1.6 Rocker Arms for /6
- Thread starter 6pakattack
- Start date
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slantsix.org you can hear plenty of bad stories about dealing with Clifford now. From what I understand, the 'old man' passed away and the descendants aren't running it nearly as well as 'old man' did and alot of their stuff is now made overseas ("Go East, Young Man?").
madmax/6
Well-Known Member
Ras stories are sure to bee comming soon.Guzzi Mark
srixon4406
TURBO TOAD
so I've been following this thread with a ton of interest and I've come to the conclusion that the stock rockers are about the best option for the slant six nation please correct me if I'm wrong
Here is a photo of a slant 6 rocker arm with a piece of spaghetti showing a straight path that could be cut to enable the adjuster screw to be moved about .080" toward the shaft, which would increase the lift ratio somewhat. I did some measuring and that amount seemed to be about right for a 1.6:1 geometry.
Those rockers are heat treated, so it's going to take an aggressive cutter to get the job done. Once they are in 2 pieces, a jig will have to be used to hold them in proper alignment for proper welding.
Someone (probably Aaron???) might have the skills to accomplish this. I would try it, but I KNOW there are guys out there who could do this blindfolded, while ~I~ was thinking about it...
What do you guys think??? Is this do-able?
I can't wait to see how this comes out and would like to see the process of cutting and re welding it.
So are you gonna glue it back together with spaghetti?
805moparkid
Slant and AFX Guy
6pakattack
Well-Known Member
I have read many posts by people whom are far more knowledgeable than I both in racing and mechanical aspects,and I hear what you and they both say !!I guess I just have to find out for myself the hard way !!Damn,that sounds like my life story !! If they don't end up working for me,I do want to give the 1.6 Stockers a try !!:violent1::violent1::violent1::banghead::banghead::banghead:
Me.too. This is not my idea; it's been done (successfully) before...
There's a lot of area for weld; probably at least an inch, on each side.
I think that, that large (approx. 1-inch long on each side) area, when properly welded, should be sufficiently strong not to pull apart or break, during usage.
Now, to build a fixture (or, "jig") to hold the two pieces in proper alignment and position, while they're being welded.
Shouldn't be too hard...
I've heard that Vermicelli works better, with a little garlic...:blob:
srixon4406
TURBO TOAD
does any of the members have a set of altered rockers I'd really like to see just how there changing the ratio a couple pics would be helpful
if I could see just what needs to be done I have the resources to possibly attempt this but I need some more clarification and a better understanding
Aaron
if I could see just what needs to be done I have the resources to possibly attempt this but I need some more clarification and a better understanding
Aaron
805moparkid
Slant and AFX Guy
ok well your altering the lift ratio by changing the fulcrum point... the farther the adjuster gets away from the shaft center line the closer to 1:1 the lobe lift to valve ratio gets...
so by moving the adjuster closer to the shaft you increase the valve lift...
for a jig i would weld a peice of the shaft to a peice of plate... then make a adjustable arm that holds an adjuster... cut it up and install the adjuster into the adjusting side of the rocker... now line up and weld...
6pakattack
Well-Known Member
And it's going to be just that simple ??
Can I just send you mine?
805moparkid
Slant and AFX Guy
as long as the cut is straight and you get the angle right it should be pretty easy...
lol im not ready to pull that off yet but i could mess around with it...
Why am I scared
805moparkid
Slant and AFX Guy
talk about a typo!!!!!!!!!1111:wack:
Unless you're a good enough machinist to take some chunks of heat treated 6061 and whittle out new pieces from scratch, it seems like it would be a whole lot easier, cheaper, and more reliable to just have a cam ground to the specs you want end up with using the stock rockers, and not screw around with modifying them.
I have wondered how practical an idea it would be to redo the rocker shaft stands to accommodate some sort of high ratio V8 rockers and shafts, or if there's even room in the slant head for those kind of shenanigans, although I bet Madmax or Mr. Dutra have or would have gone down that road if it was viable.
I have wondered how practical an idea it would be to redo the rocker shaft stands to accommodate some sort of high ratio V8 rockers and shafts, or if there's even room in the slant head for those kind of shenanigans, although I bet Madmax or Mr. Dutra have or would have gone down that road if it was viable.
srixon4406
TURBO TOAD
this is what I found from a hotrod article I found I've been doing research all day on this matter
it shows that the difference between the ratio is the length of the valve stem side which in my mind is to open the valve to its fullest right or wrong if my thinking is wrong
now if a builder were to mill the head lets say. .080 wouldn't that change the geometry of the valve train making the push rod .080 of a inch longer which would in turn would open that valve that much farther
please correct me if I'm wrong
aaron
it shows that the difference between the ratio is the length of the valve stem side which in my mind is to open the valve to its fullest right or wrong if my thinking is wrong
now if a builder were to mill the head lets say. .080 wouldn't that change the geometry of the valve train making the push rod .080 of a inch longer which would in turn would open that valve that much farther
please correct me if I'm wrong
aaron
Aaron; here's what I learned today, talking (but, mostly, listening) to my close friend, Bobby Roper, who is a (retired) very knowlegable machinist.
He told me some interesting things I hadn't known to consider, To wit:
He said to try and file a groove of any size in the rocker arm. If it was too tough to file, then, it's "heat treated."
I tried to file it... It's definitely heat treated.
He said IF it is (heat treated,) before you can machine it successfully, the heat treatment must be nullified by annealing the rockers. That will make them worthy candidates for the kind of surgery I am thinking might work.
The most expiditious initial machining operation would be to affix the rockers to a "jig" that would hold them in place while a hi-speed, rotary cutter wheel of the RIGHT THICKNESS, slices a thin, straight, line completely through the body of the rocker in the location of the spaghetti in my photo of a while back (yesterday.) See below...
He said it is important to remove as exactly as possible, JUST the amount (.080") of material (thickness,) so that the two "halves" can be pushed together, with no space to fill, by the weld.
He thinks a T.I.G. welder will be optimum for this.
Once a bead has been run down both sides, and the rocker is in one piece, again, it should be a genuine 1.6:1 ratio unit. Or, close to that...
Then, it can be taken BACK to the folks who annealed it, and heat treat it (them, actually... all12,) all over again.
I asked him if I could cut the rockers with a diamond-surfaced cut-off wheel, without annealing them, and he said, sure... but you'll have a lot of trouble getting a satisfactory weld, then, even with a T.I.G. welder. Heat-treated material just won't weld successfully. He thinks it would be "brittle."
So, I asked him if the "cut" could be too large, (thick,) leaving a gap to be filled in with weld, and he said, "No, the pieces need to butt each other accurately, with NO gap, because the welding rod might not match the metalurgy of the parent pieces, exactly, and it would result in a poor weld (weak.)
Damn...
This operation just gets curiouser and curiouser....
I'm going to go, tomorrow, and investigate the $$$$ in all this heat treat removal process, and also the re-heat treatment.
I'm also going to try to find out the Rockwell hardness of these things, and what kind of material they are made of. He thinks they are probably 4160.
Only after we know all of that, will a decision as to whether it's worth all this song and dance for a little more cam...
Please.... any ideas would be more than welcome!!!
Thanks in advance...
this is what I found from a hotrod article I found I've been doing research all day on this matter
it shows that the difference between the ratio is the length of the valve stem side which in my mind is to open the valve to its fullest right or wrong if my thinking is wrong
now if a builder were to mill the head lets say. .080 wouldn't that change the geometry of the valve train making the push rod .080 of a inch longer which would in turn would open that valve that much farther
please correct me if I'm wrong
aaron
To change (increase) the ratio you need to either move the pushrod pocket closer to pivot point (center of the rocker shaft in this case) or lengthen the distance from the pivot to center of the valve. A longer arm on the valve side of the rocker would also require you to move the rocker shaft farther from the valve stem to keep the tip of the rocker centered on the valve stem). Pushrod length would change only if a change was needed to keep the new configuation rocker arm (different ratio in this case) sweeping accross the center of the valve stem as it moves up and down following the cam lobe. Hope that makes it a little clearer.
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