Cam follower issue

[Henson]

Why is this doing this?

My #4 exhaust follower has jumped off for the second time. The first time it happened was during one of my test secession by my house. I fixed it immediately, ignored the Cam scratches and ran it a Mid-Ohio last fall. The second time was when I was exiting the Key Hole at that Mid-Ohio event. It seems to do it about 6000~6200 rpm. I need your help I’m running out of ideas. The Hyd lifters are fine this time. The first time I had a bad #3 exhaust lifter and thought this some how this caused the #4 to jump.

I have a currently one of those AMS Performance cams that I bought a while back. I lost the grind profile. But I measured the Base circle and got 1.187” approximately. I’m running the stock valve height I think. The valves come from Esslinger (big valve). I may be able to find the receipt.

Somewhere I read that some people shim the lifters. Some do this with dimes? I have no shims at all.

How can I fix this?

I plan to buy an Engle TCS-65HYD.
It’s the only one that I see that has 114° separation.

Oh, this is 2.5l and so far a T3.

Thanks

Henson

[svono50]

Sounds like either you are floating the valves (i.e.- improper springs) or maybe the lifters are pumping down and allowing the follower to jump. I can't say what the "right" spring rate is, so someone else will have to chime in there. You could call and pester Martin @ AMS to find out his recommended springs for his cam.

I would check your 'collapsed tappet gap' and adjust with shims under the lifters. This is what I had to do with all 3 aftermarket cams (Engle 55, 111 & SVO A237). I used a used/old lifter and gutted it for mimicking the collapsed height. So far, no jumped lifters.

BTW, check and see if Engle still offers the TCS-111 cam. That was my previous cam and it worked really well. I had my quickest ET & MPH with my previous combination. Just my $0.02.

[Henson]

Thanks. I have Esslingers High tension springs (the duel ones). What did you adjust your lifters to? 0.050”?

[SVOeric]

I think you already found the shim thread --
http://www.svoca.com/forum/showthread.php?t=9653
collapse a lifter, and check the distance between the cam, and the roller with a feeler gauge. it should be in the 0.040-0.050 range.
If it's not, you need to shim the lifter, or trim some if it's too little.

To collapse a lifter that is used, you will probably have to take it apart, which is not a big deal.

[Pat_in_L.A.]

I lost the grind profile. But I measured the Base circle and got 1.187” approximately.

You may be able to get another copy of the cam card specs from the manufacturer. You should be able to check the installed spring height without tearing the head off. Remove a spring. Then reinstall the retainer and measure the distance from upper to lower spring seats (inner and outer spring) with a snap gauge. Then have a local machine chop check the open and closed spring pressures at the installed height to see if you're within spec. While they're on the spring gauge, check the inner and outer separately for coil bind with a feeler gauge. Some of those spring sets require machining the spring seat on the head ~.050".

[Henson]

Ok Ok, I had an old lifter from the first incident, I popped the top and installed it. The clearance is 0.013”.

Now I’m thinking the duration on this Cam is to short. I think there is too steep of a ramp causing the valve to stay open, creating a slapping motion. There is ware and dents on all of the exhaust lobes on the opening side of the lobe. Add to this the high back pressure. I think that the lifter pumps up taking up this slack making the situation worse at every revolution. Some how it gets so high that the #4 lifter jumps. This is hard for me to believe because of the high tension springs that I have on it. But I can’t think of any thing else that it could be.

This would explain why the engine runs rough at 5200 to 6200 rpm. And it might explain why I blew the top of the #3 lifter cap. Also the beaten up valve tips.

Thoughts.

[THESVOTRUST]

Could Valve stem caps help???

If the stem is not to "mushroomed" Could valve stem caps help??

You would have to check coil bind and what (if any) increase lift would do but it maybe a way to temporaly fix the stems without total disassembly!

Mark

[Henson]

Some of those spring sets require machining the spring seat on the head ~.050".

This was done.

I'm about two shakes away from pullling the head and installing solid lifters.

[Henson]

Alright. I was reading the Esslinger tech section. It said that the lash should be between 0.040 ~ 0.050”. Now what would happen if the lash was 0.013? Hmm

[SVOeric]

the rocker could get into a bind, and pop out,
that's my thought.

[Pat_in_L.A.]

At .013" you are just about .003 from having a solid lifter. What you were theorizing is likely what happened.

Look at this cam as an option. Can be used as HYD or solid:

E2277 Cam 2.3 Turbo 238/228-465/441
Esslinger Cam: Turbo
Intake Lift .489 Dur @ .050: 241 Lash at Cam Cold .010
Exhaust Lift .443 Dur @ .050: 219 Lash at Cam Cold .010

From Joe Morgan:
That's the cam I spec'd for them. It's not rowdy at
all. It idles better than that 237 cam, only it makes
power.

[Henson]

So your in agreement, I pumped it till she popped!

Is the 2277 in the Essy book? I’m not seeing it.
What’s the separation?
Price? Like it maters.
I’m pulling the head. What do you think, cut it for solid?

What besides noise does hydraulic do for you? I open it up before every season anyway. Like noise is an issue in my car.

Things to buy:
1. Big Valve set
2. New Chromemoly followers
3. Lifters (solid/ hyd)
4. Head studs
5. Valve Seals

What am I missing?

[Henson]

I think we all agree that somehow the valve must be staying open and the beefy Essy springs are not the problem. They’re stiff.

What do we know at this time.
1. The lifter is not in the 0.040 ~ 0.050” lash range.
2. All of the exhaust lobes are dented.
3. #3 lifter blew a cap.
4. #4 follower can’t stay on at high rpm. Twice now.
5. Power will choke at higher rpm.

Mike, I’m not worried about the lash as much as the lifter pumping up when the exhaust valve is open at a time it should be closed.

I was talking to a Ford Engineer today about this. He spoke to some test engineers and they evidently have this happen all the time during testing. He said you be surprised about the exhaust back pressure keeping the valve open.

And as Mike mentioned heat and expansion. (I didn’t think of that)

What ever it is, I have the right combination.

[Ernie Orwig]

Cam follower

Henson, the cam is $ 395.00 and are 2 weeks out having them. The 2277 is advertised as a solid roller but it is really a hydraulic roller. Ernie

[Pat_in_L.A.]

I have a currently one of those AMS Performance cams that I bought a while back. I lost the grind profile.

Cam Specs:
Intake Valve Lift: 0.420"
Exhaust Valve Lift: 0.420"
Intake Valve duration @ 0.050": 215
Exhaust Valve duration @ 0.050": 235
Lobe Separation Angle: 116°

-= Cam Material =-
Special cast alloy designated for roller follower type cam use and currently used by TRW, Federal Mogul, and other OEM manufacturers of roller cams