Valve Adjustment

[Endangered Species]

I went over to start winterizing the car, so before anything I run the valves and leak the motor down to make sure everything is ok and there is no surprises.
Before I get started. I always adjust the valves cold because I feel it's more consistent. And I usually adjust the valves the Ma-Mopar way, start at TDC adjust 2in and 8ex then go 90deg and adjust 1int and 4exh etc etc. The cam card says .028in - .030exh HOT. So I've been setting them .025int. and .028exh. It's a little on the loose side I know.

Never the less before Norwalk I decided to adjust them they way everyone does it, When the exh opens adjust the Exh and when the Intake closes half way adjust the Exhaust. Again I set them .025 intake and .028 exhaust.

The car ran GREAT at Norwalk, running 9.93, 9.92, 9.93, 9.89 and 9.93, in the heat on Sunday, MPH all in the 135 - 136 range
That brings be to today. I go to check the valves and only #6 intake was at .025 and #4 was at .026, the rest of the intakes were .028 and .030. And as far as the exhaust goes they ranged from .030-.035
I've never run into this before. Now I've had one or two out a couple of thou. OR I've had one or two that were WAY out and that always was the result of some damage.
I see nothing wrong... the push rod's look ok the motor turns over smooth, I drained the oil out of the Systems One filter and it looked good.

This is going to drive me nuts, Why would only two valves stay with in spec the rest go out this much?

 

[mopar 3 B]

Go back to the ma Mopar way. That way adjustment can not be made on the lobe ramp and is likely the reason for the variance.

 

[GTX MATT]

I've never had an issue with EOIC, but I'd guess that you were on a ramp on some of them somehow. I've never tried the "Mopar" method though.

 

[dvw]

I always use EOIC. Much quicker. My cam is fairly big, 285/[email protected]". Lash never varys. How far was the exhaust open when the intake was checked? How close was the intake to closing when the exhaust was checked? Was it stone cold when done? Was it stone cold when checked? Same spot every valve every time will result in good accuracy.
Doug

 

[Endangered Species]

Thanks for all the replies guys. I am going back to the Mopar Chart way... it wasn't broke so I don't know why I tried to fix it.

The cam is 785/760 284/286 @.050 so it's pretty stout. The motor was stone cold when I set it and it was stone cold when I checked it yesterday.

I'm adjusting when the exh starts to open I'm doing the intake. When the Intake closes half way (there is a difference from when it starts to close) I set the exhaust.

The one thing I like about doing it every 90deg. there is no doubt you're adjusting it on the same spot every time.

I'm going to re set them doing it by the chart and start it up get it hot a couple of times then check them again to see if they change. If they don't change then I'm putting into hibernation for the winter.
What do you guys think?

Thanks for the input guys! This one shocked me.

Kev

 

[1962savoy]

I dont want to highjack your thread but could I ask about doing the adjustments on an all aluminium world block? do the valves have to be adjusted hot only??
Any input would be of great help?
thank in advance!!!

 

[HEMI-ITIS]

With your engine,I would do it hot and then let it cool over night and see what they are cold. Now you know how to adjust cold

 

[Endangered Species]

Somewhere I read that the rule of thumb is aluminum heads and steel block subtract.004 from the cam card. Aluminum block and aluminum heads subtract .006 from the cam card.
You really should set them hot then check them cold.
I just did ours tonight, be it known the heads were only 115 deg. there was only .003 difference. I'm sure at 180. they would be .004