet when switching to a air-to-oil cooler.

Also the 'H' on the rotor housing and the boss around the spark plug holes rules out the '79-80 engine.

John