John thanks for the reply. I would guess one place is no better than the other to get vacuum?  Gerry

Lake Forest California  5th inf 77 Armor Div. VN 68/69

If you put your town and state in your signature

help might be closer than you think.

Sorry Gerry, didn't mean to hi-jack the thread. When I did my FMX hybrid I took the vacuum off the back of the manifold. I've got 2 splitters, so 1 line goes to the power breaks and the other does the trans and a vacuum gauge in the car. Works Great!



John, I will check the RPM of the lag tomorrow. Thanks as always.



- John

John: Lake Forest, IL



'57 Fairlane 500 - Looking better every day.

Ok I did some testing on the way to work today:  If I'm standing on the gas and don't let off, the car will run up to about 5200 before it shifts.  It seems to start to lag at about 4500 and I'm just waiting for the next gear.  I think it runs 1st up to about 40mph and then 2nd to 65mph

Sometimes it would move along nicely through the gears when at about 4000-4500.  But I'm sure I was feathering off the gas.  Any thoughts?

- John

Edit: I also noticed that when the RPMs get up that high, I start to get that rattle again.  I don't think it's timing because I can drop it 6 degrees at the speed by adjusting my MSD control and it's still there.

John: Lake Forest, IL



'57 Fairlane 500 - Looking better every day.

John:

I don't remember the particulars on your engine.  It sounds like it has a stock cam, and the power is dropping off above 4500 because that's about all the cam has.  The 5200 rpm rattle could be valve float if you have stock springs.  It actually sounds like the FMX is doing its job correctly.

John

John - "The Hoosier Hurricane"

Yes sir... Engine to my knowledge has pretty much stock internals.  So the FMX is working well, it is the engine that needs some help.  Do I need to be concerned about the valve float?  Will I do any damage driving the car?  I probably just can't lay into it too much. 

I just got engaged so now things like a house and living expenses take priority, ugh 

- John

John: Lake Forest, IL



'57 Fairlane 500 - Looking better every day.

John:

Avoid valve float.  It can damage the cam, lifters, bend pushrods, break valve springs, break valves.  Would hate to see you miss a house payment to fix your car and maybe end up with your wife and kids living under a bridge.

John

John - "The Hoosier Hurricane"

Ok, so I drove the car around a lot this evening to get some more information on this rattle...  It only seems to happen in 2nd and 3rd gear when the motor is running warm.  I could rev the motor up in 1st gear, no problem.  But when the temp gauge is at the end of the horizontal line and the motor is under load in 2nd or 3rd gear I can hear it.  Any thoughts???

Yeah, I think the ford would be parked in the driveway dead before I had to miss a mortgage payment.  HA! Thanks guys! 

John: Lake Forest, IL



'57 Fairlane 500 - Looking better every day.

John:

Valve float would only happen at top rpm in any gear.  That's not your rattle.  It's either too much timing or too poor a quality gasoline.  Oh, another possibility.  Excessive carbon buildup in the combustion chambers over the years, raising the compression ratio.  Does 93 octane take the noise away?

John

John - "The Hoosier Hurricane"

I always use 92/93 depending on what the station has.  I tried to use regular when I first got the car but it would diesel when I turned it off.

After some more driving and reading, I'm sure it is detonation.  I don't think it is timing though.  Definately heat and probably compression due to carbon build up.  I didn't think that carbon would increase the ratio that much to make a difference.  The weather was probably 70 yesterday and the car was running hot.  Like I said, a lot of the time the car runs great, so I don't want to mess with the timing too much.  It is just that as soon as the engine temp gets up there, I get the rattle. 

What's the best next step?  Pull the heads and check out the inside of the cylinders?  Use a octane additive boost?  Thanks!

John: Lake Forest, IL



'57 Fairlane 500 - Looking better every day.

John:

Do you know what the timing actually is at cruising speed.  If it is too much or too little, it can cause overheating, which makes the problem even worse, as you found out.  Are you using both mechanical and vacuum advance?  Try unhooking the vacuum advance, set the timing to about 34 degrees at about 3000 rpm, and see if the the knock goes away.

Also, a lean mixture will also cause those symptoms.  Does it run without pinging until it warms up enough for the choke to come off, then start pinging?  Maybe it's not engine temp but lean mixture causing the problem.

John

John - "The Hoosier Hurricane"