Another GT40 valvetrain noise question

[Leukay]

So out of curiosity I switched from the .040" shims to the .020" shims (again, called .060"and .030" but actually measure .040" and .020"). It starts and runs good, and the noise seems to be much less pronounced, but there also seems to be a little more valve train noise, more of the standard clicking noises. The lifter preload was more like 3/4 turn past zero lash, as opposed to the approx 1/2 turn with the thicker shims. I can still spin the pushrods with my fingers with the valve closed. Seemed to run good and had plenty of power.

I've switched back to the thicker shims for now with fear of floating valves etc. I figured the thicker shims were safer until I can really get things figured out. Not sure what this means at this point.

[Walking-Tall]

Interesting... I'm not sure you're getting the actual x-turn lifter preload you think you are if thinner shims (increasing lifter preload) reduced the valve train noise you were hearing. Keep in mind the difference between 16 or 24 threads per inch of the differing rocker arm bolts/studs. I'm not certain which thread pitch those 5/16 (?) bolts are off hand, but it's a fair bit of distance difference per turn.

Clicking or clatter means clearance, or it means lifter plungers contacting snap rings. In your case, push rods don't and shouldn't be contacting the cylinder heads or non-existent guide plates, but only the lifter plungers and the rockers.

I have yet to have to deal with bolt-down rocker arms, and never will if I can help it, but I pulled out (a few were "pulling" out after a few hundred miles as is) circa '72 302 non-adjustable "positive-stop" rocker studs, tapped the head pedestal holes 7/16-NC and added 3/8 screw-in rocker studs, with no guide plates but re-used the "rail" rockers for alignment, but with SBC rocker balls and nuts. That engine (and any other I've touched) got the initial assembly pre-adjustment of 1/4-turn down past the rocker/pushrod slop taken up (very slight drag to pushrod rotation), beginning at TDC (compression stroke) for #1 and setting those rockers, and then rotate the crankshaft 90-degrees for setting each of the cylinder's rocker adjustments following the firing order, eight times in total, followed up after break-in by re-doing 1/4-turn preload on the hot running engine. Never any noise or problem, and the sucker revved beyond 6500rpm for many years and miles.

Thicker shims, reducing lifter preload, does decrease the chance or tendency of valve float (the temporary inability of valves to fully close) depending on whether there was too much preload. When preload is too much the lifter plunger can end up well below where it's supposed to operate within the lifter, as well as it'll have lots more it can travel upward, to cause float.

I think your thinner shims and the much less pronounced noise is a sign... either of slight valve train clearance, or not enough lifter preload (the distance between the plunger in the lifter and the snap ring, when the lifter bottom is on the base circle of the camshaft and the valve is closed). Have you verified the preload of each of the cylinder's lifters/pushrods at the rockers going by the firing order and when each of those cylinders is at TDC of the compression stroke? All of this is moot if not...

[Walking-Tall]

For reference:



So, at #1 TDC of it's compression stroke (whereabouts it's spark plug fires), check/set #1's rockers. Rotate the crankshaft 90-degrees in it's normal running rotation, clockwise, and check/set #3's rockers. Continue rotating the crankshaft another 90-degrees each time and do the same checking/setting with the rest in order, numbers 7-2-6-5-4-8.

... and here's some more info: http://static.summitracing.com/globa...277-16(2)1.pdf

[Supersonic G.T.350]

There is no 1/2-3/4 turn preload adjustment on factory style rockers in these newer engines. Idk where you keep getting this from. They bolt down, torque to 20# and done. The pre-load is non-adjustable from the bolt. The only way you can change lifter preload is by A) changing the pushrod length, B) milling the heads or C) changing the shims. If you have rocker arm noise it's because there's not enough preload on the lifter or you have a bad lifter but the is NO pre-load adjustment based on the bolt, just proper Torque spec.

[Walking-Tall]

There is no 1/2-3/4 turn preload adjustment on factory style rockers in these newer engines. Idk where you keep getting this from. They bolt down, torque to 20# and done. The pre-load is non-adjustable from the bolt. The only way you can change lifter preload is by A) changing the pushrod length, B) milling the heads or C) changing the shims. If you have rocker arm noise it's because there's not enough preload on the lifter or you have a bad lifter but the is NO pre-load adjustment based on the bolt, just proper Torque spec.

There most certainly is preload "adjustment", as you've indicated with your ABC's, but minus your "done" bit. The OP is talking about the amount of rotation his bolts have after (apparently, hopefully) observing zero lash/preload, up until the bolt torque specification. Rocker arm noise is because of clearance, and/or not enough preload so that the lifter's plunger is contacting the snap ring that limits it's travel. You're right, there's no adjustment based solely on the bolts, but again, the OP is referring not to adjustment but observation or measurement of the bolts' amount of rotation equivalent of preload after zero lash is surpassed until the bolts are torqued, with the varying thickness shims he's tried... Eether, either, potato, potawto, he needs to individually check and set (with shimming, or pedestal machining) each of the lifter preloads instead of following any non-existent rule based on head milling or whatnot. Besides conversion to be fully adjustable, that's all that can be done with the idiotic mechanical a$$hole of a system it's been since the '70's.

[Supersonic G.T.350]

There most certainly is preload "adjustment", as you've indicated with your ABC's, but minus your "done" bit. The OP is talking about the amount of rotation his bolts have after (apparently, hopefully) observing zero lash/preload, up until the bolt torque specification. Rocker arm noise is because of clearance, and/or not enough preload so that the lifter's plunger is contacting the snap ring that limits it's travel. You're right, there's no adjustment based solely on the bolts, but again, the OP is referring not to adjustment but observation or measurement of the bolts' amount of rotation equivalent of preload after zero lash is surpassed until the bolts are torqued, with the varying thickness shims he's tried... Eether, either, potato, potawto, he needs to individually check and set (with shimming, or pedestal machining) each of the lifter preloads instead of following any non-existent rule based on head milling or whatnot. Besides conversion to be fully adjustable, that's all that can be done with the idiotic mechanical a$$hole of a system it's been since the '70's.

Well see, now it makes sense, I couldn't gather that from the way he was describing it.

[Leukay]

Is there anything special that needs done to bleed down the lifters? They seem to stay pretty much pumped up. If I want to try the smaller shims, it seems like I'd need them to bleed down so they can adjust to the different shims. Or should they just adjust automatically after the smaller shims are installed and the engine runs?

[Walking-Tall]

Just tightening down the bolts to the torque spec will relocate the lifter plungers that slight bit different amount downward.

[bwguardian]

^^^...like he said. One thing about that though...make sure the lifter is on the base circle and not the lobe of the cam. Those rocker bolts are not that strong and you will likely snap one in doing this...don't ask me how I know this...

[Leukay]

Just tightening down the bolts to the torque spec will relocate the lifter plungers that slight bit different amount downward.

^^^...like he said. One thing about that though...make sure the lifter is on the base circle and not the lobe of the cam. Those rocker bolts are not that strong and you will likely snap one in doing this...don't ask me how I know this...

Thanks guys, that's what I figured was the case. I switched back to the small shims and ran it for a few days, it seemed to run fine and the noise was mostly quieter but it would flare up occasionally at a stop light which still has me worried. I've since pulled the intake back off and have pulled out the lifters for further inspection. It seems they are all pumping up as expected, but some of the rollers have markings as seen in the image below. These markings were there the first time I disassembled everything, but I had no issues before so I assumed it was nothing. Peeking through the lifter bores I can also see that some of the cam lobes look a little marked up as well. Does this look abnormal enough to cause the noise I've been hearing?

Lifter Roller groove (I can feel it with a fingernail) - 4-5 lifters have similar markings, some have multiple grooves


Marked cam lobe through lifter bore


Same lobe viewed from drain hole in valley


Smooth looking cam lobe

[Walking-Tall]

The one thing that's different when at a stop light is the lowest of whatever the engine's oil pressure is. I think I asked above what it's hot running oil pressure is, and if you mentioned it, I missed it...

I don't know how long you've owned this engine, or how many miles are on it or those lifters, but it all can have had variations of being well taken care of or not, like regular oil changes with quality oil, etc. It looks a bit grubby inside, and who knows what (hard enough to cause a groove) debris caused the grooving. Hopefully all such debris is long gone with oil changes, but some fresh and thicker oil in it might not hurt, especially since you notice a bit of the apparent valve train "noise" at stop lights, at idle at lowest oil pressure.

[erratic50]

It it's a manual, turn the idle up. Helps with cooling, keeps the oil pressure up, etc. I have always kept mine at 1000. Then I don't have to step on the gas when I gently release the clutch.

[bwguardian]

What oil filter are you running and what brand was on it when you bought the car?

[Leukay]

The one thing that's different when at a stop light is the lowest of whatever the engine's oil pressure is. I think I asked above what it's hot running oil pressure is, and if you mentioned it, I missed it...

I don't know how long you've owned this engine, or how many miles are on it or those lifters, but it all can have had variations of being well taken care of or not, like regular oil changes with quality oil, etc. It looks a bit grubby inside, and who knows what (hard enough to cause a groove) debris caused the grooving. Hopefully all such debris is long gone with oil changes, but some fresh and thicker oil in it might not hurt, especially since you notice a bit of the apparent valve train "noise" at stop lights, at idle at lowest oil pressure.

I've had the car for about a year, and it barely ran because of carburator issues and a bad oil pan gasket when I got it. I fixed the issues and drove it all summer with no real issues. I just decided to do this head swap this winter while I was doing the 8.8 swap with 3.55s and the suspension rebuild, but at this point I'm just regretting it.

The unfortunate thing was when I pulled the intake for the head swap, the lifter valley was a bit gunky in the corners and edges, and there was old remnants of gasket laying in there... The lifters didn't appear to be cruddy at all though. Knowing that everything ran well last year, I just cleaned everything up, and while I had the pushrods out I removed the lifters and disassembled/cleaned them all. Possibly important note: I reinstalled the lifters in their original holes, and I tried to put them in the same direction as well, but Iwouldn't be shocked if a couple were installed rotated 180 degrees. I'm just wondering if there is slight pitting on the cam lobes from the past and there is a fresh ungrooved section of the roller riding on it there could be some noise there? I'm just taking shots in the dark at this point though.

I haven't had a mechanical oil pressure gauge hooked up to check exactly, but when cold it is up around 3/4, and when at operating temp it is around 1/2, maybe slightly less. This is in line with what I saw last year when it was running seemingly perfectly.

What oil filter are you running and what brand was on it when you bought the car?

I have been running Motorcraft filters since I've gotten the car, I don't recall what was on it before, I know it wasn't one of the orange FRAM filters, as I know to stay away from those. I'm now running a Purolator Boss since they came with some oil I bought in a deal.

It it's a manual, turn the idle up. Helps with cooling, keeps the oil pressure up, etc. I have always kept mine at 1000. Then I don't have to step on the gas when I gently release the clutch.

I have been playing with the idle speed recently, anywhere between 800-1100, and the sound is present at both speeds. I fear that at higher rpms there is just much more noise drowning out that particular noise, so it's hard to tell at that point.

I really appreciate all your guys' help here, I'm at a total loss and I will continue to read each of your comments closely for anything that might help.

Thanks,
Lucas

[bwguardian]

You did two things besides swap the heads that were different from when you started...1.) Cleaned the gunky lifter valley, and 2.) Took apart and cleaned the lifters. If you are certain not much gunk got down one of the drain back holes, I would look at the lifters. The couple that are making the noise should be taken back apart and inspected. However, at this point, I would be looking at installing that TFS cam and new lifters you were talking about earlier...

[erratic50]

FL1A motorcraft or PH8A is the Fram number for the filter size that works best on the SBF.

[bwguardian]

FL1A motorcraft or PH8A is the Fram number for the filter size that works best on the SBF.

Motorcraft FL1A is the only oil filter that should be utilized. Do some research on this site relative to the Fram unit.

[Leukay]

You did two things besides swap the heads that were different from when you started...1.) Cleaned the gunky lifter valley, and 2.) Took apart and cleaned the lifters. If you are certain not much gunk got down one of the drain back holes, I would look at the lifters. The couple that are making the noise should be taken back apart and inspected. However, at this point, I would be looking at installing that TFS cam and new lifters you were talking about earlier...

I'm wondering if maybe the increased valve spring pressure made the lifter rollers a little louder against the cam lobes that are starting to look scoured. Or maybe when I disassembled the lifters I somehow messed them up, although I don't see how I could have.. In either case, it looks like I'll be pulling the cam and installing a TFS Stage 1 cam with new Ford Racing OEM Lifters. Hopefully that will take care of the noise and I'll gain a few horses in the process. Fingers crossed!

[erratic50]

The reason I mentioned the Fram number was not so someone would run one.... the point not to run Fram had already been made. The reason I said it was because for some stupid reason those cheap pieces of crap are a very commonly used filter and therefore that's a good cross reference number.

That being said, I ran nothing but Fram for years -- before I knew better -- and honestly nothing bad happened! But I did change my oil every 2000-3000 miles religiously and I also always ran a quality high detergent conventional oil. (Mobile 10w40)

My motor has been beat hard its entire life and it's stayed together (knock on wood) for over 440K miles which works for me.

My assessment of the topic at hand is that something happened during the disassembly and cleanup and reassembly of the lifters. Now my concern is there is metal going through the motor. Drain the oil and check it.

if budget does not allow "proper" redo I would put strong magnets on the pan reservoirs and oil filter then toss in a new cam, timing set, lifters, rockers, pushrods, patch it up, and hope for the best.

My general recommendation is to pull it, tank it, put in new cam bearings and cam and lifters. I would evaluate the condition of the pistons, cylinder walls, and crank. Assuming all OK ridge ream it. I would put in a set of chrome rings plus rod bearings, main bearings, replace torque yield bottom end fasteners, oil pump, pickup, gaskets, new cam, new lifters, new timing set, etc.

I don't think anyone has asked what the seat pressure checked out at on each valve. Make sure the valve springs are shimmed so the seat pressure is both sufficient and even. Make sure the springs are OK for the lift you run so they don't bind- bind makes terrible noises.

[Walking-Tall]

What's up with Fram (besides the fact that I know of at least one large facility in Stratford Ontario Canada that was not only shut down, putting many out of work, but the whole city block leveled...)? I have always used what's purportedly Fram's blemished oil filters, branded as Motomaster, from Canadian Tire, with never an issue with none of 'em babied... coupled with their heavy duty straight 30W (during warm months) changed every ~2000 miles...

[erratic50]

Filter surface area compared to competitive brands.

Filter quality - they don't catch as small of particles compared to other brands. Then again if your oil flow doesn't keep up the bypass gets tripped and unfiltered oil circulates so is it REALLY a terrible thing - not sure.

Ive seen instances where a car sat for a long time - 5+ years - with the same oil and filter. The dummy that bought it didn't bother to do an oil change before trying to fire it. The paper went to crap from sitting oil soaked and went throughout the motor upon startup.

[Walking-Tall]

Okay.

Good points. I've had no issues, debris or otherwise, with regular changes, so I'll continue paying comparative peanuts for them, lol

Yikes...

[erratic50]

Yep - pick your poison. A filter is only as great as it flows. If it doesn't keep up it gets bypassed. Just the way it works.

IMO magnets on the pan is an aircraft trick that's often overlooked on cars. I've used them ever since the very first detectable shine of metal in my oil 20 years ago. I pull them off when I drain the oil which helps limit the circulation of metal particles in my tired old engine.