[Douglas Willinger]

What sort of potential could be achieved with a roller V Max Rhodes lifter setup?

Originally Posted by Cliff R

+3 and we can use some "old" technology to bring modern variable valve timing into the equation by using Rhoads lifters and high ratio rocker arms.

To this day it surprises me that folks building these engines with flat cams don't take advantage of that scenario.

Most of the negative press on Rhoads comes from the associated noise when using them.

If you upgrade to the V-Max variety they added an internal steel shim/spacer to limit plunger travel and designed them as short travel "high performance" lifters. They also fast bleed off rates like standard Rhoads lifters. They are designed to be adjusted with the plungers bottomed out and lashed very precisely much like solid lifters.

Using a feeler gauge between the rocker and valve tip the installer/tuner then has very precise control of the leak down available to each valve. You can also control or limit the bleed-down available and associated noise that goes with it. Set at .030", for example they will make no more noise fully warmed up with the engine heat soaked and oil thinned out as a flat tappet solid cam set pretty close to the same specs. For less noise they could be set at .020" and even tighter if you want pretty much no noise at all. Of course you start to loose the bleed down and variable valve timing feature the closer you get to zero lash.

The end result when using Rhoads lifters/high ratio rocker arms is that you can produce power very similar to a well chosen hydraulic roller cam at much less cost. I did back to back dyno runs to verify this and found that investing $1000 in a HR set up with the same .050" specs as the flat cam being replaced only netted 3hp/4ft lbs torque improvement, and that was on a 468CID engine with 10.48 to 1 compression and 260cfm KRE aluminum "D" port heads........Cliff

[STEELCITYFIREBIRD]

I Don’t believe they make Rhodes Roller Lifters for Pontiacs...that I know of.

[Douglas Willinger]

I know that.

I was asking what would be the potential benefits, and will ask an accompanying question that I have asked at other times- what would it take to bring such a working set up into existence.

Originally Posted by STEELCITYFIREBIRD

I Don’t believe they make Rhodes Roller Lifters for Pontiacs...that I know of.

[dmac]

Originally Posted by Douglas Willinger

I know that.

I was asking what would be the potential benefits, and will ask an accompanying question that I have asked at other times- what would it take to bring such a working set up into existence.

Summit lists these as fitting a pontiac, but probably the corporate Pontiac that is really a chevy-

https://www.summitracing.com/parts/rhl-21488x?rrec=true

Benefits would be less cam wear, no real 'break-in, the ability to use a more aggressive lobe, and the variability factor making a cam that is made to operate at a higher rpm run smoother at lower rpm.

[Douglas Willinger]

Originally Posted by dmac

Summit lists these as fitting a pontiac, but probably the corporate Pontiac that is really a chevy-

https://www.summitracing.com/parts/rhl-21488x?rrec=true

Benefits would be less cam wear, no real 'break-in, the ability to use a more aggressive lobe, and the variability factor making a cam that is made to operate at a higher rpm run smoother at lower rpm.

Any idea about more specific quantitative measurements aka theoretical power curve, and what it is going to require to create such a set up.


What about the start up costs for an entity as Rhoads to create such? What would be the minimum perceived market for starting such a project?

[Steve C.]

They don't even make them for a traditional Chevy V-8 let alone a Pontiac.

.

[Douglas Willinger]

http://rhoadslifters.com/sc2/agora.c...x_Flat_Tappets

They list 2 possible numbers for Chevrolets,:

CHEVY V-8 OE ROLLER 21488X
V-MAX FITS: Chevy, GMC & Truck (Buick, Cadillac, Oldsmobile, Pontiac)
1987-88 - 249 (4.1L) Allante
1994-97 - 265 (4.3L) Hi-Performance
1988-92 - 275 (4.5L)
1991-95 - 300 (4.9L) Vin B Cadillac
1987-03 - 305 (5.0L)
1987-03 - 350 (5.7L)

And this:

CHEVY BIG V-8 OE ROLLER 22798X
V-MAX FITS: Chevy, GMC & Truck (Buick, Cadillac, Oldsmobile, Pontiac)
454 (7.4L), 502 (8.2L)

---

The references to Buick, Cadillac and Pontiac are confusing, especially in conjunction with the 7.4 and 8.2 ltr displacements.

Originally Posted by Steve C.

They don't even make them for a traditional Chevy V-8 let alone a Pontiac.

.

[tom s]

A reg SBC for the most part would work depending on the base circle of the cam core just like all other SBC chevy hyd roller lifters.Tom

[Steve C.]

They told me on the phone these Rhodes hyd roller lifter were not for a "regular" SBC. I'm no Chevy expert but I took that as the 1955 and 2003 type engines.


.

[pmd400]

Took the car out again today. Backed the timing 4 degrees so initial is now 8 and overall is 30. I can’t notice any detonation. Weather was over 90*F.
The last cam still had audible detonation at 28* in the middle of winter, so for sure the longer lobes on a wider lsa has made the engine less octane sensitive.

[krisr]

Hey mate, what distributor are you running and what do the plugs look like? That's surprising it pings with a 12/34 curve with no vacuum advance... It sounds like you're heading in the right direction though with the new camshaft and it's just a matter of dialling it in now.

[pmd400]

Hey,
Running a factory HEI. Plugs look a bit black. Probably running a bit rich. AFR gauge shows under 12:1 at WOT. Going to put in 1 stage cooler spark plug

[krisr]

Yeah I think I run 7's in my e-heads, definitely something to try. What's the AFR look like when it was pinging/rattling? It's just when it's cruising yeah? By the sounds it wasn't too overly lean. It was also hot as hell the last few days. I just had mine out now because I just got the diff back into it after putting 4.3 gears in it, I saw air temps around 39*C so if you have somewhere similar over your way then it wouldn't surprise me if it has a rattle here/there if you've not had much time to dial it in. Another thing you could try is slightly heavier dizzy springs to slow the advance curve down a bit too.

[pmd400]

It was about 34*C when I took it out. Pings at WOT in 3rd gear(manual) only. Cruise is fine. I guess in 1st and 2nd the load isn’t enough for it to ping. It is ok at 30* overall. Plugs are 5 heat rating at the moment. Going to put 6 in. Hopefully it might allow me to put a couple degrees timing back. Then I’ll slow the curve down a bit. Going by magazine articles most 455 with iron heads seem to only need 32-34 total so I should get there

[ta man]

I didn't go back thru all the posts but was TDC confirmed with TDC on the balancer. What rpm does the mechanical advance timing stop? Have you confirmed no advance creep at higher rpms? Have you confirmed the vacuum advance works and fully retracts at WOT?

[pmd400]

Originally Posted by ta man

I didn't go back thru all the posts but was TDC confirmed with TDC on the balancer. What rpm does the mechanical advance timing stop? Have you confirmed no advance creep at higher rpms? Have you confirmed the vacuum advance works and fully retracts at WOT?

TBC mark on the timing cover is in the correct location. Mech advance stops about 3000rpm. Iv added a stop to the advance, it can only add 22*. WOT tests were done with vac advance disconnected

[77 TRASHCAN]

Originally Posted by Steve C.

They told me on the phone these Rhodes hyd roller lifter were not for a "regular" SBC. I'm no Chevy expert but I took that as the 1955 and 2003 type engines.


.

Factory Chevy roller lifters started in 1987 for the most part.

Was helping my brother on his 89 Chevy 1/2 ton, 350. Mind you pickups seem to get newer technology last, his 350 had flat tappets in it, about 250,000 miles to boot, and NO flat lobes..

.(we were changing the intake gaskets and a broken fitting in the intake...). The roller lifters that GM started using in 87 were unique, not interchangeable into an older engine (or at least easily...), required alignment bracketry in the lifter valley to keep the lifters form spinning.

[Steve C.]

"The roller lifters that GM started using in 87 were unique, not interchangeable into an older engine (or at least easily...), required alignment bracketry in the lifter valley to keep the lifters form spinning."

Thanks. I wasn't sure on the dates but that's what I was alluding to. And what Rhodes was indicating, if I understood them correctly.


.

[steve25]

The fact is that other then in a true race solid Roller set up a solid lifter lobe can kick the valve open faster and that's just what a 455 and bigger stroke motors want with there very early big demand for air .

[Cliff R]

The 1987 and later blocks were machined for "hardware" to use roller camshafts in them even though they still used flat camshafts in many applications. This machining includes flat areas at the top of the lifter bores for the lifter guides to keep the roller lifters from turning and drilled holes to bolt down the lifter retainer that holds the guides in place. The lifters are machined to accept the guides to keep them from turning. It's a very simple and effective system and eliminates the needs for a bar between the lifter pairs.

This hardware will include what is shown below plus the front of the block is also machined for a thrust plate to retain the camshaft in the block:

https://www.jegs.com/i/Comp-Cams/249...CABEgIrRvD_BwE

Earlier blocks require vertical bar style or "retro-fit" lifters to be used plus on an SBC build a cam "button" is required to keep the cam from walking forward in the block.......Cliff