Maximum limit of milling heads?
12-29-2004, 12:08 PM
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Maximum limit of milling heads? Hello. I read through pages of search results, but never found a definitive answer.
I'm going to be running a TSP 233/239 cam with a set of ported 5.3L heads. After a bit of reading (thanks Spinmonster), I'd like to run a lot of static compression (around 12, if possible) as that is what is needed to make high overlap cams come to life.
How much can I mill the heads to get to this number before I run into valvetrain geometry or other issues? I will be flycutting the pistons so P/V is not an issue.
Here is a good link about static/dynamic CR and onger duration cams-
http://www.e30m3performance.com/myth...omp_ratio2.htm
Thanks
Ben
I'm going to be running a TSP 233/239 cam with a set of ported 5.3L heads. After a bit of reading (thanks Spinmonster), I'd like to run a lot of static compression (around 12, if possible) as that is what is needed to make high overlap cams come to life.
How much can I mill the heads to get to this number before I run into valvetrain geometry or other issues? I will be flycutting the pistons so P/V is not an issue.
Here is a good link about static/dynamic CR and onger duration cams-
http://www.e30m3performance.com/myth...omp_ratio2.htm
Thanks
Ben
Last edited by RX-Ben; 12-29-2004 at 12:16 PM.
12-29-2004, 12:18 PM
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Originally Posted by PREDATOR-Z
without flycutting your pistons, I'll doubt it. Call TSP they will tell you for sure, after all, they designed that cam 
Also- will I run into problems with the intake manifold sealing with a .050 mill?
thanks
Ben
12-29-2004, 12:34 PM
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According to the LS1\LS6 book: .060
Thats what I did on mine but I have to install them. I made this thread last week:
https://ls1tech.com/forums/generation-iii-internal-engine/253059-milled-heads-060-what-problems-can-i-expect.html
I already have dished diamond pistons with valve reliefs so my P-V clearance should be okay. The only thing that might be a problem is the intake alignment.
I read this from Robert Bartsch
The only thing you would need is shorter pushrods.
Thats what I did on mine but I have to install them. I made this thread last week:
https://ls1tech.com/forums/generation-iii-internal-engine/253059-milled-heads-060-what-problems-can-i-expect.html
I already have dished diamond pistons with valve reliefs so my P-V clearance should be okay. The only thing that might be a problem is the intake alignment.
I read this from Robert Bartsch
i have heads milled .055 and no intake alignment issues...some with .030, however, have alignment issues...
...these are not serious, however...to solve this problem remove the four metal alignment pins from the plastic intake and shave some metal off the diameter and length...use a file, sandpaper or whatever....
reinstall the pins and it should aling...you will know if you have a problem if the long intake bolts don't line up with the threads in the heads...
...these are not serious, however...to solve this problem remove the four metal alignment pins from the plastic intake and shave some metal off the diameter and length...use a file, sandpaper or whatever....
reinstall the pins and it should aling...you will know if you have a problem if the long intake bolts don't line up with the threads in the heads...
Last edited by rodent; 12-29-2004 at 01:39 PM.
12-29-2004, 01:36 PM
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I heard of some from accoss the pool shaving .080 off of them. I'm sure the deck is left super thin, but I'm not certain how much exactly.
Probably the best way to remove volume is angle milling. Less material removal is required to reach a specific volume. The process also straightens the angle between the valves and pistons some, so angle milling to reach a specific chamber volume will require smaller fly-cuts for the valves. The intake mounting bolt holes would require a little machining as stated already, but it's a pretty simple job. With either method of milling, the pushrod holes should be opened up some as well.
My last set of heads were angle milled a good bit. The new geometry hadn't any negative effects on any part of the valvetrain. All were examined after some beefy solid cam punnishment and all checked out fine-no odd wear patterns.
Probably the best way to remove volume is angle milling. Less material removal is required to reach a specific volume. The process also straightens the angle between the valves and pistons some, so angle milling to reach a specific chamber volume will require smaller fly-cuts for the valves. The intake mounting bolt holes would require a little machining as stated already, but it's a pretty simple job. With either method of milling, the pushrod holes should be opened up some as well.
My last set of heads were angle milled a good bit. The new geometry hadn't any negative effects on any part of the valvetrain. All were examined after some beefy solid cam punnishment and all checked out fine-no odd wear patterns.
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12-29-2004, 02:45 PM
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Thanks very much for the replies, this is encouraging information.
I have a feeling that my local shop won't have much experience with this- how much should the pushrod guides be opened up?
Thanks
Ben
I have a feeling that my local shop won't have much experience with this- how much should the pushrod guides be opened up?
Thanks
Ben
12-29-2004, 04:51 PM
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Originally Posted by NoseUp
I heard of some from accoss the pool shaving .080 off of them. I'm sure the deck is left super thin, but I'm not certain how much exactly.
Probably the best way to remove volume is angle milling. Less material removal is required to reach a specific volume. The process also straightens the angle between the valves and pistons some, so angle milling to reach a specific chamber volume will require smaller fly-cuts for the valves. The intake mounting bolt holes would require a little machining as stated already, but it's a pretty simple job. With either method of milling, the pushrod holes should be opened up some as well.
My last set of heads were angle milled a good bit. The new geometry hadn't any negative effects on any part of the valvetrain. All were examined after some beefy solid cam punnishment and all checked out fine-no odd wear patterns.
Probably the best way to remove volume is angle milling. Less material removal is required to reach a specific volume. The process also straightens the angle between the valves and pistons some, so angle milling to reach a specific chamber volume will require smaller fly-cuts for the valves. The intake mounting bolt holes would require a little machining as stated already, but it's a pretty simple job. With either method of milling, the pushrod holes should be opened up some as well.
My last set of heads were angle milled a good bit. The new geometry hadn't any negative effects on any part of the valvetrain. All were examined after some beefy solid cam punnishment and all checked out fine-no odd wear patterns.
12-29-2004, 07:29 PM
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This GA location is only temporary. Our home (in Destin, FL) was trashed by hurricane Ivan. Until it's fully repaired, we're in the house my wife purchased before we were married. I haven't been out to any shows or events in this area. The closest events are held in ATL. I haven't had the time for the drive (busy working on some products for you guys ). I usually run on an 1/8th mile track (Holt) near home in FL, and occasionally get the time to get out to the closest 1/4 mile track (Alabama). I haven't found much of anything around here. It's good for business focus anyway...
). I usually run on an 1/8th mile track (Holt) near home in FL, and occasionally get the time to get out to the closest 1/4 mile track (Alabama). I haven't found much of anything around here. It's good for business focus anyway...
12-29-2004, 11:03 PM
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Oh, sorry to hear about your home. I thought from the "UGA-town" that you might be somewhere near Athens, GA. We do have some friends down around the Tallahassee area if you're interested. Any hint as to what you're working on?
12-30-2004, 12:21 AM
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I'm right outside Athens, but only temporarily. Just a few more months, give or take...
We have about 40 products for the F-body and LSx engine in the works. A few will be available within the next couple weeks (hopefully). We should have our opening and should be setup as an LS1Tech sponser within the next couple weeks. Details will be released then, along with some pretty competitive opening prices for LS1Tech members.
Ben: Sorry, drifted a bit off-topic...Anyone doing headwork should know how much to open them. You could take a lot out w/o hurting anthing, but not much material removal would be required.
We have about 40 products for the F-body and LSx engine in the works. A few will be available within the next couple weeks (hopefully). We should have our opening and should be setup as an LS1Tech sponser within the next couple weeks. Details will be released then, along with some pretty competitive opening prices for LS1Tech members.
Ben: Sorry, drifted a bit off-topic...Anyone doing headwork should know how much to open them. You could take a lot out w/o hurting anthing, but not much material removal would be required.
