Porting & Milling 5.7L Heads
05-07-2005, 12:37 PM
#1
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Porting & Milling 5.7L Heads Hey guys,
I'm going to being doing some head porting here on some stock 241 cast 5.7L heads, and I'm wondering about how much milling is going to be ok coupled with my F13 cam.
I've seen lots of posts about milling 5.3L heads, but not much on 5.7L heads.
Anyhow, I'm thinking about milling twenty thousands (0.020) to raise the compression up (should be around 10.5:1 or so), but also adding a 2.02 intake valve and leaving the stock exhaust valve. Is 0.020 safe, can you go more? less?
Otherwise, if the milling won't work at all with that sized intake valve, I'll just leave the stock valves alone completely on this little experiment.
Thanks guys!
I'm going to being doing some head porting here on some stock 241 cast 5.7L heads, and I'm wondering about how much milling is going to be ok coupled with my F13 cam.
I've seen lots of posts about milling 5.3L heads, but not much on 5.7L heads.
Anyhow, I'm thinking about milling twenty thousands (0.020) to raise the compression up (should be around 10.5:1 or so), but also adding a 2.02 intake valve and leaving the stock exhaust valve. Is 0.020 safe, can you go more? less?
Otherwise, if the milling won't work at all with that sized intake valve, I'll just leave the stock valves alone completely on this little experiment.
Thanks guys!
05-07-2005, 12:54 PM
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.020" will be safe IMO. Not sure about anymore than that. I have milled a set .019" with that cam and it did fine. P/V clearance between 5.7 and 5.3 heads are the same.
05-07-2005, 01:12 PM
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Originally Posted by Bo White
.020" will be safe IMO. Not sure about anymore than that. I have milled a set .019" with that cam and it did fine. P/V clearance between 5.7 and 5.3 heads are the same.
05-07-2005, 01:45 PM
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Originally Posted by 66deuce
i thought i saw on a couple of posts that the 5.3 heads have a lower valve drop than the 5.7s?am i wrong?
05-07-2005, 02:53 PM
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Originally Posted by Bo White
I do not know exact #s but I have machined both types many times and they are close enough to call to each other. I have a couple of sets each I have to do and will measure them this evening
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05-09-2005, 12:45 AM
#8
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ttt
From the responses, looks like 0.020 mill on the stock 5.7L heads will be safe, but still not sure if that changes if you move up to 2.02 intake valves. Anyone else wanna chime in?
From the responses, looks like 0.020 mill on the stock 5.7L heads will be safe, but still not sure if that changes if you move up to 2.02 intake valves. Anyone else wanna chime in?
05-09-2005, 08:13 AM
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Originally Posted by Bo White
.020" will be safe IMO. Not sure about anymore than that. I have milled a set .019" with that cam and it did fine. P/V clearance between 5.7 and 5.3 heads are the same.
With a 2.02 valve installed in both a 5.7 and a 5.3 head the valve drop is .030" less on the 5.3 head. The 5.3 head has less piston to valve clearence than any other LSx cylinder head we have measured. So you should be ok with a .020" mill.
05-09-2005, 09:22 AM
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Thanx Brent, I was fixin to post about this since I measured this morning and found the same outcome as your post. Glad the big dogs here help like they do
05-09-2005, 09:38 AM
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Originally Posted by BrentB@TEA
5.3 head has more valve drop than a 5.7 head.
With a 2.02 valve installed in both a 5.7 and a 5.3 head the valve drop is .030" less on the 5.3 head. The 5.3 head has less piston to valve clearence than any other LSx cylinder head we have measured. So you should be ok with a .020" mill.
With a 2.02 valve installed in both a 5.7 and a 5.3 head the valve drop is .030" less on the 5.3 head. The 5.3 head has less piston to valve clearence than any other LSx cylinder head we have measured. So you should be ok with a .020" mill.
With a 2.02 valve installed in both a 5.7 and a 5.3 head the valve drop is .030" less on the 5.7 head
05-09-2005, 09:43 AM
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Originally Posted by josh99ta
Should that read...
Sorry if I'm confused here. Just wanting to make sure I'm understanding right. 5.3 and 5.7 both milled, the 5.7 will have MORE clearance than a 5.3 head, correct?
Sorry if I'm confused here. Just wanting to make sure I'm understanding right. 5.3 and 5.7 both milled, the 5.7 will have MORE clearance than a 5.3 head, correct?
valve drop is measured from the edge of the closed valve to the deck surface. A 5.3 heads valve is closer to the deck surface so therefore it has less valvedop than a 5.7 head.
05-09-2005, 11:01 AM
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brent, I just recently bought a set of 5.3's from a girl named crystal in florida. They come from your shop, ordered by a guy named john who was the person doing the work. 1 is used the other is new. They look like they have not been milled & there are a few nicks in the edge were they have been dropped lightly. I would like to get them milled a little for higher compression.
What would this cost me.
I also bought the cam with it she had, the #'s are ground off. Did this come from you also. She said it did.
Any tip or advice. Thanks!
What would this cost me.
I also bought the cam with it she had, the #'s are ground off. Did this come from you also. She said it did.
Any tip or advice. Thanks!
05-09-2005, 02:44 PM
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Originally Posted by (JRracing 24
brent, I just recently bought a set of 5.3's from a girl named crystal in florida. They come from your shop, ordered by a guy named john who was the person doing the work. 1 is used the other is new. They look like they have not been milled & there are a few nicks in the edge were they have been dropped lightly. I would like to get them milled a little for higher compression.
What would this cost me.
I also bought the cam with it she had, the #'s are ground off. Did this come from you also. She said it did.
Any tip or advice. Thanks!
What would this cost me.
I also bought the cam with it she had, the #'s are ground off. Did this come from you also. She said it did.
Any tip or advice. Thanks!
Milling up to .010 is 50.00 plus shipping. You may be able to get it done cheaper locally if you have any good machine shops close by.
As for the cam. We do not grind off numbers here at our shop. If you by a cam from us you get it like we get it from comp. If we do not want the lobe numbers to get out we ask that the customer does not tell anyone. If he tells oh well he tells we leave it at that.
05-09-2005, 03:13 PM
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Originally Posted by CarsRFun
sorry I am following this post as well, was the final virdict its okay
to mill .20 over with the 2.02 valves 5.7 heads with an F13 cam, does lsa matter?
Thanks
Jason
to mill .20 over with the 2.02 valves 5.7 heads with an F13 cam, does lsa matter?
Thanks
Jason