Automotive Forums

Just picked just this 83 Ford F100 with a built 302. The kid could not tell me anything about the engine other than it was a 302.

Short story is I have gone over the engine and it is a 302 block with 351 heads. The cam is a little on wild side and the carb is your standard Holley 600cfm. I have rebuilt the Holley just for good measure. I also went through and checked the distributor location and settings with TDC.

After final checks I started the engine. Sitting there idling the engine sounds real good. I went through and checked timing and made some small adjustments on the Holley.

Happy with myself I put her in gear and started backing out of the garage. Bad things started at this point.

Under any kind of load the thing backfires through the carb. Now, it has been a few years since I worked on any kind of hot engine. Most of you will understand, wife, kids and the dogs.

Only thing I can think of is the timing, but anything anyone can point me too will help.


 

You are going in the right direction because backfire thru the carb equals timing problem. The valves could also be not adjusted properly causing this also. On a further note unless you have modified your holly... one backfire will wipe out the accelerator pump. Also adjance the timing about 4 degrees and make sure you vac. advance is pulling off the carb and working properly.  

I want to post back at what I have found so far with the little project.

I got the engine idling fine and did the little old carb clean test around the intake..ohhh, baby did I get a reaction. Engine died.

I started checking the intake bolt and 8 of the 12 were just hand tight. HUGE leak there. Pulled the intake off and found out that the block is a 1980 casting. Did a little more looking and the engine number is that of a 302 placed in a 1984 Mustang GT.

So, what I found was that the Distributor placement was wrong, intake leaking, and firing out off.