5.3L heads milled .030
02-21-2002, 11:46 PM
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5.3L heads milled .030 the searches I did were inconclusive. It seems that some people are stating they get over 11:1 compression w/ untouched 5.3 heads and others have to mill to get over 11:1. <img src="images/icons/confused.gif" border="0"> I don't want to wind up with some crazy compression ratio. I'm shooting for somewhere around 11.2:1
I just ordered some 5.3's milled .030, so what compression ratio am I going to end up with?
thanks,
Steve
I just ordered some 5.3's milled .030, so what compression ratio am I going to end up with?
thanks,
Steve
02-21-2002, 11:57 PM
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Re: 5.3L heads milled .030 It all depends on how much the chambers are opened up to unshroud the valves. I do a few things that bring the volume up a little because I know I can and still make 11:1. <img src="gr_stretch.gif" border="0">
Talk to your head porter and ask what he's doing with the chambers.
Scott
Talk to your head porter and ask what he's doing with the chambers.
Scott
02-22-2002, 12:01 AM
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Re: 5.3L heads milled .030 Depends on how much work the porter does in the chamber. When installing 2.02/1.57 valves in the truck heads, you have quite a bit of work in the chamber to unshroud the valves. So, your chamber is going to be opened up some there. If you are really worried about it, have the guy porting the heads CC the chambers before they mill them. If you are shooting for 11.2:1, then the chambers should be right at 60cc (which is what a stock 5.3l chamber is).
02-22-2002, 12:08 AM
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Re: 5.3L heads milled .030 thanks for the quick replies guys, <img src="gr_stretch.gif" border="0">
Jason,
they are GTP stage 2's, so do you know what Craig does to them chamber wise?
Steve
Jason,
they are GTP stage 2's, so do you know what Craig does to them chamber wise?
Steve
02-22-2002, 01:52 AM
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Re: 5.3L heads milled .030 Just for chits and giggles, here's pictures of a stock 5.3 chamber w/2.02 1.57 valves and my ported/polished chamber. This give you an idea of how much work is involved.....and how many cc can be added to the chambers.
Stock 5.3 Chamber
Ported/Polished 5.3
The valves are open around .300-.400 where they tend to be shrouded. If the links don't work, copy and paste into window.
Stock 5.3 Chamber
Ported/Polished 5.3
The valves are open around .300-.400 where they tend to be shrouded. If the links don't work, copy and paste into window.
02-22-2002, 07:26 PM
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Re: 5.3L heads milled .030 [quote]Originally posted by Top Fuel:
<strong>thanks for the quick replies guys, <img src="gr_stretch.gif" border="0">
Jason,
they are GTP stage 2's, so do you know what Craig does to them chamber wise?
Steve</strong><hr></blockquote>
He, as well as the other porters, unshroud the valve quite a bit. With those heads and taking 30 thousandths off, your compression should be around what you expected (maybe a little on the higher side).
<strong>thanks for the quick replies guys, <img src="gr_stretch.gif" border="0">
Jason,
they are GTP stage 2's, so do you know what Craig does to them chamber wise?
Steve</strong><hr></blockquote>
He, as well as the other porters, unshroud the valve quite a bit. With those heads and taking 30 thousandths off, your compression should be around what you expected (maybe a little on the higher side).
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03-02-2002, 09:53 PM
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Re: 5.3L heads milled .030 Steve, FYI, we have CC'd a few sets of GTP 5.3l truck heads milled 15 thousandths and the chamber comes out to close to ~60cc. This puts the compression (using factory pistons, head gasket,etc) at close to 11.3:1.
03-03-2002, 12:14 AM
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Re: 5.3L heads milled .030 [quote]Originally posted by Jason99T/A:
<strong>Steve, FYI, we have CC'd a few sets of GTP 5.3l truck heads milled 15 thousandths and the chamber comes out to close to ~60cc. This puts the compression (using factory pistons, head gasket,etc) at close to 11.3:1.</strong><hr></blockquote>
Thank you very much Jason. <img src="gr_stretch.gif" border="0"> Craig won't be starting my heads for a couple weeks, so I'll call him on Monday have it changed to .015"
thanks again,
Steve
<strong>Steve, FYI, we have CC'd a few sets of GTP 5.3l truck heads milled 15 thousandths and the chamber comes out to close to ~60cc. This puts the compression (using factory pistons, head gasket,etc) at close to 11.3:1.</strong><hr></blockquote>
Thank you very much Jason. <img src="gr_stretch.gif" border="0"> Craig won't be starting my heads for a couple weeks, so I'll call him on Monday have it changed to .015"
thanks again,
Steve
