Lifter madness
#21
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Joined: Mar 2012
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From: Cape coral, FL
#22
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Joined: Feb 2009
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From: NW Michigan
Your not alone here so don't feel bad anyway. Remember the simple hyd flat tappet days? Simple and inexpensive to boot.
#25
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Joined: Jul 2004
Posts: 11,332
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From: chicago
Its really not the body height that you need to worry about , its the pushrod cup height, and the base circle of the cam, that will dictate whether or not a change in pushrod length will be needed.
#26
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Joined: Oct 2007
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From: yorkville,il
That is the same kit that I use. Eddie Young told me that as long as the top of the lifter doesn't fall below the dogbone on the base circle and as long as it doesn't hit the dogbone at max lift, that they will work fine. I installed a set on my 575SCI 4 years ago and 160 hrs ago and they are working fine. Couldn't ask for them to be more trouble free. Now, the guys at Bullet cams told me that about 400# spring pressure is all that they can handle. Might be accurate, might not be.
#27
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Joined: Jul 2004
Posts: 11,332
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From: chicago
The real question, isnt what will physically work and fit clearance wise. Well, it is first and foremost, but all hydraulic lifters are not created equal, from a performance standpoint. The main reason many guys years ago, went to morel lifters , was because of their rpm ability. Today, guys are running hydraulic rollers in excess of 7000rpm. A gm lifter just isnt gonna get that done. To sustain 7000rpm, you need spring pressure. The stock valving in the GM lifters, will likely start giving up and bleeding down much sooner than say a morel, or johnson. A good real world test, would be to heat the oil to 200 degrees, and then do some back to back pulls with each style of lifter. Theres a good chance, the aftermarket lifter will show power gains. Also, while the GM lifter might do fine on a mild lobe profile, they might really start giving up when the lifter acceleration rates get up there.
The other benefit was going to a larger roller wheel diameter. Just like going to 55mm or 60mm cam cores, .903 or even larger body lifters in aftermarket blocks, all to keep pushing the envelope further on what the valvetrain can accomplish without destruction.
With that being said, you have a mild setup, and the GM lifter should work just fine. There is a reason the high end lifters cost what they do, and the GM lifters cost what they do.
The other benefit was going to a larger roller wheel diameter. Just like going to 55mm or 60mm cam cores, .903 or even larger body lifters in aftermarket blocks, all to keep pushing the envelope further on what the valvetrain can accomplish without destruction.
With that being said, you have a mild setup, and the GM lifter should work just fine. There is a reason the high end lifters cost what they do, and the GM lifters cost what they do.
#28
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Joined: Jun 2006
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Just installed a .610 lift EFI cam in my new 502 block with the stock GM lifters and see no issues with either the bottom or top clearance with dogbones. Stock worked fine with that lift in my last 502 build and it ran to 5900 rpm with no issues.
#29
I talked to Travis @ E Young marine yesterday about one of my lifter plungers being fairly easy to push in, he wasn't much concerned about it with bleed off, so he told to me to prime the engine and see how it looks, we talked about the springs on my heads and said if they have a single blue marking they are the pac springs and replace them, well they are suppose to be almost new and they have no markings, Ive used some isky 8005a springs on some other heads and he said that's what they use as a replacement spring on the 525 head....so I really don't know what spring I have other than the machine shop said they all tested good.




