I have a situation on my 327 SBC in which the start lugs when I crank it. Not all the time but pretty often. The curious thing is I replaced the cam and wanted to ciruclate oil so I disconnected the HEI 12V source and the starter spun just like normal. I reconnected and it lugged again. It seems that my HEI is sapping power from my Starter. Does this make sense. The 12V lead is run from the HEI to my ignition switch and then to the BAT+. I have a 2' 1g ground mounted to the block daisy chained with ground straps to the frame and then the body, in addition I ran a 10g wire from the Bat- around to one of the Belhousing bolts. Does this make sense to anyone??

Additional info:
Optima Battery
Comp cam (244/280 dur and 477/480 lift)
Timming set 22 degrees advance

Is the 22* timing just the initial advance?

If so, it is way too high.

John 8)

That is what a local shop set the timming to. The mechanic said the larger cam I put in required that much advance.

Timing set too high will cause your starter to act like a weak sister

Timming ??? Also the 12V HEI power source wire goes to the ing. fuse panel 12v not between the key and the panel 12v.

Its kicking back on the starter. retard the timing.

I think R Pope is correct as well.
This is a little off topic... but for anyone looking to replace their starter in the near future; I would encourage you to consider putting in a better starter than the oem replacement. If the engine has been modified for higher compression or has problems dragging when the motor is hot (heat soaking) for about $150 you can get a 4.4:1 reduction high torque starter. The powermasters are incredible in my opinion.

Powermaster at Jegs (http://www.jegs.com/webapp/wcs/stores/servlet/CategoryDisplay?lang=-1&catalogId=10002&storeId=10001&categoryId=84460)

http://myweb.cableone.net/JBURROW/elcamino/starter.jpg

Classic problem of starter fighting advanced ignition.

You *do* need more ignition advance at idle with that cam and that is why they set it up that way. But there is a way to get both the advance you need at idle and the retard your starter needs. What you need to do is find out what your vacuum is at idle. Then install a vacuum advance can that provides full advance at 1-2" less vacuum and connect it to manifold vacuum. If you idle at 15", pick a can with full advance at 13" or so.

You really want to check and validate your total ignition timing without vacuum though. This is much more critical than initial timing as too much can destroy an engine and too little will hurt performance and economy. You will want about 36*-38* without vacuum advance, and this is for any cam (more affected by cylinder head and valve design). With this set, then see where your initial is and if it is still higher than you want/need you will need to modify the distributor mechanical advance for more travel. The mechanics may have put an advance tuning kit in it to limit advance travel. May be as simple as removing a couple of sleeves/bushings in the advance mechanism.

BTW I run about 30* at idle and it is NOT too much. And I have no problems with startup because it is only 18* initial plus 12* vacuum advance.

A starter motor will easily draw 150 amps while a HEI system even at full tilt will not draw more than 5 amps so the problem is not that the HEI is drawing current from the starter. With 22 degrees of initial advance the starter motor is struggling to turn thr engine over. I'm not going to get into the argument of manifold vacumn vs. ported vacumn for the vacumn advance but suffice to say that depending on the engine some do best with manifold vacumn and others with ported. Try backing off the initial timing to about 12-14 degrees and connect the vacumn advance to manifold vacumn and see how the engine runs. If you have tip-in throttle detonation you will have to go back to ported vacumn for the advance and recurve the distributor to allow the mechanical advance to come in quicker. In any case you should shoot for 36 degrees total advance (vacumn advance disconnected and plugged) all in by 2800rpm.
When you reconnect the vacumn advance this will give you an additional 8-12 degrees but only at small steady throttle openings. Don't underestimate the importance of a correct ignition curve as it can make a huge difference in engine performance.

Ported vacuum is not going to have any affect on potential throttle tip-in detonation. People do not seem to get this no matter how many times it is said, but once you have opened the throttle ported == manifold.

If you have the right vacuum can that provides full advance at 1-2" less vacuum than you have at idle... then it will be backing out advance already at tip-in since vacuum drops pretty quickly with low RPMs and throttle movement.

To better explain the starter issue... optimally you want to achieve maximum cylinder pressure around 20* after TDC. So the actual ignition needs to occur some time prior to that point, typically before TDC. But if the ignition is too early, or the engine speed is too low, you increase cylinder pressure early and even before TDC. At this point the engine wants to run backwards and the starter has to fight it to get it going forwards.

Lastly I will emphasize it yet again: when you change initial timing you also change total timing. So just changing from 22* initial down to 14* initial will clobber total timing if it is otherwise correct. How well will that engine perform with 28* total advance timing?

The factory specified initial timing because A) it can be set with a very basic timing light B) it does not require a degreed balancer and C) they controlled the entire engine configuration. This last point will get a lot of people in trouble today because it you (or a prior owner) change cams, intake manifold, carb, or non-stock distributor then those original factory specs no longer apply. By way of example in the factory manual for 1968 there is an entire page of different distributor specifications and setups because they were tailored to different engine/car combinations. It is much more reliable and consistent to set total timing as this number is usually very close to the same for all combinations.

I don't want to get into a pissing match with you but as a factory service rep in the mid seventies this was a big issue and I got right into the middle of the problem. At small throttle opening and no load with the vacumn advance attached to manifold vacumn the engine will have whatever advance the initial timing is plus some mechanical advance and the full vacumn advance. Opening the throttle a little will cause the vacumn advance to back off but not fast enough and if the AF ratio is on the lean side you will have too much ignition advance and the engine will ping. Been there and done that.

I don't want to get into a kissing match with you but as a factory service rep in the mid seventies this was a big issue and I got right into the middle of the problem. At small throttle opening and no load with the vacumn advance attached to manifold vacumn the engine will have whatever advance the initial timing is plus some mechanical advance and the full vacumn advance. Opening the throttle a little will cause the vacumn advance to back off but not fast enough and if the AF ratio is on the lean side you will have too much ignition advance and the engine will ping. Been there and done that.
As antisocial as I am, and as much as it pains me to agree with anyone. I have to agree with Mrapii...(much to his dismay :)) But then again, I run 22 initial with total 35 in by 2600..

No mention of if the motor runs or not. Any chance when you replaced the cam you did not get the the cam aligned to the crank index by a tooth?