Maximum Head Milling Possible?
07-06-2008, 09:49 AM
#3
Thanks for the link, but that really was not what I was after.
I was once a tool-maker, so alignment is something I've already considered.
I've also done the compression measurements.
What I am after is experience from people who have milled say .100" off their stock head decks. Was there any noticeable warp-age or lifting after say 5,000 miles on naturally aspirated engines?
Specialized head manufactures have deck thicknesses of .750" and can safely be milled .100". I am guessing the GM head deck thickness is .550" from the factory.
It's not a question of how it should be done, or why it should be done, or even how much.
I was once a tool-maker, so alignment is something I've already considered.
I've also done the compression measurements.
What I am after is experience from people who have milled say .100" off their stock head decks. Was there any noticeable warp-age or lifting after say 5,000 miles on naturally aspirated engines?
Specialized head manufactures have deck thicknesses of .750" and can safely be milled .100". I am guessing the GM head deck thickness is .550" from the factory.
It's not a question of how it should be done, or why it should be done, or even how much.
read all the thread it might help.
read what tony mamo from afr said.
https://ls1tech.com/forums/showthrea...ght=milled+afr
abby
read what tony mamo from afr said.
https://ls1tech.com/forums/showthrea...ght=milled+afr
abby
07-06-2008, 01:36 PM
#4
TECH Senior Member
What do you hope to achieve with 48.2cc heads. Flow will seriously be hurt.
Whatever your purpose, milling is not the way to do it, you should consider welding the chambers to make them smaller, same as PP used to do to their 6.0 castings.
Whatever your purpose, milling is not the way to do it, you should consider welding the chambers to make them smaller, same as PP used to do to their 6.0 castings.
07-06-2008, 01:54 PM
#6
TECH Senior Member
Yeah, but unless the OP is off his rockers, I'm sure he realises that. Anyone considering 48cc heads must know what he is doing.
Vee8 that is one sweet setup man, it makes my mouth water and gives me sweaty hands. Shiiiiit
Vee8 that is one sweet setup man, it makes my mouth water and gives me sweaty hands. Shiiiiit
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07-07-2008, 03:29 AM
#8
TECH Senior Member
Plenty experience, enough to tell me that you just do not mill a LS1/LS2/LS6 head to 48cc and expect a high performing output. What you are asking doesn't make rational sense in motor building. If super high compression is your goal, then that is why they invented domed pistons.
You still did not tells us what you're trying to achieve!
You still did not tells us what you're trying to achieve!
07-07-2008, 03:55 AM
#10
Okay, I think it is obvious I'm trying to raise my compression over 12:1
But, I am not going to switch out my -14cc pistons.
There is an easier way.
Okay Predator-Z, you claim to have experience, let's hear it.
What have you milled you heads down to and the end results?
But, I am not going to switch out my -14cc pistons.
There is an easier way.
Okay Predator-Z, you claim to have experience, let's hear it.
What have you milled you heads down to and the end results?
07-07-2008, 04:33 AM
#11
stock is 10:1.
dome pistons and 5.3 heads but bee careful!
/end thread
Besides for asking for answers to a question that would cost thousands of dollars to answer. The reason why people go with what works is because it is what makes money for those doing the work. Nobody cares about hypothetical questions.
dome pistons and 5.3 heads but bee careful!
/end thread
Besides for asking for answers to a question that would cost thousands of dollars to answer. The reason why people go with what works is because it is what makes money for those doing the work. Nobody cares about hypothetical questions.
07-07-2008, 07:27 AM
#13
TECH Senior Member
Mine was easy, 58cc heads, pistons -2cc, 4.03 bore .050 gasket, 6.125 rods, .010 out deck height,3.622 stroke
This is the info I need:
Bore
Stroke
Rod Length
Number of cylinders=8
Deck Height(piston in or out of hole, how much?)
Piston Dome or Dish (- for a dome + for a dish)
Compressed Head gasket thickness
Then I will give an experienced answer
07-10-2008, 07:48 AM
#14
PREDATOR-Z:
I'm not asking for an analysis of my compression.
The question is: "What is the maximum anyone has milled their 243 series heads?"
Nothing hypothetical here.
The answer would come in the form of thousands of an inch (.xxx"), or millimeters (x.xx mm).
I'm not asking for an analysis of my compression.
The question is: "What is the maximum anyone has milled their 243 series heads?"
Nothing hypothetical here.
The answer would come in the form of thousands of an inch (.xxx"), or millimeters (x.xx mm).
And this is for a 346? or your 402? or you Avalanche 5.3L?
Mine was easy, 58cc heads, pistons -2cc, 4.03 bore .050 gasket, 6.125 rods, .010 out deck height,3.622 stroke
This is the info I need:
Bore
Stroke
Rod Length
Number of cylinders=8
Deck Height(piston in or out of hole, how much?)
Piston Dome or Dish (- for a dome + for a dish)
Compressed Head gasket thickness
Then I will give an experienced answer
Mine was easy, 58cc heads, pistons -2cc, 4.03 bore .050 gasket, 6.125 rods, .010 out deck height,3.622 stroke
This is the info I need:
Bore
Stroke
Rod Length
Number of cylinders=8
Deck Height(piston in or out of hole, how much?)
Piston Dome or Dish (- for a dome + for a dish)
Compressed Head gasket thickness
Then I will give an experienced answer
Last edited by Gregory; 07-10-2008 at 07:54 AM.
07-10-2008, 08:56 AM
#15
You don't even know what your asking.
Anyone with the knowledge to answer you is gonna need more info that that to give you a correct answer. Different setups for different people.
Some people mill only so much others more because they have other supporting mods for the extra milling. Besides predator z already answered once.
Anyone with the knowledge to answer you is gonna need more info that that to give you a correct answer. Different setups for different people.
Some people mill only so much others more because they have other supporting mods for the extra milling. Besides predator z already answered once.
07-10-2008, 09:08 AM
#16
Dude Predator knows his ****. And he is correct. If your wanting to up your comp. & keep decent flowing heads, your not gonna want to mill them that much.
Your just not getting the big picture. It's not a matter of can it be done it's a matter of it being a move backward. your not gonna make any more power & your head flow will seriously suffer. You don't have to have head milling experience to realize that. It's basic engine building math.
Your -14cc piston are killing you so if your unwilling to swap those I highly doubt you'll see over 12:1 comp. What your wanting to do does not make sense from a engine builder point of view.
Now if you had some -2cc pistons & some milled 5.3 heads or 243 heads, then you would be able to obtain your goal much easier & keep great flow in the heads. But the way your attempting to approach this is setting you up for future failure.
Your just not getting the big picture. It's not a matter of can it be done it's a matter of it being a move backward. your not gonna make any more power & your head flow will seriously suffer. You don't have to have head milling experience to realize that. It's basic engine building math.
Your -14cc piston are killing you so if your unwilling to swap those I highly doubt you'll see over 12:1 comp. What your wanting to do does not make sense from a engine builder point of view.
Now if you had some -2cc pistons & some milled 5.3 heads or 243 heads, then you would be able to obtain your goal much easier & keep great flow in the heads. But the way your attempting to approach this is setting you up for future failure.
07-10-2008, 11:21 AM
#17
Hey, you guys are getting into this far too deep. Everything that has been brought up has already been considered, or is not a concern. I appreciate your trying to help by considering the extraneous factors, but they have already been taken care of.
I am sure Predator-Z is a very smart person. I am sure he knows his formulas, he has ported many heads, he has built many powerful engines, owned a speed shop or two, and won lots of races. But, I am not asking for all that, and I am not asking for any opinions.
I certainly hope this clears things up. The question is simple.
I am sure Predator-Z is a very smart person. I am sure he knows his formulas, he has ported many heads, he has built many powerful engines, owned a speed shop or two, and won lots of races. But, I am not asking for all that, and I am not asking for any opinions.
I certainly hope this clears things up. The question is simple.
07-10-2008, 11:41 AM
#19
Hey, you guys are getting into this far too deep. Everything that has been brought up has already been considered, or is not a concern. I appreciate your trying to help by considering the extraneous factors, but they have already been taken care of.
I am sure Predator-Z is a very smart person. I am sure he knows his formulas, he has ported many heads, he has built many powerful engines, owned a speed shop or two, and won lots of races. But, I am not asking for all that, and I am not asking for any opinions.
I certainly hope this clears things up. The question is simple.
I am sure Predator-Z is a very smart person. I am sure he knows his formulas, he has ported many heads, he has built many powerful engines, owned a speed shop or two, and won lots of races. But, I am not asking for all that, and I am not asking for any opinions.
I certainly hope this clears things up. The question is simple.
Well with that being said what advantage are you tryin to achieve on a high comp. motor with very poor flowing heads??
I know there is a suggested thickness for the deck on LS based heads that you should not mill past due to how the Aluminum will react to heat & pressure considering the warping of the decks, but I cannot remember the minimum thickness. Personally I wouldn't mill a set of heads too far just b/c of how easily Aluminum can be distorted under heat/pressure. I'd upgrade heads before risking milling a set so thin that the heads are rendered useless in any application due to being severly warped from being too thin.
