I just got another Camaro. It has a 350, Vortec heads, XE274 cam, Edelbrock Performer, Holley 650 DP, and Rhoads lifters.

Are those lifters loud at idle? The noise sounds like a mix of solid lifters and an exhaust tick. It gets louder up until about 3000 RPM, then I can't hear the noise anymore. I don't know if that's because the exhaust is just that loud, or if they quiet down the more they're "pumped up", or whatever you call it.

How do these things work? And what makes them louder (if they really are louder)?

Thanks for any help,
AJ

 

I think you have it right.

I've heard that they will make a little noise until they pump up, but that also gives you a bit more torque under 3000 rpm.

 

Yes they really are louder.

Hydraulic lifters have a little chamber inside them, that normally fills with oil which then is held in place with a check valve, thereby taking up the slack in the valve train. Those, and other similar "fast bleed" lifters, have an orifice that allows the oil to escape, such that at low RPMs, the lifter literally shortens itself over the duration of the valve event, so it closes faster. At low RPMs the oil all comes out soon enough that the plunger bottoms. That's what makes the noise.

I used a few sets in people's motors when they came out 20 years ago, when they believed the hype that went with them about "covering up" too much cam (not enough motor really) at low RPMs, and gave them to me to put in as part of a build. Nobody I knew was satisfied with them, and all of them changed them after not too long.

That cam isn't really too much cam for the rest of that motor, if it's built right. I'd put a set of regular lifters on it if it was mine. I can't stand that racket. I won't even let my solid cammed motors degenerate to the point that they make that much noise.

 

Well if these things are supposed to smooth out the idle, they don't. This car has the most irratic idle I've ever seen. It's not that cool "rump rump rump" idle that we al love. It's more like the Car X commercial sound. I've had 302* solid cams with .510" of lift and 106* LSA that idled better.

As soon as the guy I bought the car from said "And it has Rhoads lifters", he expected me to be happy or something. :lala: He told me right after he said "It has a .480 Comp Cam." I just looked at him and was thinking "why rhoads lifters?"

But hey, whatever.

And yes..... they are annoying as all hell. The worse part is there pushing stamped steel rockers.

So is it OK to drop new lifters on a used cam? Or should I shell out the dough for a new bump stick?

 

So the cam is probably the HE 280 cam, 230°/230° 480"/480". Not a particularly radical cam or anything. Those rubber rockers may be flexing enough that the valve specs are all over the place, that'll sure make a motor run rough.

Who knows what condition the cam is in..... if you knew that the cam was fairly new, low miles and all with proper break-in, you could probably get away with changing just the lifters. But not knowing that, and that cam is not a real good match for those heads anyway, so you might want to just swap it all out.

If the heads have had their valve guides cut down, the XE274 woudl be good; if not, the XE268 is about as far as you want to push it.

 

Well, I went through and adjusted all the lifters.

I pulled all the plugs to make it a little easier to rotate the engine and found another problem.

The guy that had the car put platinum tip spark plugs in.

They were gapped to .055" so I brought them back to .045". I'll be replacing them tomorrow.

Anywho, it idles much better (smoother, yet still rumps) and pulls MUCH stronger now. Last night I took a friend for a ride and the car fell on it's face ~5000 RPM. Now it pulls REAL STRONG all the way to 6000 RPM :rockon:
I'm gonna guess that's more from the plugs than the lifters though.

The annoying tap is still there at idle, but that will change eventually. It's sounds like an exhaust leak and drives me CRAZY!!

Just so you know how bad the guy was to this car...
It's a '72 Camaro. 350/350 w/ 3.42 gears and an Auburn posi. It had no air cleaner, no breathers, the vacuum advance wasn't hooked up, no fuel filter, platinum spark plugs, single throttle return spring, the base timing was set to 20* BTDC, the flex fan was on backwards with no spacer, the battery wasn't fastened down, and he had a 1" spacer under the carb. PLUS it has 16" IROC wheels on it.

I had to buy the car just to save the poor thing from him.

 

Oh yea....

RB, I got my cams confused. It is the XE268.

 

I dunno I like my Rhoads lifters just a slight sound at idle somtimes but not noticable to the untrained ear due to the aluminum valve covers. Hi-tech makes a good quality lifter if your wanting to replace your current ones. They have a nice feature other lifter makers should follow. (its a secret)