Home porting on heads?
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From: Texas, it's like your state, but better.
well, it can be done, just takes ALOT of time, and some knowledge of what your doing. my first set of ported heads made 420 RW w/ a small cam through an M6 and a 9"
got a few pics up on my site.
got a few pics up on my site.
Polish the intake runner if you want. It wont make any difference, but the theory of "fuel puddling" is of no concern when you have an EFI injector hanging into the intake port shooting directly at the back of the intake valve.
Mabye if you yank your LS6 intake off and swap on a Holley Dominator carb should you be concerned with gas puddling your runners.
An ideal head port job for a turbo engine would be different than a blower engine, which would be different for a solid roller engine.. etc.
Mabye if you yank your LS6 intake off and swap on a Holley Dominator carb should you be concerned with gas puddling your runners.
An ideal head port job for a turbo engine would be different than a blower engine, which would be different for a solid roller engine.. etc.
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From: Germantown, MD
Originally Posted by Whistler
Polish the intake runner if you want. It wont make any difference, but the theory of "fuel puddling" is of no concern when you have an EFI injector hanging into the intake port shooting directly at the back of the intake valve.
Mabye if you yank your LS6 intake off and swap on a Holley Dominator carb should you be concerned with gas puddling your runners.
An ideal head port job for a turbo engine would be different than a blower engine, which would be different for a solid roller engine.. etc.
Mabye if you yank your LS6 intake off and swap on a Holley Dominator carb should you be concerned with gas puddling your runners.
An ideal head port job for a turbo engine would be different than a blower engine, which would be different for a solid roller engine.. etc.
Originally Posted by Whistler
I'm cracking up at the though of someone porting away at their cylinder heads with a dremel. Anyone with head porting experience knows why this is funny.. 
Teching In
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From: buffalo/rochester NY
what is wrong with dremel What is wrong with using a dremel, i have a dremel with the long reaching attachment. I'm no pro, but my heads turned out great, not major porting, just cleaning up flash,ridges, etc. thanks
Make sure you wear a resperator. The gases released for aluminum are very dangerous. Also, I have heard that LS1 heads need to be ported differently than the standard 350 heads. Find someone that has ported LS1 heads not LT1 heads. I am not trying to bash but just trying to help. Good luck. Let me know how it goes. I too would like to port a set of heads myself.
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Verdad Gallardo Thread Starter
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From: Germantown, MD
So when you guys are talking about a 5 angle valve job what exactly are you referring to? Are the vlave seats removable? If I wanted to enlarge my valves would this be difficult?
So is there a general consensus on whether fuel injected cars need to worry about fuel pooling?
Mike
So is there a general consensus on whether fuel injected cars need to worry about fuel pooling?
Mike
On The Tree
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Originally Posted by buschman
Can someone explain the theory behind not polishing the intake ports? Also would you port a head differently for a blown car than you would an N/A car?
Mike
Mike
I would also like to know why not to polish the intake runner.
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From: Germantown, MD
Any have any input on the intake runners? I've been watching head porting vids, but they are usually for carborated cars. So in that instance I can understand why not to polish the intake ports. But for fuel injection, is it going to make a difference? I would think it would just slow down velocity.
Mike
Mike
Originally Posted by Trans Am Kid
Sorry I didn't get this up last night, I had to work late. I will tell you the on thing porters don't want you to know, the angles of the valve job. intake angles on seat for my heads are 17,30,50,60,75, with 49 on valve face with 32 back cut, exhaust side was radius cut on seats, 45 valve face and 31 back cut. All the port work on my heads was blending the seats and bowls, removing some material around the guides and smoothing the area around guides, and removing the bump for the rocker bolts on the intake ports. Also DO NOT, I repeat DO NOT polish the intake ports, leave them rough. You can polish the exhaust ports and CC to reduce carbon build up. After all the port work was done my intake ports were only 207cc. Here are my before and after flow number, from the same bench, it was and old SF500 bench. By the way I have the stock valves just new angles on them.
stock
intake exhaust
.050 34 24
.100 68 52
.150 91 77
.200 122 96
.250 151 114
.300 178 133
.350 200 147
.400 214 156
.450 222 163
.500 219 170
.550 223 176
.600 227 180
Ported
intake exhaust
.050 35 25
.100 66 56
.150 94 84
.200 142 105
.250 172 125
.300 207 144
.350 227 159
.400 249 180
.450 255 198
.500 267 209
.550 275 213
.600 280 220
Exhaust port were flow test with out pipe, both stock and ported, the flow numbers would have been 15-20 cfm higher with a 1 3/4 pipe on them. I hope this info helps, I was happy with my results because I am only using an 02 LS6 cam.
stock
intake exhaust
.050 34 24
.100 68 52
.150 91 77
.200 122 96
.250 151 114
.300 178 133
.350 200 147
.400 214 156
.450 222 163
.500 219 170
.550 223 176
.600 227 180
Ported
intake exhaust
.050 35 25
.100 66 56
.150 94 84
.200 142 105
.250 172 125
.300 207 144
.350 227 159
.400 249 180
.450 255 198
.500 267 209
.550 275 213
.600 280 220
Exhaust port were flow test with out pipe, both stock and ported, the flow numbers would have been 15-20 cfm higher with a 1 3/4 pipe on them. I hope this info helps, I was happy with my results because I am only using an 02 LS6 cam.
And just a couple of corrections from earlier posts. The intake runners should have a slightly rough surface to provide some turbulence. This allows for a better air/fuel miture entering into the cylinder. Also, aluminum does not give off a gas when porting the heads. it's the dust that you need to worry about. I don't think many people will get the heads hot enough to turn aluminum to a gas
.Chris
Nice trick when porting to prevent aluminum from plugging your bits, use WD-40. A small amount will go along way and will act as a cutting agent. Works great! I only use 6 and 2 inch shanks for porting. Cannot reach the middle of the runners without a good 6 inch shank.
You really don't need to polish your heads with sandpaper grit great then 40. 80 is ok, but 80 really not needed on the intake side. Exhaust side you can go to 120 if you want but I have found "80 grit stars" work much better for polishing.
You really don't need to polish your heads with sandpaper grit great then 40. 80 is ok, but 80 really not needed on the intake side. Exhaust side you can go to 120 if you want but I have found "80 grit stars" work much better for polishing.
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From: Germantown, MD
Originally Posted by Cliff
Nice trick when porting to prevent aluminum from plugging your bits, use WD-40. A small amount will go along way and will act as a cutting agent. Works great! I only use 6 and 2 inch shanks for porting. Cannot reach the middle of the runners without a good 6 inch shank.
You really don't need to polish your heads with sandpaper grit great then 40. 80 is ok, but 80 really not needed on the intake side. Exhaust side you can go to 120 if you want but I have found "80 grit stars" work much better for polishing.
You really don't need to polish your heads with sandpaper grit great then 40. 80 is ok, but 80 really not needed on the intake side. Exhaust side you can go to 120 if you want but I have found "80 grit stars" work much better for polishing.
Mike
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From: Concord NC.
while there are some things you can do to your stock ports to pick up the airflow there is no guarantee of good results. You could very easily trash your heads and drop them from the stock airflow. One of the first sets of heads I did after I had a flowbench to use actually lost air with the first few backyard type of mods I did and only after doing a good valve job and applying some of the things I learned from some expert head porters did I start seeing real gains. Having done several sets of heads now I know a lot more about where to start and what to look for but it is still not easy to really pick up the flow in a set of heads and still keep the ports small. Though it is not that hard to just hog out a port and get some decent numbers but that never makes for a good running set of heads. My opinion on it all is I guess if you have the time and money to spare then get your stock heads flowed then try your hand at porting and get them flowed when you are done. Dont be disappointed if you dont get the results you expect though. If you want real results bring your heads to a reputable head porter and spend the extra money.
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From: Germantown, MD
I'm not saying home porting is for everyone. I truly hope I don't lose any CFM as I'm not shooting for a stage 3 port job. It just seems to me that machinists act like head porting is some black art and very few are willing to share what they know. I've found a couple of very helpful people in this thread that have given me good advice. I think with their advice and the idea that I just want to open the heads up a tad bit. I think I will show an increase. I'll report back with results.
Now I just need to find someone who will bench test them for a resonable amount of $.
Mike
Now I just need to find someone who will bench test them for a resonable amount of $.
Mike
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From: Bedford, TX
To be honest with you I had a local (well known) head porter do my valve job, all I asked him for was the angles, not the width of the angles, he also told me about the radius exhaust angles, i too have no idea what that means but, it looked like the exhaust seat had no defined angles to it, what ever he did must work cause my heads flow damn good for what I did to them. FWIW the guy that did my valve job, has some 5.3l heads flowing 240@.600 on the exhuast side WITHOUT a pipe, I watched him flow a set right after he flow tested my heads.
carbide cutters should be used by experienced head porters, sand stones cut slower on aluminum so you can monitor your progress better. A cheaper alternative to WD-40 is the wal-mart brand spray lubricant it works just as good and is alot cheaper if you plan on doing a lot of cutting with the carbide cutters. If you screw up your heads I have a few extra sets laying around the shop.
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From: Germantown, MD
I'm looking at my gaskets and just realized there is no intake plenum gasket. How do I scribe the intake ports to know where to cut? Anyone have a template or some advice? These are new heads so it's not like there is dirt or any residue for me to reference.
Mike
Mike
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From: Flower Mound, TX
I've done several sets that have proven great results very similar to Vents. One trick I picked up is to cover the valve seat with electrical tape to keep from damaging it with the chank of the bit. If you think you can't control the carbide tip enough when you're near the seats then you need to back off the caffeine and find a better way to steady your hand
Alot of guys think it's a black art, but mostly it's an art of feel. It's hard to describe exactly where you need to make shape changes, but when I run my finger over them, I can tell you when they are good. I know that doesn't help though. I'll see if I can get some pics of the work I've done on LS1 heads.
BTW, find a good trashed head to practice on first.. it'll help you get familar with the ports, and also give you an idea on how fast the different bits can cut.
Alot of guys think it's a black art, but mostly it's an art of feel. It's hard to describe exactly where you need to make shape changes, but when I run my finger over them, I can tell you when they are good. I know that doesn't help though. I'll see if I can get some pics of the work I've done on LS1 heads.
BTW, find a good trashed head to practice on first.. it'll help you get familar with the ports, and also give you an idea on how fast the different bits can cut.