Thread: valve adjustments 1968 Ford Thunderbird Thunderjet 429

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I look in the old Chilton books and they say that the old v-8 engines are non adjustable valves, and to bottom out the rocker arm nuts. I try this and bend the push-rods. How do I adjust them correctly. Do I just start the nuts down a ways and crank the engine, and tighten them up until they stop tapping, and then tighten them up 1/2 a turn or what? I'm getting a little frustrated. Please help me on this.

I don't wanna say too much since I am no pro on this or nothing but basically you have to use a fealer gauge (sp) and then check the gap, etc and then you do a quarter turn. At least that is how I was told. Anyway's, welcome to the boards. I hope you stick around and not be a one timer. There are tons of smart geezers here to help and just chat with.
Good luck.

I have hydrolic lifters in this engine. I guess you are talking about putting the camshaft on the back side of the lobe, and then adjusting the rocker arms, and if so, what size feeler gauge should I use? Do I do it when the engine is cold, hot or what? I've always thougt I was a pretty smart fellow on these old motors, I grew up working on them. but either I forgot how to set the valves or I'm not as smart as I thought I was. Sorry, I'm 50 years old, and I may be losing my mind.

Heh, we all forget things at times. That is why asking questions helps. I am not sure on that one man sorry. Someone here will be here real soon to jump in on this one I am sure of that. Give it a day or a night and you will have list of answers here.
Hope all works out for you.

The Backyard method was to have a set of old valve covers with the top's cut out of them,,put them on,,,and adjust when the engine was running untill the engine started to Lugg and then back off a quarter of a turn, (i think,,i'm getting close to you in age).
This method was by no means accurate,,,but it served the junk yard well.

I will try that method, Thanks a lot. I just don't understand why I keep reading that the 68 429 thunderjet engine has non-adjustable valves and when I bottomed out the self-locking nut, boy my pushrods bent like crazy. I appreciate your advice and again THANKS.

Originally posted by Thunderbucket
The Backyard method was to have a set of old valve covers with the top's cut out of them,,put them on,,,and adjust when the engine was running untill the engine started to Lugg and then back off a quarter of a turn, (i think,,i'm getting close to you in age).

Originally posted by baggettjd
I will try that method, Thanks a lot. I just don't understand why I keep reading that the 68 429 thunderjet engine has non-adjustable valves and when I bottomed out the self-locking nut, boy my pushrods bent like crazy.

Do Not try The Above Method. This ain't no chebby nor are the valves adjusted in the manner that the chebby is.

Your 429 Thunderjet came from the factory with non-adjustable positive stop rocker arms and valve train. You just screw it together and you're done...sort of. Assemble the valve train and when the rocker nut botttoms/hits the shoulder, you just torque to 18-20 foot pounds. However, the rocker arm mechanism that is being installed must have it's cam lobe at the base circle. You cannot just throw the valve train on and then randomly start tightnening bolts, or indeed, you can bend pushrods. IF the cam is not at it's base curcle, final tension is forcing the intake valve to open and the pushrod must endure the preload.

Also, it may be necessary for your hydraulic lifters to bleed off, so if you are at the base circle of the cam, AND have the stock pushrods (8.673")/valve train, AND the bolt still won't bottom, then just leave it where it is and walk away for fifteen minutes and check afterwards to see if the lifter has bled down...then you may continue tightening.

(Incidentally, I am assuming this is a stock engine with OEM parts. Otherwise, if you are building a new performance engine, you may need a different length pushrod. If not, then disregard this statement.)

Paul

Everything is stock on this engine. I just purchased some new push rods, and I will try your method. You sound like you know what you're talking about. Lots of thanks. I'll let you know later how it turned out.

Thanks for the heads up on that one, kane.
It's been along while since i done an engine so i'm getting alittle rusty,,,,it's nice there are people out there who can correct you if your wrong,,,and i dont mind being wrong,,but i think my memory is starting to fail me.
Time to double dose the geritol,,,LoL

Thunderbucket, you were right on the money with your advice. I tried what Paul said to do, and I have a stock cam, stock pushrods, and hydrolic lifters, and my pushrods still bent. I replaced them and just tightened them up where I couldn't turn the pushrods, and cranked my engine, and slowly backed off until the lifter started rattling, and then tightened them up until they quit making noise, then I tightened them up an additional 3/4 turn, and my engine is purring like a cat. It has power and runs real smooth. I really appreciate all the advice I received from you fellows, and I will surrely put you'll in my prayers. Thanks so much, and I hope I can help someone in the future. Bye and good luck............................

It's nice to be vindicated once in a while,,,glad it all worked out for ya.