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R
RonMacPherson
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Not gonna roller bearing it? Like the domestic builders are doing to all the latest v-8 engines....
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Number 1 cylinder, top dead center
- Thread starter 2wrench
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Brosky
Great Pumpkin
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In order to do so, I would have to have a flat tappet cam ground with a radius on the lobe face that would be compatible with the base of a roller lifter.
It's not for lack of trying Ron, but this one is beyond what I'm willing to spend or risk if the grind fails and I scatter an engine.
With all of the talk of cam issues these days, I just want one to last half as long as my original did. By then, I'll probably be to feeble to drive it anyhow. I could go sit in in it, in the garage and make vroom, vroom noises like I did when I was a kid.
It's not for lack of trying Ron, but this one is beyond what I'm willing to spend or risk if the grind fails and I scatter an engine.
With all of the talk of cam issues these days, I just want one to last half as long as my original did. By then, I'll probably be to feeble to drive it anyhow. I could go sit in in it, in the garage and make vroom, vroom noises like I did when I was a kid.
R
RonMacPherson
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Sorry, I was talking about roller bearing the front, flat face bearing between the lockplate and the cam. Like you see in Jegs catalogues all the time.
To me it would appear to be a lot of extra machining, full circle lock plate, and cutting it for the right clearance between the cam. Just dunno if the effort would be worth the machining cost and time with the cam riding on steel. Now if it had bearings in the block..........?
To me it would appear to be a lot of extra machining, full circle lock plate, and cutting it for the right clearance between the cam. Just dunno if the effort would be worth the machining cost and time with the cam riding on steel. Now if it had bearings in the block..........?
RonMacPherson said:
I have been wondering about that in my spare daydreaming time also. It really would not be difficult to do. It needs hardened races on both the engine block and gear sides. This would not be difficult and spacers so that the cam is in the correct location would also be simple. However, in order to use a roller bearing a "cam bearing" is needed to keep the cam from moving forward. Basically it is a small button which prevents forward motion of the cam under deceleration etc. Otherwise the oil pump gear pulls the cam backwards. This would need a bit of creative engineering and probably require a stronger front cover since the cam gear pushes against the cover. Of course the benefit would be quite minimal for the amount of work required. Incidentally it would not technically require a different cam design.
Ultimately it would be quite possible to build a Triumph engine with roller cam followers, roller bearings on the cam and a bunch of other friction reducing techniques used on modern engines with relatively simple modifications of off the shelf common parts. However, I suspect that it would not be a profitable enterprise.
OP
2wrench
Luke Skywalker
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Parts supplier and machine shop both said: Flat surface
and sand 'er down yerself.
Okay. Working on it. I'll be out of time and out of
town. Teaching Boy Scouts how to tie the ole taught
line hitch and the basics of camping and the like.
So, I'll miss the Forum and it is going to be killing
me not to be able to work on my engine.
Weather is getting warm here and man I wanna drive.
Best to ya'll,
and sand 'er down yerself.
Okay. Working on it. I'll be out of time and out of
town. Teaching Boy Scouts how to tie the ole taught
line hitch and the basics of camping and the like.
So, I'll miss the Forum and it is going to be killing
me not to be able to work on my engine.
Weather is getting warm here and man I wanna drive.
Best to ya'll,
TR3driver
Great Pumpkin - R.I.P
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Torrington bearings can be had with washers that form the hardened races (this is what the Stag uses for the gearbox countershaft).
AFAIK, the "cam button" (between the camshaft & timing cover) is only needed on blocks that have the lifter bores mis-cut, so that one or more of the lifters tries to walk the cam forwards. At least that's what I recall reading in one of the "hot rod" magazines, many years ago. Some engine builder was presenting his conclusion as to why some engines would tear up the inside of the timing cover but most would not. And they weren't particularly reinforcing the cover, just installing the nylon button to touch down first, before the chain did. Not much force involved.
But I don't think you'd ever be able to even measure the resulting improvement, unless you're also converting to a "roller" cam profile with ridiculously high valve accelerations and spring rates. Even then, the improvement would be miniscule IMO; not worth the effort for any scenario I can think of. The folks that get into this sort of thing are racing in classes where these mods are allowed and other mods (like supercharging) are not.
Now, what would really be cool is to implement Variable Valve Timing by moving the camshaft back and forth in the block. Better gas mileage AND better performance !
AFAIK, the "cam button" (between the camshaft & timing cover) is only needed on blocks that have the lifter bores mis-cut, so that one or more of the lifters tries to walk the cam forwards. At least that's what I recall reading in one of the "hot rod" magazines, many years ago. Some engine builder was presenting his conclusion as to why some engines would tear up the inside of the timing cover but most would not. And they weren't particularly reinforcing the cover, just installing the nylon button to touch down first, before the chain did. Not much force involved.
But I don't think you'd ever be able to even measure the resulting improvement, unless you're also converting to a "roller" cam profile with ridiculously high valve accelerations and spring rates. Even then, the improvement would be miniscule IMO; not worth the effort for any scenario I can think of. The folks that get into this sort of thing are racing in classes where these mods are allowed and other mods (like supercharging) are not.
Now, what would really be cool is to implement Variable Valve Timing by moving the camshaft back and forth in the block. Better gas mileage AND better performance !
R
RonMacPherson
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Yeah, but see, you're fulfilling the dreams that a lot of 6 owners have. Rebuilding with modification the 6 motor. So, we're just throwing more ideas at you on top of the great ideas that you've already presented.
Brosky
Great Pumpkin
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Oh.......
Well now that you put it so nicely, I'll consider the options as we go along.
Yesterday's additional expense package included finding that the intake valves that the previous shop said were fine, are really not so fine.
And that two of my new SS exhaust valves were leaking at the seats after only 275 miles.
It never ends......
Well now that you put it so nicely, I'll consider the options as we go along.
Yesterday's additional expense package included finding that the intake valves that the previous shop said were fine, are really not so fine.
And that two of my new SS exhaust valves were leaking at the seats after only 275 miles.
It never ends......
R
RonMacPherson
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Sure am glad you are at a GOOD machine shop now.
Kinda like when we were on the line. Some guys are good, some shouldn't be fixing kids bikes.
Kinda like when we were on the line. Some guys are good, some shouldn't be fixing kids bikes.