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Flat Tappet vs Roller Specs

General engine tech -- Drag Racing to Circle Track

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frnkeore
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Re: Flat Tappet vs Roller Specs

Post by frnkeore »

CamKing wrote: Thu Jan 14, 2021 10:34 am For those that want to understand the math, here's what we use.
Lifter face Radius, minus .012"(safety margin), multiplied by .0174524064373(sin of 1 degree) = Max lifter velocity per degree.
High School Trigonometry. :lol:
Is it possible to use as little as a .008 safety margin? I have that written in my notes but, no source for it.
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CamKing
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Re: Flat Tappet vs Roller Specs

Post by CamKing »

frnkeore wrote: Thu Jan 14, 2021 1:05 pm
CamKing wrote: Thu Jan 14, 2021 10:34 am For those that want to understand the math, here's what we use.
Lifter face Radius, minus .012"(safety margin), multiplied by .0174524064373(sin of 1 degree) = Max lifter velocity per degree.
High School Trigonometry. :lol:
Is it possible to use as little as a .008 safety margin? I have that written in my notes but, no source for it.
Yes, on the racing profiles, we use .008", but the lifter bores need to be true'd
Mike Jones
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Re: Flat Tappet vs Roller Specs

Post by CamKing »

David Redszus wrote: Thu Jan 14, 2021 12:15 pm Depending on the specific lobe design, maximum lift typically occurs at about 72 CS degs
after the end of the ramp.
With our more aggressive EMV series flat tappet designs, we hit max velocity, around 50 crank degrees from the end of the lash ramp.
The quicker it gets to max velocity, the longer it can stay at max velocity, before it need to slow down towards max lift.
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Re: Flat Tappet vs Roller Specs

Post by David Redszus »

CamKing wrote: Thu Jan 14, 2021 2:07 pm
David Redszus wrote: Thu Jan 14, 2021 12:15 pm Depending on the specific lobe design, maximum lift typically occurs at about 72 CS degs
after the end of the ramp.
With our more aggressive EMV series flat tappet designs, we hit max velocity, around 50 crank degrees from the end of the lash ramp.
The quicker it gets to max velocity, the longer it can stay at max velocity, before it need to slow down towards max lift.
Mike,
May I ask, what is the cam lift and duration (after ramp) for the cam lobe shape you mentioned?
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Re: Flat Tappet vs Roller Specs

Post by CamKing »

David Redszus wrote: Thu Jan 14, 2021 2:49 pm May I ask, what is the cam lift and duration (after ramp) for the cam lobe shape you mentioned?
These are in the seat duration range on 288-304, with Lobe lift in the range of .352"-.377"
.842" diameter lifters
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Re: Flat Tappet vs Roller Specs

Post by Bill Chase »

xxdabroxx wrote: Thu Jan 14, 2021 10:58 am That's why they pay you the big bucks. =D>
When you factor the overhead, equipment purchase costs, and all the time Mike spends talking to knuckle heads like me it's a wonder he makes any money. His prices being what they are. It has to be a labor of love. Probably a decent living. But I bet he isn't getting wealthy off of his labors.

But then again, doing what you love and doing it for yourself vs what you have to do to make a living while making some corporate schmuck nice dividend checks... that has its own rewards.

If Mike charged for all the pro advice he does out so freely.. he probably could have retired 10 years ago hahaha
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Re: Flat Tappet vs Roller Specs

Post by xxdabroxx »

Bill Chase wrote: Thu Jan 14, 2021 4:29 pm
xxdabroxx wrote: Thu Jan 14, 2021 10:58 am That's why they pay you the big bucks. =D>
When you factor the overhead, equipment purchase costs, and all the time Mike spends talking to knuckle heads like me it's a wonder he makes any money. His prices being what they are. It has to be a labor of love. Probably a decent living. But I bet he isn't getting wealthy off of his labors.

But then again, doing what you love and doing it for yourself vs what you have to do to make a living while making some corporate schmuck nice dividend checks... that has its own rewards.

If Mike charged for all the pro advice he does out so freely.. he probably could have retired 10 years ago hahaha
I can’t wait to get my cam from him even though I don’t have the block and rotating assembly back from the machine shop yet. I think his cam prices are pretty reasonable but what I was really after was the selection expertise that I know I don’t have.
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