Well after driving some including two parades our shake down tour and some other trips (about 100 miles, or so total) I really don't see much difference using the cast iron intake over the aluminum one. Mileage stayed about 15 MPG over all. Get up and go may even be just a little better with the cast iron intake but that could be the cool Oregon weather. The first parade the outside temp was in the low 80's and even with my old round tube radiator and Atlas water pump the engine temp was good. I may have to open the high speed needle a notch or close it a notch, I'll try both, because I am still getting a burp or back fire when shifting in to high, but not all the time. It's ether a lack of fuel or it's loading up. As far as advancing and retarding the spark, I can't just pull the lever down and leave it, she is very fickle about engine speed and load, if I don't reduce the spark with the speed she sure likes to ping. She was that way before the gear, intake and carb change.
So those that missed my other posting, the engine has a low head, New Day timer, 7 1/2 advance timing gear and OF carb. with about 55 compression and the valves are set at .010 and .012. with motorcraft plugs.
Change to Champian X plugs.
Runs the same with Motorcraft or Champions. I like the Champions but there gets to be a point where they do just get worn out and leaky. When I have time I will rebuild a set of 5 and put them back in.
Except for a couple of plugs that leaked in the crimp area, I found that the Motorcraft seat better in the head without tape or aluminium foil.
Some of your comments I find interesting.
1. At 55 psi compression I am amazed you can get the engine to "ping" Perhaps it is a quirk of the advanced cam gear (I have never run one).
2. A old bit of wisdom; 90% of my carb problems have been ignition!!!
3. I would suggest you spend some time figuring out your ignition. Some general rules as follows;
At idle you want about 8 degrees of advance
At 2000 rpm you want about 30 degrees (this is also about as much as you want on any spark engine).
Between these two points you want a general progression of advance
It pinged before I changed timing gears, intake, carbs and reset valve clearance or should call it a knock. I ruled out the rods as I checked them. It's more pronounced on deceleration if I don't retard the spark to match speed of motor. Without putting a degree wheel on it, having set the timing at full retard just past top dead center, I would say that is pretty close to what it's running. Maybe it needs premium fuel!
The aluminium manifold it an original 1914 style, I had an off line question about it.
The pinging is more pronounced on deceleration? That doesn't make sense to me. Maybe I'm missing something, but I wonder if you are actually hearing pinging? JMHO. Dave
OK I have never had a motor "ping" (spark knock) on deceleration
You could try running a little more clearance on your valve lash and or double check to make sure you have at least that much. is it a stock or aftermarket cam, if i remember correctly the aftermarket cams can run tighter clearance than stock. to tight lash can cause evil sounds and hard starting also.
I would check and see that the head gasket isn't leaking coolant into the chamber while running and causing a piston to rattle also.
Stock cam, it did this before I adjusted valves. It's done the same thing, low or high head, new or used head gasket, stock or advance gear, Anderson, Tiger or New day timer for the last couple of years. The pistons and rings are new (less then 2000 miles new)but could have had less clearance. I had it bored over sized before I had the pistons and knew what I know now. I just retard the spark and it goes away. Not much carbon on the pistons. Could be piston slap, but for now I will live with it. Only have one T and it's tour season.
Mark - If what you hear is piston slap, I would think that it would be more pronounced when the engine is cold, and become less audible as the engine warms up. That would be an indication of piston slap; for what it's worth,......harold
I'd be interested in hearing how you checked the rods. What you're describing sure sounds like piston slap or rod knock.
The rod were checked winter before last when I had the engine out. Between then and our shake down tour maybe have put 5-600 miles on. After our shake down tour this month, which was about 62 miles of hills and flat travel, I could hear a light tick. I checked by doing the short test, sound was coming from what I thought was No 4. Pulled the inspection plate, No 3 was looser then should be so adjusted it, No 1 and 2 felt fine and after spending about two hours to get the nuts off No 4 it was close and only needed a minor adjustment. Also took 1 and 2 mains up. When I first started hearing the noise I thought it was backlash from the timing gears but after putting the new gear on the noise was still there. It is more pronounced when the engine is not up to operating temperature but is still there if I don't adjust the spark, just not as loud when the engine is up to temp.
What spark plug gap are you using? Have your coils been rebuilt and then adjusted on a HCCT or Strobo Spark?
.032 and Yes. I have come to the conclusion that even though the compression is good, the oil pump she is, is not good and it's time for a bore and new pistons. With all that oil shes pumping, the plugs look good! I am surprised she doesn't smoke all that much. When I put the early cast iron muffler on I made the inner pipe out of water pipe, maybe it's acting like a catalytic converter? I did enlarge the holes in the inner pipes in the muffler in case I was getting too much back pressure, haven't really got a chance to see if that helps. The dry hole is No 4.
Mark, You said in an earlier post that the ping was actually a knock. You then said that the knock went away when you retarded the spark. This is a classic case of advancing the spark to far. You need to lengthen the timer rod to retard the spark. Spark should occur just past top dead center with spark fully retarded.
Fully retarded is just past TDC, that's where it is set. Speeds over 25 she knocks, under a load she doesn't knock. If I back off the throttle the knock get less. If I back the spark off to much then she gets a little on the hot side. She has done this for a long time, it just has gotten a little worse. Don't think the 7 1/2 advance gear should have made it worse (the knock was there before I put it on). I'll try driving with less advance on the spark till I pull her down and do some work on the oil problem. The pistons were new less then 3000 miles ago, but the bore was on the loose side, my fault. The rings were new winter before last. That's why I am leaning to piston slap, although I have never heard that sound so am at loss what it should sound like and the only person that might know can't hear well enough to tell me if that's what it is.
Another thing I could try, swap out my poor battery and try her running an battery instead of magneto.
I'll bet your not hearing a knock caused by the timing, but are able to mask the sound by retarding the spark.
Advancing the cam gear advances the spark as you are also moving the Timer roller pin hole in the cam to the left while the timer body stays where it is. This in effect advances timing. When you advance the cam you should retard the spark by the same amount by modifying the roller pin hole. You should move the roller to the left by moving the pin hole to the right. This will return ignition timing back to where it should be with the advanced cam.
I think centre main bearing. But it looks like rings are in your future as well.
I just took up the front and center main. Read my post Smoking Jack Rabbet for more update.