Hydraulic roller lifter SB mystery - Help Needed

[wrogers55]

I'm replacing a CompCam cam and hydraulic roller lifters in a SB 418. Previous posts here showed I found what might have been a soft lobe (maybe not too) during an inspection of the motor and Comp replaced the cam but thought it really wasn't necessary and I decided to replace the lifters as well. A little background, the motor was built with all top shelf parts, triple springs on AFR 205s, extreme duration and lift, FI, street use only and was an absolute monster, probably near 575 HP. I bought it in the car with a couple thousand miles on it, so I'm getting to know the internals as I go.

Now, the mystery is there is a huge difference in the internal spring pressure of the original lifters and the new Comp lifters. I mean huge. The old lifters can hardly be budged when you put pressure where the pushrod goes. It will move, but it takes all my weight to make it move a few thousands. The new lifters are actually pretty easy to push down a bit with one hand. The old ones actually feel like they are solid, but I can feel a very slight movement when I put just about all my weight on top of it.

Another interesting thing is the motor was set up with zero valve lash, no preload at all, just flat zero all the way around.

I have it limited to 6,250 and never once had a float or tick issue. Ran great.

So, what' the deal? Is this some kind of "trick" lifter acting like an almost solid roller? This is a new one for me but I have found some interesting stuff in this motor along the way.

I'm also wondering if this is what might have beat the cam up as well.

I really want to just put in the new lifters from Comp, degree the thing up and be on my way.

Any ideas will be greatly appreciated.

Pictures are easy if necessary.

[Gaz64]

Wayne,

You are comparing a lifter full of oil to a new empty lifter, quite normal in comparison.

I would set your hydraulic roller at 1/4 turn past zero lash. The roller skids on the lobe if it comes off the lobe.

I would also consider a rev kit and a slightly lighter valve spring rather than the super heavy valve springs you have.

[mreid]

X2 on the "old oil filled vs. new not oil filled yet" lifter difference. As for your springs, the more aggressive the lift and duration, the more spring pressure you need. roller cams have extreme lobe angles and they are over the top when you up the lift and duration. You need a heavier spring. Go with what the manufacturer recommends.

[blykins]

The lifter's filled with oil...or....someone has probably shimmed the spring internally so that it couldn't pump up, which would jive with the zero preload statement that you made.

As for valve springs, do you have triple springs or double springs with dampers? Some AFR heads are set up for a solid roller and some solid roller springs could be too much for a hydraulic roller lifter/cam.

I normally run about 150-160 lbs seat pressure and 375-385 open pressure for my more aggressive hydraulic rollers. If you need help with selecting a spring, call me, or one of the other venders and we can help you. A cam manufacturer won't know exactly what to give you, since they don't know the exact install height of your current setup.

Normal lifter preload is 1/2-3/4 turn after zero lash. That's where I would stick it...

[DAVID GAGNARD]

The cam card with your new camshaft should have the recommended valve spring pressure........your valve springs need to be checked to see exactly what the installed height spring pressure is....I would have them checked and set your valve spring pressure according to what's recommended for the camshaft.....

David

[wrogers55]

Old stiff and new lifters are empty of all or and cleaning liquid. I even took one each apart to look and learn. The new one comes apart easily and looks normal. The old stiff one was impossible (no real effort) to pull the internal guts out or knock them out by banging it upside down on the bench after removing the pushrod cup. Since it will move slightly, it must have some kind of spring in there but I can't get at it. All I can see is a hollow insert after the "top" is removed. I guess it doesn't matter at this stage since I think the best thing to do is toss them anyway.

So, I'm just going back with the new lifters. Several of the old ones have circular score marks on the rollers, not fingernail deep, just marked up a bit.

The valve springs are listed as "green stripe" shipped by AFR already installed on the 205s, according to AFR, Manley springs No. 221425. One of the triple springs is flat wound, so I suspect it may just be a damper. The springs could have been messed with by the builder. I have no way to measure the pressure and don't want to take it down any farther. It was running great, just a few marks on the rollers and a lobe that was starting to show some minor wear pattern on the nose and coloration. Whole thing might not have been necessary, or maybe I saved an even bigger headache later.

Now to see if I can get it back in and all the stuff pointing in the right direction.

Really appreciate the comments. Great group to help.

[blykins]

I would always be very cautious about following anything on a cam card. The cam card is based on the lobes, not the engine. The same lobes can be used for a SBC or a 460 Ford, and we all know which one has the heaviest valvetrain components....

[blykins]

I'd check spring pressure.....you may not have enough. It's very easy to run to a local engine builder or machine shop and check a spring...it could save you from having to do this again.

[wrogers55]

After a discussion with AFR and looking at serial numbers, here is what was shipped on the heads.

AFR-8022 (Manley Green Stripe Springs)

1.640 OD 320# @ 2.040 870#@ 1.190 Silicon Nextek

This doesn't sound good for a street motor. Man, it ran good though, for over 4,000 miles and never a whimper.

If those numbers turn out to be correct, I suppose I really need to change them for street use only???

Feel like I'm on a roller coaster with this thing. All I really wanted to do was fix a pan leak when I spotted a few little marks on one lobe!

Wayne

[blykins]

If those are indeed the springs you have.....they are WAY too much for a hydraulic roller and is the reason you have worn lobes and worn lifters....that's overkill for most solid roller cams, much less a hydraulic roller.

You need to be about half that on the seat pressure....

You really didn't make it 4000 miles without a whimper....you wore a cam and lifters out.

[wrogers55]

blykins;that's overkill for most solid roller cams, much less a hydraulic roller.

You really didn't make it 4000 miles without a whimper....you wore a cam and lifters out.

OK, you win. I'll call for recommendations and you can get me another pile of parts so I can continue with all this excitement.

Wayne

[blykins]

Do you know who the builder was?

[Jerry Clayton]

from the sound of your writings---are you sure its not a solid roller?

[madmaxx]

Buy cam and springs from blykins, he has history of what works. Return the can you bought unless it is one he has used. Cam is brain of engine in addition to most demanding service. You can really screw up an engine fast with to light or to heavy spring. Normal joe working on engine has little chance of optimium combo coupled with crappy aftermarket parts which come bad from the manufacturer, just buy a package deal from him.

[blykins]

Originally Posted by madmaxx

Buy cam and springs from blykins, he has history of what works. Return the can you bought unless it is one he has used. Cam is brain of engine in addition to most demanding service. You can really screw up an engine fast with to light or to heavy spring. Normal joe working on engine has little chance of optimium combo coupled with crappy aftermarket parts which come bad from the manufacturer, just buy a package deal from him.

We'll get Wayne fixed up. He's going to measure his install height and then I'll shoot him some springs/retainers.

As for the cam, Comp replaced it for free, so I wouldn't pass that up...