Hi Dennis,15/16 hg of vacuum with a non stock cam is ok at idle,but schould not drop to 5 when you put the air filter on.If its bouncing from 5 to 10 it is a vacuum leak.
Check your hoses maybe the filter is hittig somewhere you didn't noticed.Be pacient,i rebuilt my engine from the ground as you did and took me over a year to work all the bugs out and get it running like it schuold!!!!

If you caught my earlier post about the water leak- you may already know that I have finished the run-in process and finally have the timing pretty well dialed in.

I am getting a constant 15-16 on the vacuum gauge with the stock air cleaner off. As soon as I put the stock air cleaner (oil bath type) back on, the vacuum dropped down to between 5-10. I'm planning on converting the old air cleaner to a modern filter and cut a few extra breather holes. Anyone have a similar experience? do you think this will help the problem?


Thanks, Dennis.

56 F100 - 272 Y Block
NSW, Australia.

Dennis: I don't know if you'd want to pay the shipping..but a possible contact for another "G" head might be John Mummert in Calif.. ( see link) Because he has stated that he has run across later posted heads that were cracked, which may have resulted in a good head left over? He has shipped to Australia... Or you could try another guy that has many parts, (Mike) Henaults Enterprises in La Grange Calif. Call 209-852-2476 (calif time) or e mail-  henaults@jps.net     


Paul

Charlie, I asked this question a while back, seems that in the short term it probably won't matter too much, but the long term effects would be unknown. It would be interesting to know though.

It's just so hard to find anyone that wants to sell a decent spare ECZ-G head. And seeing that the engine won't be in the car and driving for another year I will just keep searching until one pops up.


Thanks, Dennis.

56 F100 - 272 Y Block
NSW, Australia.

That is quite a mis-match with the heads.  It will be impossible to tune well because you effectively have 2 engines sharing a common crank and carburetor, each with different fuel and timing demands.  It could contribute to a rough running condition.


Lawrenceville, GA

It would be interesting to see what the cranking compression is on the opposite side to see how much, if any, difference there is between the two different heads.

The heads are mismatching at the moment. I'm trying to track down another matching head. I have 1 big letter ECZ-G and 1 COAE.


Thanks, Dennis.

56 F100 - 272 Y Block
NSW, Australia.

What heads are on this engine?

Degreeing a cam was always a "black art" to me. Once I learned by following exact instructions and knowing true TDC everything became easier. It was really difficult when there were very few ways of moving the crank or cam gear other than an offset key and if you were building an engine that didn't have a chain you had to think in reverse. The cam card is a must and is one the most important references you never throw away. Now I do it with the heads off and the largest degree wheel I can find.
Today with crank gears with at least 3 settings all is a little easier with the correct tools. On our current racing V8 we use an adjustable cam gear which we can do by removing the water pump and a plate on the timing chain cover. It is not a Y.
Many, many years ago guys could never figure out why some stock cars just ran better than others right from the factory. Some guys knew about rear gears being a edge but some were just plain lucky with an engine that had a 2-3* advance cam. Good Luck

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Refer to the instructions to understand how to use the timing light.  If you leave it at 0, then it should work like a regular light.

I would expect that cam to be a slightly lopey at idle.


Lawrenceville, GA