Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: Masejoer on November 16, 2008, 12:37:22 PM

Title: Noisy Valvetrain
Post by: Masejoer on November 16, 2008, 12:37:22 PM
So the noise I'm having IS valve train related but I'm not sure why. I've got the stock HO cam, both block and heads were surfaced for flatness, gt40p heads, and Crane 1.7 RR's. Valve covers are stock HO ones with the oil baffle removed on he passenger side. All rockers tightened to torque at exactly 1/2 turn past zero lash. I've pulled the valve covers off to recheck them and everything remains the same. My valve train is more than "sewing machine" as I've heard it put with these rockers. I can hear the valve train over the exhaust (Flowmaster 50's) 50 feet away. Nothing sounds horrible, just loud tapping coming from the valve covers and from both entire banks of rockers.

What else could be wrong? If anything, the pushrods would be slightly too long and cause more preload at the same torque spec. We've checked pushrod length with an adjustable and solid lifter so I don't know what's up.

Any idea other than to go with different rocker arms? There is no exhaust leak sounds coming from around the headers, just from the valve covers themselves. With correct (and basically stock) valve train geometry, with rockers not touching the valve covers, what's wrong? It quiets down after a second of running but comes back after the oil heats up.

Just live with it?
Title: Noisy Valvetrain
Post by: Kitz Kat on November 16, 2008, 12:47:07 PM
Sound like you covered everything, I normally only do 1/4 turn on the rockers. You do have oil pressure?
Title: Noisy Valvetrain
Post by: Masejoer on November 16, 2008, 12:54:32 PM
Great oil pressure - don't remember the exact number though. I only hooked up a gauge on first fire and I think it was around 65psi on cold idle. The stock gauge reads at the 3/4 mark at this pressure level. Also, the lifters in there are basically new Comp Cams HE ones - they should have no more than 500 miles on them but I don't remember the exact mileage I put on the car after install.
Title: Noisy Valvetrain
Post by: TurboCoupe50 on November 16, 2008, 01:02:08 PM
Tighten them up another 1/4 turn(3/4 total), wont hurt anything... Loosening will no doubt increase noise... But really, sounds as if you have some high leak down lifters... Rhodes and a couple other mfgr's sell them to cut lift & duration at idle... Yes they are noisy...
Title: Noisy Valvetrain
Post by: Cougar5.0 on November 16, 2008, 04:21:28 PM
I have those rockers and they will only quiet down with closer to 3/4 turn. I've always shimmed them so they range between 5/8 - 3/4 turn after you can't spin the pushrod.
Title: Noisy Valvetrain
Post by: Masejoer on November 16, 2008, 04:43:37 PM
Quote from: Cougar5.0;243304
I have those rockers and they will only quiet down with closer to 3/4 turn. I've always shimmed them so they range between 5/8 - 3/4 turn after you can't spin the pushrod.


Is that the way it goes? From going over it in my head, it'd seem that longer pushrods would take more to get to torque. We're only going valve spring vs lifter spring. I really don't know which I'm pushing against on different setup heights - it's confusing. I thought to get more preload, I'd need more pushrod? Less pushrod (shorter and/or shims) would mean more slack - less preload.

We don't have shims anywhere on the heads - we left the .030's on that were on the last engine and it was clattering horribly so after rechecking them, no shims seemed to fit perfect. I'm going to look at the wear pattern on the valves after a few miles to get a better view of exactly where they are running - they were perfectly in the center with the black marker and mockup.
Title: Noisy Valvetrain
Post by: Cougar5.0 on November 16, 2008, 04:57:23 PM
In my case, I was able to go to the thinner shim on 1/2 of the valves (like 0.015 vs. 0.030) & no shims on the other half. But the shimming is all dependant on your heads, pushrod length, headgasket thickness, any head grinding done, so your setup will be different. It seems like you already know what you're doing here, but if you had to already completely remove the shims with longer pushrods - your only option to get more preload would be to get slightly longer pushrods & reshim using a Crane shim kit. Working with pedestal rockers can be annoying at times!
Title: Noisy Valvetrain
Post by: SR71TC on November 16, 2008, 07:39:22 PM
Sometimes fuel injectors will sound like valve train noise.
Title: Noisy Valvetrain
Post by: Masejoer on November 16, 2008, 11:55:21 PM
I swear the last engine did not have this issue and it was similar with exception of gt40 heads instead of P's. It also had the stock exhaust manifolds. Of course, the Cobra GT40's are supposed to be milled a bit from the factory so I'm thinking that may be why they were quieter - they DID tighten around 3/4 turn instead of 1/2 so I'm thinking of trying some slightly longer pushrods on this motor.

The car's going to sit for a few more weeks now as I was having trouble with the 4r70w's lockup disengaging every time I'd completely let off the throttle when on the highway - the TPS voltage would go to idle and it'd disengage. Just touching the pedal slightly again would make it reengage and clunk around - this is a continuous thing when at light throttle on flattish terrain. After pulling off 3 times and changing the lockup tps voltage settings, I had to give up as it seemed to not be using my changes on lockup. Other changes would work according to what I put into the computer. I'll be calling Baumann tomorrow.

I also think I heard some detonation or something a couple times when I was on the exit to turn around and take the car back to the driveway. The computer only throws 3 codes - thermactor and egr which have been existing codes for years. Timing is at exactly 10 degrees based only on the markings on the Pioneer balancer. Compression on the motor is at 180psi with the 87 octane that's been sitting in the car for months. Vacuum is 22 inches at idle in park, 20 in drive, 25 on rev. Engine has roughly 70 miles on it. Idle loses its smoothness when in park/neutral after running for more than 15 minutes.

I did have 37mpg going away from the house on the interstate and 25mpg going back up the hill so things seem to be going good in terms of efficiency. Both calculations taken AT SPEED to the destination - highway only and variable between 35 (yes, people on the highway at 5pm on Sunday are idiots) and 65mph with 3 total short exit stops on the drive.

Lastly, the valvetrain was even noisier after this drive - I don't feel it safe for the engine's well being to continue running the motor as it is. I will be talking with my machine shop tomorrow but it sounds like I need another .015 of preload to get me closer to where I should be. CompCams says these lifters must be as close as possible to the .030-.050 preload range (closer to 3/4 turn past zero lash) so I think I have some very precise tweaking to do. I have to buy new pushrods first.
Title: Noisy Valvetrain
Post by: Masejoer on November 17, 2008, 12:09:38 AM
Quote from: Cougar5.0;243311
In my case, I was able to go to the thinner shim on 1/2 of the valves (like 0.015 vs. 0.030)


How sure are you that it's .015 and .030? All the kits I've seen, and have, are .030 and .060. If I could find some .015's, it'd be great but I've never seen one for anything other than valve springs.

Sucks that all the 6.30" pushrods are $100+. Would have to shim .030 since that's the smallest I can find (but that'd be the rest of the 3/4 turn).
Title: Noisy Valvetrain
Post by: Cougar5.0 on November 17, 2008, 01:12:40 AM
You're right - my perception that they were 0.015/0.030 was from memory and is wrong. They were from the Crane kit and were 0.030/0.060.

Either way, pedestals are a pain. Also, I initially got el-cheapo rods when I had shaved heads (shorter) which I bent after like one rev-up (Comp XE cams aren't for kids), so I didn't skimp next time when I went with the one-piece Trickflow hardened rods and haven't had an issue since. They're $87 at Summit.
Title: Noisy Valvetrain
Post by: Masejoer on November 17, 2008, 09:07:23 AM
Quote from: Cougar5.0;243395
They're $87 at Summit.


Yeah, I saw this. Summit also has an eBay store so MS CashBack  brings it down to $65 + shipping.
Title: Noisy Valvetrain
Post by: thunderjet302 on November 17, 2008, 05:34:50 PM
My guess is push rods. I bet you'll gain some power with the right ones ;)
Title: Noisy Valvetrain
Post by: Masejoer on November 29, 2008, 08:27:17 PM
So I installed 6.3" pushrods and shimmed the entire range .030 - they all became around 3/4 turn past zero lash but the valve train is still as noisy as before. I haven't lost or gained any vacuum.

These lifters are a pain to adjust as they do seem to bleed down very slowly so I had a harder time getting things torqued consistently as before but if anything, 20 thousands should be much quieter. I don't know where to go from here. I think my options are to either try different lifters or rocker arms - is there anything else to try? It IS coming from the valve covers and not around the headers so something's got to be amiss within there, yet the wear pattern on the valve stems is perfectly centered.
Title: Noisy Valvetrain
Post by: Haystack on November 29, 2008, 10:56:45 PM
I'll bet the head was machined down some or you have a thicker head gasket. I ran the motor and just finger tightened the bolts, then i did a half turn on them. When my push rods were too short they did the same exact thing.

I changed out the heads (went with e7's,) cam and lifters and pushrods. I got everything but the heads from kits. It all worked fine after that. I think the last motor had either a badly worn cam, or had bad lifters or a thicker head gasket. I would go to a machine shop and have them look at it.
Title: Noisy Valvetrain
Post by: Masejoer on November 30, 2008, 11:52:57 AM
I cannot get the lifters' plunger to move at all today - trying to readjust the rockers is pressing on the valve spring rather than the lifters - this is happening on all 16. This is happening right at zero lash, the valve springs start moving. Shimming and stock pushrods are doing the same thing. I'm thinking of putting the Melling ones back in and giving them a try, rather than these "High Energy" ones.
Title: Noisy Valvetrain
Post by: Cougar5.0 on December 02, 2008, 12:12:45 AM
The Comp high energy roller lifters are essentially Ford OEM lifters, aren't they? I bought a set those for $100 on Ebay and I couldn't tell the difference between them and the original Ford roller lifters.

I'm surprised you're still having a lot of noise, though I did have to adjust mine 3 times before they were quiet - I think it's probably the Crane 1.7's that are most responsible for the noise.
Title: Noisy Valvetrain
Post by: Masejoer on December 02, 2008, 09:05:57 AM
Quote from: Cougar5.0;245749
The Comp high energy roller lifters are essentially Ford OEM lifters, aren't they?


Yeah, according to Comp Cams, they're very similar to OEM. I don't think I can get quiet without different rockers, roller or stamped.
Title: Noisy Valvetrain
Post by: Cougar5.0 on December 02, 2008, 09:57:00 AM
If you ever find a roller rocker that is as quiet as stock, let me know!
Title: Noisy Valvetrain
Post by: V8Demon on December 02, 2008, 10:57:47 AM
Quote
Comp XE cams aren't for kids

(http://www.listangs.com/forum/images/smilies/hysterical2.gif)