Another GT40 valvetrain noise question

[Leukay]

Hey all,

I'm a newbie here, but I have a noise after my GT40 head swap I thought I'd run by you all to get your thoughts. Details of my setup below. The noise only shows up when the engine gets at/near operating temp, and is definitely is coming from the top end. It sounds like a dull hollow noise, almost like the rockers lightly tapping the valve covers. It is clearly not a harsh tapping or knocking noise. I've tried the double stacked valve cover gasket trick and it still seems to be there, but loudest near the baffled area. The engine seems to run nice and smooth, but only had it on the road for a few miles before I noticed the noise and decided to bring her back home.

It doesn't really sound THAT ominous, but I just want to make sure it's not causing any wear/tear on the newly freshened up heads or the rest of the engine. It definitely sounds different than most other videos of valvetrain noise I've found, so I really am in the dark here.

My thoughts/possibilities:
1. Rockers tapping valve covers, but the double gaskets should have eliminated it
2. Stock stamped rockers sweeping the top of the valve stem accentuated by the stiffer springs
- Maybe it would go away after the rockers and valve stems get used to each other?
3. Preload / pushrod length issue? (hoping not, this stuff is a nightmare to me)
4. Open to suggestions here!

Details of the car:
85 Mustang LX Vert 5.0 5 Speed - ~50k miles
96 Explorer heads
- Milled either .020 or .030, double checking
- Upgraded springs, not sure of the specs
Stock stamped rockers
- Shimmed .040 (preload between 1/2 and 3/4 turn)
Stock pushrods and lifters
Weiand stealth intake manifold, new during head swap
Holley 4160

Link to a video - Shot with the single valve cover gaskets installed, just after a good drive.
https://goo.gl/photos/CyHkUSNeGwBZ3iZ98

I appreciate your time!
Lucas

[erratic50]

Pull the valve covers and roll the push rods on a piece of plate glass looking for any that are bent. Double check your pushrod length.

Take them rockers down to zero lash plus 1/4 turn. Make certain the rocker touch at the center of the valve stem.

inspect your rockers at their three points of contact. Tip, fulcrum, pushrod.

inspect your mounting hardware carefully.

If your heads have press in studs make sure they are not loose. Check them with a pry bar and several hundred pounds of upward force. If they are moving on you report back for ways to solve this.

check to see if the baffle is making contact with a rocker arm.

[Walking-Tall]

Welcome Lucas,

That sounds like something up front. PS pump, water pump, idler/tensioner, alternator... The noise is more pronounced as your camera pans across up front. Maybe warm the engine up and remove the belt and run it again for a short time and see if that shuts it up. If so, one of those items' bearing or other might be pooched...

Curiosity - how was this, "- Shimmed .040 (preload between 1/2 and 3/4 turn)" established/set without rocker adjust-ability?...

[bwguardian]

Stock rocker arms are fulcrum type bolt down. I don't understand why post #1 and #2 mention preload adjustment. Stock units get tightened down to 20 ft. lbs., end of story. I did listen to the video and to me it sounds like the air pump for the smog stuff...is it still hooked up?

[Leukay]

Stock rocker arms are fulcrum type bolt down. I don't understand why post #1 and #2 mention preload adjustment. Stock units get tightened down to 20 ft. lbs., end of story. I did listen to the video and to me it sounds like the air pump for the smog stuff...is it still hooked up?

I appreciate everyone's help here. At work so replying on mobile, but I will respond more fully when I get home.

Correct, the rockers are the standard bolt down pedestal type, and I installed .040 shims on the pedestals in order to get the preload back to about 1/2-3/4 turn since the heads were milled. And unfortunately it's not the smog pump, that is long gone. And the noise seems isolated to where the baffles are in the valve covers (front of head on driver's side, rear of head on passenger side) so I don't believe it is any of the front accessories, but I will try that test tonight as well

[bwguardian]

I appreciate everyone's help here. At work so replying on mobile, but I will respond more fully when I get home.

Correct, the rockers are the standard bolt down pedestal type, and I installed .040 shims on the pedestals in order to get the preload back to about 1/2-3/4 turn since the heads were milled. And unfortunately it's not the smog pump, that is long gone. And the noise seems isolated to where the baffles are in the valve covers (front of head on driver's side, rear of head on passenger side) so I don't believe it is any of the front accessories, but I will try that test tonight as well

I still don't understand your reference to 1/2-3/4 turn preload as the factory fulcrum style rocker arms get bolted down to 20 ft. lbs. of torque...there is no adjustment, unless you utilize shims. Speaking of shims, most all the ones I have seen are .030" and .060", which allow .090" when stacked. I would pull the valve covers after the engine is up to operating temperature and run the engine. While you are at it, take a picture of the valve train and post it in here. You really need to find out more about those springs...pressures, maximum lift to bind, retainers/keepers, etc. Are you running the stock cam?

[Leukay]

I still don't understand your reference to 1/2-3/4 turn preload as the factory fulcrum style rocker arms get bolted down to 20 ft. lbs. of torque...there is no adjustment, unless you utilize shims. Speaking of shims, most all the ones I have seen are .030" and .060", which allow .090" when stacked. I would pull the valve covers after the engine is up to operating temperature and run the engine. While you are at it, take a picture of the valve train and post it in here. You really need to find out more about those springs...pressures, maximum lift to bind, retainers/keepers, etc. Are you running the stock cam?

Yes I'm using the stock cam. We had the machinist upgrade to springs that would support the tfs1 cam if/when I decide to upgrade in the future. I'll need to call him to get the rundown on the springs he used.

The shims are called .30 and .60, but they actually physically measure .20 and.40 (according to American muscles website and I double checked with a set of calipers). I used the .40 shim so I would only have about a 1/2 turn of preload by the time I get to 20 ft/lbs. Without the shims there would be well over a turn before I got to the correct torque spec due to the milling of the heads.

I appreciate the patience and sorry for any confusion as I try to explain my situation haha. I will try to figure out a way to run the engine without spraying oil everywhere without the valve covers on. I agree that will help clear things up a little

[bwguardian]

If you do nothing more than loosen the valve covers a little and lift up on the part where the baffle is, you will be able to tell quick and not have to run that long. I take a piece of cardboard and cut it about 6" or so high and a little longer than the rail on the head such that you can curl it around inside that rail on each end to allow me to run the engine for rocker arm adjustment on studded units. This keeps the oil spray fairly controlled.

You definitely need to get more information about the heads. What thickness head gasket did you use?

[Leukay]

So I'm home from work and I'm digging into this thing. I got it nice and warm, noise was there, I pulled the valve covers and set up some cardboard and ran it, no noise. Tried 3 stacked gaskets on the loudest side and left the other side open. Still seems to be no noise... Now before the head swap the PO had cork valve cover gaskets. I used the felpro permadry gaskets which could be thinner than the cork ones. This seems a little odd to me, but I really don't hear it with 3 of those gaskets stacked up. I have my doubts about that sealing long term, so I guess I need to find either some thick gaskets or some other fix. I love these stock valve covers so I'd like to stick with them.

Either way, if anyone has suggestions about the best way to solve this, I'd love to hear them. But it sure seems like my gut instinct was right, but two gaskets just wasn't enough

[erratic50]

Cut the bottom off of an old pair of covers, turn them into spacers. Install as gasket, spacer, gasket, valvecover.

Or 3D print spacers out of ABS.

Good luck!

[306gt]

Fel pro make a 5/16" thick cork valve cover gasket. or you could remove the baffles and make some flat sheet metal baffles and tack weld them in your factory covers. But They should clear the factory rockers especially if you are using the factory cam.

[Leukay]

Ok well here's where I feel dumb. I didn't trust myself because it seemed weird to need that much clearance under the valve covers, so I went back out and ran without the valve covers a little more. Using a screwdriver to my ear on the bolt head that holds the rocker down, I isolated a couple rockers that were noticeably more noisy than the others. I removed them to inspect them, but didn't find anything super out-of-the-ordinary. I have a half set that were original to the explorer heads (the stampings look slightly different but the placement of everything looks identical), so I swapped those in for the two noisy ones. This was much much quieter, even when I moved back to one single valve cover gasket on each side.

I went for a drive and everything seemed pretty good, but as I pulled back into the driveway I noticed the noise had started to come back. Not as bad as before, but was definitely more noticeable than right after I swapped those rockers. So I'm afraid I might be back at square one with this...

[erratic50]

The spacers I suggested making are actually readily available now.

Example
http://www.speedwaymotors.com/Ansen-...FQMaaQodEwwLDg

The explorer rockers are not strong enough to stand up to the lift of an HO cam - especially considering the stronger springs required to run HO cams with P heads.

try the crane 1.7 roller rockers like those found on the 1993 cobra.

If the problem persists you don't have a lot of options other than tear it back down and inspect everything. Pull the valves and clean then make sure none are bent. Debris can sometimes end up getting into the damnedest places when working on a motor.

As you know if you keep toying with it and don't tear it down you run the risk of scattering it right where it idles.

[bwguardian]

Ok well here's where I feel dumb. I didn't trust myself because it seemed weird to need that much clearance under the valve covers, so I went back out and ran without the valve covers a little more. Using a screwdriver to my ear on the bolt head that holds the rocker down, I isolated a couple rockers that were noticeably more noisy than the others. I removed them to inspect them, but didn't find anything super out-of-the-ordinary. I have a half set that were original to the explorer heads (the stampings look slightly different but the placement of everything looks identical), so I swapped those in for the two noisy ones. This was much much quieter, even when I moved back to one single valve cover gasket on each side.

I went for a drive and everything seemed pretty good, but as I pulled back into the driveway I noticed the noise had started to come back. Not as bad as before, but was definitely more noticeable than right after I swapped those rockers. So I'm afraid I might be back at square one with this...

From what you are saying now...that the noise is still there with the valve covers off while running...it sounds like a valve train issue.

[Leukay]

From what you are saying now...that the noise is still there with the valve covers off while running...it sounds like a valve train issue.

Well without covers I don't really hear it, but holding a screwdriver to my ear on the bolt heads of each rocker arm I can tell there are a couple that are more noisy than the others. I think it just echos through​ the valve covers when they're on to make it much louder. I wanted to avoid roller rockers because one of the main drawbacks of them is noise, but I'm wondering if the springs that were installed are too much for even the stock stamped mustang rockers. I'm at a loss. I need to call the machinist to get the details on those springs and get his input, and I'll need to do more tinkering this weekend.

The problem with going with roller rockers is mostly prices, and many of the good quality ones are 1.7 ratio, which will change my piston to valve clearance. Now that the engine is back in the car I'd rather not have to pull it all apart again

[mrriggs]

The shims are called .30 and .60, but they actually physically measure .20 and.40 (according to American muscles website and I double checked with a set of calipers). I used the .40 shim so I would only have about a 1/2 turn of preload by the time I get to 20 ft/lbs. Without the shims there would be well over a turn before I got to the correct torque spec due to the milling of the heads.

Sounds like you may not have enough preload. Unless I'm mistaken, you need at least 1/2 turn from zero lash until you just start to feel resistance on the bolt. Once the fulcrum hits the head, any further turning [to reach the torque spec] is only stretching the bolt and not adding preload to the lifter.

[bwguardian]

I would not go the roller rocker route if you are not already liking the noise. I believe your issue lies with the shims and you need to find out how much was taken off the heads and what thickness head gasket you utilized. I would be willing to bet that the smaller shims would solve your problem.

I have GT40p heads with an E303 cam with factory roller lifters and stock fulcrum rocker arms. My heads had .005" or .010" taken off them and I utilized a .040" compressed head gasket. The springs were set up at 110#'s on the seat and around 300#'s with room enough to support up to a .550" cam before coil bind. Everything was torqued down to spec with no shims and I have had zero problems years later.

[Leukay]

I would not go the roller rocker route if you are not already liking the noise. I believe your issue lies with the shims and you need to find out how much was taken off the heads and what thickness head gasket you utilized. I would be willing to bet that the smaller shims would solve your problem.

I have GT40p heads with an E303 cam with factory roller lifters and stock fulcrum rocker arms. My heads had .005" or .010" taken off them and I utilized a .040" compressed head gasket. The springs were set up at 110#'s on the seat and around 300#'s with room enough to support up to a .550" cam before coil bind. Everything was torqued down to spec with no shims and I have had zero problems years later.

I'm still trying to get ahold of the machinist, but I'm 90% sure the heads were milled .020". The compressed thickness of the head gasket is written down at home, don't have it on hand unfortunately.

Are you using the factory pushrods? I do know without any shims and with the original pushrods the P2V clearance was too close. I suppose the smaller shims could work (called .030", but physically measure .020"), but I think I'd be getting over a full turn of lifter preload before the bolt is taken to 20 ft/lbs, which seems like too much according to what I read.

[bwguardian]

I'm still trying to get ahold of the machinist, but I'm 90% sure the heads were milled .020". The compressed thickness of the head gasket is written down at home, don't have it on hand unfortunately.

Are you using the factory pushrods? I do know without any shims and with the original pushrods the P2V clearance was too close. I suppose the smaller shims could work (called .030", but physically measure .020"), but I think I'd be getting over a full turn of lifter preload before the bolt is taken to 20 ft/lbs, which seems like too much according to what I read.

Yes, factory pushrods that were checked for straightness even though I knew they would be, given I knew the cars history since new because he is a good friend. So you are now saying the factory stock pushrods are not in the mix as stated in your original post? I went back and looked at the video again. What is going on with the passenger side valve cover cap near the fire wall?...it appears open with no hose connection...

[Leukay]

Yes, factory pushrods that were checked for straightness even though I knew they would be, given I knew the cars history since new because he is a good friend. So you are now saying the factory stock pushrods are not in the mix as stated in your original post? I went back and looked at the video again. What is going on with the passenger side valve cover cap near the fire wall?...it appears open with no hose connection...

Oh yeah, sorry, I am still using the factory pushrods. I also checked for straightness, but that crimp thing towards the top made it a little tough. All appeared straight. But with that stock length, and the .020 milling, the smaller shims will probably give too much lifter preload by the time the bolt is torqued down. I thought about 1/2 - 3/4 turn was pretty good with the larger shims that are on there now.

And yeah, the plastic piece that comes out of the valve cover cap broke just before I parked the car to pull the engine for all this work. The other side is the PCV and is connected to a vacuum port on the carb, and the broken side used to connect under the air cleaner.

[Leukay]

A little update as I've been messing with things. I've installed the felpro double thick cork gaskets, and while the noise is still there I don't hear it resonating through the valve cover anymore. Holding a screwdriver toy ear against the valve cover is very quiet with the cork gaskets. Strangely enough, feeling around a little more with my screwdriver, I'm hearing it through the sides of the intake manifold. Kind of a resonance at certain points towards each corner of the intake manifold. At this point I'm totally lost. During the head swap I removed and disassembled/cleaned all the lifters, and all of them were nice and free when I reinstalled them (same order, same orientation). Any clues as to what could be going on? Am I overreacting to nothing?

[bwguardian]

A little update as I've been messing with things. I've installed the felpro double thick cork gaskets, and while the noise is still there I don't hear it resonating through the valve cover anymore. Holding a screwdriver toy ear against the valve cover is very quiet with the cork gaskets. Strangely enough, feeling around a little more with my screwdriver, I'm hearing it through the sides of the intake manifold. Kind of a resonance at certain points towards each corner of the intake manifold. At this point I'm totally lost. During the head swap I removed and disassembled/cleaned all the lifters, and all of them were nice and free when I reinstalled them (same order, same orientation). Any clues as to what could be going on? Am I overreacting to nothing?

How did you clean the lifters? Did you soak them in oil prior to installation and/or prime the engine prior to starting it?

[Leukay]

I just disassembled them, sprayed them out and soaked the pieces in fresh oil before reassembling them. Installed them as is, so I could visually see the preload of the lifter when torquing the rocker bolts down. They are definitely pumped up at this point

[bwguardian]

You should always soak them in oil when they are assembled prior to installation and/or primed the motor. Hopefully you didn't damage a pushrod or another part of the valve train.

[Walking-Tall]

How much oil pressure is there when the engine's warmed up?

As well, if there's perceptible clatter at all, there's clearance somewhere. Ideally, all dimensions and tolerances of every piece are closely held, but that only goes so far with mass-production. Too bad the rockers aren't adjustable, because initial assembly and checking/setting hydraulic lifter pre-load are good things, but there's nothing at all like checking/setting the lifter pre-load on a hot running engine, with the real world running conditions of all the items. If the hot oil pressure is good, and there is some actual hot pre-load everywhere (though maybe not enough in some places), some of the noisier ones may need a bit thinner shim.