Hi guys,
I have something that is bugging me for some time now.
When I rebuilt my 292 back in 2010 I installed a Isky E-4 cam. The car runs great, and even tough at the time I installed the cam out of the box, without deepening the oil groove, the engine has great oil flow to both heads.
The thing that buggs me is the idle. The car never had the same idle it had when all stock. I was told the E-4 is not enough to alter the idle (not that I wouldn't install it because of that) but my engine doesn't idles as smooth as before. Along with the cam, the engine also has double valve springs, and 1,54 rockers. When all stock she had the lower ratio rockers.
Valve lash is correct, the carburetor is good (Autolite 4100), the car has no ignition problems, and drives super well, with no hesitations, flat spots, and has lot's of power. The problem is just the idle that is more vibrant than a stock engine.
My fear is having messed something out when rebuilding the engine.
For you guys with more experience on comparing cams, is the E-4 enough to change the idle?
Other than that, I've put more than 20 K miles on the 292, and it uses no oil, has more than 30 PSI of oil pressure idling at 750 RPM hot, and has a little more than 60 PSI on highway.
What do you think??


Túlio Lazzaroni "FORD", Florianópolis SC Brasil.

'74 Ford Galaxie 500 292 V8

'82 Ford Galaxie Landau 302 V8

'98 Chevrolet S10 4.3 V6

'01 Ford Focus 1.8 Zetec

Hi, I had that problem a long time ago and after a lot of work I changed the motor mounts (advise from an old man, now I am an old man) the rough idle went away (hard old mounts).

Cliff

I'm sure you will get a lot of responses from more knowledgeable people then me, but I am wondering why the double valve springs? I don't believe the E4 cam has that high of a lobe lift to require that.  Did you have double valve springs installed before you rebuilt the motor?
regards,
Rono

  Ron Lane,  Meridian, ID

It is larger than most factory cams so it could have a little more rough idle.  Shouldn't be too bad, though.  What is the vacuum?



Lawrenceville, GA

Thanks guys.
I didn't measure the vacuum on the intake, so I don't have that info.
On the vale springs, two of mine were shot, so I ordered a new set, and when it arrived it was the double springs. I installed it when rebuilt the engine. Figured it wouldn't be a bad thing to have since I use oil with high ZDDP. I wanted to go with a larger cam, but ended using the E-4. I didn't loose too much of the low end torque, as the car is very heavy (same body as a '66 Galaxie four door sedan), and my town has a lot of hills.
The idle is not exactly rough, it has more vibration than stock. The kind you can feel on the floor pans if you pay attention to it.
Both motor mounts, and the transmission mount were replaced with new parts back in 2010.
Friend of mine even put the guilt on my exhaust, that is dual with glasspacks.
The last mufflers I had when the engine was stock was a pair of Thrush Welded mufflers. I replaced them short after rebuilding the engine as they were too quiet...
This is how she idles:



Túlio Lazzaroni "FORD", Florianópolis SC Brasil.

'74 Ford Galaxie 500 292 V8

'82 Ford Galaxie Landau 302 V8

'98 Chevrolet S10 4.3 V6

'01 Ford Focus 1.8 Zetec

Comments, Tulio.
1) Like Rono, I'm surprised that you're running dual valve springs unless you're counting a damper coil as an actual spring.  No, a second spring would not be responsible for a change in the idle quality.  It's an unrelated thought.  I'm just thinking in terms of your usual rpm operating range for street and highway use and valve train wear and tear factors.
2) I'm with Charlie in trying to get a handle on your idle quality concern.  What kind of a vacuum gauge reading are you getting at idle?  In addition to the gauge reading number, is it a steady reading, or rapidly twitching (pulsing), or slowly fluctuating ('walking')?

GooD to hear from you.  It's been awhile.  Glad that you got that 4100 carb working okay! 

Regards,


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

Charley, great to hear from you too!!
Maybe I was mistaken, my "inner" spring is the flat kind. Not really a second spring. Around here they are called double springs, and the other triple.
I have to get a vacuum reader borrowed with someone. Then I can tell what it reads.
When I rebuilt the engine, all work was done by me and a friend that owns a shop, and we measured it. It was solid as a rock. But again it was back in 2010, and I don't recall the actual reading.


Túlio Lazzaroni "FORD", Florianópolis SC Brasil.

'74 Ford Galaxie 500 292 V8

'82 Ford Galaxie Landau 302 V8

'98 Chevrolet S10 4.3 V6

'01 Ford Focus 1.8 Zetec

Here are the valve springs. Just pulled a valve cover and took a picture:




Túlio Lazzaroni "FORD", Florianópolis SC Brasil.

'74 Ford Galaxie 500 292 V8

'82 Ford Galaxie Landau 302 V8

'98 Chevrolet S10 4.3 V6

'01 Ford Focus 1.8 Zetec

Maybe a harmonic from the muffler change? I've had cars that needed resonators added, but at cruise, not idle. The comment about feeling it in the floor pan is what prompts this.


miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

That is a damper, not an  inner spring.  The vacuum gauge will tell you more.



Lawrenceville, GA