Engine Build Time
Thread Starter
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Elite HDF Member
Joined: Sep 2012
Posts: 3,791
Likes: 57
From: N Texas
AMS told me no worries, but that was with a .008" in the hole deck height. Here is my plan(as of this moment in time...): Install the rear cylinder and get its' deck height, call AMS and see if they can get me the .030" head gaskets - if so, no claying, if not then I will discuss the situation with AMS and decide.
Just wondering, does claying ruin your head gaskets?
Seasoned HDF Member
Joined: Mar 2007
Posts: 66,948
Likes: 4,573
From: TOAK western branch
You sure know what is grinding around in my brain
AMS told me no worries, but that was with a .008" in the hole deck height. Here is my plan(as of this moment in time...): Install the rear cylinder and get its' deck height, call AMS and see if they can get me the .030" head gaskets - if so, no claying, if not then I will discuss the situation with AMS and decide.
Just wondering, does claying ruin your head gaskets?
AMS told me no worries, but that was with a .008" in the hole deck height. Here is my plan(as of this moment in time...): Install the rear cylinder and get its' deck height, call AMS and see if they can get me the .030" head gaskets - if so, no claying, if not then I will discuss the situation with AMS and decide.
Just wondering, does claying ruin your head gaskets?
Road Captain
Joined: Jun 2013
Posts: 669
Likes: 4
From: Rockwall,TX
You sure know what is grinding around in my brain
AMS told me no worries, but that was with a .008" in the hole deck height. Here is my plan(as of this moment in time...): Install the rear cylinder and get its' deck height, call AMS and see if they can get me the .030" head gaskets - if so, no claying, if not then I will discuss the situation with AMS and decide.
Just wondering, does claying ruin your head gaskets?
AMS told me no worries, but that was with a .008" in the hole deck height. Here is my plan(as of this moment in time...): Install the rear cylinder and get its' deck height, call AMS and see if they can get me the .030" head gaskets - if so, no claying, if not then I will discuss the situation with AMS and decide.
Just wondering, does claying ruin your head gaskets?
1 time use on head gaskets after you squish em they are done X2 on what soft02 said
Stellar HDF Member
Joined: May 2009
Posts: 2,066
Likes: 97
From: Northern VA
Alan,
I'm just asking questions. .nothing more
This is the one area of building a motor I've been somewhat confused on. You've gotten the cylinders on with new pistons, you can tell they're x amount below flush at TDC, now what? How do you know the valve with a higher lift cam won't contact the piston eyebrow etc, and if it does. .bigger head gasket? Please post your findings (either from AMS or from elsewhere) as I'd like to know.
Matt
I'm just asking questions. .nothing more
This is the one area of building a motor I've been somewhat confused on. You've gotten the cylinders on with new pistons, you can tell they're x amount below flush at TDC, now what? How do you know the valve with a higher lift cam won't contact the piston eyebrow etc, and if it does. .bigger head gasket? Please post your findings (either from AMS or from elsewhere) as I'd like to know.
Matt
Road Captain
Joined: Jun 2013
Posts: 669
Likes: 4
From: Rockwall,TX
Alan,
I'm just asking questions. .nothing more
This is the one area of building a motor I've been somewhat confused on. You've gotten the cylinders on with new pistons, you can tell they're x amount below flush at TDC, now what? How do you know the valve with a higher lift cam won't contact the piston eyebrow etc, and if it does. .bigger head gasket? Please post your findings (either from AMS or from elsewhere) as I'd like to know.
Matt
I'm just asking questions. .nothing more
This is the one area of building a motor I've been somewhat confused on. You've gotten the cylinders on with new pistons, you can tell they're x amount below flush at TDC, now what? How do you know the valve with a higher lift cam won't contact the piston eyebrow etc, and if it does. .bigger head gasket? Please post your findings (either from AMS or from elsewhere) as I'd like to know.
Matt
Bingo ..you have hit on the magic part of race motor building...will it go boom? .. to find out there are several ways to find out you can do the math based of measuring everything or you can go direct route by measuring an assembled motor. one way in to assemble and full torque the bolts bring piston to TDC and using a very low pressure valve spring push the valve down til it contacts and take a measurment subtract that from your total cam lift at the valve and thats your clearance. Another methode would be the model clay fully mocked up motor run it through a complete cycle take apart and measure the thickness of the clay on the piston I am sure there are more methods those ar the ones I know of
Thread Starter
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Elite HDF Member
Joined: Sep 2012
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Likes: 57
From: N Texas
Matt I read a lot on this subject then backed off when AMS told me no worries. Several things have big impacts on whether you decide to clay or not. One of the biggest reasons I did a 107" BB was to get the pistons with bigger valve reliefs - these pistons(CP) are used with much bigger cams than I chose, so confidence there. Also, the valve lift at TDC Compression is the # that counts, so if you pick a cam with a relative normal # there it helps. Then of course the squish/quench clearance as you have brought up, if you use a more common amount say .035" to .040" then less worries. Lastly, and probably most importantly is the shops' experience doing your heads and cylinders - no telling how many motor builds AMS has done and Eric did not flinch at all when I brought this subject up even with shaving .032" off my heads for compression. Of course the conservative thing to do is to go ahead and clay it, just adds more time.... And at my pace......
Here is a reference that is interesting:
http://www.nrhsperformance.com/tech_valvetopiston.shtml
Here is a reference that is interesting:
http://www.nrhsperformance.com/tech_valvetopiston.shtml
Last edited by HD Pilot; Mar 7, 2014 at 11:29 AM.
Road Captain
Joined: Jun 2013
Posts: 669
Likes: 4
From: Rockwall,TX
Matt I read a lot on this subject then backed off when AMS told me no worries. Several things have big impacts on whether you decide to clay or not. One of the biggest reasons I did a 107" BB was to get the pistons with bigger valve reliefs - these pistons(CP) are used with much bigger cams than I chose, so confidence there. Also, the valve lift at TDC is the # that counts, so if you pick a cam with a relative normal # there it helps. Then of course the squish/quench clearance as you have brought up, if you use a more common amount say .035" to .040" then less worries. Lastly, and probably most importantly is the shops' experience doing your heads and cylinders - no telling how many motor builds AMS has done and Eric did not flinch at all when I brought this subject up even with me shaving .032" off the heads for compression. Of course the conservative thing to do is to go ahead and clay it, just adds more time.... And at my pace......
with the build you are doing being so common as it is, the piston manufacturer usually tells you piston good up t X lift anyway and AMS having done so many I am sure you can rely on their word I think the only thing you might want to know is what is your actual squish which you can measure with the motor dissassembled
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Thread Starter
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Elite HDF Member
Joined: Sep 2012
Posts: 3,791
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From: N Texas
Hardly any time to work today, but was able to install the rear cylinder in about 1/4 the time it took yesterday - much better with the Kramm-Lox and the ring compressor is very nice:
Looks like I'm about .003" down on the rear cylinder too. Anybody else notice that aftermarket pistons bring up the deck height .005"?
Looks like I'm about .003" down on the rear cylinder too. Anybody else notice that aftermarket pistons bring up the deck height .005"?
Last edited by HD Pilot; Mar 7, 2014 at 03:22 PM.
Road Master
Joined: Apr 2012
Posts: 1,096
Likes: 17
From: San Jose
IIRC the CP pistons have a compression height of 1.085" not sure what stock is?
When I did my bottom end I used the H beam rods. Seems these are a bit longer than stock as well. My pistons were out of the hole +.006, I had to get the .040" head gasket.
When I did my bottom end I used the H beam rods. Seems these are a bit longer than stock as well. My pistons were out of the hole +.006, I had to get the .040" head gasket.