Need Help Adjusting Timing with Timing Light

[man-of-war]

Hi all, <br />I bought a Innova 3555 timing light today that has advance timing up to 60 degrees. This engine has a Thunderbolt IV that has a stamp on it that says V824. The last 2 digits are (24). Is this my total timing? 8 degrees top dead centre plus 16 degrees = 24 degrees top dead centre. I need someone to walk me through ....... After adjusting my idle at 700 rpm and adjusting the air mixture screws, I hooked up the timing light and got the crank pulley to line up with number 8 dead on by turning the distributor. To adjust the advance - do I rev the engine to 3000 rpm and adjust the advance dial on the timing light to 16 degrees? At this rpm should the mark on the pulley line up to number 8? There is a metal plate by the crankshaft pulley that has numbers on it. The numbers are 16 dip 12 dip 8 dip 4 dip 0 dip 4. Any help on this would be greatly appreciated. Thanks.

 

[Bondo]

Re: Need Help Adjusting Timing with Timing Light

After adjusting my idle at 700 rpm and adjusting the air mixture screws, I hooked up the timing light and got the crank pulley to line up with number 8 dead on by turning the distributor.

That's It,....................You're Done..................<br /><br /><br />The Dial-in feature on your light is for checking advance,.... There's Nothing to Adjust......<br /><br />That's 24* Advance,......... 8* Initial,+ 24* Advance,..... Equals 32* Total.........

 

[man-of-war]

Re: Need Help Adjusting Timing with Timing Light

Bondo,what can cause my plugs to still be wet with gas ? in the driveway ,i started the engine set the timing to 8* fuel pressour is 7psi plugs are NGK BR6FS GAP .35 The holley was surviced on tuesday.The float level was adjusted new power valve new nedel and seats.thanks

 

[Haut Medoc]

Re: Need Help Adjusting Timing with Timing Light

Serviced how? And Bondo can certainly answer the question I'm sure. The plugs should not be wet with gas. If they are - someting is up...To me ....Something is still goofy with the carb. All engines run on fumes not liquid.....Look down the carb at idle & shut off. There shold be no dumping of fuel unless the throttle is pumped & the acc. is involved. Wet plugs=Bad....JK

 

[Bondo]

Re: Need Help Adjusting Timing with Timing Light

I Agree with JK,......<br /><br />Fuel Pressure is on the High side of acceptable,......4 to 6psi is Better....<br />I prefer AC MR43T plugs,......<br /><br />But,....... Whatever Servicing that was done to the Carb. was either Wrong, or Incomplete......<br />Or,.. Is the Fuel Pump Leaking,..???

 

[man-of-war]

Re: Need Help Adjusting Timing with Timing Light

The fuel pressure is 7psi, i was wondering if restricting the fuel line on the out of the fuel pump line to create a 5psi,to see if that has an effect on the plugs?....... i have a set of AC MR43T plugs that were used once, when the engine exploded. they have a .40 gap is that ok?...... i did a compleat check of that fuel pump .ran varsol through it at 5 psi and pluged the outlet with my finger held it there for a min pump the arm no leaks from the back side or the bleed hole.removed the varsol and pump 7psi of air in it while holding the outlet shut, filled the backside of the pump where the springs/arm are with soapy water ,pump the arm and no bubbles.its good........... could the power valve be to week ? ill take the carb back to him today and see what he can do again to it.ill ask him to loan me a carb and see if i get the same problem.......thanks again

 

[man-of-war]

Re: Need Help Adjusting Timing with Timing Light

also did a compression test #1,135...2,145...3,155...4,145....5,145....6,130.. 7,140...8,140 ...........#1 and #6 looks a little low for a 5 hour engine.......the engine was cold and throttle wide open.

 

[ron7000]

Re: Need Help Adjusting Timing with Timing Light

Originally posted by man-of-war:<br />The last 2 digits are (24). Is this my total timing? 8 degrees top dead centre plus 16 degrees = 24 degrees top dead centre.

I can't speak for the thunderbolt style ign systems, but basically they all operate the same- as rpm increases they advance timing. Most all systems advance timing a total of 24 degrees, give or take. When you set timing by turning the distributor at idle, you are setting base timing. When doing this, you need to disable any type of advance- if mechanical distributor then an idle <= 700 rpm pretty much ensures there's no advance happening. With electronic distributors, there should be a procedure. You set base timing at 8-10 deg BTDC. So with base timing at 8-10 deg, the ignition system is able to advance 24 more degrees to give you a total of 32-34 deg of timing which would happen at high rpms. Most all v-8's operate this way. I think my 3.0L 4-cyl has a total adv of only 24-28 deg though, the principle is the same but the actual #'s can very so it's a good idea to verify.<br /><br />On your timing light, it sounds like you have a dial on it that you can set from 0 to 60? If so, that'll just adjust where/when the light flashes on the crank timing marks. Set the dial at 0, and you should illuminate the 8 on the crank timing mark for 8 deg BTDC. Set your dial at 8 on the timing light and the 0 should illuminate on the crank for 8 BTDC. Timing marks on the crank only go out to 15 or so, when you're at high rpm and have a total advance of 32 deg happening, you set the dial on the gun at 32 and you should see 0 illuminate on the crank, that's how you use the gun to verify what timing is at higher rpms.