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5.0 non roller balance issue

New User
Posts: 2
Joined: 03/13
Posted: 03/06/13 11:24 AM

Let me start by saying I am new to the forum and mostly new to small block Fords. Hoping I can get some help here with a problem I cannot figure out. I have an RX7 with a 302 roller motor that has major problems. Really low compression on 2 cylinders and water out the exhaust. Rather than rebuild, I found a .030 over,  302 balanced short block with 9:1 pistons. I got such a great price I brought it home. Have pulled the old motor and had the GT40 heads that were on it done. Now as I am putting this thing together I have couple problems. The guy that I bought it from says it came from an ’85 Lincoln, but the serial number on the block says it is an 80. The assembly numbers say it was assembled in ’83. So, it has a one piece rear main seal which ,makes it at least an ’81? The real issue is balance, I understand that anything after ’81 is 50 oz. I want to reuse the balancer and flex plate from the roller motor. The new shortblock has a non roller cam and lifters and the block does not have the tapped holes for the roller cam spiderweb. Another piece of the confusion is that the new shortblock has a single roller timing chain. I am swapping the serpentine system I have from the roller over to the new shortblock which meant I have to use the timing cover and water pump  from the roller motor. This necessitated cutting down the cup shaped deal on the end of the cam in the short block. I am kind of stuck right now primarily because of the balance issue.
To net this all out, I am confused as heck right now. The shortblock serial number is E0AE , with a D30 under that and a 6 under the D30. The assembly code is 3J28.

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New User
Posts: 36
Joined: 03/12
Posted: 03/06/13 02:19 PM

Don't worry about where the 302 came from for now.

You need to use what came with what engine. IE.The roller engine the balancer and flex plate should stay with that.

The Non Roller engine may have been balanced with the balancer and flex plate that is on it.

You may have to purchase some additional parts to get the serpintine belts system to work.

I ran through Jegs real quick. They have most of the parts you'll need.

Don't mix and match parts. Swap what you can, but when it comes to balancers (damper) and flex plates, that engine may have been balanced with the balancer and flex plate. Then you will have 2 engines with balance problems. I hope this helps.

Bob aka-pepsi1  

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New User
Posts: 2
Joined: 03/13
Posted: 03/07/13 03:57 AM

I got real good answers on another site, but thanks for the response.
Use 50 oz. Heads work with the right pushrods and it is an '83 motor!  

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