Rhoads lifters
Discussion
Having read up a little on Rhoads lifters (after a previous thread here), and being informed that they drop straight in....
Why are we all not running around with Stealth/H404 cams with Rhoads lifters?
Seems like the perfect solution to broad torque bands, with high BHP and improved low-down torque.
Or am I missing something here?
If they are too noisy for general road use, don't there seem to be some quieter ones that do a similar job..?
Genuinely surprised - seems like a low-cost solution to improving power and road manners....
Dom
Why are we all not running around with Stealth/H404 cams with Rhoads lifters?
Seems like the perfect solution to broad torque bands, with high BHP and improved low-down torque.
Or am I missing something here?
If they are too noisy for general road use, don't there seem to be some quieter ones that do a similar job..?
Genuinely surprised - seems like a low-cost solution to improving power and road manners....
Dom
Hi bleed lifters are designed to run with high revving engines. As the name describes they have a larger tolerance which allows them to bleed down quicker and prevents them being pumped up at high revs. This ensures that the pushrod stem / lifter clearance is always maintained.. downside bigger clearance maintained and more valve train noise...The old addage is
"A Happy tappet is a tappy tappet"
if you want power from a wild cam and a quiet valvetrain then you fit a roller cam.
N.
"A Happy tappet is a tappy tappet"
if you want power from a wild cam and a quiet valvetrain then you fit a roller cam.
N.
Edited by heightswitch on Friday 30th May 13:45
blitzracing said:
You are missing the point here- they create a large valve / push rod clearance to reduce the cam lift and duration and that's what makes all the noise, so you cant but quieter ones.
Sorry - perhaps I put too much emphasis on the noise aspect - that was just a side point.As I understand it, Rhoads lifters have 2 benefits - low revs & high revs benefits...
At low revs, they reduce the lift/duration - providing better low rpm manner/torque than if you were using the wild cam with *normal* lifters.
At high revs, they reduce the "pumped up" effect that normal lifters suffer, again increasing again torque & therefore BHP.
So - if they provide improvements at both ends of the rev range, why (in our performance-focussed sports cars) are we not all using wilder cams with Rhoads lifters to get improved torque/bhp curves..?
Wild cam + Rhoads lifters seem to give the best of both worlds..?
Or do I have this wrong..?
domV8 said:
Sorry - perhaps I put too much emphasis on the noise aspect - that was just a side point.
As I understand it, Rhoads lifters have 2 benefits - low revs & high revs benefits...
At low revs, they reduce the lift/duration - providing better low rpm manner/torque than if you were using the wild cam with *normal* lifters.
At high revs, they reduce the "pumped up" effect that normal lifters suffer, again increasing again torque & therefore BHP.
So - if they provide improvements at both ends of the rev range, why (in our performance-focussed sports cars) are we not all using wilder cams with Rhoads lifters to get improved torque/bhp curves..?
Wild cam + Rhoads lifters seem to give the best of both worlds..?
Or do I have this wrong..?
You have it wrong.As I understand it, Rhoads lifters have 2 benefits - low revs & high revs benefits...
At low revs, they reduce the lift/duration - providing better low rpm manner/torque than if you were using the wild cam with *normal* lifters.
At high revs, they reduce the "pumped up" effect that normal lifters suffer, again increasing again torque & therefore BHP.
So - if they provide improvements at both ends of the rev range, why (in our performance-focussed sports cars) are we not all using wilder cams with Rhoads lifters to get improved torque/bhp curves..?
Wild cam + Rhoads lifters seem to give the best of both worlds..?
Or do I have this wrong..?
N.
For ref where this info came from..:
High rpm stuff: What you said...
Low rpm stuff: Rhoads website product description or Rhoads website product homepage
High rpm stuff: What you said...
Low rpm stuff: Rhoads website product description or Rhoads website product homepage
Original Rhoads Variable Duration Lifters became famous for increasing low-end torque, engine vacuum and idle quality on engines equipped with performance hydraulic cams, while maintaining maximum top-end power. Many satisfied customers also reported better fuel economy and improved emissions quality, allowing them to pass emissions testing when they otherwise would have failed. Original Rhoads Lifters reduce lift and duration at idle by approximately .010" to .020". Duration is reduced by approximately 10 to 15 degrees. Total lift and duration are restored at approximately 3500 rpm. Typical vacuum increases range between 1 to 3 inches. They can be used with both adjustable and non-adjustable rocker arms. Since they are not non-collapsible or fully adjustable like the V-Pro design, the V-Pro design is recommended instead of the Original for all street applications with adjustable rocker arms. Their legendary ticking at idle make them sound similar to solid lifters. The Super Lube Groove Option is highly recommended for better lubrication and longer cam and lifter life.
Seems like your assumption is right Dom. I have no experience of them tho.
Seems like your assumption is right Dom. I have no experience of them tho.
carsy said:
Original Rhoads Variable Duration Lifters became famous for increasing low-end torque, engine vacuum and idle quality on engines equipped with performance hydraulic cams, while maintaining maximum top-end power. Many satisfied customers also reported better fuel economy and improved emissions quality, allowing them to pass emissions testing when they otherwise would have failed. Original Rhoads Lifters reduce lift and duration at idle by approximately .010" to .020". Duration is reduced by approximately 10 to 15 degrees. Total lift and duration are restored at approximately 3500 rpm. Typical vacuum increases range between 1 to 3 inches. They can be used with both adjustable and non-adjustable rocker arms. Since they are not non-collapsible or fully adjustable like the V-Pro design, the V-Pro design is recommended instead of the Original for all street applications with adjustable rocker arms. Their legendary ticking at idle make them sound similar to solid lifters. The Super Lube Groove Option is highly recommended for better lubrication and longer cam and lifter life.
Seems like your assumption is right Dom. I have no experience of them tho.
Fit a set and see how you get on.Seems like your assumption is right Dom. I have no experience of them tho.
N.
Here is a quote also taken from the internet but by one of the most well respected engine builders that has ever lived...
NZV8: What do you think of Rhoads lifters?
DV: They’re the variable duration lifters — to get them to work is incredibly difficult. The bottom line is for the most part, if you have a stiff cam that is short to give you the bottom end you will make the top end using these lifters. At the end of the day, if you’re having to use Rhoads lifters and they’re working then you quite probably have the wrong cam.
N.
NZV8: What do you think of Rhoads lifters?
DV: They’re the variable duration lifters — to get them to work is incredibly difficult. The bottom line is for the most part, if you have a stiff cam that is short to give you the bottom end you will make the top end using these lifters. At the end of the day, if you’re having to use Rhoads lifters and they’re working then you quite probably have the wrong cam.
N.
If you want something approaching solid lifters but without the noise and regular adjustment have a look at
Crane Lifters
various options but I have the anti pump up hydraulic ones in my 7k rpm motor
Crane Lifters
various options but I have the anti pump up hydraulic ones in my 7k rpm motor
Its not the high end that interests me, thats what the lairy cam is for.
Its the extra torque at low revs, counter-acting the lack of low-down torque inherent in said lairy cam - giving you a wider torque band than any cam would do on its own with standard lifters...
low down torque = from rhoads lifters
high end torque = from lairy cam
...in theory
Its the extra torque at low revs, counter-acting the lack of low-down torque inherent in said lairy cam - giving you a wider torque band than any cam would do on its own with standard lifters...
low down torque = from rhoads lifters
high end torque = from lairy cam
...in theory
People are running Stealth & H404's on hydraulic lifters are they not? (deffo Stealth)
Any higher end cam that produces a drop in low-down torque could surely benefit from these lifters... (on the assumption there is no problem with using them).
Just thinking if they are around the £100-odd pound mark and they provide more low-end torque - just seems like a no-brainer to me, and surprised they are not used more, if they do what they say on the tin.
Any higher end cam that produces a drop in low-down torque could surely benefit from these lifters... (on the assumption there is no problem with using them).
Just thinking if they are around the £100-odd pound mark and they provide more low-end torque - just seems like a no-brainer to me, and surprised they are not used more, if they do what they say on the tin.
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