[ID67goat]

Just installed a Melling SPC8 with Hylift Johnson lifters. Fired up immediately and performed break-in. Ran great and no lifter noise etc.

After break-in, pulled the valve covers and found number 7 exhaust pushrod not spinning. Swapped that single lifter with another new one and the same thing. Nothing out of the ordinary found, the lifter moves smoothly within the lifter bore.

I am guessing these parts are done? Order another cam and lifters? Don’t want to go roller on this engine if possible. What would you guys do in this situation?

[nUcLeArEnVoY]

If you replaced the lifter, I'm guessing you had the lifter valley exposed in order to actually visualize the camshaft. Does the corresponding cam lobe look roached? If not, maybe it's just the lifter or something else. Maybe the pushrod is binding on something.

[ID67goat]

Yes, the cam lobe looked fine from what I could see and when on the base circle of the lobe the pushrod spins free. Pushrods are brand new and not bent.

I guess I will have to tear it down again and pull the cam this time for a better inspection to see if that lobe has the proper taper ground into it.

[dataway]

If it wasn't spinning during a 20 min. break-in at 2000 rpm .. my guess is there would be evidence of that on the cam lobe already.

Possible the lifter starts rotating at higher rpms. Ideally they all spin nice and synchronized but my experience is they all seem to like their own speed.

Before I'd tear it back down I'd run it with the valve covers off ( or a windowed set) and see if you can reach in and give that push rod a help to turn. Can be a bit intimidating but it's mostly just a bit warm and messy.

See if tries to keep turning when you give it a twist to start it off. Make sure oil is making to the rocker through the pushrod.

Last cam I did was a Melling SP8 and Hylift-Johnsons ... had one not spinning, trashed the lobe before I spotted it. Got a new Melling cam and went with Melling lifters and had success the second time around.

[steve25]

Did you reuse used push Rods?

[ID67goat]

Originally Posted by steve25

Did you reuse used push Rods?

This was a running engine that had a solid roller in it before. Just trying to tone down this engine to swap it into another car. Put in new heads, cam, and lifters, which required new longer push rods.

I did try to manually turn the pushrod while running, and while I can turn it without much effort, it just stays exactly where I left it…..tried less lifter pre-load, run at higher rpm, etc. Really suspect there is something going on with this 1 lobe….

[mgarblik]

I know this is allot of extra work. But if you really want to nail down the component, take the lifter out of a location that is spinning the pushrod perfectly and put it on the suspect lobe. Now see what it does. If it still won't spin, the problem is the camshaft. If it spins, it probably the lifter. I know all about NOT mixing lifters and such, but this is for diagnostic purposes.

[Jay S]

My guess is there is a problem with the lobe, and your not going to have any luck correcting it. I would look over that lifter bore really good, and if it checks out, I would try another cam. The Melling cams are ground by CMC on a machine that grinds all the lobes at the same time, probably a Landis. They generally are either spot on or junk (most are spot on), but you see a bad lobe every once and a while from a grinding wheel being irregular. Most of the other cam manufacturings use machines that grind the cam one lobe at at time (Berco machine) with the same grinding wheel. If the Berco grinds something wrong it will show up across all the lobes of the cam.

[JB Eng Wis]

Check the Roundness on that lifter hole vs a few others..... I had one, on a ford that would not spin....had to bush the ONE lifter hole.

[KEN CROCIE]

My guess is a worn lifter bore. They don't wear round, they wear oval, as JB suggests. The roller lifter doesn't care because it's linked.

[Dragncar]

Originally Posted by Jay S

My guess is there is a problem with the lobe, and your not going to have any luck correcting it. I would look over that lifter bore really good, and if it checks out, I would try another cam. The Melling cams are ground by CMC on a machine that grinds all the lobes at the same time, probably a Landis. They generally are either spot on or junk (most are spot on), but you see a bad lobe every once and a while from a grinding wheel being irregular. Most of the other cam manufacturings use machines that grind the cam one lobe at at time (Berco machine) with the same grinding wheel. If the Berco grinds something wrong it will show up across all the lobes of the cam.

Thanks for posting that, learned something.
Do you work in the industry ?

[Jay S]

Originally Posted by Dragncar

Thanks for posting that, learned something.
Do you work in the industry ?

It is more from spending thousands of dollars from various cam grinders that has made me squirrel away info like that. It is a difference between OEM and aftermarket cam suppliers.

I think the other guys are correct in saying the lifter bore is more likely the culprit, that bore needs checked before moving forward with another new cam. I probably should have emphasized that first and phrased my comment differently, finding an issue from a cam coming from a Landis machine is going to be very very rare. But if an issue does occur it can be confined to one lobe like that with that type of grinding machine.

I would have thought if it was an issue with a lifter it would have made a groove on the lobe already and taken out the taper. Especially since the second lifter did not fix it and has not ate up that lobe. The lifter bore may need touched up with a hone and made more true if the engine last used a roller cam.

[ID67goat]

Thanks for the feedback so far. I tore it apart again to check everything out.

1. Swapped a spinner with the non-spinner -> Non spinner now rotating fine, known good spinner not rotating anymore. Performed this test just cranking it over with the starter.

2. Check movement of all lifters within their bores -> all feel the same and slide/rotate very easily. Can't feel any excessive play.

3. Using snap gauge, compare multiple working lifter bores to the suspected bad one. I didn't mic the snap gauge to measure true size, but just used as a go/ no-go measurement. -> All feel nearly the same... and all are all not perfectly round and a little larger on the thrust side.

4. Checked all lifter wear patterns -> Most have a nice large round pattern on them, a couple have a smaller round wear pattern, and 2 have horizontal wear pattern...(the original one that that was not spinning at all, and found another that is just barely spinning)


Not sure which direction to go from here....maybe just bite the bullet and put a small roller back in? Was trying to make this as low-buck as possible as the engine is nothing special (557 block with cast 4.25 crank built 20 years ago, but had only around 3000 miles on it). Made 470 RWHP with Edelbrock heads and solid roller. Pulled my good heads / solid cam out of it and threw some Black Friday Speedmaster heads and Melling SPC-8 cam in. Was going to go Roadkill style and swap it into a 1970 Firebird that is currently a 6 cylinder, 3 on the tree car. But maybe it is all just a waste of time....

[tstroud]

Did the non spinner follow the lifter or stay with the hole?

[Formulas]

Did you verify the pushrod is straight able to spin?

[ID67goat]

Originally Posted by tstroud

Did the non spinner follow the lifter or stay with the hole?

Non spinner stayed with the hole.

Originally Posted by Formulas

Did you verify the pushrod is straight able to spin?

Yes, pushrod is confirmed straight and can be easily spun by hand, it is not hanging up on the guid plate or pushrod hole.

Need to pull the cam next to see if it wiped the taper off those 2 lobes I think…

[mgarblik]

IMO, you have isolated the issue to a camshaft lobe or possibly the lifter bore. I have installed single bronze bushings in Pontiac blocks specifically for lifter bore damage. I have not personally experienced a lifter that would not spin specifically from wear. Not saying it could not happen, just unlikely IMO. With the engine in the car and the heads installed, measuring lifter bores for out of round and size is difficult. My lifter dial bore gauge won't fit properly with the heads installed. A snap gauge and MIC could be used but they are difficult to get consistent readings in a partially assembled situation.

Honestly, with the engine in the car, the easiest and least expensive way to proceed would be to slide a new or known good camshaft in the engine and try your test again. No super easy fix on this one unfortunately. Of course a roller cam solves the spinning situation with the lifters but is expensive and opens you up to the myriad of problems with roller lifters, from noise to roller failures, to material issues and such. If it were my car and I did not want to remove the engine, I would try another flat tappet cam. Hope you get it solved.

[Jay S]

470 RWHP was a formidable 557 build with a big crank. I hope it has main studs. The 557 blocks need help clamping the caps down so they don’t start cracks from extra leveraging the dowels. The main bolts don’t have enough clamping force on 557s, they tend to start cracks at the dowels and break out the webbing eventually with big cranks. But for a roadkill build, I guess taking some chances is part of the fun.

Sounds like you eliminated the lifters as the issue. At this point I would pull that cam out and measure the taper on the trouble lobes and compare it with the lobes that spin. If the taper measured the same the issue is still likely with the lifter bore. If there is not much taper, you just found your problem. If it is a lifter bore issue, it may just need touched up with a small hone, just to clean it up a bit. Not removing much metal, more like what shops do after the engine gets bead blasted. I think If you went back with a HFT I would switch to a cam that uses narrower lobes also, SPC-8 used wider lobes than most aftermarket. Which is good, but I think can also be bad, the narrower lobes probably promote the lifter spinning more.

It is not hard to find good used roller cam stuff if you bail on the flat tappet and want to keep on that roadkill budget. But swapping out to a roller kind of stinks on this since you have to change nearly everything in the valve terrain.

[i82much]

i think it is worth a shot to put some marking compound on that pushrod, fire it up one more time, rev it to 3000 rpm or so and make absolutely sure that you really have a problem. you probably do, but still ...

[steve25]

Take advantage of your labor time being free .
Replace the cam and lifters with another hydro cam.

During the reassembly confirm like you just did that all the lifters spin before buttoning things up.

Go thru the extra pain in the ass of breaking in the new cam with your inner springs removed or shimmed up stock used springs so break in goes fine with a minimum of spring pressure.

I have an old set of springs I will ship you if you like.

On a side note you must, 100% MUST break in the new parts with straight weight NON DETERGENT oil like you use in your lawn mower.

A detergent oil once it starts getting kicked around with the engine running will just wash off moly or break in lube.

Lucas engine oil additive I find makes a near unremovable film on metal to use as an assembly lube.

I no longer use Moly or any other type of Cam break in lube.