confused on engine rebuild
New User
Joined: Aug 2009
Posts: 1
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I'm new here but..
It sounds to me like they have used the standard 351M/400 timing set.
If this engine has a clevland camshaft then it is made to be run with a "straight up" timing set. If they used the 4 degrees retarded gears found on the 351M/400, (which they likely did) the engine will never run properly and the problems you describe are the result. Anyone who has ever put an aftermarket camshaft in their 351M/400 (properly) will agree with me.
If this engine has a clevland camshaft then it is made to be run with a "straight up" timing set. If they used the 4 degrees retarded gears found on the 351M/400, (which they likely did) the engine will never run properly and the problems you describe are the result. Anyone who has ever put an aftermarket camshaft in their 351M/400 (properly) will agree with me.
Posting Guru
Joined: Oct 2005
Posts: 1,017
Likes: 3
From: Longwood, Fl
dieseling can be easily stopped regardless of your timing advance and has nothing to do with "too much" timing at low speed. Stop and think about it for a minute-----.
A diesel does not ignite from a "spark" created by the distributor/coil, it ignites from cylinder pressure that is above the ignition point of the fuel. In fact, your car/truck would "diesel" even if the dist was totally removed! There is a simple cure and was provided by the Mfg from the factory------the "antidieseling solenoid".
The "antidieseling" solenoid, when the ignition is turned on, pulls the butterflies off their seat, from totally closed to idle speed. When the key goes off, the solenoid falls off and allows the butterflies to completely close, which shuts off air and fuel. That kills the engine, regardless of timing or camshaft. Timing and camshaft are independant of dieseling and they should not be adjusted against each other. Been there, done that.
A diesel does not ignite from a "spark" created by the distributor/coil, it ignites from cylinder pressure that is above the ignition point of the fuel. In fact, your car/truck would "diesel" even if the dist was totally removed! There is a simple cure and was provided by the Mfg from the factory------the "antidieseling solenoid".
The "antidieseling" solenoid, when the ignition is turned on, pulls the butterflies off their seat, from totally closed to idle speed. When the key goes off, the solenoid falls off and allows the butterflies to completely close, which shuts off air and fuel. That kills the engine, regardless of timing or camshaft. Timing and camshaft are independant of dieseling and they should not be adjusted against each other. Been there, done that.
Super Moderator
Joined: Apr 2004
Posts: 34,499
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These were famous for running on when new. The anti-dieseling solinoid is important. But I also think these heads were prone to hot spots, and rough spots that would hold material hot enough to provoke dieseling. Shouldn't be built up with carbon etc on a new engine though...
Maybe there was a reason it's on shelf.....
Maybe there was a reason it's on shelf.....
Elder User
Joined: Jan 2004
Posts: 887
Likes: 0
From: Colorado
Being a tooth off on the gears / chain for the timing set can do what you are describing. I had an old chevy truck that jumped a tooth on the timing set, and it ran like crap. Replaced it with a new one and made sure it was lined up correctly and the thing ran like a champ.
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Senior User
Joined: Jun 2008
Posts: 264
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From: Bozeman, MT
I took it to a family friend/mechanic and he retarded the timing 6 degrees. I thought a new timing chain was supposed to set the timing at TDC? How much retarded was the original timing for these engines? The timing chain and sprocket is new but it was fairly cheap. Do I need a new more expensive one?
Posting Guru
Joined: Oct 2005
Posts: 1,017
Likes: 3
From: Longwood, Fl
Thats a little curious---6 deg from where? 6 from where you had it set or relative to the timing marks.
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Freshman User
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I don't know who did your woek but I'd be pissed as well! If I spent 3 grand on a motor and it ran like you are describing, I'd be either at their door or the mechanic that set it up for you. You motor is not off 180 degrees, Johnboy is right, it would not run. Your timing may be off, but I would think that would show up under a timing check. The fact that they told you it was a Cleveland cam proves that they should not be in the motor building business or at least not in the motor "selling" business. There is no Cleveland cam!. Again, Johnboy is right. Your 400 is a completely different block than a Cleveland, but the cams are interchangeable. I would check your timing then start checking for vacuum leaks. If you are using a vacuum advance on your carb, that would be a good place to start.
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Senior User
Joined: Jun 2008
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From: Bozeman, MT
well i called the shop again today and the guy told me that the camshaft they put in those engines are a 4-barrel cleveland cam which is the stock cam out of the cleveland engines and i believe he said it was a twin valve engine of something. does this help at all?
Senior User
Joined: Oct 2005
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I sounds like to me you have alot of unknowns. Is the dist stock and/or has it been recurved?? Is the egr intact and working?? The timing chain snapped?!?!? That would be a huge concern to me. Is the intake stock and sealed?? I have never heard of a "twin valve" on a cleveland. If I were you, I would REALLY try to find the specs on the cam, insure the dist is timed correctly, insure the dist is re-curved and operating correctly. Is the timing chain retarded or straight up?? Where is your timing set at initial and at full advance. Is the carb new, rebuilt, and generally operating correctly?? I just see a huge lack of information in trying to have this thing running correctly without it
Senior User
Joined: Sep 2007
Posts: 265
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My guess is that your carb is jetted way lean. A 600 is usually jetted for a 351 sized engine. Had that problem when i ordered my carb and installed it. Motor ran really hot and had no power. Went up 3 steps on the mains i believe (been 2 years) and it ran like a champ. If I were u I would advise pulling the spark plugs and taking a close look at them. They will tell you alot about whats going on in your engine.
