A timing question?

[f_inscreenname]

I have never been able to get rid a of timing rattle just before my 4 barrels kick on. The 4's start to open at 4200rpm's. The timing rattle (like the timing is to far advanced but its not,I have tried many different settings) starts at about 4100 and goes away as soon as the 4's start to open. I have had the dist apart (also cleaned and oiled, everything moved freely) when I installed the Pertronix igniter a month or two ago. It did the same thing with the points. Would it be the advance springs inside the dist? I am out of ideas.<br />Chrysler 360ci/320hp with a Volvo 270 outdrive.

 

[snapperbait]

Re: A timing question?

F_inscreenname.. When you say "timing rattle" do you mean detonation/pre-ignition like knocking?<br /><br />If so and the timing's spot on accurate, you might have a lean condition at that rpm before the 4's get going..<br /><br />Don't know what carb your running, but maybe look into getting the secondarys (the 4's) to kick in at a lower rpm... Different spring in the vacuum secondary maybe?

 

[akriverrat]

Re: A timing question?

sounds to me like the secondaries are coming in really late. if they are, noise could be from lean mixture. really hard on pistons and valves. the engines i have messed with(all gm)the secondaries start opening in mid to late 3000 range.

 

[akriverrat]

Re: A timing question?

snapperbait types faster than i do.

 

[snapperbait]

Re: A timing question?

Nahhh Akriverrat... I'm just a "hunt & peck" typist... <br /><br />peck peck peck..

 

[f_inscreenname]

Re: A timing question?

Like when you get cheep gas. I trailer so I can get the good stuff at the local gas station (I have tried a couple different ones so that isn't it) not that marina crap gas. Bought a new carb over the winter. 4's kick on when they should (I guess,built many of motors over the years and in relationship to WOT at 4900 rpm's it sound about right) and the last carb functioned the same as this one. As I said before I did the Pertronix upgrade also over the winter thinking that would cure it. It fixed all my timing problems except this one. I am pulling 320hp out of a small block Mopar and am using the old motors dist with the upgrade. That's what made me think of the advance springs.

 

[Crazy]

Re: A timing question?

How many hours are on your motor , and how fresh is your fuel ? had a old Chev that would rattle with 87 fuel ... put in 89 or 91 and no more rattle . Good luck

 

[f_inscreenname]

Re: A timing question?

About 50hrs and the gas is new 92oct or better.

 

[magster65]

Re: A timing question?

You could be right about the advance springs, one may have come off or they've become weak. If not it does sound like a lean condition. Can you adjust your carb. so the secondaries open a little sooner?