Last weekend I started this engine for the first time since I rebuilt it back around 2003 (I decided I'd take care of the body while I had the engine out and things got a bit out of hand). Got the cam broken in, no surprises (important ones, anyway), runs and sounds good. I should give some background- this is the second time I've built this particular engine, first time around 1996, grenaded in 2003 (turns out there's almost, but not quite, enough clearance for umbrella valve seals inside the dual springs).
It's a 200, Mallory Unilite with both vacuum (disconnected) and mechanical advance, originally a 272deg Clifford cam w/Rhoads lifters, now a 260deg Comp with matching lifters.
When I went to time the engine the first time back in '96 I was surprised to see that it seemed to want around 45deg advance, which I chalked up to a slipped harmonic balancer. It ran fine, made lots of power, decent mpg, etc., etc. Needless to say, this time it got a new harmonic balancer.
When I dialed the distributor in last week I indexed it at around 8deg advance, assuming that's where it would be happy. Being paranoid I verified TDC on the compression stroke of #1 with the valve cover off and both valves closed, manually verified the piston was indeed at TDC, and saw that the timing mark on the balancer was dead on TDC. All is good, right? When I went to to the initial startup I had to move the timing a bit to get it to start. After the cam break-in I went to adjust the timing at idle, tweaked it a bit until it smoothed out nicely and rpm peaked. I hit it with the timing light and was shocked to see it back at 45deg advance again.
It will neither start nor idle at 8-12deg. Idle rpm are fairly low, down around 750-800, so I doubt if the mechanical advance is kicking in. I am at a loss- did I miss something, twice? It seems to run OK, but something clearly must be out of whack.
It's a 200, Mallory Unilite with both vacuum (disconnected) and mechanical advance, originally a 272deg Clifford cam w/Rhoads lifters, now a 260deg Comp with matching lifters.
When I went to time the engine the first time back in '96 I was surprised to see that it seemed to want around 45deg advance, which I chalked up to a slipped harmonic balancer. It ran fine, made lots of power, decent mpg, etc., etc. Needless to say, this time it got a new harmonic balancer.
When I dialed the distributor in last week I indexed it at around 8deg advance, assuming that's where it would be happy. Being paranoid I verified TDC on the compression stroke of #1 with the valve cover off and both valves closed, manually verified the piston was indeed at TDC, and saw that the timing mark on the balancer was dead on TDC. All is good, right? When I went to to the initial startup I had to move the timing a bit to get it to start. After the cam break-in I went to adjust the timing at idle, tweaked it a bit until it smoothed out nicely and rpm peaked. I hit it with the timing light and was shocked to see it back at 45deg advance again.
It will neither start nor idle at 8-12deg. Idle rpm are fairly low, down around 750-800, so I doubt if the mechanical advance is kicking in. I am at a loss- did I miss something, twice? It seems to run OK, but something clearly must be out of whack.
