Nobody seems to do this, so I’m asking…
On a mild performance build, is there anything wrong with running a stock style non adjustable valvetrain with a mild hydraulic roller cam? As long as the lifter preload falls somewhere in the .025-.040” range, and the rocker to valve tip contact looks good, I don’t see a problem. But I want to make sure I’m not overlooking anything.
Non-adjustable valvetrain w/mild performance cam?
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Re: Non-adjustable valvetrain w/mild performance cam?
What are you referring to a shaft mounted valve train?
A general answer to your question is yes, as long as
1) you can get the push rod length set for decent geometry since the Roller Cam base circle will be lower then stock.
2) the push rod preloads they lifter some when then needed length is set for the best geometry.
3) stud mounted the rockers will need a long enough stud slot for the amount of valve lift.
4) valve spring pressure is enough to deal with the added weight of the greater mass of a roller lifter.
5) the valve spring still has enough room to be out of its coil bind spec.
A general answer to your question is yes, as long as
1) you can get the push rod length set for decent geometry since the Roller Cam base circle will be lower then stock.
2) the push rod preloads they lifter some when then needed length is set for the best geometry.
3) stud mounted the rockers will need a long enough stud slot for the amount of valve lift.
4) valve spring pressure is enough to deal with the added weight of the greater mass of a roller lifter.
5) the valve spring still has enough room to be out of its coil bind spec.
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Re: Non-adjustable valvetrain w/mild performance cam?
Was done all the time back in the day. OEMs had them in their performance catalogs.travis wrote: ↑Sun Jul 25, 2021 7:17 am Nobody seems to do this, so I’m asking…
On a mild performance build, is there anything wrong with running a stock style non adjustable valvetrain with a mild hydraulic roller cam? As long as the lifter preload falls somewhere in the .025-.040” range, and the rocker to valve tip contact looks good, I don’t see a problem. But I want to make sure I’m not overlooking anything.
It's theoretically possible to regrind a profile which takes too much off the heel and get rocker angle cattywhompas, but OP did specify "mild".
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Re: Non-adjustable valvetrain w/mild performance cam?
Will work well and won't come out of adjustment.travis wrote: ↑Sun Jul 25, 2021 7:17 am Nobody seems to do this, so I’m asking…
On a mild performance build, is there anything wrong with running a stock style non adjustable valvetrain with a mild hydraulic roller cam? As long as the lifter preload falls somewhere in the .025-.040” range, and the rocker to valve tip contact looks good, I don’t see a problem. But I want to make sure I’m not overlooking anything.
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Re: Non-adjustable valvetrain w/mild performance cam?
No problem using stock valve train with mild camshafts, except you still have to check that the lifter is preloaded properly, even if the engine has a non adjustable valvetrain. I have seen some of the cheaper mild camshafts, that to get the lift and duration they wanted they reduced the base circle on a stock cam core. So in that case you need a longer push rod. I had several LA mopar engines that If I remember right used a mild Melling camshaft, still got a pile of stock length mopar push rods in my storage pile.