Port and Polish by Comiittee thread (Cool pics throughout)
03-13-2008, 03:49 PM
#31
Rennlist Member
Good stuff. I actually read every word, but im weird like that.
You know where im going with this. Im pretty good at the boring jobs. I did a pretty good job with port matching the US Ljet "U" to the euro throttle body. It took FOREVER with the dremel, but it was possible. However, with the air tools, it cut that opening dangerously fast. Kind of like when i was cutting the piston cut outs.
If i have time, do you think its worth just cleaning up the ports, leaving the valves in place, and just doing a "shade tree" job?? I could see hitting that intake and exhuast opening and makin it nice and smooth, but i certainly wouldnt want to do it, if it is not worth it, or if i could do more damage than good
keep it going!
Mk
You know where im going with this. Im pretty good at the boring jobs. I did a pretty good job with port matching the US Ljet "U" to the euro throttle body. It took FOREVER with the dremel, but it was possible. However, with the air tools, it cut that opening dangerously fast. Kind of like when i was cutting the piston cut outs.
If i have time, do you think its worth just cleaning up the ports, leaving the valves in place, and just doing a "shade tree" job?? I could see hitting that intake and exhuast opening and makin it nice and smooth, but i certainly wouldnt want to do it, if it is not worth it, or if i could do more damage than good
keep it going!
Mk
I think I'm qualified to write about this. However, just because I think I am, doesn't mean that I actually am qualified.
What does that mean? It means that there is not a guide written for how to port heads...that I've ever seen...that is worth the price of printing it. It means that porting and polishing are kind of up to the "expert" that has the stuff in front of him. It means that the whole thing is kind of a "mystery" art. A bunch of trial and error....more error....in most cases.
The other problem is discussing this is that it is going to have to be very long and verbose to do anybody at home any good. And....I tend to be very verbose to start with! That comes from writing for magazines. They generally want filler (details.) Therefore, anything I write will be very, very boring for someone who doesn't care....and probably boring for those that do care!
The amount of information needed to help anybody at home is significant. There is no possible way to do this in one or two sittings. My eyes would fall out, my wrists would fall off, and you would all be looking for something to slash your wrists to end the boredom.
If you guys are game...I'll try. You'll have to tell me when I've bored you to death and ask me to stop. The first thing we will need is someone to tell me how to post pictures on this Forum. I'm too stupid to figure this out on my own. The instructions will need to be specific and detailed.
With pictures, I can show what tools work best, for me. I also have two sets of heads sitting here, waiting to be ported. They are scheduled to be started in 3 weeks. That will not happen. I've got 3 transmissions, 3 engines to finish, two engines to "trial assemble", a couple of race cars that need to go to the track, and a bunch of regular work to do before the heads will get touched. However, I can use those heads to show details.
I started porting heads when I was 16. Forty years ago. Volkwagen stuff. I started with a Dremel tool and used Cratex Rubberized Abrasives to polish. Very slow work. I burned out an untold quanity of Dremel tools, when I found a big electric tool at Sears. Worked much faster. Spun at one speed. Control was poor, as it was large. I found a variable speed controller for it. it worked pretty good, but was very tiring to control, as it was bulky and heavy. I burned out several controllers and tools. Finally went to air in about '72. Used one of those 110 volt Sears compressors. Melted several. They would actually smoke and burn up. I'd have to stop every few minutes and wait for the compressor to catch up every few minutes. I liked air. The tools were smaller and they had speed controls right on them. When I opened my shop in 1975, I finally got a 3 phase big conpressor and I could ruin heads at a much quicker pace. I bought my first flow bench in about 1980. This did not help with porting skills, but helped with shape and finish issues.
In that time, I've literally ported thousands of individual ports. I've ruined several, expecially in the "development" stage of working up a head design. I do not flow every port. This would cost a fortune, if someone actually did it. Generally, most of the people that claim they measure every port, lie about this. A set of ported heads, individually flowed, would cost more than the rest of the engine combined. It takes a bunch of time and effort. CNC stuff helped with this issue. Someone could develop a port design that worked and duplicate it many times over. Made individual port flow checking not needed.
The downside of CNC porting is that it is also possible to duplicate crappy ports......exactly! You can ruin ports in volume! However, the good news is that they will be ruined exactly the same way! So, the first step is to make a port that works, then duplicate it as close as possible.
To develop a port and CNC duplicate it for under $10,000.00 is not going to happen! The time required to do the development work, build fixtures to hold the head, and then program a 4 axis machine to dupicate that port takes a zillion hours. I think Mike Simmard can shed light on how tough it would be and the time required to fixture and program a port for machining. The good news is that the next 1000 would be quick and cheap.
That being said, here's what I won't do and what I actually do. I will not cut a cast iron port. Too slow, too dirty, way too hard. I do heads that I've developed and have patterns for. I don't have the time to develop heads that I've not worked up in the past. When I need a trick head for one of my big blocks Chevys, I call and buy heads from the best people I can find. I like Air Flow Research heads and I've had success with Dart.
So, what you think? Too boring? Too much effort. Let me know and I'll quit or continue.
greg brown
What does that mean? It means that there is not a guide written for how to port heads...that I've ever seen...that is worth the price of printing it. It means that porting and polishing are kind of up to the "expert" that has the stuff in front of him. It means that the whole thing is kind of a "mystery" art. A bunch of trial and error....more error....in most cases.
The other problem is discussing this is that it is going to have to be very long and verbose to do anybody at home any good. And....I tend to be very verbose to start with! That comes from writing for magazines. They generally want filler (details.) Therefore, anything I write will be very, very boring for someone who doesn't care....and probably boring for those that do care!
The amount of information needed to help anybody at home is significant. There is no possible way to do this in one or two sittings. My eyes would fall out, my wrists would fall off, and you would all be looking for something to slash your wrists to end the boredom.
If you guys are game...I'll try. You'll have to tell me when I've bored you to death and ask me to stop. The first thing we will need is someone to tell me how to post pictures on this Forum. I'm too stupid to figure this out on my own. The instructions will need to be specific and detailed.
With pictures, I can show what tools work best, for me. I also have two sets of heads sitting here, waiting to be ported. They are scheduled to be started in 3 weeks. That will not happen. I've got 3 transmissions, 3 engines to finish, two engines to "trial assemble", a couple of race cars that need to go to the track, and a bunch of regular work to do before the heads will get touched. However, I can use those heads to show details.
I started porting heads when I was 16. Forty years ago. Volkwagen stuff. I started with a Dremel tool and used Cratex Rubberized Abrasives to polish. Very slow work. I burned out an untold quanity of Dremel tools, when I found a big electric tool at Sears. Worked much faster. Spun at one speed. Control was poor, as it was large. I found a variable speed controller for it. it worked pretty good, but was very tiring to control, as it was bulky and heavy. I burned out several controllers and tools. Finally went to air in about '72. Used one of those 110 volt Sears compressors. Melted several. They would actually smoke and burn up. I'd have to stop every few minutes and wait for the compressor to catch up every few minutes. I liked air. The tools were smaller and they had speed controls right on them. When I opened my shop in 1975, I finally got a 3 phase big conpressor and I could ruin heads at a much quicker pace. I bought my first flow bench in about 1980. This did not help with porting skills, but helped with shape and finish issues.
In that time, I've literally ported thousands of individual ports. I've ruined several, expecially in the "development" stage of working up a head design. I do not flow every port. This would cost a fortune, if someone actually did it. Generally, most of the people that claim they measure every port, lie about this. A set of ported heads, individually flowed, would cost more than the rest of the engine combined. It takes a bunch of time and effort. CNC stuff helped with this issue. Someone could develop a port design that worked and duplicate it many times over. Made individual port flow checking not needed.
The downside of CNC porting is that it is also possible to duplicate crappy ports......exactly! You can ruin ports in volume! However, the good news is that they will be ruined exactly the same way! So, the first step is to make a port that works, then duplicate it as close as possible.
To develop a port and CNC duplicate it for under $10,000.00 is not going to happen! The time required to do the development work, build fixtures to hold the head, and then program a 4 axis machine to dupicate that port takes a zillion hours. I think Mike Simmard can shed light on how tough it would be and the time required to fixture and program a port for machining. The good news is that the next 1000 would be quick and cheap.
That being said, here's what I won't do and what I actually do. I will not cut a cast iron port. Too slow, too dirty, way too hard. I do heads that I've developed and have patterns for. I don't have the time to develop heads that I've not worked up in the past. When I need a trick head for one of my big blocks Chevys, I call and buy heads from the best people I can find. I like Air Flow Research heads and I've had success with Dart.
So, what you think? Too boring? Too much effort. Let me know and I'll quit or continue.
greg brown
03-13-2008, 03:52 PM
#32
Rennlist Member
Thread Starter
Like anything else, I was thinking that there was the 80/20 rule.
80% of the improvement can be had with the first 20% of the work, and the last 20% of the improvement can only be achieved with 80% more work.
80% of the improvement can be had with the first 20% of the work, and the last 20% of the improvement can only be achieved with 80% more work.
03-13-2008, 03:57 PM
#33
Rennlist Member
Thread Starter
Is the chamber supposed to be this shiney?
03-13-2008, 04:01 PM
#34
Man of many SIGs
Rennlist Member
Rennlist Member
Greg, I think alot of people would love to read what you have to say about porting heads. Either start your own thread about it or put it all here if its OK with Brendon.
If you have any problems with pictures PM me and I will help any way I can. I will even host them if necessary.
If you have any problems with pictures PM me and I will help any way I can. I will even host them if necessary.
03-13-2008, 04:11 PM
#35
Rennlist Member
Thread Starter
These are Honda S2000/RSX heads -
It looks like you want to take out any real transition from the port to where it becomes the valve seat? Obviously not touching the valve seat area.
It looks like you want to take out any real transition from the port to where it becomes the valve seat? Obviously not touching the valve seat area.
03-13-2008, 04:12 PM
#36
Rest in Peace
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I sure am not one of the pros when it comes to porting heads.
But you are right, there are head porting pros here.
I think it is a area that is best left to someone who does this for a living.
It is not my heads, so go for it.
That is my fear of trying to doing them.
If I had a set that I wanted ported, I would send them to you.
But you are right, there are head porting pros here.
I think it is a area that is best left to someone who does this for a living.
It is not my heads, so go for it.
That is my fear of trying to doing them.
If I had a set that I wanted ported, I would send them to you.
03-13-2008, 04:50 PM
#38
Rennlist Member
Thread Starter
Thanks John.
03-13-2008, 05:08 PM
#40
Rennlist Member
Thread Starter
If there is any problem with the photobucket process, many of us could just give our email address and we could post the pics.
03-13-2008, 05:13 PM
#41
Nordschleife Master
Great point as i recall the SC ports and 3.2 carrera ports are quite a bit larger, I think in the 35 to 39mm range, i believe though that they are 37mm.
think about that one for a while...
03-13-2008, 05:38 PM
#42
Rennlist
Basic Site Sponsor
Basic Site Sponsor
Thanks for the clues about posting pictures. I have a good digital camera and my computer knows it, well. I send pictures all the time on email. I can even get pictures to go onto my websites.
I just don't know how to get them onto Rennlist. Brendan: Is that why I need to go to photobucket...they have to load them onto the Forum's site?
I just don't know how to get them onto Rennlist. Brendan: Is that why I need to go to photobucket...they have to load them onto the Forum's site?
__________________
greg brown
714 879 9072
GregBBRD@aol.com
Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!
greg brown
714 879 9072
GregBBRD@aol.com
Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!
03-13-2008, 05:53 PM
#43
Man of many SIGs
Rennlist Member
Rennlist Member
Thanks for the clues about posting pictures. I have a good digital camera and my computer knows it, well. I send pictures all the time on email. I can even get pictures to go onto my websites.
I just don't know how to get them onto Rennlist. Brendan: Is that why I need to go to photobucket...they have to load them onto the Forum's site?
I just don't know how to get them onto Rennlist. Brendan: Is that why I need to go to photobucket...they have to load them onto the Forum's site?
03-13-2008, 06:22 PM
#44
Rennlist Member
Greg: don't worry about boring us. Only us 928 cultmembers/groupies here. I think your porting of a 16 valve US motor is documented in an old issue of VW/Porsche, but I have never seen anything about what you do with 32 valve motors.
03-13-2008, 06:34 PM
#45
The Lady's Man
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You can put them on Rennlist direct but they can't be over like 5 inches wide at 72 res. To do so click go advanced and then click manage attachments and use browse to find them on your computer and click upload.
Photo bucket allows you to post larger images.
Photo bucket allows you to post larger images.
