Tapping From Vavle Train Sounds Like Tractor?

Joe Scrivens · Aug 27, 2014

Hey guys I have a 347 Stroker motor I hand built. I have probe racing internals. It has a holley 750 Carburetor. 7qt Moroso Oil pan. Cast Iron GT heads ported and milled. approx 11.0 Compression.

The engine fired up and ran from day 1. My only dilemma is valve-train noise or what seems to be valve train noise. I have only started and driven the car around the block for testing.

After a few starts and testing the motor, it started making this tapping//knocking/tractor sound from around the heads/valve-train.

background on the valve train. Comp Cams Xtreme energy cam with .575 lift on exhaust .565 on intake. i have comp cams hydraulic lifters, measured push rods going into 1.6 full roller aluminum rockers double spring comp cams and i forgot what valves. What I do not remember doing was tightening the rockers down in any specific order however I was told that didn't matter since they are pedestal mount rockers(not sure if I believe that i don't have to do them in the turn the motor over by hand check style and tighten flow).

Last night i took off the valve cover everything seems to still be as snug as I remember. push rods have no play are solid on the compression phase and slights spinnable during the uncompressed phases of the valve (possible valve float issue?)

Now the sounds always seems to be traveling.

I thought maybe it was lubrication issues but there is the Melling HV oil pump and the 7 quarts double sump keeps oil in every place it needs to be.

could this just be a pinging issue for timing? or is it mechanical in the valve train?

to make it clearer in what it sounds like, picture an old Volvo diesel truck =P

Thanks in advance!

Lscam580 · Aug 27, 2014

Do you know what your installed heights are on the valves? did you do a clay test from valve to piston clearance? I had the same problem on a motor only to find out the springs didn't have the correct shims to get correct installed height and the valves were tapping the piston but not enough to do catastrophic damage.

Joe Scrivens · Aug 27, 2014

Lscam580 said:
Do you know what your installed heights are on the valves? did you do a clay test from valve to piston clearance? I had the same problem on a motor only to find out the springs didn't have the correct shims to get correct installed height and the valves were tapping the piston but not enough to do catastrophic damage.

hey that is a good suggestion. no I didn't clay the pistons (and I am not ready to take apart the motor just yet =/).

However i did call PROBE racing just before and asked if there potentially could be a clearance issue with piston to valves with my valve-train setup, He indicated that i get actually am safe with a full .650 lift clearance with the pistons (triple valve reliefs), which I am no where near at the moment. I also contacted comp cams and the nice fellow over the phone cut me off once i told him i have dual springs and asked if I assembled the motor WITH the springs installed. He explained how my push-rod length could be the blame since the dual spring is stronger than the lifter without the motor on that i could have a false reading on the length of the push-rods since i was more than likely collapsing the lifter when tightening versus getting a proper length reading.

I am going to recheck the pushrods length and if that doesnt solve the issue I will have to remove the cylinder heads. while im there i guess I can finally fix the intake manifold leak I have too LOL

Thanks LSCAM580!

Gearbanger 101 · Aug 27, 2014

Sounds like you didn't set up your lifters correctly.

Heads/Cam/Intake? That seems like an awful lot of cam for a set of stock heads?

Pedestal rockers shouldn't take more than 1/4-2/3 of a turn to reach 20lbs/ft. More than that and you probably need another shim under them. Less than that, and you probably need to remove a shim. I generally like to shoot for between .020-.030 pre load on the lifter. Make sure the valve is centred on the top of the valve stem.

Check the inside of your valve covers for areas where the rockers may have made contact. Depending on the style of valve cover you have, you may need to clearance them a little. Double valve cover gaskets helps too.

Joe Scrivens · Aug 27, 2014

Gearbanger 101 said:
Sounds like you didn't set up your lifters correctly.

Heads/Cam/Intake? That seems like an awful lot of cam for a set of stock heads?

Pedestal rockers shouldn't take more than 1/4-2/3 of a turn to reach 20lbs/ft. More than that and you probably need another shim under them. Less than that, and you probably need to remove a shim. I generally like to shoot for between .020-.030 pre load on the lifter. Make sure the valve is centred on the top of the valve stem.

Check the inside of your valve covers for areas where the rockers may have made contact. Depending on the style of valve cover you have, you may need to clearance them a little. Double valve cover gaskets helps too.

I have Moroso Valve Covers and No contact at all. The heads are the GT Cast Irons but I upgraded everything in the valve train. Comp Cams and a local engine shop told me the torque on the pedestal mounts shouldn't matter because the point of pedestal is to just seat them and the pushrod length handles the rest. I may have to have someone with more knowledge handle the valve train if the pushrods dont fix the issue.

After taking a peak at the rockers last nigh tno, the rockers are leaning real close to the edge of the valve stem top on valve opening. which is another sign of a long pushrod.

I am going to buy a set of stock length pushrods and start from there just to get them long rods out & get it mobile then bring it to a trustworthy engine shop and let them fine tune everything from the carburetor to the rockers and ingition.

Thanks for the input!

Lscam580 · Aug 27, 2014

The length of the push rod can be measured in your own garage. Most cam company's will recommend a certain length of pushrod, but every reputable engine builder will always tell you use a good pushrod length tool kit. You can pick one up for a decent $60. Imo I think $60 for a tool is better then spending mega $ on a new set of pistons/ heads /valves / or worse case new motor if you snap that valve off sending it through the lower end.
Also had to look it up to give you the right answer on the springs 650 lift on a flat tappet is different then 650 lift on the hyd, roller.

Gearbanger 101 · Aug 27, 2014

Did you get shims with the rocker arms? Shimming the rockers can also help and in many cases will be mandatory....and certainly cheaper than longer pushrods.

You didn't mention how much you needed to turn the rocker bolt after zero lash to lock it down. The torque doesn't matter so much, but it gives you a point of repeatability to know exactly how much you're turning each bolt. If it takes 1/4 turn to lock one arm down and 1 1/2 turns to lock down another, things are going to get out of whack. Not using consistent torque on each bolt is going to make it near impossible to know how much rotation each is getting after zero lash?

Too much rotation will cause excess preload on the lifters can cause them to fill with excess oil and cause valve float, hanging valves, rough idle, noise, etc.

Cranking it down less than 1/4 of a turn can not provide enough preload on the lifter....which can also make the valvetrain noisy, cause premature purshod wear alignment issues, etc.

Do yourself a favour, pick yourself up a shim kit and a torque wrench and start over. You really shouldn't need different length pushrods for stock heads, but I have seen them need shims.

Also keep in mind, your cam is fairly aggressive. Comp Xtreme Energy camshafts have a fairly quick opening and closing rate. This improves their performance, but also make for a noisier valve train.

Joe Scrivens · Aug 28, 2014

Lscam580 said:
The length of the push rod can be measured in your own garage. Most cam company's will recommend a certain length of pushrod, but every reputable engine builder will always tell you use a good pushrod length tool kit. You can pick one up for a decent $60. Imo I think $60 for a tool is better then spending mega $ on a new set of pistons/ heads /valves / or worse case new motor if you snap that valve off sending it through the lower end.
Also had to look it up to give you the right answer on the springs 650 lift on a flat tappet is different then 650 lift on the hyd, roller.

Hey thanks for responding. I did the push-rod length check during build and did it again last night.

I took the rocker arms off and pushrods out.

Nothing was bent. all seemed normal.

I rechecked length. The pushrods I am using right now are the MAGNUM compcams 6.350. Stock length is 6.250. So the different is only a tenth of an inch. I am not sure how a tenth relates to in valvetrain.

I torqued them all down to +/- 20FT/lbs. I rotated the engine for each valve set to get the piston into compression phase so all valves were closed. firing order 1-3-7-2-6-5-4-8.

I also made an order for the stock length 6.250 length rods. I am reading however that Compcams DOESNT measure their pushrods to include the rod tops so maybe they are actually longer than the numbers on the rods?

on the note of 650. My engine isn't running 650. the 650 remark was PROBE industries tellin gme that the piston clearnace allows a lift of 650 on a SBF.

Joe Scrivens · Aug 28, 2014

Gearbanger 101 said:
Did you get shims with the rocker arms? Shimming the rockers can also help and in many cases will be mandatory....and certainly cheaper than longer pushrods.

You didn't mention how much you needed to turn the rocker bolt after zero lash to lock it down. The torque doesn't matter so much, but it gives you a point of repeatability to know exactly how much you're turning each bolt. If it takes 1/4 turn to lock one arm down and 1 1/2 turns to lock down another, things are going to get out of whack. Not using consistent torque on each bolt is going to make it near impossible to know how much rotation each is getting after zero lash?

Too much rotation will cause excess preload on the lifters can cause them to fill with excess oil and cause valve float, hanging valves, rough idle, noise, etc.

Cranking it down less than 1/4 of a turn can not provide enough preload on the lifter....which can also make the valvetrain noisy, cause premature purshod wear alignment issues, etc.

Do yourself a favour, pick yourself up a shim kit and a torque wrench and start over. You really shouldn't need different length pushrods for stock heads, but I have seen them need shims.

Also keep in mind, your cam is fairly aggressive. Comp Xtreme Energy camshafts have a fairly quick opening and closing rate. This improves their performance, but also make for a noisier valve train.

Yes I have and found the shims kit. I didn't put any as I am fearing that the Pushrod is on the long side already. however I am a little confused. I followed a video on how to torque the pedestal mounts and did it exactly now my thing is what actually is Zero lash? when the pushrod doesn't move at all during pre-torquing or just get it hand tight with an allen key/tool til i can move it with my fingers? becuase last night/3am 6 hours ago (lol) what I had to do and was exactly the same for each rocker bolt was get it to where the pushrod didnt spin just using an allen key then grabbed my torque wrench preset at 20 ft/lbs. One turn got to feeling tighter, then one more 3/4 turn gave me the 20ft/lbs on the bolt. Now being as I am unfamiliar with zero lash etc. am I putting too much preload? or does that sound right?

I research some more and the Xtreme Energy Comp Cams are NOISY no matter what setup someone has. I dont mind the valve noise just as long as I can rest assured a valve isnt going to fly through the valve cover one day LOL

Thanks!

Lscam580 · Aug 28, 2014

That tenth could be just enough to get a small tap from valve to piston.

In minor cases I have done a pre load start with valve cover off and took my zero lash from there. And that will help tell that you are ok. But that is very old fashion. If you don't use shop rags to cover the other rockers could be a oil mess.
But in any case lets see where you are at after you install the other pushrods

Joe Scrivens · Aug 28, 2014

Lscam580 said:
That tenth could be just enough to get a small tap from valve to piston.

In minor cases I have done a pre load start with valve cover off and took my zero lash from there. And that will help tell that you are ok. But that is very old fashion. If you don't use shop rags to cover the other rockers could be a oil mess.
But in any case lets see where you are at after you install the other pushrods

I have a gut feeling you may be right about that tenth.

But you must say thats a pretty close measure on my part if I was just a tenth off =P

Yea I will put the 6.248 Pushrods in tonight after a fresh oil change and Wheel polishing (ya know gotta look good even if it dont move) and I will report back here after. If the stock length pushrods still give a clackitty clack, I am hands and

Lscam580 · Aug 28, 2014

After you install the pushrods I honestly think your gonna travel down the perfect avenue.
Just make sure you pull the coil wire and give her a good roll over so you don't get a dry pushrod fire. You want to be able to hear for noises and not a tap from rockers jumping back up.
I'm waiting for this winter for the new stang paint. I'm laying down new ford charcoal metallic gray. That charcoal just catches my attention every time I see it wether on a f150 or a mustang just appealing to my eye

Gearbanger 101 · Aug 28, 2014

Joe Scrivens said:
I followed a video on how to torque the pedestal mounts and did it exactly now my thing is what actually is Zero lash? when the pushrod doesn't move at all during pre-torquing or just get it hand tight with an allen key/tool til i can move it with my fingers? becuase last night/3am 6 hours ago (lol) what I had to do and was exactly the same for each rocker bolt was get it to where the pushrod didnt spin just using an allen key then grabbed my torque wrench preset at 20 ft/lbs. One turn got to feeling tighter, then one more 3/4 turn gave me the 20ft/lbs on the bolt. Now being as I am unfamiliar with zero lash etc. am I putting too much preload? or does that sound right?

Zero lash means that there is no air gap at all between the plunger in the lifter and the push-rod cup on the rocker arm. This is the point where you should not be able to achieve any vertical movement on the pus-rod and there should be the slightest contact between the push-rod at both the plunger and cup ends as well as the roller tip of the rocker and the valve. It should remain firm in place, without the ability to rattle the push-rod up and down, yet not so firm that you start feeling excessive drag on the push-rod when you rotate it back and forth between your fingers. You should just about be able to achieve this threading in the rocker bolt by hand. When you start to feel slight resistance in the push-rod when spinning it and all three points (plunger, push-rod cup and roller tip) are making contact, you are then at zero lash.

Once you have achieved this point, take your torque wrench (which is set at 18-20lbs) and position it at the 12, 3, 6, or 9 o'clock position (whichever is the most convenient start point for you) and begin your rotation. From there you should be able to reach your torque setting somewhere between 1/4-2/3 of a turn. Crane and FRPP state you can go as much as one full turn, but I've always found that the lifters like a little less preload on them, over a little more.

If you're doing all of this and are seeing 1 and 3/4 of a turn like I believe I am understanding, then you are putting too much preload on the lifter and you're either going to bottom out the plunger and/or are going to hold the valve slightly off the seat. This is going to cause a slight loss in compression, as the valve will not fully close. The result could be down on power, rough idle and worst case....valve float and piston to valve contact.

If you still have the stock length push-rods handy, I would throw them in and try the procedure again. My guess is that the slightly longer push-rods your running are what's causing this issue. Once you've got the stock length rods in there, you should be much closer to your goal. If you are in fact "slighty" out at that point, this is where the shims would come into play and you can fine tune from there.

Truth be told....unless the heads have been milled to some great degree, you really shouldn't need anything other than the stock pushrod length for OE E7TE Mustang GT heads.

Joe Scrivens · Aug 28, 2014

Gearbanger 101 said:
Zero lash means that there is no air gap at all between the plunger in the lifter and the push-rod cup on the rocker arm. This is the point where you should not be able to achieve any vertical movement on the pus-rod and there should be the slightest contact between the push-rod at both the plunger and cup ends as well as the roller tip of the rocker and the valve. It should remain firm in place, without the ability to rattle the push-rod up and down, yet not so firm that you start feeling excessive drag on the push-rod when you rotate it back and forth between your fingers. You should just about be able to achieve this threading in the rocker bolt by hand. When you start to feel slight resistance in the push-rod when spinning it and all three points (plunger, push-rod cup and roller tip) are making contact, you are then at zero lash.

Once you have achieved this point, take your torque wrench (which is set at 18-20lbs) and position it at the 12, 3, 6, or 9 o'clock position (whichever is the most convenient start point for you) and begin your rotation. From there you should be able to reach your torque setting somewhere between 1/4-2/3 of a turn. Crane and FRPP state you can go as much as one full turn, but I've always found that the lifters like a little less preload on them, over a little more.

If you're doing all of this and are seeing 1 and 3/4 of a turn like I believe I am understanding, then you are putting too much preload on the lifter and you're either going to bottom out the plunger and/or are going to hold the valve slightly off the seat. This is going to cause a slight loss in compression, as the valve will not fully close. The result could be down on power, rough idle and worst case....valve float and piston to valve contact.

If you still have the stock length push-rods handy, I would throw them in and try the procedure again. My guess is that the slightly longer push-rods your running are what's causing this issue. Once you've got the stock length rods in there, you should be much closer to your goal. If you are in fact "slighty" out at that point, this is where the shims would come into play and you can fine tune from there.

Truth be told....unless the heads have been milled to some great degree, you really shouldn't need anything other than the stock pushrod length for OE E7TE Mustang GT heads.

Lscam580 said:
After you install the pushrods I honestly think your gonna travel down the perfect avenue.
Just make sure you pull the coil wire and give her a good roll over so you don't get a dry pushrod fire. You want to be able to hear for noises and not a tap from rockers jumping back up.
I'm waiting for this winter for the new stang paint. I'm laying down new ford charcoal metallic gray. That charcoal just catches my attention every time I see it wether on a f150 or a mustang just appealing to my eye

Gearbanger 101 said:
Zero lash means that there is no air gap at all between the plunger in the lifter and the push-rod cup on the rocker arm. This is the point where you should not be able to achieve any vertical movement on the pus-rod and there should be the slightest contact between the push-rod at both the plunger and cup ends as well as the roller tip of the rocker and the valve. It should remain firm in place, without the ability to rattle the push-rod up and down, yet not so firm that you start feeling excessive drag on the push-rod when you rotate it back and forth between your fingers. You should just about be able to achieve this threading in the rocker bolt by hand. When you start to feel slight resistance in the push-rod when spinning it and all three points (plunger, push-rod cup and roller tip) are making contact, you are then at zero lash.

Once you have achieved this point, take your torque wrench (which is set at 18-20lbs) and position it at the 12, 3, 6, or 9 o'clock position (whichever is the most convenient start point for you) and begin your rotation. From there you should be able to reach your torque setting somewhere between 1/4-2/3 of a turn. Crane and FRPP state you can go as much as one full turn, but I've always found that the lifters like a little less preload on them, over a little more.

If you're doing all of this and are seeing 1 and 3/4 of a turn like I believe I am understanding, then you are putting too much preload on the lifter and you're either going to bottom out the plunger and/or are going to hold the valve slightly off the seat. This is going to cause a slight loss in compression, as the valve will not fully close. The result could be down on power, rough idle and worst case....valve float and piston to valve contact.

If you still have the stock length push-rods handy, I would throw them in and try the procedure again. My guess is that the slightly longer push-rods your running are what's causing this issue. Once you've got the stock length rods in there, you should be much closer to your goal. If you are in fact "slighty" out at that point, this is where the shims would come into play and you can fine tune from there.

Truth be told....unless the heads have been milled to some great degree, you really shouldn't need anything other than the stock pushrod length for OE E7TE Mustang GT heads.

Awesome thanks for the input on the Zero Lash issue I was concerned about. Yea I think Im getting preload issues and I am certainly going to go to stock length.

I ordered these:
http://www.compperformancegroupstor...e_Code=CC&Product_Code=7826-16&Category_Code=
til I can afford to get the Magnum one piece pushrods again. I have the 6.350 Magnum One pieces now ( i trust them over the ball tip ones). Do you think these will hold up on a stroker motor with big lift?

Yea I have a gut feeling like I mentioned this has been the issue, and shimming it would definitely help once I get closer to that point.

Thanks for all your help!

Joe Scrivens · Aug 28, 2014

Lscam580 said:
After you install the pushrods I honestly think your gonna travel down the perfect avenue.
Just make sure you pull the coil wire and give her a good roll over so you don't get a dry pushrod fire. You want to be able to hear for noises and not a tap from rockers jumping back up.
I'm waiting for this winter for the new stang paint. I'm laying down new ford charcoal metallic gray. That charcoal just catches my attention every time I see it wether on a f150 or a mustang just appealing to my eye

yum charcoal grey! I love dark colors. I painted mine with the Rustoleum Flat Paint and I AM IN LOVE!!!

These are the new pushrods I ordered

http://www.compperformancegroupstor...e_Code=CC&Product_Code=7826-16&Category_Code=

and will have tonight to slide into my motor to see finally if I am making progress with my valvetrain.

THANKS!

Gearbanger 101 · Aug 28, 2014

Those will work fine. I'm running stock pushrods in my 331 stroker.

Joe Scrivens · Aug 28, 2014

Gearbanger 101 said:
Those will work fine. I'm running stock pushrods in my 331 stroker.

This makes me feel more at ease =) Thanks!

Joe Scrivens · Aug 28, 2014

Lscam580 said:
That tenth could be just enough to get a small tap from valve to piston.

In minor cases I have done a pre load start with valve cover off and took my zero lash from there. And that will help tell that you are ok. But that is very old fashion. If you don't use shop rags to cover the other rockers could be a oil mess.
But in any case lets see where you are at after you install the other pushrods

Hey so I have an update.

Aside from the heads I finally put on my Rear centerline wheels with NITTO Extreme Drag tires today.

i DIDNT change the pushrods yet BUT i did a complete/semicomnplete tuneup. Spark plugs Oil and Oil filter. It seems that maybe the engine oil was all broken down and/or didnt have enough oil that was causing the tapping.

The tapping is pretty much GONE. I still get some tapping(which is more than likely from what I have been reading can primarily the XE Comp Cams Roller cams' aggressive open and closing ramps) but NOTHING at all like before. It sounds more cushioned and flowing and less clackitty-clackitty-clack. the engine is much more responsive and feels tougher. One weekend soon i WILL change the pushrods to the shorter 6.248 for testing, but for now I will leave the 6.350.

I forgot to Mention I have a 7 quart double sump MOROSO oil pan. I put 7 quarts plus one to make up for whatever gets lost in the oil galleys and oil filter. she feels stronger than ever.

could just be as simple as broken down Oil and not enough of it.

Gearbanger 101 · Aug 28, 2014

I would not scream that engine up to top RPM (or for that matter, drive it) until you verify that you've got the right push-rods in there. You could end up introducing one of your valves to your pistons you float them.

Joe Scrivens · Aug 29, 2014

Gearbanger 101 said:
I would not scream that engine up to top RPM (or for that matter, drive it) until you verify that you've got the right push-rods in there. You could end up introducing one of your valves to your pistons you float them.

yea im going to do more checks during the up coming weeks on all the valve train parts, that would be a bad end result to all the hard work on this motor. thanks

Tapping From Vavle Train Sounds Like Tractor?

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