AFR heads, leaking valve cover studs
Thread Starter
Racer
Joined: Nov 2006
Posts: 264
Likes: 0
From: McLouth Kansas
AFR heads, leaking valve cover studs
This fall I installed a set of new AFR heads. I keep finding oil leaking out around the 4 valve cover studs.
I tried different gaskets and looked for a gasket surface flaw and they still seep oil and they mess up my clean engine.
Anyone with AFR heads have this problem ? and fix it. Grrrr
I tried different gaskets and looked for a gasket surface flaw and they still seep oil and they mess up my clean engine.
Anyone with AFR heads have this problem ? and fix it. Grrrr
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Welcome to world of crappy AFR heads. They might have the best flow in the biz, but they never fixed the oil return problems that they have known about since day one. They did not cast tall enough rails and the poor oil return has your valve seals and gaskets swiming in oil.
You can find articles on how to machine an oil return trough outside of the springs. You also need strong valve covers and rubber metal gaskets
You can find articles on how to machine an oil return trough outside of the springs. You also need strong valve covers and rubber metal gaskets
Thread Starter
Racer
Joined: Nov 2006
Posts: 264
Likes: 0
From: McLouth Kansas
Welcome to world of crappy AFR heads. They might have the best flow in the biz, but they never fixed the oil return problems that they have known about since day one. They did not cast tall enough rails and the poor oil return has your valve seals and gaskets swiming in oil.
You can find articles on how to machine an oil return trough outside of the springs. You also need strong valve covers and rubber metal gaskets
You can find articles on how to machine an oil return trough outside of the springs. You also need strong valve covers and rubber metal gaskets
The valve covers are from Billet Spec and they are cast covers BTW.
Since my seals and gaskets are swimming in oil.
>> I do have a oil burning problem and my rings are new, could this be the cause??
>>> And when my RPM is around 3200 or so 75mph my oil pressure drops off all at once and it acts like there is no oil in the pan and I have a Milton 6qt pan
>>> And there was no performance improvement in these heads, I was running some Bow Tie heads with some port work before I put the AFRs on.
Any thoughts
Burning Brakes
Joined: Aug 2006
Posts: 911
Likes: 8
Holey jesus....... If I had known that I would have never bought these heads and for the price I paid.
The valve covers are from Billet Spec and they are cast covers BTW.
Since my seals and gaskets are swimming in oil.
>> I do have a oil burning problem and my rings are new, could this be the cause??
>>> And when my RPM is around 3200 or so 75mph my oil pressure drops off all at once and it acts like there is no oil in the pan and I have a Milton 6qt pan
>>> And there was no performance improvement in these heads, I was running some Bow Tie heads with some port work before I put the AFRs on.
Any thoughts
The valve covers are from Billet Spec and they are cast covers BTW.
Since my seals and gaskets are swimming in oil.
>> I do have a oil burning problem and my rings are new, could this be the cause??
>>> And when my RPM is around 3200 or so 75mph my oil pressure drops off all at once and it acts like there is no oil in the pan and I have a Milton 6qt pan
>>> And there was no performance improvement in these heads, I was running some Bow Tie heads with some port work before I put the AFRs on.
Any thoughts
An easy way to gain capacity without having to pull motor and change the pan is to add an oil cooler...with a thermostat if you're on the street and want it to stay warm. It will add a quart or two which might help if you are running out.
Sorry to hear of your hassles.... I've got a one piece piece oil pan gasket thats giving me troubles....
sucks to put oil all over everything when it's nice and pretty.... 
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
AS Gkull explains the oil return is lousy, I have leaks at the back of my valve covers because the oil builds up there and have tried almost everything to fix it but they still leak.
Do a search this is common problem with AFR heads, built a brand new motor with AFR 227's and I still see oil under the car, and I can see where it is coming from with UV oil detection kit I have. If you are using a racing oil pump ( like high volume and high pressure ) the valve covers will be holding most of your oil if it is leaking all the way to the front valve cover bolts
Do a search this is common problem with AFR heads, built a brand new motor with AFR 227's and I still see oil under the car, and I can see where it is coming from with UV oil detection kit I have. If you are using a racing oil pump ( like high volume and high pressure ) the valve covers will be holding most of your oil if it is leaking all the way to the front valve cover bolts
Le Mans Master
Joined: Apr 2000
Posts: 7,562
Likes: 9
From: B'Ville NY
Cruise-In III Veteran
St. Jude Donor '05
Wow I thought they would have fixed this in their new heads. I had this problem after putting my 388 together.
From AFR, you can see the oil pooling with the engine off and not pumping oil to the heads:
This is after milling the groove you can see at the bottom of the springs and opening p the drain back hole some:
No more problem with burning oil and having my car look like the engine needs a new ring job when driving.
From AFR, you can see the oil pooling with the engine off and not pumping oil to the heads:
This is after milling the groove you can see at the bottom of the springs and opening p the drain back hole some:
No more problem with burning oil and having my car look like the engine needs a new ring job when driving.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
I take it you shared that repair with AFR and they couldn't care less??? 
That bit of additional machining included during the rest of the machining work on those heads would amount to about an extra 15 seconds of machining time per head. Hmmm....too much loss to consider such an improvement for their customers.... 
That bit of additional machining included during the rest of the machining work on those heads would amount to about an extra 15 seconds of machining time per head. Hmmm....too much loss to consider such an improvement for their customers....
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Drifting
Joined: Jul 2009
Posts: 1,534
Likes: 14
From: Dallas-Fort Worth TX
Now ya tell me. Hmmm, maybe that is where one of my unexplained oil leaks is coming from.
I have felpro blue with metal insert gaskets, but I have noticed when I remove the valve cover which are chrome, there is a oil pooled up in the rear lower corner of the gaskets ribbed edge. Wonder if its making its way thru and ending up around my dust shield and drain plug...
I have felpro blue with metal insert gaskets, but I have noticed when I remove the valve cover which are chrome, there is a oil pooled up in the rear lower corner of the gaskets ribbed edge. Wonder if its making its way thru and ending up around my dust shield and drain plug...
Thread Starter
Racer
Joined: Nov 2006
Posts: 264
Likes: 0
From: McLouth Kansas
In the head picture above, look at the stud hole for the bolting down the valve cover. There is a slot just behind the threads, in my case oil is working is way up those threads and out the top. That slot lets the oil have access to the threads. Then the oil drains along the bottom of the valve cover and goes down the side and back of the block. Very irritating to me !!
Can anyone answer me this question:: Will that heavy pooling of oil around the springs cause me to experience some burning of oil ? I assume the oil is getting past the valve guides. Sometimes and not always,, when I start the engine up I get a poof of smoke as one would expect to see with a head with worn valve guides. It does not always happen especially when the engine is cold and usually when it is hot and has cooled down some. As when me and my gf go out to eat and we leave and I start up and>>>> poof of smoke
And I have a standard pressure oil pump but it is a high volume type. And yep I have oil consumption and I see some faint smoke when the engine is running, especially during warm up or when I blip the throttle.
Can anyone answer me this question:: Will that heavy pooling of oil around the springs cause me to experience some burning of oil ? I assume the oil is getting past the valve guides. Sometimes and not always,, when I start the engine up I get a poof of smoke as one would expect to see with a head with worn valve guides. It does not always happen especially when the engine is cold and usually when it is hot and has cooled down some. As when me and my gf go out to eat and we leave and I start up and>>>> poof of smoke
And I have a standard pressure oil pump but it is a high volume type. And yep I have oil consumption and I see some faint smoke when the engine is running, especially during warm up or when I blip the throttle.
Last edited by Racer11; Nov 11, 2011 at 06:09 PM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Certainly, oil pooling around valve seals can't be helpful. And, if there is any pressure applied to that pooled oil by the movement of valve springs, etc. the problem will only be increased.
Thread Starter
Racer
Joined: Nov 2006
Posts: 264
Likes: 0
From: McLouth Kansas
I did a google and found that Iam not the only one to be dealing with this problem.
Looks like the only good fix is what smoketires has done to his heads.
That involves me taking the heads off for some machining work and spending some more dollars on something that I should not need to do because of poor design from AFR. My winter project I guess, and I had other stuff in mind.
Looks like the only good fix is what smoketires has done to his heads.
That involves me taking the heads off for some machining work and spending some more dollars on something that I should not need to do because of poor design from AFR. My winter project I guess, and I had other stuff in mind.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Ive never seen this on Eliminator heads and have sold/installed a bunch on cars that are running and being beat on
Did you contact AFR?
If you feel the drainback hole isnt big enough just pull the intake and do it right there on the car. Put something underneath the hole to catch any debris shouldnt take but a few minutes to do this.
Did you contact AFR?
If you feel the drainback hole isnt big enough just pull the intake and do it right there on the car. Put something underneath the hole to catch any debris shouldnt take but a few minutes to do this.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
In the head picture above, look at the stud hole for the bolting down the valve cover. There is a slot just behind the threads, in my case oil is working is way up those threads and out the top. That slot lets the oil have access to the threads. Then the oil drains along the bottom of the valve cover and goes down the side and back of the block. Very irritating to me !!
Can anyone answer me this question:: Will that heavy pooling of oil around the springs cause me to experience some burning of oil ? I assume the oil is getting past the valve guides. Sometimes and not always,, when I start the engine up I get a poof of smoke as one would expect to see with a head with worn valve guides. It does not always happen especially when the engine is cold and usually when it is hot and has cooled down some. As when me and my gf go out to eat and we leave and I start up and>>>> poof of smoke
And I have a standard pressure oil pump but it is a high volume type. And yep I have oil consumption and I see some faint smoke when the engine is running, especially during warm up or when I blip the throttle.
Can anyone answer me this question:: Will that heavy pooling of oil around the springs cause me to experience some burning of oil ? I assume the oil is getting past the valve guides. Sometimes and not always,, when I start the engine up I get a poof of smoke as one would expect to see with a head with worn valve guides. It does not always happen especially when the engine is cold and usually when it is hot and has cooled down some. As when me and my gf go out to eat and we leave and I start up and>>>> poof of smoke
And I have a standard pressure oil pump but it is a high volume type. And yep I have oil consumption and I see some faint smoke when the engine is running, especially during warm up or when I blip the throttle.
I was very bumbed about my New AFR motor build. Within a short period of time I was getting the blue smoke at start up or when you let off the gas at higher rpm. this was at very low miles. I was ashamed to drive a smoking Vette. So I replaced the cheap factory seals with nice PC seals. I saw what the problem was
the seals were below the oil level. the motor was ready for a rebuild before 20K miles so that is when I modded my 210's.You have some bigger problem if your oil pressure goes away at 3200 rpm. I would get the motor up to temp. then have a buddy watching the pressure gage and you watching with the breather or some other valve cover access removed and run the motor up to see if you ar indeed filling the valve covers with oil and draining the pan to the point of oil pressure loss.
Thread Starter
Racer
Joined: Nov 2006
Posts: 264
Likes: 0
From: McLouth Kansas
I PM you already, but Smoketires shows his machining. I was a little more agressive on my AFR 210's
I was very bumbed about my New AFR motor build. Within a short period of time I was getting the blue smoke at start up or when you let off the gas at higher rpm. this was at very low miles. I was ashamed to drive a smoking Vette. So I replaced the cheap factory seals with nice PC seals. I saw what the problem was the seals were below the oil level. the motor was ready for a rebuild before 20K miles so that is when I modded my 210's.
You have some bigger problem if your oil pressure goes away at 3200 rpm. I would get the motor up to temp. then have a buddy watching the pressure gage and you watching with the breather or some other valve cover access removed and run the motor up to see if you ar indeed filling the valve covers with oil and draining the pan to the point of oil pressure loss.
I was very bumbed about my New AFR motor build. Within a short period of time I was getting the blue smoke at start up or when you let off the gas at higher rpm. this was at very low miles. I was ashamed to drive a smoking Vette. So I replaced the cheap factory seals with nice PC seals. I saw what the problem was
the seals were below the oil level. the motor was ready for a rebuild before 20K miles so that is when I modded my 210's.You have some bigger problem if your oil pressure goes away at 3200 rpm. I would get the motor up to temp. then have a buddy watching the pressure gage and you watching with the breather or some other valve cover access removed and run the motor up to see if you ar indeed filling the valve covers with oil and draining the pan to the point of oil pressure loss.
BTW the cover gaskets still leaked or seeped.
Safety Car
Joined: Oct 2005
Posts: 3,570
Likes: 1
From: Algonac Michigan
I understand that you have a problem with the oil pressure and I can't really help you there but I have an idea on the leaking valve covers.
Is it possible that the nuts you are tightening on the studs are bottoming out on the shoulder of the stud so that they cant apply enough pressure to make the gasket seal?
Just a shot in the dark....
Is it possible that the nuts you are tightening on the studs are bottoming out on the shoulder of the stud so that they cant apply enough pressure to make the gasket seal?
Just a shot in the dark....
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
There must be too much oil in the valve train area, lowering the oil in the sump below the pickup. Another possibility is that the oil pickup head/tube isn't sealed well and is sucking air at higher engine rpms.