Need help from the flathead gurus...? Valve clearance issue

[flatheadmurre]

Originally Posted by Mart

I'm a little out of my depth here, but this is an interesting subject. The thing that occurs to me though, is that it is an offset of the cam lobe to the lifter centre that promotes a rotation in the lifter. The radius may be a red herring as far as rotation is concerned. If the cam lobe wiped directly across the centre of the lifter it would not want to rotate. Offset that wipe area and the lifter will receive a little rotational push every time.

Mart.

This i agree with fully !
And valve rotators has nothing to do with lifter rotation, they promote uniform heat, wear and deflection of the valve and helps keep the seat clean from deposits.
So not a bad idee to use them in my book.
The weight difference between rotators and non rotators are 3g so more to be gained from hollow lifters for weight.
And that they should break....they are used with the same design on heavy diesels with lot´s of more springpressure then any race flathead ever is going to see.
Then when it comes to mixing parts...lot´s of ways of doing it...not only one way that is correct.
Most of the time personal taste is what descides....

[crazycasey]

Originally Posted by flatheadmurre

This i agree with fully !
And valve rotators has nothing to do with lifter rotation, they promote uniform heat, wear and deflection of the valve and helps keep the seat clean from deposits.
So not a bad idee to use them in my book.
The weight difference between rotators and non rotators are 3g so more to be gained from hollow lifters for weight.
And that they should break....they are used with the same design on heavy diesels with lot´s of more springpressure then any race flathead ever is going to see.
Then when it comes to mixing parts...lot´s of ways of doing it...not only one way that is correct.
Most of the time personal taste is what descides....

I think the way this motor WAS set up, it probably would have run pretty good. The valve clearances were all a little off, but the rotator retainers held the spring at a 1.950"-ish height yielding something like 55 lbs on the seat, and the flat bottom lifters wouldn't have likely caused any issue. Now I'be got a much stouter setup, and everything is very well sorted, but I've spent another $500 and I have no idea if it was worth it. Glad for the knowledge though, and I'm already planning my next flathead build.

[Tim Ayers]

Originally Posted by crazycasey

I think the way this motor WAS set up, it probably would have run pretty good. The valve clearances were all a little off, but the rotator retainers held the spring at a 1.950"-ish height yielding something like 55 lbs on the seat, and the flat bottom lifters wouldn't have likely caused any issue. Now I'be got a much stouter setup, and everything is very well sorted, but I've spent another $500 and I have no idea if it was worth it. Glad for the knowledge though, and I'm already planning my next flathead build.

Awesome and great attitude. Certainly learned a lot from this thread.

[JSeery]

I have a question, have you checked the NOS lifters you just received for length? I remember your original ones were all over the place, are the NOS ones fairly consistent on length?

[crazycasey]

Originally Posted by JSeery

I have a question, have you checked the NOS lifters you just received for length? I remember your original ones were all over the place, are the NOS ones fairly consistent on length?

No, they were all 1.720" +/- 0.001".

[AnotherDay2020]

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I drag race my flathead, have for years. No trouble with adjustments using double Isky springs, high lift cam, fuel injected alcohol at 6000 rpm.

Now that said I'm building a new motor and am trying to source non-rotating radius bottom hollow adjustable lifters, I am using the Isky 404 jig and tool kit from the 50's.

Has anyone seen a set of lifters like this?
Thanks good talk!