Wietse
Well-Known Member
I think that is going to be the last thing to happen with this B3 geometry kit.
Degree an installed/unknown camshaft
- Thread starter Wietse
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I think that is going to be the last thing to happen with this B3 geometry kit.
Wietse
Well-Known Member
It might be a stupid question, but just to confirm.
The oil feed channels to the rocker shaft are inside the 2 rocker posts between cyl 5 & 7 and cyl 6 & 8 right?
The second last rocker stands at the tranny end of the engine. (both sides)
I see there are these cast channels in the push rod area leading up there.
The B3 kit has two spacers that have additional cavities machined inside to allow the oil to flow inside the rocker shaft and these need to be installed at the oil feed rocker stand.
The oil feed channels to the rocker shaft are inside the 2 rocker posts between cyl 5 & 7 and cyl 6 & 8 right?
The second last rocker stands at the tranny end of the engine. (both sides)
I see there are these cast channels in the push rod area leading up there.
The B3 kit has two spacers that have additional cavities machined inside to allow the oil to flow inside the rocker shaft and these need to be installed at the oil feed rocker stand.
Wietse
Well-Known Member
Thx, i've seen that diagram before.
It doesn't tell the exact rocker stand but i must be on the right one.
Anyone any tips and tricks on measuring push rod length?
I had in mind to use a solid lifter, after i can add/substract the height difference of the solid lifter compared to the hydraulic one i am using and add the lifter pre-load.
Currently the rocker adjustment screw sticks out around 0.300", and it seems i will not be able to reduce it much more due to the position of the oiling hole in the rocker arm. This is positioned quite low so i might require the 0.300" length.
I believe this is prefered to be as short as possible but that is going to be difficult.
It doesn't tell the exact rocker stand but i must be on the right one.
Anyone any tips and tricks on measuring push rod length?
I had in mind to use a solid lifter, after i can add/substract the height difference of the solid lifter compared to the hydraulic one i am using and add the lifter pre-load.
Currently the rocker adjustment screw sticks out around 0.300", and it seems i will not be able to reduce it much more due to the position of the oiling hole in the rocker arm. This is positioned quite low so i might require the 0.300" length.
I believe this is prefered to be as short as possible but that is going to be difficult.
451Mopar
Well-Known Member
Use the actual lifter you plan to run. Adjustable pushrod to set length.
Set the rocker arm adjuster at the recommended highest setting, and measure pushrod length. (long limit)
Set rocker arm adjuster at recommended lowest setting, and re-check pushrod length. (short limit)
if Hydraulic lifter Add the lifter preload.
if Solid lifter Subtract lash.
Pushrod NEEDs to be between the longest and shortest. You could take an average and be pretty safe. If you want to bias the rocker adjuster a bit higher or lower just add/subtract the bias from the average.
By bias, I mean for example on a Hydraulic lifter I add 0.040" preload. If I plan to maybe adjust to run with less preload, I might subtract 0.010" from the average pushrod length. Same with running a solid with tighter lash than specified, just add a bit to average pushrod length.
This should result in the rocker adjuster in the center of its' adjustment range for best pushrod cup oiling. This assumes the rocker to pushrod geometry was designed correctly.
If using offset rockers, do both intake or exhaust.
You could also calculate intake length with offset rocker by calculating the cosign length difference of the exhaust pushrod and the intake rocker offset.
Set the rocker arm adjuster at the recommended highest setting, and measure pushrod length. (long limit)
Set rocker arm adjuster at recommended lowest setting, and re-check pushrod length. (short limit)
if Hydraulic lifter Add the lifter preload.
if Solid lifter Subtract lash.
Pushrod NEEDs to be between the longest and shortest. You could take an average and be pretty safe. If you want to bias the rocker adjuster a bit higher or lower just add/subtract the bias from the average.
By bias, I mean for example on a Hydraulic lifter I add 0.040" preload. If I plan to maybe adjust to run with less preload, I might subtract 0.010" from the average pushrod length. Same with running a solid with tighter lash than specified, just add a bit to average pushrod length.
This should result in the rocker adjuster in the center of its' adjustment range for best pushrod cup oiling. This assumes the rocker to pushrod geometry was designed correctly.
If using offset rockers, do both intake or exhaust.
You could also calculate intake length with offset rocker by calculating the cosign length difference of the exhaust pushrod and the intake rocker offset.
Wietse
Well-Known Member
I have no idea who is the manufacturer of the rocker arms, from hear and say they are likely to be an MP product from several moons ago. (produced for MP by some known brand)
I don't know what would be the min/max adjuster setting.
I found a how-to on Hughes their website where they recommend a "base" setting of 0.300" and check max valve lift; after that you should increase/decrease the push rod length, compensate the adjuster screw and check again for max. valve lift.
Depending in which direction you get more lift, you need to keep playing in that direction until you find the push rod length where you find the highest valve lift.
This should indicate you have found the best geometry possible with that setup.
Makes sense in a way, but i don't know if i am giving up something else by obtaining the highest valve lift possible.
I mean, by getting the max valve lift i might put additional stresses on the rocker arm/adjuster screw and reduce life of these parts, or in a bad case scenario, break a rocker arm.
Here is the article:
http://www.hughesengines.com/Upload/productInstructions/HUG8220.pdf
I will have to do some final adjustments on the rocker arm shims to get them to sit straight above the valve stem and after i will remove the whole lot for another cleaning session before "final" assembly.
After that i will start fingering with the adjustable push rod and see what i get.
I don't know what would be the min/max adjuster setting.
I found a how-to on Hughes their website where they recommend a "base" setting of 0.300" and check max valve lift; after that you should increase/decrease the push rod length, compensate the adjuster screw and check again for max. valve lift.
Depending in which direction you get more lift, you need to keep playing in that direction until you find the push rod length where you find the highest valve lift.
This should indicate you have found the best geometry possible with that setup.
Makes sense in a way, but i don't know if i am giving up something else by obtaining the highest valve lift possible.
I mean, by getting the max valve lift i might put additional stresses on the rocker arm/adjuster screw and reduce life of these parts, or in a bad case scenario, break a rocker arm.
Here is the article:
http://www.hughesengines.com/Upload/productInstructions/HUG8220.pdf
I will have to do some final adjustments on the rocker arm shims to get them to sit straight above the valve stem and after i will remove the whole lot for another cleaning session before "final" assembly.
After that i will start fingering with the adjustable push rod and see what i get.
451Mopar
Well-Known Member
I am not sure about the process of adjusting for maximum lift? I think the maximum lift adjustment would end up with the adjuster straight in-line with the pushrod at max cam lobe lift? I think it really depends how much angle the adjuster part of the rocker has, and your cam lift.
From my setup, I think at max cam lobe lift, the pushrod to adjuster alignment is slightly over-centered so I may not hit maximum valve lift, but have slightly less max valve lift for a longer duration with less pushrod deflection and better pushrod to adjuster angularity when the valve is closed.
Wietse
Well-Known Member
The longer the adjuster sticks out from below the rocker, the more of a radial swing it will make, and therefore the radial swing becomes loss is vertical travel...or lift.
This also increases the side load on the adjuster and puts a lot of stress on it and the rocker arm.
Hughes gives a starting point, and from there increase or decrease to find the point where the vertical travel is best.
For geometry a cup style adjuster is better as this brings the turning point even closer to the rocker, but than oiling becomes a problem unless you have an internal oiling channel in the push rod.
I am not too obsessed with getting max lift, i rather stay in a safe area but it is hard to determine where that is.
Last measurement i found .580"/.582"lift where the cam specs say .572"/.576" so i have gained over the specs of the cam.
Tomorrow i will have another try, set the adjusters 1 thread below the rocker and see what i get from there.
wyrmrider
Well-Known Member
may be that the "runninr out of valve tip" is because the pushrod length is off
You are on the right track
set the pushrod for mid lift and the shortest adjuster that works
You are on the right track
set the pushrod for mid lift and the shortest adjuster that works
Wietse
Well-Known Member
The push rod length will not change anything on the sweep pattern, playing with the rod length and adjuster only changes valve lift.
The sweep pattern is determined by the position of the rocker shaft relative to the valve stem.
But this goes by 2 dimensions, height position of the rocker shaft and the distance of the centerline from the rocker shaft to the centerline of the valve stem.
B3 their kit moves the rocker shaft in both directions to get it at the correct position.
I've seen sweep patterns of other users of his kit and the sweep is as tight as tight can be.
I've checked the sweep pattern and i still found it being wide, around 0.040"
Before was more than 0.070" so it has improved already but i was expecting and want to see a more narrow pattern.
I've emailed Micheal from B3 racing for some advice on how to proceed, IMO it seems the shims below the rocker shaft need rotate in clockwise direction a bit more to bring the shaft closer to the valve.
In that case the height does not change much (or not at all) but should move the shaft a little closer to the valve which should reduce the sweep pattern.
The sweep pattern is determined by the position of the rocker shaft relative to the valve stem.
But this goes by 2 dimensions, height position of the rocker shaft and the distance of the centerline from the rocker shaft to the centerline of the valve stem.
B3 their kit moves the rocker shaft in both directions to get it at the correct position.
I've seen sweep patterns of other users of his kit and the sweep is as tight as tight can be.
I've checked the sweep pattern and i still found it being wide, around 0.040"
Before was more than 0.070" so it has improved already but i was expecting and want to see a more narrow pattern.
I've emailed Micheal from B3 racing for some advice on how to proceed, IMO it seems the shims below the rocker shaft need rotate in clockwise direction a bit more to bring the shaft closer to the valve.
In that case the height does not change much (or not at all) but should move the shaft a little closer to the valve which should reduce the sweep pattern.
wyrmrider
Well-Known Member
Learn something new all the time
I was thinking the pushrod would change the adjuster distence out which would change things if the adjuster was not in line with the pushrod at half lift
many rockers do not have the adjuster at the correct angle for a mopar which i do know
good support from B3 as usual
I was thinking the pushrod would change the adjuster distence out which would change things if the adjuster was not in line with the pushrod at half lift
many rockers do not have the adjuster at the correct angle for a mopar which i do know
good support from B3 as usual
Wietse
Well-Known Member
After some more fiddling around i got it all in place and was happy with it.
Michael from B3 confirmed that all is good by sending him some pictures.
And yes, Michael is a helpfull person and sells a good product, i can highly recommend his kit to anyone that wants to correct the f*cked up geometry of the stock heads.
Bear in mind, this problem with geometry really kicks off when changing to roller rockers.
The longer the adjuster screw becomes the more of a radial motion it starts to make, this radial motion becomes a loss in efficiency because it should move in a linear motion, there is a sweet spot for it but all recommendations that are about are to keep the adjuster screw as short as possible and use a long as possible push rod.
Also, when going to roller rockers it changes the pivot point, with the OEM rockers the pivot point is where the rocker tip touches the valve stem.
With a roller rocker the pivot point moves to the center of the roller, which in my case is 0.500" diameter so the pivot point is moved upwards 0.250" but the rocker shaft stays in the same position and that needs to be compensated for.
Because the rocker shaft stands are under an angle, not parallel to the valve stem, which causes that when you raise the rocker shaft with a shim you also bring it more towards the valve which is also not helping geometry.
Now you can see in the pictures that the B3 kit raises the rocker shaft but also moves it away from the valve, now the sweep pattern is as good as centered on the valve tip and has a narrow sweep of around 0.035"-0.040". (Coming from +0.070")
You can also see the angle of the push rod and adjuster screw in valve closed and full open position, it is not under an insane angle in either position.
But as mentioned before, the best you can do there is go for a long as possible push rod and keep the adjuster as short as possible.
Michael from B3 confirmed that all is good by sending him some pictures.
And yes, Michael is a helpfull person and sells a good product, i can highly recommend his kit to anyone that wants to correct the f*cked up geometry of the stock heads.
Bear in mind, this problem with geometry really kicks off when changing to roller rockers.
The longer the adjuster screw becomes the more of a radial motion it starts to make, this radial motion becomes a loss in efficiency because it should move in a linear motion, there is a sweet spot for it but all recommendations that are about are to keep the adjuster screw as short as possible and use a long as possible push rod.
Also, when going to roller rockers it changes the pivot point, with the OEM rockers the pivot point is where the rocker tip touches the valve stem.
With a roller rocker the pivot point moves to the center of the roller, which in my case is 0.500" diameter so the pivot point is moved upwards 0.250" but the rocker shaft stays in the same position and that needs to be compensated for.
Because the rocker shaft stands are under an angle, not parallel to the valve stem, which causes that when you raise the rocker shaft with a shim you also bring it more towards the valve which is also not helping geometry.
Now you can see in the pictures that the B3 kit raises the rocker shaft but also moves it away from the valve, now the sweep pattern is as good as centered on the valve tip and has a narrow sweep of around 0.035"-0.040". (Coming from +0.070")
You can also see the angle of the push rod and adjuster screw in valve closed and full open position, it is not under an insane angle in either position.
But as mentioned before, the best you can do there is go for a long as possible push rod and keep the adjuster as short as possible.
451Mopar
Well-Known Member
I never checked the stock rocker geometry to see if it is off or bad. But the stock cam was only around 0.450" lift, and the stamped non-adjustable rockers likely are quite a bit different than an aftermarket adjustable rocker. I just think saying the stock geometry is f* up is an overstatement, it just is not correct for your application.
Not sure how raising the rocker helps geometry when using a higher lift cam. I thought the rocker is supposed to be perpendicular to the valve at mid lift?
Not sure how raising the rocker helps geometry when using a higher lift cam. I thought the rocker is supposed to be perpendicular to the valve at mid lift?
Wietse
Well-Known Member
That is very true, stock setup will be very close if not correct.
What i wanted to say is, the f*cked up situation begins when changing to roller rocker arms.
Then a correction must be done.
It's not really because the higher lift that makes the rocker shaft to be raised, it is required when using a roller rocker arm just by itself. As the pivot point moves upwards because of the roller tip, the rocker shaft needs to come along with it.
Then the total lift comes in to play; this point is taken from the height of the valve stem relative to the rocker shaft centerline, then half of the lift is included to see if you need to adjust the rocker shaft more in higher/lower direction to meet that half lift point to be exactly in the centerline of the rocker shaft.
And, as i mentioned, when just raising the rocker shaft with normal shims, you also bring it closer to the valve which is not good.
Therefore you need to move it also away from the valve when raising it, like an eccentric movement.
Ceedawg
Well-Known Member
I’m certainly not going to read thru all these posts so I’ll say one thing about tdc. There’s not any more accurate way of checking tdc than bringing the piston up to a stop then reversing the other way to the same stop. A dial indicator on top of a rocking piston is close at best, also there is a dead spot at the top of the stroke where the crank can turn a slight amount with no change in reading plus there’s the bearing clearance to deal with, usually.003 of play. The stop way...no bearing clearance, no rock, no movements.
Wietse
Well-Known Member
Very true about getting the TDC position right.
But that task was done a few pages back, i am already finalizing valve train components
But that task was done a few pages back, i am already finalizing valve train components
Ceedawg
Well-Known Member
Great If I find the time I’ll read all of themVery true about getting the TDC position right.
But that task was done a few pages back, i am already finalizing valve train components
wyrmrider
Well-Known Member
451
it's the addition of the .250 radius of the roller that's the problem
you want the center of the rocker fulcrum/ shaft and the roller to be perpendicular at half lift which is why you have to raise the fulcrum, otherwise you start with the rocker tilted up and you can see what happens at half lift and full lift
also the acceleration is greater toward full lift when the cam is trying to slow down the valve going over the nose so you have to use stronger springs and can float the valve easier
it's the addition of the .250 radius of the roller that's the problem
you want the center of the rocker fulcrum/ shaft and the roller to be perpendicular at half lift which is why you have to raise the fulcrum, otherwise you start with the rocker tilted up and you can see what happens at half lift and full lift
also the acceleration is greater toward full lift when the cam is trying to slow down the valve going over the nose so you have to use stronger springs and can float the valve easier
Wietse
Well-Known Member
That's what i wanted to say, just lacking the right words in english....i need half a page to write that
Wietse
Well-Known Member
Guys,
Anyone a recommendation on what pre-load i should run?
I asked the same in a separate topic but i think most do not dare to advise...
https://www.forbbodiesonly.com/moparforum/threads/choosing-pushrods-for-my-440.183896/
At first i was under the impression that running 0.020" would suffice, but after reading up on various sources (websites) i seem to find that most recommend an average pre-load of 0.040" - 0.060".
And i think that would work out well by going with a 9,400" push rod, and adding 0.050" for pre-load gets me a 9,450" total. (effective length will be 9.300")
As mentioned before, Hughes recommends a pre-load of 0.080" - 0.090" when using their camshaft and valve train components.
I do not know what lifters i have and cannot really follow these (quite high) settings so going half for a start should not give me any trouble.
Anyone a recommendation on what pre-load i should run?
I asked the same in a separate topic but i think most do not dare to advise...
https://www.forbbodiesonly.com/moparforum/threads/choosing-pushrods-for-my-440.183896/
At first i was under the impression that running 0.020" would suffice, but after reading up on various sources (websites) i seem to find that most recommend an average pre-load of 0.040" - 0.060".
And i think that would work out well by going with a 9,400" push rod, and adding 0.050" for pre-load gets me a 9,450" total. (effective length will be 9.300")
As mentioned before, Hughes recommends a pre-load of 0.080" - 0.090" when using their camshaft and valve train components.
I do not know what lifters i have and cannot really follow these (quite high) settings so going half for a start should not give me any trouble.
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