I currently work with a friend that is an experienced head porter. I also have 2 Ecotec engines that I am building. My friend that does the head porting looked at my Ecotec head and showed me several places that the head would benefit from a port job. He is about half done and you can see a clear improvement by comparison. I will post pictures as soon as I can.

I asked him if he would be willing to offer this service to the members of this forum for a special rate. He agreed.

Here are his terms.
1) He ports YOUR head, no exchanges.
2) The head is shipped to him stripped, no valves, springs, cams, ect..
3) Average 5 Day turn around from when it arrives
4) $500 + Shipping/Insurance

Send me a message if you would like his contact information or post a reply.

I just looked at what I posted again and it kind of looks like an ad. I didn't intend for it to be an ad. My friend ports Harley heads exclusively in his business. I work with him in the sense that I work on my bike at his shop as a hobby. I figured it would be a good thing to offer it to the group if he would.

I took pictures of the ports last night. You can see some of the improvements. There are other improvements that I just can't seem to capture with the camera. The ports have lots of obstructions in stock form. All the obstructions are removed and the port floor reduced for much improved flow around the valve. When my friend is done porting it I will go in with a sanding drum and clean up all the cutter marks. I am also considering polishing the exhaust ports and combustion chambers. I will post more pictures when I can.

Cool, thanx for the info. It has to warm up a little here before i pull any head`s. Good information, thank`s

Great alternative for those that need head port and polishing done. Good job on those ports.

What are the before and after flow numbers? Looks mean nothing.

Actually looks do have a lot to do with it. When you look into the port before cutting, there are clear obstructions in the air flow. Including the ridges you see in the picture. Also the floor has a sharp right angle that will effect the flow in the port. These are dealt with in the porting.

He is only going to port 3 cylinders and I am working on a jig to fit the head to his flow bench. We will then flow a "before" and "after" cylinder head. The actual flow numbers are irrelevant, I am just looking for an increase. Maybe a few percent or more would be good. In a street built engine you don't want a ported to the max head, it will actually hurt your low end torque. It puts all your horsepower in the higher RPM range. Thats fine if you're drag racing but I want to drive my car and have some fun off the line and not sacrifice my low and mid range torque. I don't plan on putting in larger valves either, that reduces the amount of pressure on the piston and costs you on the low end also.

When I figure out the percentage of improvement I will post it here. But if you are looking for an all out RACE head then this probably isn't for you. If you are looking for 180+ Hp from a NA engine, I think this would help you get there. Although I haven't gotten there yet, I am shooting for 200Hp. Cams, Ported head, increased throttle body and MegaSquirt. I'd like to get 200Tq also.

Megasquirt on Ecotec, wonder how that will work. I'd just like to comment, as I am in the process of porting my own Ecotec head, that there are more obstructions that can be smoothed out or removed there. I'll post pics when mine are done, I think I'm going quite a bit more radical..

Opel GT wrote:Actually looks do have a lot to do with it. When you look into the port before cutting, there are clear obstructions in the air flow. Including the ridges you see in the picture. Also the floor has a sharp right angle that will effect the flow in the port. These are dealt with in the porting.

He is only going to port 3 cylinders and I am working on a jig to fit the head to his flow bench. We will then flow a "before" and "after" cylinder head. The actual flow numbers are irrelevant, I am just looking for an increase. Maybe a few percent or more would be good. In a street built engine you don't want a ported to the max head, it will actually hurt your low end torque. It puts all your horsepower in the higher RPM range. Thats fine if you're drag racing but I want to drive my car and have some fun off the line and not sacrifice my low and mid range torque. I don't plan on putting in larger valves either, that reduces the amount of pressure on the piston and costs you on the low end also.

When I figure out the percentage of improvement I will post it here. But if you are looking for an all out RACE head then this probably isn't for you. If you are looking for 180+ Hp from a NA engine, I think this would help you get there. Although I haven't gotten there yet, I am shooting for 200Hp. Cams, Ported head, increased throttle body and MegaSquirt. I'd like to get 200Tq also.

Make sure to post up the numbers. I'd like to see what the gains are from .100 lift to .400 in .050 increments.
I realize that the things he worked on are nomally important, but, if it hurts low lift flow to gain high lift, you may see a loss in power(especially torque).
I just ask this because you are in the best position to provide real data. It would be a waste for you to not give all the info possible.
How long before you think you will get the head flowed?
Thanks for your efforts!

you can't look at it and say it flows better.... a few differt companies have messed with porting the ecotec head and gave up because its hard to get gains out of the head, not worth the time/cost. Simply saying "He is about half done and you can see a clear improvement" doesn't mean anythign since you can't see flow. A head can flow a million CFM but if its not at a usable range then its worthless, plus hand porting means different results everytime. I agree with what Phil de Lorm just said

Removing visual obstructions in the port is the FIRST thing you do when porting. I am not looking to port the head for drag racing but just for an improved flow. I would bet dollars to donuts that just removing the visual obstructions from the port will increase the flow.

We have not had time to complete the porting and flow it. But it will happen and I will post some numbers. But the numbers really mean nothing, they are just for comparison. I can open the port up and put in bigger valves and I will improve flow numbers a lot !! This will also decrease the velocity and lower my torque at lower RPM's. The bottom line is that I am trying to increase the volumetric efficiency and keep the velocity up.

If you look at the pictures of the ports and tell me that removing the obvious obstructions, that you can clearly see, won't help, then you really don't know anything about porting or flow at all. I am not just guessing at what I am doing. Engines don't run on parts and guess work. They run on MATH. There is a formula for virtually every aspect of the motor. This is not rocket science, it is just a motor.

OpelGT, you got this head back on yet? Interested in how you are getting along.


Power Curve

Any news?

Opel GT wrote:Removing visual obstructions in the port is the FIRST thing you do when porting. I am not looking to port the head for drag racing but just for an improved flow. I would bet dollars to donuts that just removing the visual obstructions from the port will increase the flow.

We have not had time to complete the porting and flow it. But it will happen and I will post some numbers. But the numbers really mean nothing, they are just for comparison. I can open the port up and put in bigger valves and I will improve flow numbers a lot !! This will also decrease the velocity and lower my torque at lower RPM's. The bottom line is that I am trying to increase the volumetric efficiency and keep the velocity up.

If you look at the pictures of the ports and tell me that removing the obvious obstructions, that you can clearly see, won't help, then you really don't know anything about porting or flow at all. I am not just guessing at what I am doing. Engines don't run on parts and guess work. They run on MATH. There is a formula for virtually every aspect of the motor. This is not rocket science, it is just a motor.

What formula are you using to determine that the grinding you did will make more power? Head porting is not math, it is trial and error until you know what works. Port one section, flow test. Port another, flow test. I agree, removing obstruction to airflow normally will make more power, but not always. And you may spend hours porting to pick up 3hp or none at all, or you may make things worse. You just dont know unless you flow the head.
I do know what I'm talking about. I have degrees in Automotive and Racecar technology, as well as 12+ years working in the racing industry, oh yeah, one of my friends has a porting shop and does work for many Fastest Street Car type guys and Pro Mod engine builders. He also has done quite a bit of development work on Honda heads for some race teams.

Good job pocket porting that head some people have talent some dont


see ya!

I know this thread is getting pretty old now. But i enjoyed the reading and thought I would provide some before and after flow numbers on an ECOTEC I recently ported.
Still need to get the pictures off my camera... But if anyone cares to see those, I'll post them up here too. Looks quite a bit different then from what is above.

These tests are taken before the valve job. Also working on a custom valve job cutter for this head but have not completed them yet.

Intake
Lift Stock Ported
.05 37.52 37.89
.10 76.23 76.12
.15 115.29 115.98
.20 153.72 155.57
.25 186.49 190.13
.30 212.68 220.11
.35 232.23 246.44
.40 242.59 265.13
.45 250.88 271.43
.50 254.39 280.79
.55 254.11 282.32

Exhaust
Lift Stock Ported
.05 33.95 34.6
.10 61.27 62.44
.15 95.12 97.23
.20 118.07 128.76
.25 130.57 151.13
.30 135.38 164.65
.35 138.90 174.74
.40 140.20 179.88
.45 141.68 184.04
.50 142.42 187.46
.55 143.35 187.22

matt, looks like you ported that head with the mind set o fusing about a 0.470-0.500 lift intake came and 0.420-0.460 lift exhaust cam. Thats where your flow chokes so it should be the cam lift you use. When porting a head of the street you must know the valve lift and port it till your flow bench tells you that your flow is beginning to choke just above max lift. This typically makes for a good flowing head that has minimal to none low end torque loss.


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Well, as far as my target cam lift to use, i just researched performance cam shafts available to get a range. Since the customer is salt flat racing, he is not as concerned about low end power,. Lucky me.
My two main concerns for lift is whether the valve will get out of the way (too little lift like the 4AG or RB25), and like you mentioned when it backs up on the bench.
But, as far as max power for racing or maintaining a broad power band for street, what i focus on isn't the lift but cam duration vs velocity of the air through the port.
This port will still work really well with the not as aggressive duration (and lift) cam shafts on the street.

nice specs
I'm really interested and debating this...



Buddy Club Ecotec Cavalier
* More to come *

Sure, I'm always open to see what people think and how they go about porting a head. Its how we all get better right?