I read alot about the rhoads type lifters that many brands make but what I dont see listed is how much duration on average do they bleed off at the lower rpms? Ive also read they dont like a hv oil pump, is this correct?

Any input would be helpful. Thanks.

All the noise of an old school loose lash solid......without the power or rpm capability.

Thanks for the positive reply, but that still didnt give me a answer to my question.

From the Rhoads website:

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.

Q. Can a high volume or high-pressure oil pump be used with Rhoads Lifters?
A. Yes. As the bleed off is a function of rpm a high volume/pressure pump can be used without any problem at all.

Q. Is the Rhoads Lifter an anti-pumpup tappet and how many rpm can I turn before they begin to float?
A. Rhoads Lifters are simply the very best anti-pumpup tappet on the market and will rev higher than any other hydraulic lifter you can buy. Revs in excess of 7000 rpm is common, but the total amount will largely depend on camshaft profile and valve spring pressure. Rhoads V-Max Lifters will rev even higher than Original Rhoads Lifters.

The lifter is designed to bleed down. It's simply a designed and controlled leak. So both the oil pump pressure (I.e. more low rpm pressure from high volume pump) and oil weight/viscosity will effect the leak/bleed rate. Higher idle pressure and thicker oil will bleed less.

mark engle told me that in every dyno test they ran with rhoads lifters they lost power.

Thank you for the replies.

I did find a bit on them here. http://speedtalk.com/forum/viewtopic.php?f=1&t=29745

For what im doing is pretty simple and might be semi inline with what they can do without wild expectations.

I used Crane Fast Bleed lifters in a low comp 383 with a 284-484 Purpleshaft and a 3:23 rear gear. They sure made it a lot more fun to drive around town,and was easier than a cam change. I wasn't looking for more power just trying to make up for a poor cam choice. Would I run them as a first choice---no,but they do have their place. I don't the Cranes' make as much noise as Rhodes.

I may not even need them ive more or less a blueprinted low comp 340 (73) and a oem 340 cam is said to be 208@50 and 268 adv. The cam ive got is 226@50 and 284 adv single pattern and ive a converter just a bit above stock 2k with a 4.56 gear. I want it to hit as hard as possible for light to light or 1/8 bracket. I cant walk well so I dont drive much, I just want it to hit semi hard and its not a high rpm deal.

So im thinking run the fast bleed lifter on the intake side.

If it dont do as I think it should I will either change out the intake side lifter or just toss a small solid in it.

The other thing with that style of lifter is....... a lot of the added noise coming from the engine isn’t coming from where you think it is....... or for the reason(most) people think.

When the valve is closing, imagine where the point on the cam lobe the lifter is, when the engine is at low speeds and the lifter is partially collapsed....... and what the profile intensity is at that point, compared to the intensity at the designed closing point.

Yea, I know they are not "parts" friendly with more or less letting things slam shut but its a old easy profile cam and what the heck if it dont work out I will know first hand.

I ought to just run solids on it.

Said differently, how much of the closing ramp is being used with a bled down lift making a hard landing for the valve.

Plus rate of cam and spring pressure might have an impact on bleed down rate.

All this nay saying aside, I have run Rhodes lifters and was happy with them.But I also like all of the racket coming from the valve train.

Here is my recommendation. Zero lifter preload, 10/30 oil, standard volume pump but high pressure spring and use an old school slow rate cam.