Setting Timing

[Large Arbor]

Ok, put new head gaskets on and seem to have no leaks oil or water.. Having trouble getting timing set though. Is this the process?

Bring #1 cylinder to TDC. Check balancer to that it shows at the zero mark or is at TDC. Builder said to set at 35 degrees at 4,000 rpm. When it was at idle it seemed rough and I did not want to get there. Once sure all is at TDC start up, warm up go to 4,000 RPM And use timing light to get to 35 degrees before TDC.

Seems simple enough although I have found ways to make it hard.

The connectors pulled out to the distributor from the ERA harness. Purple and Green on the ERA side black with purple stripe and black with orange strip on the MSD distributor side. Which goes to which?

Phil

[Large Arbor]

A pic for reference below.

[patrickt]

Purple and Green to the magnetic pickup in the distributor. Orange and Black to the coil. Another Orange is also the tach feed.

[bobcowan]

Base timing should be wherever you get best vacuum. Different builds - especially different cams - will require different base timing settings. But best vacuum will be about right for just about every motor.

Once the engine is good and hot, make sure it will start right away. If it seems to stutter and bog down while cranking, back the timing off another 2* or so until it starts easily.

Once base timing is set, adjust the advance until you get 35* total at 4,000 rpm - just as your builder recommends.

You might be able to make more power by changing you total advance curve. But you'll need a dyno to do that accurately. Unless you're racing and need every last bit of power, there's really no need to do that.

[1795]

Not meaning to ask a stupid question, but you do have your valve covers off when you are trying to find TDC on number one right? Was not sure if the picture you showed was in relation to finding TDC, as the valve covers are on. With the distributor in place and spark plugs out, rotate the crank until the intake valve opens and then closes and the exhaust valve is still closed or just starting to move. That is TDC. Notice where the rotor is pointing. Place your cap on and make sure that the rotor is pointing towards the spark plug wire going to the #1 cylinder, If it is not, then you need to pull out your distributor and turn it 180 degrees so that the rotor is pointing towards the #1 cylinder.

Check with your builder to see how much advance he has set on the engine. You want to focus on the base timing (timing at idle) and then once you get that close, you can worry about adjusting towards the full advance. It is very difficult to try to get the engine to run if your focus is on the full advance timing. How low is your idle? With enough advance your base timing will be high and it will run rough at idle. You may need to increase your idle.

[Gaz64]

Originally Posted by Large Arbor

Ok, put new head gaskets on and seem to have no leaks oil or water.. Having trouble getting timing set though. Is this the process?

Bring #1 cylinder to TDC. Check balancer to that it shows at the zero mark or is at TDC. Builder said to set at 35 degrees at 4,000 rpm. When it was at idle it seemed rough and I did not want to get there. Once sure all is at TDC start up, warm up go to 4,000 RPM And use timing light to get to 35 degrees before TDC.

Seems simple enough although I have found ways to make it hard.

The connectors pulled out to the distributor from the ERA harness. Purple and Green on the ERA side black with purple stripe and black with orange strip on the MSD distributor side. Which goes to which?

Phil

Hi Phil,

One would think the Black Violet goes to Violet, but Black Violet goes to Green, Black Orange goes to Violet.

Pull no. 1 spark plug, turn the engine by hand with your finger sealing the spark plug hole, when you start to feel compression with your finger, continue turning the engine until 10 BTDC.

Fit the distributor with the rotor pointing to no.1 in the cap, turn the distributor so the paddles on the reluctor are lined up, fit the cap etc.

Fit a timing light, get someone else to help start the engine, check the base timing first.

Your engine probably wants something in the 14-18 zone at idle.

What bush and springs are in the distributor now?

Gary

[undy]

MIne is 16 deg BTDC initial and 38 deg total

[Large Arbor]

Thanks for all the responses. Builder wants timing set at 35 degrees at 4,000 rpm. I do not know what that translates at startup.

Right now I have the rotor button at #1 and the balancer at 0. If I rotate the crank once, the rotor button goes to #6. Rotate twice and I am back to 1.

Is it likely that once I set at 35 degrees at 4,000 rpm that the idle will smooth out? Sorry for so many questions as I am learning here.

Phil

[patrickt]

Originally Posted by Large Arbor

Thanks for all the responses. Builder wants timing set at 35 degrees at 4,000 rpm. I do not know what that translates at startup.

With the MSD distributor, your total timing is the sum of the limit marked by the color of the bushing and your initial timing amount. The bushing that limits my total advance is the silver one (25 degrees). My initial timing at idle is 10 BTDC. So, my total, all in, timing is 35 degrees BTDC and my curve, with the light silver spring and the blue spring, brings it all in well before 3000 RPM.

[patrickt]

... and you know you don't actually stick your hand in your engine, while it's revving at 4000 RPM, and turn the distributor while it's revving that fast. You turn the distributor while it's idling, then rev it up to 4000 and put your light on the marks to see what it is. Then go back down to idle and turn the distributor until you get it right.

[Bernica]

A good adjustable timing light is very handy to have to dial it in. So is a TDC indicator that you insert in the #1 spark plug hole to nail it on TDC. Then, you look at the markings on the damper and will see if you are set right. Sometimes you end up re-marking the damper because the TDC does't jive with true TDC as evidenced by the indicator. Of course, you can also do same with the valve cover off...
Just my 2c.

[Bernica]

Something like this. There are many out there and this is just an example...

Innovative Products of America Standard Top Dead Center Indicators 7880 - Free Shipping on Orders Over $99 at Summit Racing

[patrickt]

Just don't crank the engine with the TDC finder screwed in to the spark plug hole.

[Bernica]

Originally Posted by patrickt

Just don't crank the engine with the TDC finder screwed in to the spark plug hole.

Yeah, that could be most tragic!

[patrickt]

But he is right that you should confirm your TDC marking on your damper. The pointer could have gotten banged around, and some FE dampers are like seven degrees different than others. I don't know why. It literally takes two minutes to confirm your TDC with the little screw in tool and AutoZone has them, as does most of the chain auto part stores.

[Bernica]

I have seen many fresh builds that don't line up with TDC over the years. I have also seen many that are right on. But for peace of mind, confirming it yourself is good info to know. I don't know that it matters, but did the engine builder say he indexed the cam?

[patrickt]

There's easy to follow instructions on setting up your TDC from when my damper came apart six years ago Crankshaft Dampner Separated -- Arghh! Damn, I'm getting old....

[Bernica]

Great old post! I have the Romac and double-checked it with MSD tape.

[Bernica]

I actually used a Pi-Tape to get exact diameter of my damper before I set things up. Call me crazy, I guess....just love having cool tools!

Diameter Tape, Precision Diameter Tape by Pi Tape Texas, LLC, the original manufacturer of Pi Tape brand precision measuring tape, outside diameter, linear, Go/No-Go, inside diameter, O-rings, exteneded range tapes, Pipeline diameter measurement and

[lippy]

First, don't drop anything into the dizzy hole, like I did.

For your first start, rotate almost to TDC #1 by checking the #1 valves with that valve cover off. To do that, roll it through the cycle with a breaker bar on the crank until you see #1 exhaust valve open and close, and then the intake valve open and begin to close. If you want to set it at, say 18 initial, then line up the timing mark on the damper 18 degrees before you get to TDC. Now remove the distributor and prime the oil pump so you are sure you have pressure. Put the distributor back in, and mark the base of the distributor at the center of the #1 plug. Take the cap off and rotate the distributor so the rotor is centered on the mark you just made. Now you should be at 18 BTDC on #1. Fire it and it should start right up. If you get any backfiring, you are retarded, so to speak. Rev it until all the timing is in and set total timing, say to 36 degrees. Your total timing is important. Initial timing, not so much.