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Valve train misalignment. What is the cause of this?

Old Jun 23, 2019 | 03:57 PM
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Valve train misalignment. What is the cause of this?

Helping a guy out with resetting his lifters (solid flat tappet cam) and I noticed how misaligned the rockers were. What would cause this? My first assumption is that the pushrod guides are off and need to be cut or replaced with adjustable ones. Or maybe bad machining on the heads themselves? Thoughts?

Dart Pro1s. Dont know the brand rockers, knockoffs Im betting. 1.6s on exhaust, 1.5s on intake IIRC



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Old Jun 23, 2019 | 04:08 PM
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Re: Valve train misalignment. What is the cause of this?

Fairly typical. Those look fine to me.

The factory design doesn't put the rockers dead-on straight in the first place; they're intended to be slightly off-center to make the valves rotate. Aftermarket heads, where they've widened the intake ports and done other things such as that, are often even more exaggerated than stock. Note that the one that "looks" more off, is the intake, which is the valve and port that are usually more heavily massaged in the aftermarket.

Doesn't particularly matter in most cases. If it's REALLY bad, like if the rocker rollers are about to fall off of the valve stems, you can cut the guide plates in half and re-weld em to straighten it out some. But you don't want to take out ALL of the "misalignment" regardless.
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Old Jun 23, 2019 | 04:20 PM
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Re: Valve train misalignment. What is the cause of this?

Wow I never knew that. Thanks Sofa! Reckon we will set them and button her back up! Just needed some reassurance. Thanks!
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Old Jun 23, 2019 | 09:15 PM
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Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
Re: Valve train misalignment. What is the cause of this?

Originally Posted by sofakingdom
you can cut the guide plates in half and re-weld em to straighten it out some.
I did that on some BBC heads before installing shaft rockers.

I agree that those look normal. It's nice to have them centered but not a requirement. It's more important to get as small a sweep as possible across the valve tip through the cam lobe rotation. This also isn't required to be directly on the center of the valve tip.
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Old Jun 23, 2019 | 10:35 PM
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Re: Valve train misalignment. What is the cause of this?

Wow, I would have thought there was a problem here too. Glad you guys could confirm that this is OK. Lesson learned.
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Old Jun 24, 2019 | 02:29 PM
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Engine: 97 5.7 Vortec LT4 hotcam
Transmission: 700 r4
Axle/Gears: 3.73
Re: Valve train misalignment. What is the cause of this?

Originally Posted by DynoDave43
Wow, I would have thought there was a problem here too. Glad you guys could confirm that this is OK. Lesson learned.
Glad I'm not the only one.

Thanks alky for weighing in as well!
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Old Jun 25, 2019 | 10:48 AM
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Engine: 350 Vortec, FIRST TPI, 325 RWHP
Transmission: 700R4 3000 stall.
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Re: Valve train misalignment. What is the cause of this?

Yeah - I had to do some searching when I encountered this situation building my Vortec. I did get adjustable guide plates and made things as close as possible but with full rollers the trunnion bearing has some side-to-side slop and is going to flop around back forth across the tip of the valve stem. I tried to split the difference but the adjustable guide plates are a motherlover to keep in one position while tightening the rocker studs.

In the end one just has to embrace the fact that these are 1950's technology. Not a swiss watch.

GD
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Old Jun 25, 2019 | 11:32 AM
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Re: Valve train misalignment. What is the cause of this?

Yeah on some heads adjustable plates are needed to align things. But can be abit of a pain to keep aligned. Some guys tack weld them together. I didnt and it was fine
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