What's up everyone, I bring you more good news, I just got off the phone with the folks at Rhoads Lifters and asked about a set of anti pump up lifters for the 2.3 ho and was told that they can modify any hyd flat tappet lifter into one of their high rpm anti pump ups for $160.00.
So now those of you who want to run higher rpm without your lifters pumping up and hanging your valves open then these are for you. Plus with their quick bleed down at low rpms they can tame radical cams and make them more streetable at low & mid rpms and sitll give you full power in the upper range!
They can do it with any lifter, but I would recommend buying a new set and shipping them out to get modified, that's what I'm going to do.
Ship to:
Rhoads Lifters
202 East Main St.
San Manuel, Az 85631
attn: Jack Rhoads
2000 Z24 5spd header & catback for now.
do the stock 2.3 2.4 lifters fail at high rpm? ive never heard of it happening....
I don't think anyone here revs high enough to have them fail.
- 93 mph in the 1/8 mile
Member of J-Body Of Michigan.
... ya i was going to say somthing to that end..... ive taken my LG0 to 7500/8000 with no problems... (that i know of)
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
I will use stiffer valves spring before changing the lifters. Like i said before, 8k and no problem here.
Gilles
2.3 Ho
Not that the stocker fail but the more rpm you turn the hydralic lifters will eventuall pump up and cause the valves to hang open and get to know the pistons on a personal basis.
However the real benefit of these lifters is that at low rpm they bleed down faster than stockers so they can tame a radical cam and give you your bottom end back and at higher rpm they allow full duration and lift. Think variable valve timing here, suppose you have the 252* @ .050 cams in your motor with stock lifters your engine will be a total pig until 4500 - 5000 rpm but with the Rhoads lifters at idle it would cut the duration to lets say 220* @ .050 much more streetable.
That's all I'm trying to share here not saying that there's anything wrong with the factory 2.3 lifters but many times here I've seen you guys recommend against folks using W41 or larger cams because of the loss of vacuum and low to mid rpm tq/hp. These lifters eliminate that and allow you to run a more radical cam and have it be streetable where it otherwise would not.
2000 Z24 5spd header & catback for now.
well that sounds pretty nice since I was considering buying new lifters when I do the secret cam swap. But a couple of questions, so I can use the W41 cams without having to change my pistons if I use these Rhoads lifters? And also MFK-223 are u saying its wise to use stiffer valves springs before changing the lifters?
GMR has got nothing on this
The valve float on the 2.3 happen around 8-8.5k. The way to get rid of it, stiffer springs. Even gm used stocker. What Mantapart sell as better lifter has been discussed before.
Stock lifters are good enough for what people here do.
I'd rather spend the 300$+ you are going to spend for new lifters and modification on springs and retainer.
Gilles
2.3 Ho
Just a little history lesson for people who weren't into cars before the 90's...
Rhoads Lifters were a fairly famous product in the 60s, 70's, and even the 80's.
They were a "magic" cure for low end power with extremely high rpm cams and/or improved drivability in the same situation.
Their design change to a standard hydralic lifter reduced lift and duration at lower RPMs. It was an actual, although somewhat crude, variable cam timing system that was purely mechanical and not adjustable. The only noticable drawback was lifter clatter at low rpms.
Now what was this major design improvement that they had created that allowed this magic to happen????
Well for those who have never seen a hydraulic lifter taken apart, there are several pieces: an out body that contacts the cam and fits the lifter bore, a one way check valve that allows oil to enter the lifter easily but not exit easily, and a spring loaded piston. Oil enters the lifter and is kept in by the valve. The pressurized oil pushes the piston out to take up clearance space between the lifter and the rest of the valvetrain. oil remains in the piston bleeding out only extremely slowy by seeping past the piston and out of the lifter.
Rhoads magic mod is that they simply cut a groove in the piston to let the oil out quickly. Then at low RPM when the oil pressure is low, the lifter collapses and creates a gap between the lifter and the valvetrain. And that causes them to click like any bad lifter would.
High RPM pump up of hydraulic lifters is caused by 2 issues: 1- High oil pressure at high rpm overcomes valvespring tension and keeps the valves from closing completely, and 2- lifter speed exceeds valve speed during closing and the oil pumps up the lifter more than necessary to close the extra gap but since the gap really isn't there, when the cam is at zero lift, the valve stays open.
The Rhoads groove can help bleed down the lifter to cover for both those issues, but I have never seen any J motor experience those issues ever. So why would it be necessary?
BTW, most professional engine builders think the Rhoads idea is a poor fix to an issue and would never ever use them in an engine. The overly loose lash that clatters at low RPM can actually wear out valvetrain components by hammering them to death.
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All very good points Protomec and in most instances with the cams most here run the mod to the lifters would be an unnecessary expense but I've read many times here about folks with something bigger than secret cams stating that " the car doesn't pull until 4500 rpm with the HG2 cams" or don't run the W41 cams because you won't have any brakes at low speed ( due to low vacuum from the larger cams) and in these instances for these people it might be beneficial. I was just sharing information and I get beatup for it, sheesh you guys are a tough crowd lol!
2000 Z24 5spd header & catback for now.
Dale Young wrote:All very good points Protomec and in most instances with the cams most here run the mod to the lifters would be an unnecessary expense but I've read many times here about folks with something bigger than secret cams stating that "the car doesn't pull until 4500 rpm with the HG2 cams" or don't run the W41 cams because you won't have any brakes at low speed ( due to low vacuum from the larger cams) and in these instances for these people it might be beneficial. I was just sharing information and I get beatup for it, sheesh you guys are a tough crowd lol!
From someone thats running W41 cams, you can tune to get some low end power back. Failing that you can degree them differently. As for no brakes, totaly false.
13.934 @ 97.82
ALL MOTOR
The ONLY one I know who had problem was Chris (Taetsch). He had big cams but the main problem was the tune.
FYI, the W41 program idle the car at 2500rpm ANYTIME you are over 5mph. So you have brakes. I have brake with the .430 224 cams. (HG2). The HG2 will kick around 5k but what's the problem with that? I find it perfect for drag racing. At least when you take off, it's alot easier. You ahve time to get good traction before the cams kick. When you shift, you never go lower than 4500rpm (on the stock Ho program).
I have -10in hg at idle and still have brake.
Btw, the cams available for the 2.3 were mostly racing cams. They were not design for city driving (even tough they are perfect for the city). The idle of the race cars were most likely higher than 975rpm the stock W41 program has.
Gilles
2.3 Ho
Dale Young wrote:I was just sharing information and I get beatup for it, sheesh you guys are a tough crowd lol!
I was not trying to beat up anyone. I was just giving some background information.
The simple truth is that the tone of the post would lead people to believe many false ideas.
The perceived idea: many people have vacuum (brake booster) issues running anything hotter than LO size cams on a 2.4.
The truth: You can probably count the number of people who have actually run hotter than LO cams and have posted on this site on your fingers (clarify--- less than 10 people). None that I know of had any low rpm power issues or lack of vacuum issues unless they had something else wrong with the car.
The perceived idea: People running HO or hotter cams have no power till 4k+ rpm.
The truth: all of the cars I have built have had more low end torque with HO cams than with stock cams. When I installed a set of W41 cams "straight up" into a 2.4, the engine made incredible amounts of low end power (260 lb-ft @2000) and absolutely nothing above 5500 rpm. This was due to incorrect cam timing with factory 2.4 parts on the cam. I don't know of anyone else who has put real W41 cams into a 2.4.
The perceived idea: Engine used in J-bodies are prone to "pumping up'' their lifters at high rpm.
The truth: I have never seen any J engine do this... ever. I have never actually seen a J engine even float the valves at any rpm with alll stock valve components... ever also. Also of note, just like the hotter cams swaps, the actual # of people who have rev'ed beyond the stock rev limiter is also extremely low. Probably less than 50.
The perceived idea: Swapping cam makes a 2.4 behave similar to a 2.3.
The truth: All 2.3s no matter what cam is installed or build level lack any real power below 3k rpm. I have never seen a 2,4 act the same.
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