New cam / timing question. Also hose sucked shut

[Mopar to ya]

I just spent the day yesterday installing a new XE268H Comp cam and lifters into my 73 Dart Sport 318. Ran out of daylight screwing with the oil pan to timing cover seal, but that's another story. Changed oil this morning and fired it up. I left the radiator cap off to bleed the air. Ran around 2000 rpm to break in the cam and let lifters spin. After a few minutes coolant was spewing from the radiator outlet almost like you see when you have a cracked head gasket. I put the cap on and the upper hose sucked completely shut. I shut her down, filled the coolant and capped it off. When I started it back up the hose started to collapse - about halfway - then it was like I could almost see the t-stat open and it filled out to normal. It has been fine since. After 20 minutes of 2000 rpm it never got over 210 degrees. I think it was air locked. Anyone got any ideas?

Also, with the new cam, do I use factory timing specs or do I modify them? It runs very well where I have it, but I like to do things properly.

 

[moper]

Yes, air locked. If you drill a 1/8" hole in the Tstat it will bleed that air out when you fill. I never topp off the cooling system while the cam's breaking in. I leave the top row of the radiator just covered, then top it off slowly as the temps come up and the air bleeds out and the coolant expands. It keeps it from bubbling out and gettting blown all over.

 

[67Dart273]

Other than drilling the stat, all you really need to do is leave the highest heater hose disconnected just below the stat. Fill until you see coolant come "up," then connect one end of the hose with the other end slanting upwards. When the rad is full, slowly lower the end of the hose into a can until you get coolant to check that it's bled. As you drain a small amount out of the hose, the rad will drop a little.

Then hook the hose up to the other heater fitting. End of story. It's bled and you don't have to worry about it.

If you don't run a heater, pull out the plug where the heater "was" or pull out the temp. sender.

The BIG problem with airlocks, is that just like this incident, you were trying to something critical, like break in a cam. you should not have to play with coolant, timing, carburetor while this is going on. The REALLY big problem with airlocks is that THE TEMP GAUGE MAY NOT READ while the block is getting overheated.

 

[Mopar to ya]

What about timing?

 

[67Dart273]

You should be able to "learn yourself" how to set STATIC timing accurately enough that the engine will start, run, and drive.

Do this:

First you must have the no1 piston on the compression stroke and "ready to fire." So if the valve covers are off, bring the balancer around until the timing marks are "where you want" for timing, that is, 15 BTC or whatever. Examine the no1 and no6 valves and see which ones are closed. If no1 valves are both closed you are on the right "stroke," otherwise, rotate the crank one turn.

The alternate method is to pull no1 plug, bump the engine until you START to feel compression, and then finish turning the engine as the marks come "up" to whatever timing setting you want Some practice may be required.

So now we have the no1 cylinder ready to fire, and the "marks" are where you want the timing.

Now install the dist. if not already, and retard the distributor (cw for smallblock), the BRING THE TIMING ADVANCED slowly until either the points open, or the reluctor is in the middle of the pickup coil. With practice, you can ALSO do this with the key on, and listen for a spark.

Now plug the no1 wire into the hole the rotor points to, and wire from there.

This method, once learned and practiced is good enough that you should be able to start the engine right up, no fuss, no muss.

 

[Mopar to ya]

You should be able to "learn yourself" how to set STATIC timing accurately enough that the engine will start, run, and drive.

Do this:

First you must have the no1 piston on the compression stroke and "ready to fire." So if the valve covers are off, bring the balancer around until the timing marks are "where you want" for timing, that is, 15 BTC or whatever. Examine the no1 and no6 valves and see which ones are closed. If no1 valves are both closed you are on the right "stroke," otherwise, rotate the crank one turn.

The alternate method is to pull no1 plug, bump the engine until you START to feel compression, and then finish turning the engine as the marks come "up" to whatever timing setting you want Some practice may be required.

So now we have the no1 cylinder ready to fire, and the "marks" are where you want the timing.

Now install the dist. if not already, and retard the distributor (cw for smallblock), the BRING THE TIMING ADVANCED slowly until either the points open, or the reluctor is in the middle of the pickup coil. With practice, you can ALSO do this with the key on, and listen for a spark.

Now plug the no1 wire into the hole the rotor points to, and wire from there.

This method, once learned and practiced is good enough that you should be able to start the engine right up, no fuss, no muss.

Gonna look at this. I imagine the other option if the rotor is not pointing at #1 on the cap is to pull the distributor gear and set it properly. The way you describe sounds as if it doesn't matter where you start as long as #1 is where the rotor contacts. Neat idea, thanks.