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Porting Heads

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Old Jul 23, 2004 | 11:50 PM
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Default Porting Heads

My engine builder for my dragster said he would look at my heads and see if he could port and polish any....would this help? my truck has the 4.8L im not sure if those heads are even worth doin it atleast he said he would clean them up as much as he could and if i wanted he would port them for me
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Old Jul 24, 2004 | 12:01 AM
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these heads aren't like what most people are used to when it comes to cleaning them up. every bit helps but make sure he gets some info on these heads before he touches them. they are easily rendered useless in the wrong hands. page BigKid, as for he just went through his heads and did some nice stuff to them.
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Old Jul 25, 2004 | 01:38 PM
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Definately be careful!! It's not a old school small block/big block. You might consider Patriot 5.3l heads if your wanting a good flowing set of heads. $1295 for heads With 2.02 intake & 1.57 exhaust valves complete with double springs!! Then you could sell your stock heads
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Old Jul 25, 2004 | 03:24 PM
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Originally Posted by Jason 98 TA
Definately be careful!! It's not a old school small block/big block. You might consider Patriot 5.3l heads if your wanting a good flowing set of heads. $1295 for heads With 2.02 intake & 1.57 exhaust valves complete with double springs!! Then you could sell your stock heads
Dont you think those valve sizes are a little bit to big for a 3.78" bore? Just about all of you aftermarket guys think we are running a 3.9" bore like the 5.7's or the 4.00" bore like the 6.0. Im beginning to wonder if most of you even know what you are talking about at all.
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Old Jul 25, 2004 | 04:54 PM
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Originally Posted by 02Reaper
Dont you think those valve sizes are a little bit to big for a 3.78" bore? Just about all of you aftermarket guys think we are running a 3.9" bore like the 5.7's or the 4.00" bore like the 6.0. Im beginning to wonder if most of you even know what you are talking about at all.
i agree on the valve issue. it seems that 2.02 intake 1.57 exhaust is the common valve size most ls1 guys go to after a head swap.not all, but alot. wouldn't it be overdoing it to stick those size valves on a 325ci motor?
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Old Jul 25, 2004 | 08:35 PM
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I just got finished working my own heads and I think they turned out nice. Basicly all I did was blend in the valve seats to the bowls, smoothed out the valve guides and cleaned up the ports and polished the combustion chambers. There is a post with pics I made a few weeks back when I finished the first one. I got some more yesterday that I can post up as well. I have to get them to the machine shop this week to have them milled then I will be putting them on weekend after next.
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Old Jul 26, 2004 | 05:44 AM
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Originally Posted by BigKID
I just got finished working my own heads and I think they turned out nice. Basicly all I did was blend in the valve seats to the bowls, smoothed out the valve guides and cleaned up the ports and polished the combustion chambers. There is a post with pics I made a few weeks back when I finished the first one. I got some more yesterday that I can post up as well. I have to get them to the machine shop this week to have them milled then I will be putting them on weekend after next.
Yeah, post them up. How about a write up on what to remove, comparing them to some stock pictures?
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Old Jul 26, 2004 | 10:09 AM
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I wish I would have taken some before and during pics for you guys but unfortunately I didnt. I want to see how mine pan out before I start telling everyone else what to do.
btw... here is the other thread with my first set of pics. https://ls1tech.com/forums/showthrea...highlight=head I will get the other ones up when I get a chance
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Old Jul 26, 2004 | 12:33 PM
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4.8Red, there are some good publications out on cleaning up the heads on the LSx platforms. Any knowledgable shop can help you out with minor work. Like stated above, be careful if the shop is not familiar with the LSx heads. They can definitely do more harm than good.
Also mentioned is the limits on the 4.8/5.3 bore. The 3.78" bore will cause "valve shielding" which negates any flow increases due to the valves being too close to the cylinder walls.
Last, the head work would probably not be realized without a cam upgrade. Lift is lift, no matter how much intake charge is available. There are a couple of guys sticking with the 4.8L and getting great results. Post a "Help needed" in this section regarding H/C combos and options. Good luck!
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