rhoads lifters
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Elder User
Joined: Sep 2000
Posts: 936
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From: Bay area
rhoads lifters
seems there is not much information on these lifters on this site.
Who has the low down?
I am in mist of researching and buying parts for my engine that I will start building in about 1 month.
Who has the low down?
I am in mist of researching and buying parts for my engine that I will start building in about 1 month.
Junior User
Joined: Nov 2001
Posts: 57
Likes: 0
From: Renton USA
rhoads lifters
>seems there is not much information on these lifters on this
>site.
>
>Who has the low down?
>
>I am in mist of researching and buying parts for my engine
>that I will start building in about 1 month.
An engine builder told me that they are good if you have a cam that favors the higher rpms. What the Rhoads lifters do for you is have your power curve start alittle lower in the rpm range than what the cam's spec. says. Kind of goes along with the previous answer ( if he ment 200 rpm lower). If the cam power curve is lower in the rpm range, like a mild rv cam, they don't make that much of a differance.
>site.
>
>Who has the low down?
>
>I am in mist of researching and buying parts for my engine
>that I will start building in about 1 month.
An engine builder told me that they are good if you have a cam that favors the higher rpms. What the Rhoads lifters do for you is have your power curve start alittle lower in the rpm range than what the cam's spec. says. Kind of goes along with the previous answer ( if he ment 200 rpm lower). If the cam power curve is lower in the rpm range, like a mild rv cam, they don't make that much of a differance.
Senior User
Joined: Dec 2001
Posts: 356
Likes: 0
From: space city
rhoads lifters
i think GT40man was referring to another aspect of the fast-bleed lifters, and he DID mean "200 rpm higher".
when the cam lobe goes down and the valve is closing at higher rpm's, the lobe is falling fast enough so that there isn't much pressure on the little plunger doohicky inside lifter, AND there is (hopefully!) higher oil pressure...
THEN the plunger in the lifter can become "pumped up", meaning that the lifter has reclaimed the "pre-load", so when the valve is supposed to close, it will actually stay open. the fast-bleed lifters will allow the valve-spring pressure to bleed out the little bit or oil that is holding the plunger up higher than it should be.
from GT40's experience, it looks like there is about a 200 rpm band where the valves aren't actually floated yet, but there isn't enough spring pressure making it back to the lifters to keep them from pumping up.
what i wonder about is why the lifters don't bleed down as the valve is opening, causing a loss of lift & duration.
solid roller cams just keep sounding better & better to me! i just wish the lifters weren't so expensive!!!
when the cam lobe goes down and the valve is closing at higher rpm's, the lobe is falling fast enough so that there isn't much pressure on the little plunger doohicky inside lifter, AND there is (hopefully!) higher oil pressure...
THEN the plunger in the lifter can become "pumped up", meaning that the lifter has reclaimed the "pre-load", so when the valve is supposed to close, it will actually stay open. the fast-bleed lifters will allow the valve-spring pressure to bleed out the little bit or oil that is holding the plunger up higher than it should be.
from GT40's experience, it looks like there is about a 200 rpm band where the valves aren't actually floated yet, but there isn't enough spring pressure making it back to the lifters to keep them from pumping up.
what i wonder about is why the lifters don't bleed down as the valve is opening, causing a loss of lift & duration.
solid roller cams just keep sounding better & better to me! i just wish the lifters weren't so expensive!!!
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