[charlie66]

I have a solid roller cam with a exhaust lobe on #4 cylinder starting to wear on the down side of the ramp. The seat pressure is @ 255 and 600 open . The lobe with the problem has a .556 lift .242 @ 0.050 duration. Is there a way to tell if its a defect or something that is wrong in the setup making a problem?
I tried taking pictures but cant seem to get any real good ones. The wearing area is starting to track a groove the width of the roller as well as having pitting present . The lifters are Crower hipo oilers.. The roller feels perfect. no sticky points or rough areas. To me it seems like it might have been a bad lobe from the start waiting to happen, but wanted to see what others thought first before I called the vender I bought it from... The card says to lash @ .026 which I am always on top of. One thing that seems not good to me is the push rods all seem to be flexing . More on the exhaust then the intake. These are .119 side wall thick.. When I first put the cam in the car #1 intake lobe did the same thing. I sent it back and it was fixed. The fixed lobe is still ok today... This cam shaft is use in a street car with a 1000 miles on it. This motor is also boosted and a 4 cylinder...

Oh... the 2 pictures of the push rods are the intake and exhaust from #4 cylinder...


any opinions would be really appreciated....

Thank you...

[Half-Inch Stud]

Aggressive wear is fear on the lobe upside, so i wonder if the lobe downside can be remedied (in car) with a new roller, and some directed oil drain?.

Hey, thinking out of the box.

Or....have it fixed like Lobe 1 got fixed.

[charlie66]

I would feel better having the company look at it... I cant believe this even happen being I pay attention to my valve train constantly. I even use zinc on every oil change which i change more frequently then most would.... ....

[john marcella]

On a boosted motor your exhaust valve is opening up against a tremendous amount of pressure all that pressure is applied to the exhaust pushrod, making them flex. When they flex they just turned into a second spring. If your push rods are flexing your valve train is pissed off and anything can happen at that point. Vave seats are probably pounded too. BIG pushrods are your friends. Wall thickness is not the big deal diameter is !

[charlie66]

Is there anybody using bigger diameter push rods on e heads and is there a lot involved in getting them to fit? Are you talking something like 3/8? I always thought because of the bulge in the port you would have to stick with the 5/16 rod... Well that explains the exhaust push rod showing more of a wear pattern . I just sent the head off to get 3 sleeves installed, One in the center and one in each outer bolt hole because the heat is collapsing the holes . So ill have the seats checked too. I never realized how much heat goes into these areas. On the outer holes the aluminum is actually cracking and starting to chip off. Some of the cracks are U shaped .

[steve25]

I hope you are also running exh valves made for high temp boosted usage, so if those are the exh valves that came in the head then that's another wild card you are dealing with!

Also are those roller lifters made for low rev street long term street use in regards to oil flow to the Lobe?

[charlie66]

Originally Posted by steve25

I hope you are also running exh valves made for high temp boosted usage, so if those are the exh valves that came in the head then that's another wild card you are dealing with!

Also are those roller lifters made for low rev street long term street use in regards to oil flow to the Lobe?

I did have the head setup for hi boost.

I was told that these lifters are good for what im doing.. I would think if the lifters were the wrong ones ,there would be more then one bad lobe. I've been running them for over a year now...

[charlie66]

Is it real involved to get a 3/8 push rod to work on this head? Can it be done with out grinding through? I don't think epoxy and boost work too good together....

[ponjohn]

JOhn M...what is the weight difference in the prescribed push rods?

[john marcella]

Originally Posted by ponjohn

JOhn M...what is the weight difference in the prescribed push rods?

Weight is not of concern or as much of a concern on that side of the rocker arm. Its the slow side, no were near the acceleration as the valve side. But the answer to your question is....... lots, but like i said , it dont matter!

[john marcella]

Originally Posted by charlie66

Is it real involved to get a 3/8 push rod to work on this head? Can it be done with out grinding through? I don't think epoxy and boost work too good together....

IMO you might be able to get away with 3/8 push rods on the intake side but I would be thinking about 1/2 push rods for the exhaust side. personally I will never have another motor that doesn't have 1/2 push rods or bigger. Your rocker bodies could be flexing all over as well. And if your stud mount , god help you.

[charlie66]

Originally Posted by john marcella

IMO you might be able to get away with 3/8 push rods on the intake side but I would be thinking about 1/2 push rods for the exhaust side. personally I will never have another motor that doesn't have 1/2 push rods or bigger. Your rocker bodies could be flexing all over as well. And if your stud mount , god help you.

Yes it is stud mount. God help me lol. I guess I should look into rocker shaft then ..

So is it a lot of work to get a 1/2 push rod to fit a e head? What's involved to do this?

What's Rodney Butler using for push rods. 1/2? doesn't he run something like 40 or 45 psi?

Thanks for your input John...

[charlie66]

Originally Posted by john marcella

Weight is not of concern or as much of a concern on that side of the rocker arm. Its the slow side, no were near the acceleration as the valve side. But the answer to your question is....... lots, but like i said , it dont matter!

John, Do you think the push rod is why this most likely has happened?

[JSPONT]

Sorry to see this Charlie. At least you have some "big guns" (John) answering and helping you. You can always take the roller out go with a solid with lighter spring pressure. LOL Just think you talked me into a roller!

[john marcella]

Originally Posted by charlie66

John, Do you think the push rod is why this most likely has happened?

Don't know. Probably not, but it could be. I have learned when the valve train is not happy it can cause all kinds of strange problems.

[mgarblik]

Agree with John on all his posts here. We had various harmonic/parts failure issues in our N20 engine before we went to the biggest/best pushrods we could fit in. On the Nitrous car that was 7/16" intake double taper and 1/2" exhaust. On the nitro engine, 1/2" on both. All Manton, max wall thickness, series 5. Yes, they are heavy. As John mentioned, on the lifter side, doesn't matter as much as valve train chaos. Did the push rods cause the lobe issue? can't really say, but big push rods are never bad. That camshaft can likely be fixed.

[charlie66]

Originally Posted by JSPONT

Sorry to see this Charlie. At least you have some "big guns" (John) answering and helping you. You can always take the roller out go with a solid with lighter spring pressure. LOL Just think you talked me into a roller!

Thanks Jeff. I don't think you will have a problem with 10 psi...lol

[charlie66]

Originally Posted by john marcella

Don't know. Probably not, but it could be. I have learned when the valve train is not happy it can cause all kinds of strange problems.

Being all the push rods have the same wear pattern, I would think if they were the cause of the problem that all the lifters would be showing signs of failure...Well thanks for you thoughts on this....

[charlie66]

Originally Posted by mgarblik

Agree with John on all his posts here. We had various harmonic/parts failure issues in our N20 engine before we went to the biggest/best pushrods we could fit in. On the Nitrous car that was 7/16" intake double taper and 1/2" exhaust. On the nitro engine, 1/2" on both. All Manton, max wall thickness, series 5. Yes, they are heavy. As John mentioned, on the lifter side, doesn't matter as much as valve train chaos. Did the push rods cause the lobe issue? can't really say, but big push rods are never bad. That camshaft can likely be fixed.

Where can I get a set of these push rods? Was it a lot of work to get a 1/2 p-rod to fit?

Thanks

[mgarblik]

I am sorry I will not be a help to you on fitment for E-heads with stud mounted rockers. Our E-heads were bought without push rod holes and we had an offset rocker arm shaft system. That made push rod size and placement pretty easy. I am sure others will chime in and help out with your specific stud mounted situation. Even if you end up with 3/8" push rods, use the stiffest ones you can get. Manton Engineering in Lake Elsinore, CA is one of the premier push rod manufacturers in the business. Once you establish the length and maximum diameter you can fit, they can make them and ship in a week or so. Remember, they can make single and tapered ends for you to fit the tight areas. Again, push rods may be a contributor to your problem, but I think there is something additional going on. Best of luck with that cool engine.