Hot Rod Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
67 Posts
Discussion Starter #1
Just rebuilt my 390 fe engine and it dies when going into drive, I have to feather the gas to keep it going. When it does idle, it barely accelerates from idle and it'll even pop through the carb until it gets some rpm and then it goes fine, it would drive like normal if I never came to a complete stop. The engine is a mild build with intake, carb, msd ignition and hei dist, and it has a camshaft that gives it some noticeable idle. Even idling at 1000 rpm, it still dies. I've looked at timing, vacuum leaks, mixture screws, nothing changes it. thoughts anybody? the engine ran fine before the rebuild and it had the same camshaft and mods.
 

·
Registered
Joined
·
437 Posts
That's sounds like the timing chain is a tooth off or the timing is really out of whack. Does it light right up or take some effort to get going? No power down low and seems like it won't take the gas?
 

·
Registered
Joined
·
67 Posts
Discussion Starter #4
the valves are non adjustable. I guessed something with the cam, but I looked into the carb and the timing more. I had the carb idled up with way too much of the transfer slots showing and it engaged the vacuum advance or the mechanical advance in the dist making the timing off, I idled down the carb and advanced it until it ran, I thought it would be way too advanced but it read 12 degrees btc and it idles and runs great. So far it's fixed, lets hope nothing else goes wrong. Thanks for the help
 

·
Registered
Joined
·
13,426 Posts
the valves are non adjustable. I guessed something with the cam, but I looked into the carb and the timing more. I had the carb idled up with way too much of the transfer slots showing and it engaged the vacuum advance or the mechanical advance in the dist making the timing off, I idled down the carb and advanced it until it ran, I thought it would be way too advanced but it read 12 degrees btc and it idles and runs great. So far it's fixed, lets hope nothing else goes wrong. Thanks for the help
Everybody is still smarting from the SMOG era of no to little advance old memories die slowly in hot rodding as evidenced by current 20 somethings talking about "porting and polishing" a process applied to flat head Fords the last production item of which was installed to a U.S. vehicle back in 1953. Yet the term and the processes it engenders in people's minds endures to this day.

Actually 12 degrees static advance for an FE block is pretty reasonable wgen removed from firstgeneration SMOG thinking. The three big things that lean on the choice of base advance is compression ratio, higher needing less, cam duration typically more as the timing becomes aggressive, and combustion chamber shape that being modernhigh turbulance fast burn chambers less while older chambers more.

In the case of the FE excepting the 1958/59 chamber and the 1960 high performance 352 chamber all other FE chambers including the high performance 390, 406, 427, and 428 chambers are very lazy burners needing a lot of advance.

So an FE with a cam even a mild one will like the advance pushed up some and brought in somewhat fast, this however is where this motor gets tricky in that it likes a fast rise up to about 2000/2500 RPM then a slower increasing rate from there to about 3200 RPM, rushing here will get you into detonation. I keep on my desk as a pencil holder a number 8 piston out of a 1966 San Diego Police cruiser that blew in a hot persuit, the rings and ring lands on one side simply blasted out of existence. One of my better junkyard finds, seeing the cruiser in the Ford line the heads sitting on the front seat but no engine. I went to the office an asked about the bottom end, they said their guy assessed it as junk and it was on the junk motor pile waiting the scrap metals guy. I got permission to look for it and after some digging found it, a very nice heavy duty casting that cleaned in thirty over. If memory serves I paid 10 bucks for it with crank, rods (nice rods), pan, timing cover, water pump, etc.

Bogie
 
1 - 5 of 5 Posts
Top