.015 Head Gasket vs Pushrods
Thread Starter
Melting Slicks
Joined: Apr 2000
Posts: 2,145
Likes: 1
From: Ft. Walton Beach, Fl USA
.015 Head Gasket vs Pushrods
If you go from a .041 head gasket to a .015 should you automatically go with a shorter pushrod?
Can a too long pushrod contribute to or cause valve seal problems? If the pushrod is too long would it be slightly askew at the guide allowing oil seepage?
I have +.100 (.080 wall chromoly) pushrods which were recommended by TFS for their Twisted Wedge heads. I sold the TFS heads and installed WP Sportsman II's. I never changed the pushrods or checked the geometry other than visually. I've always had an oil seal prob with the Sportsman II's, first with their umbrella seals and then with teflon seals.
Since I changed the head gasket ( I had some port work done and new teflon seals installed) the problem seems to have gotten worse. But it only has the problem on some cylinders, not all.
Can a too long pushrod contribute to or cause valve seal problems? If the pushrod is too long would it be slightly askew at the guide allowing oil seepage?
I have +.100 (.080 wall chromoly) pushrods which were recommended by TFS for their Twisted Wedge heads. I sold the TFS heads and installed WP Sportsman II's. I never changed the pushrods or checked the geometry other than visually. I've always had an oil seal prob with the Sportsman II's, first with their umbrella seals and then with teflon seals.
Since I changed the head gasket ( I had some port work done and new teflon seals installed) the problem seems to have gotten worse. But it only has the problem on some cylinders, not all.
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
You should always check the valve train geometry when changing heads or anything else in the valve train for that matter. Just turn the motor over and watch the rocker tip ( probably a little easier with rollers ).
It should start one side of the valve stem and move an equal distance to the other side then back. If this is off a little, not too much to worry about, if it is off alot it will result in premature valve guide wear amongst other problems related to side loading the valve.
So yes, it will cause oil consumptin problems and no, you would not neccessarily have to change the pushrods when you change the thickness of the head gasket but I would check it.
BTW it was you doing the Rip van Winkle on the AR motor wasn't it, I never heard anymore about the motor ?
It should start one side of the valve stem and move an equal distance to the other side then back. If this is off a little, not too much to worry about, if it is off alot it will result in premature valve guide wear amongst other problems related to side loading the valve.
So yes, it will cause oil consumptin problems and no, you would not neccessarily have to change the pushrods when you change the thickness of the head gasket but I would check it.
BTW it was you doing the Rip van Winkle on the AR motor wasn't it, I never heard anymore about the motor ?
Last edited by MotorHead; Apr 7, 2005 at 11:56 PM.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Measure with a p-rod checker first before u buy p-rods.
Teflon seals can be a problem for street mtrs and i can't recall y. I think its the more miles driven on a street mtr gets the teflon hard where a race only mtr sees much less run time.
But the latest Chevy Performance seals like those used on the ZZ4 and fastburn heads are softer than teflon but stay on the guide and have read good results with them. Ok, called PC seals i think.
Have u tried a p-rod length checker? Only $10 from Summit (made by ProForm and Moroso). Easy to use - just follow instructions. Summit also sells custom length p-rods (Trick Flow) and i bought mine for <$90. This should get your rocker tip to travel from top 1/3 of vlv tip to lower 1/3 and back and as long as it stays off the edge it won't create side-loading on vlv stem and ruin the guides. But if the guides are aready ruined noth'n gonn'a help.
This a common problem/topic on the forum and u may want to do a scearch and review several posts.
Good luck. cardo0
But the latest Chevy Performance seals like those used on the ZZ4 and fastburn heads are softer than teflon but stay on the guide and have read good results with them. Ok, called PC seals i think.
Have u tried a p-rod length checker? Only $10 from Summit (made by ProForm and Moroso). Easy to use - just follow instructions. Summit also sells custom length p-rods (Trick Flow) and i bought mine for <$90. This should get your rocker tip to travel from top 1/3 of vlv tip to lower 1/3 and back and as long as it stays off the edge it won't create side-loading on vlv stem and ruin the guides. But if the guides are aready ruined noth'n gonn'a help.
This a common problem/topic on the forum and u may want to do a scearch and review several posts.
Good luck. cardo0
Pro
Joined: Jan 2002
Posts: 624
Likes: 0
From: Marietta ga
I have the Same problem
I have had my heads and block decked a couple of times (i.e. same effect as head gasket change). This is the second time I have rebuilt this motors because of oil consumption with in 10k miles. This time I think I have tracked the problem down to the valve train, hence the huge oil deposits on the intake runner side of the valves. My machinist says it is due most likely to early valve guide wear. I also have bent a couple of push rods since the motor was built. I also have a "Ghost" valve tick...l
It sounds like you and I are in the same boat. I am not sure what can be done, but as I sort through mine I will update you. Try and keep posting to this tread if you have any updates.
My heads are off the motor now and will be at the machine shop next week.
Good luck
It sounds like you and I are in the same boat. I am not sure what can be done, but as I sort through mine I will update you. Try and keep posting to this tread if you have any updates.
My heads are off the motor now and will be at the machine shop next week.
Good luck
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Nastee - Just do a visual check. rotate the motor over by hand and just watch the roller tips contact patch on the top of the valve stem. It will wipe back and forth in a pattern about 30 -40% of the valve stem tip. The correct length push rod will keep it centered the best.
Push rods are sold in .050 increments. Unless your get custom.
If you had the same heads and just changed gasket and you lost .030 your going to be off in length that amount. Also the base circle of cams is the big difference. I went from a Crane small base circle .930 inch to a Comp Cams 1.030. I had to change from .250 over length to .150 over length.
Push rods are sold in .050 increments. Unless your get custom.
If you had the same heads and just changed gasket and you lost .030 your going to be off in length that amount. Also the base circle of cams is the big difference. I went from a Crane small base circle .930 inch to a Comp Cams 1.030. I had to change from .250 over length to .150 over length.
Pro
Joined: Jan 2002
Posts: 624
Likes: 0
From: Marietta ga
Originally Posted by nastee383
If you go from a .041 head gasket to a .015 should you automatically go with a shorter pushrod?
Can a too long pushrod contribute to or cause valve seal problems? If the pushrod is too long would it be slightly askew at the guide allowing oil seepage?
I have +.100 (.080 wall chromoly) pushrods which were recommended by TFS for their Twisted Wedge heads. I sold the TFS heads and installed WP Sportsman II's. I never changed the pushrods or checked the geometry other than visually. I've always had an oil seal prob with the Sportsman II's, first with their umbrella seals and then with teflon seals.
Since I changed the head gasket ( I had some port work done and new teflon seals installed) the problem seems to have gotten worse. But it only has the problem on some cylinders, not all.
Can a too long pushrod contribute to or cause valve seal problems? If the pushrod is too long would it be slightly askew at the guide allowing oil seepage?
I have +.100 (.080 wall chromoly) pushrods which were recommended by TFS for their Twisted Wedge heads. I sold the TFS heads and installed WP Sportsman II's. I never changed the pushrods or checked the geometry other than visually. I've always had an oil seal prob with the Sportsman II's, first with their umbrella seals and then with teflon seals.
Since I changed the head gasket ( I had some port work done and new teflon seals installed) the problem seems to have gotten worse. But it only has the problem on some cylinders, not all.
