Purple Shaft lifter issues?

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67charger383

67charger383

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I’ve been trying to buy a solid roller cam for months, everything’s out of stock or on a 6 month back order.

So I was thinking of buying a .590 Purple shaft from Mancini because they are in stock and on sale, but I’ve been hearing of Q/C issues with flat tappet lifters for a while and don’t want to destroy my $5,000+ big block…

So has anyone recently used a purple shaft and done a successful break in? I’m only hesitant because I don’t know if they are recent production or NOS from Mancini.

Mark
 
I put a 484 hyd in my 340 12 years ago. Toasted a lifter after a Lil while. Just went to Napa and got a good stock replacement
 
Make sure your lifters are made in the USA and I’m sure you’ll be fine as long as you break it in properly
 
Put the lifters in a lathe and run a dial indicator across the face to make sure it has .0015-.0022 taper/radius across it.

If they have that, use a good break in oil not some off the shelf oil with an additive. If you are running a double spring pull the inners out. They make a tool to pull the retainers off with the heads on. It’s cheap.

Make sure it fires off without a bunch of cranking. Make sure the carb is full of fuel, use a good, known ignition and make sure you prime the engine before start up.

Get it lit and keep the rpm at 2000-2500 for 20-25 minutes. You can change the rpm while it’s running. It doesn’t have to and shouldn’t stay at one rpm the whole time.

Pull the rockers and add the inner springs. Retorque the heads while your in there, regardless of what gasket you use.

Fire it back off and run another 20 or so minutes with the inners in. Then send it.

If you don’t have a double spring skip that part.
 
I've had two MPP cams wipe a lobe on me. One lasted 15 years, the other went in a year. I will only run roller cams now.
 
67charger383 said:
I don’t really wanna spend $300 on just lifters.

already spent more than that on a set of lunati solid rollers
Click to expand...

My friend builds engines and he won’t use anything but those. He has been buying new old stock cams just for the lifters because they were made in the USA and good quality. Lots of stock lifters are also good as long as they are made here. The stuff from China is garbage, don’t use those lifters, the cams are OK it’s the lifters that are causing problems.

I just had another buddy install a new comp cams kit in his new 440 and the lifters wiped out on the dyno, He used the lifters that came with the cam and they are junk, this was about a month ago. Now he hast to spend way more than $300 to fix his engine...He’s not the only one this has been happening to either.
 
Unfortunately, checking for correct radius only tells half the story. It doesn't tell you the hardness [ as in: too soft ] , which is equally important.
If you want success, find some lifters that are 25 yrs or older. If used, have them re-faced, then good as new; we have been using re-faced lifters in this country for decades because of the high cost of new ones.
 
Used the 590 purple shaft about 15 years ago no problem broke in on brad penn. Chances are the camshafts in stock at manccini in that grind are older maybe not
 
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