67 Lifter problem
 

I bought a 67 mustang 302 awhile back and when we bought it they said it has a lifter problem and we went and looked at the Rocker arms and pushrods and that all seems fine but what would make the rattling noise that its making its also on both sides under the valve covers. and how tight are the rocker arms suposed to be, should you be able to wiggle the pushrod because we put them tight and when we start it up they loosen up so u can move em a little, same with the rocker arms. Any help would be appreciated.

Re: 67 Lifter problem
 

First... 302s came out in 1968... so either that is a 289, or a replacement.

Now, as far as tightening the valves. I made this mistake in my younger days. You are dealing with hydraulic lifters, they will compress when you tighten them down. When they then fill up with oil, they will have too much pressure on them and you may end up with some broken or bent parts... or at the least, a poor performing engine.

What we did was take the distributor cap off... and crank the engine by the harmonic balancer bolt...

We loosened (just enough to take off the pressure so that the rocker arms could wiggle up and down) all of the nuts that held on the rockers, then tightened them one by one depending on where the rotor was pointing.

For example, if the rotor was pointing at the #1 cylinder, we would know that both of those valves should be closed... tighten the nuts until the pushrod will no longer spin with a gentle rolling between your fingers... repeat with all 8 cylinders.

Replace the valve covers with a couple bolts, and start the engine... let the oil pressure build up for a couple seconds, then recheck all of the valves the same way.

Hope that helps.

Re: 67 Lifter problem
 

BTW... you can also double...double check things by rotating the engine by the crank bolt and tightening the valves opposite the valves that are opening...

So, if you see that the exhaust valve is open on any given cylinder, check the intake... and vice versa when the intake is open. This will ensure that the valve SHOULD be perfectly seated.

Re: 67 Lifter problem
 

Thanks for the info and ya i know the 302 came out in 1968 the people i bought it from put in a 302 because i had to go out and buy a new radiator for it cuz the old 1 was was messed up and leaked alot and made teh car over heat on long trips. and thats when my neighbore who helped me fix my transmission lines said that there making a bang noise.

Re: 67 Lifter problem
 

Well, that is certainly the cheapest and easiest of fixes...


Good to hear.

Re: 67 Lifter problem
 

well today i went out there and i tighted up the rocker arm nuts and i just put the hood down cuz i had diff stuff to do and i came back a little later and the bolts seem to loosen them selfs and most of the pushrods went back to being able to move it in circles with ur fingers. any ideas of why it would be doing this?

Re: 67 Lifter problem
 

Yes.

Because your lifters are being pressured by hydraulics.

When you tighten them up, you press against the hydraulics of the lifter... the hydraulics will give way and yield to the pressure of the valve spring over minutes or hours.

Then, when you start your vehicle, your hydraulics lifters will "reinflate"... if you have your lifters too tight, it will keep a valve open for too long (causing backfires, poor vacuum, and possibly a bent valve, or a dislodged stud).

Do NOT tighten them again. Start the engine, and recheck the valves after letting it run for a minute or so. If the valves seem to be too tight, back off the pressure until you can once again spin the pushrod. I'd rather have it a little loose (spin freely), than too tight.

Re: 67 Lifter problem
 

You can also take the lifters out, put them into some oil, and pump them manually, until the air stops coming out. Thats what I did when I built my engine. I dont know if it would matter or not running it when they arent adjusted right, might bend/break parts???