Al rumble
Active member
Hey guys.
I bought my 73 Grande a year ago. Great southern cal car that has been a pleasure to work on. It was running a little rough when I got her, typical exhaust leaks and vacume leaks, but by the end of last summer I had her running pretty good other than a knocking noise at certain rpms. Over the winter I put tons of time and $ into her and am really happy with the way she is looking now. But that Noise!
I thought it may be running lean so I put on a new fuel pump and rebuilt the carb, but it's no better. If I retard the timing to 6* with a total of around 20* it sounds less knocky. So I finally had a real mechanic check it out. He had me start it and within a minute had me stop it and told me it was bottom end, " probably main bearing or rod". Ok, makes sense, he heard it right off the start before the 351c hydro lifters had a chance to pump up. Kills my thought that it was valve noise.
He suggested lifting the engine a little to get the oil pan out and try to fix it from there. The engine is 45 years old so I am more thinking of pulling it and a complete rebuild.
My question is this... Am I foolish to put in some heavy weight oil and maybe some additive and enjoy it for the summer, driving it easy or am I risking blowing the thing up and not being able to rebuild my numbers matching block.
Input ?
I bought my 73 Grande a year ago. Great southern cal car that has been a pleasure to work on. It was running a little rough when I got her, typical exhaust leaks and vacume leaks, but by the end of last summer I had her running pretty good other than a knocking noise at certain rpms. Over the winter I put tons of time and $ into her and am really happy with the way she is looking now. But that Noise!
I thought it may be running lean so I put on a new fuel pump and rebuilt the carb, but it's no better. If I retard the timing to 6* with a total of around 20* it sounds less knocky. So I finally had a real mechanic check it out. He had me start it and within a minute had me stop it and told me it was bottom end, " probably main bearing or rod". Ok, makes sense, he heard it right off the start before the 351c hydro lifters had a chance to pump up. Kills my thought that it was valve noise.
He suggested lifting the engine a little to get the oil pan out and try to fix it from there. The engine is 45 years old so I am more thinking of pulling it and a complete rebuild.
My question is this... Am I foolish to put in some heavy weight oil and maybe some additive and enjoy it for the summer, driving it easy or am I risking blowing the thing up and not being able to rebuild my numbers matching block.
Input ?