Hyd Roller vs Hyd Flat tappet on SM heads
- Thread starter Cuda416
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Turk, post #47.
The sweep width on the valve tip is also dependent on the valve travel [ lift ]. I mentioned that in post #46. More lift, wider sweep width. If you claim otherwise, you have stumbled onto the eighth wonder of the world....
The sweep width on the valve tip is also dependent on the valve travel [ lift ]. I mentioned that in post #46. More lift, wider sweep width. If you claim otherwise, you have stumbled onto the eighth wonder of the world....
Mopowers, post #48.
Answer to your question: probably more valve lift is being used [ bigger cam ]. To keep the sweep pattern centered on the v/tip with more valve lift would need to raise the rocker to a higher starting point.
Answer to your question: probably more valve lift is being used [ bigger cam ]. To keep the sweep pattern centered on the v/tip with more valve lift would need to raise the rocker to a higher starting point.
Newbomb Turk
Well-Known Member
You're kidding right?? You think an engine with 1.00 inch of lift has a wide sweep?
Wrong again. The sweep above is too wide. The geometry is wrong. It should be fixed.
Newbomb Turk
Well-Known Member
lol ok. Let’s not forget you’re the clown who thought bigger bore sizes reduced pressure on the piston top.
You had diagrams and articles for that too. Did you forget about that? I didn’t.
Newbomb Turk
Well-Known Member
B3 Racing Engines LLC - Mopar Rocker Arm Geometry Tech
If you care about rocker arm geometry here is a link to what you need to read.
If you care about rocker arm geometry here is a link to what you need to read.
I don't have to look at the B3 website to know how geometry works. The error I pointed out a couple of years back is still there...has not been corrected. I cannot get that websire to work, but from memory, it stated that the rocker ratio never changes. It does. P'rod length can change the ratio, the ratio being valve lift divided by lobe lift. Here is just one example:
Most experts agree that the narrowest sweep on the valve tip is obtained when the rocker tip is centered on the valve tip at mid-valve lift...with the c/line of the rocker at 90* to the valve stem at mid lift. The drawings below are based on that. I have purposely exaggerated the size to make it easier to understand. The rocker tip moves through an arc, based on the radius of the centre of the rocker pivot to the rocker tip. A small rocker like the SBM, swings through a tighter arc & gives a wider sweep pattern on the valve tip [ for the same valve lift ] that a longer rocker would give.
You will see from the NONSENSE of n/bomb Turk in post #54 that he thinks somehow a 1" valve lift can have a narrow sweep pattern. 100% wrong. And he thinks geometry can 'fix' it!! Nope, not when you are ALREADY using the mid-lift method above, which provides the narrowest sweep pattern.
You will see from the NONSENSE of n/bomb Turk in post #54 that he thinks somehow a 1" valve lift can have a narrow sweep pattern. 100% wrong. And he thinks geometry can 'fix' it!! Nope, not when you are ALREADY using the mid-lift method above, which provides the narrowest sweep pattern.
Newbomb Turk
Well-Known Member
Newbomb Turk
Well-Known Member
cookietruck
Well-Known Member
The pivot location would move depending on rocker length.
Seems like simple arc and radius geometry really.
A straight line from points a to b and then measure from that line to the arc, that’s sweep on the valve stem.
That’s how a longer rocker affects the pattern. Moving the pivot location like b3 does is dealing with variables that Bewy mentioned like getting the rocker arm centered or at a right angle at mid lift.
Newbomb Turk
Well-Known Member
I get that. His saying that if you have more lift so naturally the sweep is wider is wrong.
Turk,
You are heading for the World Record of getting it WRONG.
Firstly, nothing to do with DV. See if you can find anything in his writings/books like post #61.
If you cannot understand the simple premise that more valve lift will give a wider sweep, then you should stop building engines & only a fool would buy one from you.
Cookietruck understands my post because that part of it is simple geometry.
You are heading for the World Record of getting it WRONG.
Firstly, nothing to do with DV. See if you can find anything in his writings/books like post #61.
If you cannot understand the simple premise that more valve lift will give a wider sweep, then you should stop building engines & only a fool would buy one from you.
Cookietruck understands my post because that part of it is simple geometry.
Newbomb Turk
Well-Known Member
Ok.
Then post up some actual numbers with Chrysler length rockers and show (meaning show your math) with sweep widths for say .500, .600, .700 and then for fun 1.00 of lift.
Then we will all have the math and we will all know how wide the sweep pattern will be at those lifts.
I have already provided drawings showing the concept. Although I did not provide actual measurements, anybody with half a brain could see the trend when [a] you change rocker length you change in rocker travel [ valve lift ]. It also makes no difference whether the rockers are shaft mounted or stud mounted because both types rotate around a fixed pivot point [ fulcrum ].
Newbomb Turk
Well-Known Member
Then you can't take your drawings and math and give a target sweep width. I mean it's your math and drawing. If there are trends then you should be able to post a reasonable estimate of sweep width verses lift.
Here's what I'll say about this and then I'm done. The OP is at the same lift I am. You need to explain why we both have the same lift but my sweep is less than HALF of his sweep. Show your math. You won't because you can't.
Why I go this far is so people coming along won't get swept up in the bullshit you continually post about this. I let you continue to paint yourself into a corner, and then watch you squirm. If you post a logical explanation with your work I will apologize to you right here on this forum.
That's why I posted the link to the B3 racing engines. Guys can go read the truth for themselves.
.040 is good, but .030 is better
Newbomb Turk
Well-Known Member
Evidently its impossible with .600 lift. That's my point. The OP needs to correct his geometry because the sweep is so wide. But some others say it's impossible with .600 lift to get the sweep down to .040.
It's cRaZy to not try and help someone but **** like this make it about not worth it.
Newbomb Turk
Well-Known Member
AWESOME. Would you mind showing the sweep for 1 inch lift?
Although I’m not sure if rocker lengths, ratios and such.
Cuda416
Well-Known Member
Just an observation, your "roller" is almost .6 in dia, is it supposed to be .3? That will change things a bit.
Newbomb Turk
Well-Known Member
Even if it’s off a bit, your .080 wide sweep is about 100% wider than it should be.
That’s a ton. I hope you read (or have already read) the tech articles on the B3 website I linked above.
Since the mid 1980’s it’s been a fight to get Chrysler guys to stop living with horrible geometry.
Back then, the only fix was to mill the stands and use blocks like W series heads.
Mike has made it easy and affordable to fix these issues.
There is no excuse for guys (not you specifically but people in general) to not fix this.
There is even less for guys who refuse to understand geometry and to post incorrect **** and then defend it to the death.
Cuda416
Well-Known Member
Slow down, your arguing with someone who isn't arguing with you.
I'm just pointing out a potential issue with the drawing. Do you want your point to be based on correct, or incorrect info?
Carry on...
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