Opinions/Options?? So I have a 69k motor, seems to be pretty strong but I'm getting a tic under acceleration (when the secondary opens). Under normal acceleration no problem. I have a 1972, 200ci, automatic, hyro lifters. The tic is definitely in the valve train, lifters, pushrods and or rockers. I know there are products like "honey" but I'm leaning toward a mechanical fix. Replacing the pushrods with longer ones, using different angle rocker, going with the adjustable rocker arms etc… Has anybody had good success and if so what did you do? Also, I prefer not to pull the head but I will if necessary.
I suspect there is old gas in the tank, I put about 5 gallons in when I picked it up a few weeks ago. The carb was varnished up quite a bit and I rebuilt it first thing! I'll run it to E and fill it with supreme, back it off two degree's and see what happens. I believe the car was sitting for some time. If not, I'm leaning toward an adjustable rocker assembly.
Ditto on all of the coments aforementioned, Id spray some carb cleaner down the throat, but thats just me.
Me too. Run a higher octane fuel, or back off the timing. He mentions the secondary's opening, what carb is on it ?
Carter YFA one-barrel. It's when the secondary circuit opens (squirt of fuel) under full acceleration.
I don't believe what I'm hearing is "pinging", there is a distinct valve train "ticking" under load. I’m more than willing to make the adjustments and run premium but I do think it’s going to be some time of mechanical repair.
if it is in fact a lifter tick.. then it should be LESS pronounced after cold start up/take off then when hot as the oil is thicker and cushions better.. as that previously mentioned motor honey would do as well. first of all.. check oil pressure since it sounds like you may have pressure issues under load.. and then proceed to check valvetrain. A worn cam/valvetrain or collapsed lifters are also another possibility and pulling the valve cover and checking preload would be the next best way to diagnose. You may just need to cinch down a rocker or two to get it quited down, is all. If it's non-adjustable( and I assume it is).. then going to a longer pushrod can help band aid slightly.. but you can't go overboard as geometry/tip sweep will change too much and cause other issues more severe then the one you now have.
You are hearing pinging. It used to commonly be called "valve clatter" It's not the valves or valve train you're hearing, but many small detonations colliding with each other inside the cylinder as the piston is coming up the bore. This can destoy a piston.
