Ported Heads?
07-27-2006, 06:37 PM
#1
2nd Gear Member
Thread Starter
Join Date: Jul 2006
Posts: 206
Ported Heads?
Excuse my lack of automotive education but I'm trying to learn as much as I can, as fast as I can.
What does it mean to get heads ported?
What effect does that have on your car, HP gains, risk to the blowing the engine etc?
I'm asking because, in discussing some of my mods with a friend here in Iraq (my thread about mods/UDP) he mentioned a shop in our area that will do the work for what seems to me like a really low price, lol. Like ridiculously low based on the few mentions of it here in these forums.
So....if it's really a good option, I'm looking for pro's and cons about the subject, so I can decide whether or not to go that route in the near future, after my initial modifications are done.
The shop in question is a race shop (specializing in building actual track cars for small circuit and local track competitions, which is somewhat of an amateur passion for alot of people in my area apparently) and the prices my friend mentioned were low enough that I thought renting a car to hold me over while they did the work over the course of a few days was still worth the price.
What does it mean to get heads ported?
What effect does that have on your car, HP gains, risk to the blowing the engine etc?
I'm asking because, in discussing some of my mods with a friend here in Iraq (my thread about mods/UDP) he mentioned a shop in our area that will do the work for what seems to me like a really low price, lol. Like ridiculously low based on the few mentions of it here in these forums.
So....if it's really a good option, I'm looking for pro's and cons about the subject, so I can decide whether or not to go that route in the near future, after my initial modifications are done.
The shop in question is a race shop (specializing in building actual track cars for small circuit and local track competitions, which is somewhat of an amateur passion for alot of people in my area apparently) and the prices my friend mentioned were low enough that I thought renting a car to hold me over while they did the work over the course of a few days was still worth the price.
07-27-2006, 09:19 PM
#2
3rd Gear Member
Join Date: Jun 2006
Location:
Posts: 713
RE: Ported Heads?
porting - usually comes along with polishing as well...
Heads are "cast" that is they are made by pouring molten Aluminum (in this case) into a mold.
All things considered, this process works very well, but:
a. it is not any where near as "precise" as machinig would be
b. it leaves a rough surface...
So, porting and polishing at a minimum address those 2 issues:
a. they machine the ports to ensure that they are EXACTLY as specified (most of the time they are a little smaller than spec'd)
b. they smooth out all the surfaces that touch air/fuel/exaust
Porting can also include altering the shape/size of the air/exaust ports to improve their flow.
The only risk to blowing your engine is poor installation. You/they have to pull the heads off, replace the head gaskets. That means when they put it back together they/you could screw up and:
a. incorrectly torque the bolts causing the head to warp
b. get a randomly bad head gasket and/or damage the head gasket during installation
c. inadvertantly block oil/water passages with debris/rags/sockets etc...
d. do a poor job of getting the metal shards out.
e. reinstall the cams incorrectly...
As for price - I don't know what you consider reasonable, but do make sure:
a. that price includes disassembly, P&P and reassembly - lots of machine work is pretty quick (and thus cheap) if all you do is walking the part in and walk it out)
b. they have done this on your model heads before and generally know what they are doing - they are new - so there aren't a lot of shops that can righfully claim that so far as I know...
As for what it does - if done correctly, it can increase horsepower by increasing flow. Don't have any numbers off the top of my head for this engine, but do look into that as I have heard that these heads/engines are surprisingly good for stock - so this might gain you less than it would otherwise (if the heads were crappy)...
This isn't something I would do lightly... You are talking about cracking open the engine, voiding any warranty you have and there is a risk something could go very wrong and your job will take longer than expected...
NEVER EVER have someone do that sort of work cause "it is cheap"... this is something that needs to be done right - if done wrong you have a $5000++ repair on your hands.
I cannot speak for anyone else, but this isn't something I would consider doing if I was not rebuilding or building an engine. When I did it, I was looking at an empty block (351 - not this one) and a bench full of parts - so it was easy to just walk the heads into the shop. These needed a once over and new springs anyway...
Heads are "cast" that is they are made by pouring molten Aluminum (in this case) into a mold.
All things considered, this process works very well, but:
a. it is not any where near as "precise" as machinig would be
b. it leaves a rough surface...
So, porting and polishing at a minimum address those 2 issues:
a. they machine the ports to ensure that they are EXACTLY as specified (most of the time they are a little smaller than spec'd)
b. they smooth out all the surfaces that touch air/fuel/exaust
Porting can also include altering the shape/size of the air/exaust ports to improve their flow.
The only risk to blowing your engine is poor installation. You/they have to pull the heads off, replace the head gaskets. That means when they put it back together they/you could screw up and:
a. incorrectly torque the bolts causing the head to warp
b. get a randomly bad head gasket and/or damage the head gasket during installation
c. inadvertantly block oil/water passages with debris/rags/sockets etc...
d. do a poor job of getting the metal shards out.
e. reinstall the cams incorrectly...
As for price - I don't know what you consider reasonable, but do make sure:
a. that price includes disassembly, P&P and reassembly - lots of machine work is pretty quick (and thus cheap) if all you do is walking the part in and walk it out)
b. they have done this on your model heads before and generally know what they are doing - they are new - so there aren't a lot of shops that can righfully claim that so far as I know...
As for what it does - if done correctly, it can increase horsepower by increasing flow. Don't have any numbers off the top of my head for this engine, but do look into that as I have heard that these heads/engines are surprisingly good for stock - so this might gain you less than it would otherwise (if the heads were crappy)...
This isn't something I would do lightly... You are talking about cracking open the engine, voiding any warranty you have and there is a risk something could go very wrong and your job will take longer than expected...
NEVER EVER have someone do that sort of work cause "it is cheap"... this is something that needs to be done right - if done wrong you have a $5000++ repair on your hands.
I cannot speak for anyone else, but this isn't something I would consider doing if I was not rebuilding or building an engine. When I did it, I was looking at an empty block (351 - not this one) and a bench full of parts - so it was easy to just walk the heads into the shop. These needed a once over and new springs anyway...
07-28-2006, 04:58 PM
#3
I ♥ Acer
Join Date: Jun 2006
Location: So Cal
Posts: 239
RE: Ported Heads?
ORIGINAL: cekim
porting - usually comes along with polishing as well...
Heads are "cast" that is they are made by pouring molten Aluminum (in this case) into a mold.
All things considered, this process works very well, but:
a. it is not any where near as "precise" as machinig would be
b. it leaves a rough surface...
So, porting and polishing at a minimum address those 2 issues:
a. they machine the ports to ensure that they are EXACTLY as specified (most of the time they are a little smaller than spec'd)
b. they smooth out all the surfaces that touch air/fuel/exaust
Porting can also include altering the shape/size of the air/exaust ports to improve their flow.
The only risk to blowing your engine is poor installation. You/they have to pull the heads off, replace the head gaskets. That means when they put it back together they/you could screw up and:
a. incorrectly torque the bolts causing the head to warp
b. get a randomly bad head gasket and/or damage the head gasket during installation
c. inadvertantly block oil/water passages with debris/rags/sockets etc...
d. do a poor job of getting the metal shards out.
e. reinstall the cams incorrectly...
As for price - I don't know what you consider reasonable, but do make sure:
a. that price includes disassembly, P&P and reassembly - lots of machine work is pretty quick (and thus cheap) if all you do is walking the part in and walk it out)
b. they have done this on your model heads before and generally know what they are doing - they are new - so there aren't a lot of shops that can righfully claim that so far as I know...
As for what it does - if done correctly, it can increase horsepower by increasing flow. Don't have any numbers off the top of my head for this engine, but do look into that as I have heard that these heads/engines are surprisingly good for stock - so this might gain you less than it would otherwise (if the heads were crappy)...
This isn't something I would do lightly... You are talking about cracking open the engine, voiding any warranty you have and there is a risk something could go very wrong and your job will take longer than expected...
NEVER EVER have someone do that sort of work cause "it is cheap"... this is something that needs to be done right - if done wrong you have a $5000++ repair on your hands.
I cannot speak for anyone else, but this isn't something I would consider doing if I was not rebuilding or building an engine. When I did it, I was looking at an empty block (351 - not this one) and a bench full of parts - so it was easy to just walk the heads into the shop. These needed a once over and new springs anyway...
porting - usually comes along with polishing as well...
Heads are "cast" that is they are made by pouring molten Aluminum (in this case) into a mold.
All things considered, this process works very well, but:
a. it is not any where near as "precise" as machinig would be
b. it leaves a rough surface...
So, porting and polishing at a minimum address those 2 issues:
a. they machine the ports to ensure that they are EXACTLY as specified (most of the time they are a little smaller than spec'd)
b. they smooth out all the surfaces that touch air/fuel/exaust
Porting can also include altering the shape/size of the air/exaust ports to improve their flow.
The only risk to blowing your engine is poor installation. You/they have to pull the heads off, replace the head gaskets. That means when they put it back together they/you could screw up and:
a. incorrectly torque the bolts causing the head to warp
b. get a randomly bad head gasket and/or damage the head gasket during installation
c. inadvertantly block oil/water passages with debris/rags/sockets etc...
d. do a poor job of getting the metal shards out.
e. reinstall the cams incorrectly...
As for price - I don't know what you consider reasonable, but do make sure:
a. that price includes disassembly, P&P and reassembly - lots of machine work is pretty quick (and thus cheap) if all you do is walking the part in and walk it out)
b. they have done this on your model heads before and generally know what they are doing - they are new - so there aren't a lot of shops that can righfully claim that so far as I know...
As for what it does - if done correctly, it can increase horsepower by increasing flow. Don't have any numbers off the top of my head for this engine, but do look into that as I have heard that these heads/engines are surprisingly good for stock - so this might gain you less than it would otherwise (if the heads were crappy)...
This isn't something I would do lightly... You are talking about cracking open the engine, voiding any warranty you have and there is a risk something could go very wrong and your job will take longer than expected...
NEVER EVER have someone do that sort of work cause "it is cheap"... this is something that needs to be done right - if done wrong you have a $5000++ repair on your hands.
I cannot speak for anyone else, but this isn't something I would consider doing if I was not rebuilding or building an engine. When I did it, I was looking at an empty block (351 - not this one) and a bench full of parts - so it was easy to just walk the heads into the shop. These needed a once over and new springs anyway...
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