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setting Timing on BBC

 
offthefront
I love my Chevy Chevette!
Posts: 3
Joined: 07/07
Posted: 07/28/07 02:42 PM

trying to set timing on a MIV BBC marine Motor .... standard on the 454 Merc timing is @ 8* BTDC ...  So facing the motor it rotates clockwise .. would 8* advance be To the right of the zero degree mark?  or to the left? .. I am having problems with the motor getting hot on a test stand ....thanks ..mike ...  

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GibTG
I mow my lawn and find Chevys
Posts: 1985
Joined: 10/03
Posted: 07/28/07 03:53 PM

To the left... A hot engine is a symptom of retarded timing. 8° is pretty conservative. What is the compression and camshaft we're dealing with here? Do you know how much mechanical advance is in the distributor?  
~Gibs

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dolly1
I love my Chevy Chevette!
Posts: 8
Joined: 07/07
Posted: 07/29/07 03:48 PM

speaking of timing i have a454 chevy motor that i am having a few issues with it starts runs and sounds good BUT it smells so rich it burns your eyes and when try to shut off it keeps trying to run but if i try to turn idle down low enough to shut off it wont stay running i pulled one plug out and its black i just got this motor and unfortunately i dont know what all is in it but i think it must have a good size cam in it i dont have a timing light or vacum gage i am gonna have to see if i can borrow them anyway im trying to figure out if my problem is in the carb or distributor or what  

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GibTG
I mow my lawn and find Chevys
Posts: 1985
Joined: 10/03
Posted: 07/29/07 05:38 PM

Not enough timing can appear to effect the mixture but have you checked your float levels and jet sizes?  
~Gibs

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dolly1
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Posts: 8
Joined: 07/07
Posted: 07/30/07 10:30 AM

well i have checked the float level it was ok but havent done anything with the jets  well i have moved the timing all around and it didnt seem to make any difference my plugs are black right now  

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dolly1
I love my Chevy Chevette!
Posts: 8
Joined: 07/07
Posted: 08/13/07 12:41 PM

i did check the float level and are ok wondering if the dist is in there in the right spot we brought it up on #1 compression stroke timeing mark on and put dist in at #1 it starts good andall of that but i am having to run the rpm at about 1000 rpm so it will run on its own but when i do that i have fuel coming out of the front nozzles in the carb instead of just being able to run off of the idle circut it almost seems like the timing is retarded even when i advance the dist is it possible that i need to go about putting that dist in at a different setting instead of tdc what if they set the cam and gears at some degree retarded is that a possibility or what do you think i dont have much info on the motor thats why im having trouble i know it has a roller cam in it im sort of in the dark myself as to whats in it  

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TaylorMade
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Posts: 1
Joined: 08/07
Posted: 08/25/07 11:22 AM

If the motor has or had a knock sensor on it and its disconnected you have to either change the distri. or change out the ignition module in the distri. I chanced my timing all over the place before I discovered this. Mine would run fine then the idle would fall out from under it, My timing would retard some 8 degrees...I changed my distri. and life was good again..  

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GibTG
I mow my lawn and find Chevys
Posts: 1985
Joined: 10/03
Posted: 08/25/07 11:26 AM

Knock sensor? Mk IV big block Chevy? Never heard of such a thing. There won't be one unless it's aftermarket  
~Gibs

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morgsbbc
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Posts: 2
Joined: 09/07
Posted: 09/03/07 07:57 AM

sounds like the timing gears were set up wrong.some sets have 3 positions, for 3 degrees retard,straight up,or 3degrees advance.pull the front cover and check the proper marks are aligened.  

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beebelawn
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Posts: 3
Joined: 12/07
Posted: 12/17/07 08:31 AM

8 degrees initial is fine with a 32 wot is perfect on a boat application with no vacuum advance.  

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