Valvetrain Geometry

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I'd love to see 'um. Thanks.
These are the old Comp Cams before Stainless and not Bushed. 1.5 ratio will be used with the 3/8 pushrods(shown)
And Bannana shafts and adjusters/nuts came from Smith Brothers

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The 59 degree lifter angle was a hold-over from the 318 poly block. I guess Chrysler didn't have enough money or time to get it right.
Possibly cause they still produced poly's after LA came out, sharing same angle would probably allow both share same machining operations
 
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If someone is good with the computer maybe they can grab the pictures and post them side by each. And if they are really good maybe they can draw in the centers and check the nominal ratios.

I suck at the computer so I’m out on that.

There was supposed to be a ratio change with the new rockers according to Mike and the guy at PRW whose name I forgot. If EarlyA’s numbers are correct then Im doubting they increased the ratio.

I can’t check anything on my end because I needed a different correction for my new heads so I’m waiting for Mike to bang them out and get them here.

Once they are here I’ll mock my junk up for the millionth time and see what I get. With a .3875 lobe and a 1.6 rocker Im hoping beyond hope to net .580 lift before lash. If I get that I’ll be happy.
Seems like the tip of the PRW is much higher above the centerline of the pivot than the Comp that is pictured below it. Especially if the rocker is rotated so that the adjuster bolt is vertical. That has to have an effect on something? I need to get my set of PRW out anyway to start measuring again for correction. If someone has good Paint skills, I bet it would be more obvious with some reference lines laid on top of the axle axes.

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Seems like the tip of the PRW is much higher above the centerline of the pivot than the Comp that is pictured below it. Especially if the rocker is rotated so that the adjuster bolt is vertical. That has to have an effect on something? I need to get my set of PRW out anyway to start measuring again for correction. If someone has good Paint skills, I bet it would be more obvious with some reference lines laid on top of the axle axes.

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It was obvious to me when i first looked @ the pics, that one is higher. & there was one that seems to look even higher than that, but may be has a different shot angle on it fooling me.
 
There are certainly differences in the shape of the arm and in the angularity of the adjusting screw. It’s a little harder to tell anything about the differences in the location of the contact points which is what would really matter. Does anyone have an old PRW rocker (1.6 ratio) they would be willing to ship to me for comparison testing? I have block and head combo still set up for this purpose. I’ll pay for the shipping both ways and post the results.
 
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There are certainly differences in the shape of the arm and in the angularity of the adjusting screw. It’s a little harder to tell anything about the differences in the location of the contact points which is what would really matter. Does anyone have an old PRW rocker (1.6 ratio) they would be willing to ship to me for comparison testing? I have block and head combo still set up for this purpose. I’ll pay for the shipping both ways and post the results.
I can help with the PRW rocker but you need to clear some space in your inbox or PM me.
 

I’m not sure I understand the reference to 45 degrees. 48 degrees is perfection for the SBM lifter angle. Factory stuff was 59. That’s the comparison I see.

As far as the loss of lift - that can be recovered by designing the rocker arm properly. Move the adjuster toward the rocker shaft and the rocker ratio increases.

What the bad geometry does do is create side loading on lifters, rockers, shafts and pushrods and creates a pushrod motion that ‘see-saws’ instead of traveling back and forth in a nearly straight line. All this wasted motion creates increased friction losses, increased harmonics and other unbalance forces and makes a slightly stronger valve spring necessary. It’s just increased inefficiency.
It was a comparison to the small block Chevy. I should have been more clear.
 
Is the SBC 45 degrees? I though it was 42.

Now I have to go look it up.

Edit: it is 45 degrees. But the 289/302 Dorf is 39 degrees. I thought there was a weird lifter bank angle in there.
That was sorta my question. 48 degrees seems to be the "perfect" angle. Only 3 degrees from 45. 11 degrees from 59. What I was getting at was, I'd rather have 45 than 59. lol Can the stock blocks lifter angle be "corrected" to 48?
 
That was sorta my question. 48 degrees seems to be the "perfect" angle. Only 3 degrees from 45. 11 degrees from 59. What I was getting at was, I'd rather have 45 than 59. lol Can the stock blocks lifter angle be "corrected" to 48?

Nope. There isn’t nearly enough material the to move them that far.
 
That was sorta my question. 48 degrees seems to be the "perfect" angle. Only 3 degrees from 45. 11 degrees from 59. What I was getting at was, I'd rather have 45 than 59. lol Can the stock blocks lifter angle be "corrected" to 48?
Wonder how much it could be corrected with lifter bushings? And how far could you cheat a cam core? 2,3,4 degrees?

Wonder what Bob Glidden was using for cam cores when he welded his own blocks to 48 degrees?
 
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Wonder how much it could be corrected with lifter bushings? And how far could you cheat a cam core? 2,3,4 degrees?

Wonder what Bob Glidden was using for cam cores when he welded his own blocks to 48 degrees?
That's what I was asking essentially. It could only be done with lifter bushings. I think newbomb mightta missed that. Does it or would it really matter about the cam core? Could you "cheat" that much.....or would you be actually correcting something and remove friction from the whole shoot & match? Maybe we should just all run 1st gen Chevy small blocks. lol
 
That's what I was asking essentially. It could only be done with lifter bushings. I think newbomb mightta missed that. Does it or would it really matter about the cam core? Could you "cheat" that much.....or would you be actually correcting something and remove friction from the whole shoot & match? Maybe we should just all run 1st gen Chevy small blocks. lol

I just did a quick 2D cad drawing using some of the basic dimensions and it looks like the lifter bores would have to also be "rotated" toward the centerline of the engine around the cam axis, not just tilted so even reboring the lifter bores to correct the angle would take out all of the material on the inboard side of the bores. There'd be no meat to put a bushing into.

That is assuming the lifter bores are aligned with the cam centerline so I could be wrong.
 
I just did a quick 2D cad drawing using some of the basic dimensions and it looks like the lifter bores would have to also be "rotated" toward the centerline of the engine around the cam axis, not just tilted so even reboring the lifter bores to correct the angle would take out all of the material on the inboard side of the bores. There'd be no meat to put a bushing into.

That is assuming the lifter bores are aligned with the cam centerline so I could be wrong.
Yeah that sounds about right. We're purdy much "stuck" with what we got. What is it? Ten grand for a block with better geometry?
 
Yeah that sounds about right. We're purdy much "stuck" with what we got. What is it? Ten grand for a block with better geometry?
That or a radically designed head/valve train that works with 59. Still probably cost 10k lol
 
I just did a quick 2D cad drawing using some of the basic dimensions and it looks like the lifter bores would have to also be "rotated" toward the centerline of the engine around the cam axis, not just tilted so even reboring the lifter bores to correct the angle would take out all of the material on the inboard side of the bores. There'd be no meat to put a bushing into.

That is assuming the lifter bores are aligned with the cam centerline so I could be wrong.
This is correct. The lifter bores would have to rotate around the centerline of the cam. There is enough meat to rotate some, just wonder how much.
 
Ritter blocks are around $3300-$3500. Of course shipping would add a few hundred to that. Then another $1500ish for machining. So it would be at least $5000. Probably more like $5500.
 
After making a cad drawing like a 2yo using crayons, I'm wondering if anyone has actual 2d drawings of blocks, heads etc they'd share for edumacational purposes. Not asking for the keys to the kingdom so to speak just things that you might have found floating around the internet. I've seen bell housing bolt patterns, hemi heads etc. Anyone here have small block stuff?
 
After making a cad drawing like a 2yo using crayons, I'm wondering if anyone has actual 2d drawings of blocks, heads etc they'd share for edumacational purposes. Not asking for the keys to the kingdom so to speak just things that you might have found floating around the internet. I've seen bell housing bolt patterns, hemi heads etc. Anyone here have small block stuff?
That would be great. Even factory blueprints that could be digitized.
 
We could weld two together and just go with V12's!
I had seriously thought about that. Probably take a lot, and many more stoppers than occurred to me 15 yrs ago.
Need more mains...etc etc etc. Just too much!
And I wondered if they thought about it for the Viper.
 
I had seriously thought about that. Probably take a lot, and many more stoppers than occurred to me 15 yrs ago.
Need more mains...etc etc etc. Just too much!
And I wondered if they thought about it for the Viper.
If the tractor pull crowd can do it, someone around here can figure it out. lol
 
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