Ok here is the deal 390 with headwork edel 750 10.8 to one and a big bumpstick 224/234 @ .050 with 110 lobe centers..Lumps like crazy , goes like a raped ape from 3500 rpm to 6000, will haze the tires in third gear on a good day...In a 69 highboy..Want to bring in a little bottom end...Ordered some rhodes lifters.. Q1 do they work ? Q2 how noisy are they, I have heard mixed reports.....Thanks

 

Due to the lifters bleeding off oil at low RPMs it will cause the valves to remain dormant for the first few degrees of lifter lift. This in turn lowers the total valve lift and duration. At higher rpms the oil pressure is higher and the lifter does not have time to bleed anything off and will act like a regular lifter. I have heard that they greatly decrease the life of cams and they are noisy. They do however wihtout a doubt work.

 

with 10.8:1 do you really want less duration @.050? it sounds small already if you want to avoid detonation

 

I have a friend who has them in his truck.There louder than a regular hydraulic lifter but not as loud as a solid lifter.

 

Good call man. I missed that. I'm guessing your advertised duration is around 280. I'm thinking you are planning on running race gas?

 

I'm running a 292/292 adv, 230/230@.050, lobe ctrs are 107/111 and around that magic 10.8-11.0 compression (flat top TRW pistons with valve reliefs and some head milling and block decking to square everything).

It's on the hairy edge as far as detonation. The cam is also retarded 4 degrees, trying to get some low-end grunt...

Works well, I have BFG all-terrain 33x12.50r16.5's and it's real hard to get moving without breaking them lose on dry pavement, starting off in 2nd gear (435NP) w/4.10 rear, in a highboy, at 1500RPM.

I got a high initial advance, like 20 degrees to get 11 inches of vacuum at 900RPM. Vacuum advance is connected to manifold vacuum, so it's advancing at idle. To keep from pinging and get some real good low-end grunt, the vacuum advance goes DOWN as I hit the gas, and mechanical advance comes into play. Works quite well...

Rhodes lifters have been around a long time. They make noise, period, but probably not as much as your exhaust! Not sure if they are worth it, or just retard your cam a few degrees. It will affect the absolute high-end of the RPM range though.

By the way, the problem with Rhodes lifters are at high RPM's, they can collapse or so I have been told. All that noise is going to make something break sooner than later. Most of the noise is in the valving inside the lifter though.

 

I Too am running flat tops, heads planed .025 and the block decked .010. I am currently running the cam 9 deg advanced trying to get a little bottom end..I have the inital set at 15 deg and ping is not a problem with 91 octane, but rattles like crazy on 89..I need to run at least 10 deg initial or it gets really hard to start hot, but that is to be expected with only 6 in of vacuum at 900 rpm. When I run the cam with 10 deg less duration on my desk top dyno I pick up 50 lbs of torque at 2500 rpm, but lose it on the top

I was hoping the rhodes would give me the best of both worlds, but I am worrid about the noise, stuff like that can make me insane

Ratsmoker if you are moderating..I did get you e-mail but my reply was not deliverable...lets stick with the fe board...Thanks...

 

Retard or advance? I forget which is which, but I thought it was cam retard got more on low-end? Guys?

I use 93 octane, and it doesn't ping. (Metro NY).

My vacuum advance trick helped get the idle vacuum up. And that, in-and-of-itself, helped the low end a lot.

I'll try to give more detail if you want to know more.

art k.

 

Advancing the cam will give you more bottom end. Retarding it will take it away.

 

Cool, I'll patch it over. You have to manually send me email through the boards. When I send you an email there is no reply address. Its a built in privacy thing in the forum configuration.

 

I had the Rhodes lifters when I built my 410 back in '94. I took them out a few years ago to try and stop pinging when towing. I have a Comp Cams 268 HE and I figured the Rhoads droped the duration too much for a "smaller" cam like this.

With the Rhoads lifters, I had a 15-17 vacuum reading at idle. When I swapped them out for some generic hydraulic lifters, my reading was 13-15. The swap might have helped the pinging a little, but not significant.

Idle was a little smoother with the Rhoads, but I don't miss the noise they made at all. I could hear them under the hood, inside the cab, and even when I was in the house and the truck was idling outside. The only time I didn't hear them was when the truck was first started and cold. They quiet-down a little at highway speeds, but you can still hear them. I was worried that if something started to let go inside the engine, I might not hear it until it was too late. Don't get me wrong, the noise is not loud, it just seems to carry a long ways, and it is not "natural" in my opinion for lack of a better term.

Doesn't Crane make some variable duration lifters that are supposed to be silent or at least not quite as noisy?

I didn't notice any difference in power, but since I have a automatic, it is difficult to judge low-end torque when my new so-called "RV/Towing & Mileage" torque converter stalls way-up at 2000 RPM.