Porting, Polishing, and Cams project
04-15-2007, 10:32 PM
#177
MBWorld Fanatic!
04-15-2007, 11:42 PM
#178
uhmmm, makes me wonder if they tuned for the headers when they were equal length....
04-16-2007, 08:47 AM
#179
SPONSOR
Thread Starter
MB isn't going to work on my car today. The tech assigned to the car is off today.
I called Schrick in Germany this morning and as my luck would have it, Stefan is off today as well.
This week is starting off great!
I called Schrick in Germany this morning and as my luck would have it, Stefan is off today as well.
This week is starting off great!
04-16-2007, 11:12 AM
#180
man, this sucks! i was hoping to get some answers today, as i know you were...
oh well, keep us posted...
04-16-2007, 11:46 AM
#181
MBWorld Fanatic!
Join Date: Nov 2003
Location: MILFORD,CT
Posts: 1,067
Likes: 0
Received 4 Likes
on
4 Posts
E36M3 race car/Ferrari F355 GTS/1973 Mini 1275GT/Fiat Abarth/ML63/SLK55
greetings from phuket thailand. i ponied up the big bux for a day's worth of wifi access.
Jerry, so sorry to hear about the less than stellar results. maybe a combi of the porting and the cams? i guess when the stock cams go back in that will point to culprit.
before the cams come out i may be sensible to have them recheck install make sure it was done to specs???
Jerry, so sorry to hear about the less than stellar results. maybe a combi of the porting and the cams? i guess when the stock cams go back in that will point to culprit.
before the cams come out i may be sensible to have them recheck install make sure it was done to specs???
04-20-2007, 09:46 AM
#183
SPONSOR
Thread Starter
After much trial and error, the car is almost ready. I had a huge vacuum leak that caused most of my first round problems. It appears as if the leak was coming from the intake plenums / Evosport phenolic spacers. The phenolic spacers did not cover 100% of the surface area (see picture) and this caused the intake plenums to bend slightly and cause the intake leak when the spacers were not installed. I requested that MB look at the spacers and give their opinion of the product and I left it up to them to decide if they were to be reinstalled. After reviewing them, and listening to my complaints about the design, they decided not to install them, and this caused the leak because the warped intake plenums were not flat against the head. To resolve the issue, MB had no choice but to install them again, and use gasket maker in the area with the leak.
Here is a picture of what I’m talking about.
After all of this, MB had the car working perfectly with the OEM cams and decided to move forward with the Schrick cams. Another day or two went by and I was informed that the Schrick cams were installed but the car is still not running at 100%. The car was misfiring at idle, and by the cars design, when it misfires the affected cylinder gets shut down until the codes are cleared and the car is restarted. The problem is that the cars idle is too low for the cam profile. After a few phone calls to Schrick in Germany, they suggested that the RPM be raised from our low 700 RPM to 820-830 RPM. I did a few searches on Google and this is normal for what I’m trying to accomplish. Please note: If you guys don’t port / polish the heads, there is a good chance you can drop in the cams and go. I don’t want to speak for Jgsx, but apparently his car ran fine with just dropping in the cams. My MB dealership only has the ability to raise the RPM from 700 to 760, so the remaining RPM difference will need to be taken care of by Renntech. I had MB FedEx my ECU yesterday to Renntech with hopes that they can get it shipped back out to me today for Saturday delivery. I was told the car was drivable and I attempted to find a local tuner that had the ability to raise the RPM, but I could not locate one that could do it same day. So, with my wife going to be out of town this weekend, I wouldn’t have an extra vehicle to drive, so I had no choice but to leave the car with MB and wait on the ECU from Renntech.
I’m glad things turned out the way they did, I now have a much better understanding of the internals of our car, and the way the mods affect the engine.
So far, MB has stuck to their original quote of 10.5 hours for labor and hopefully this continues until I get the car back.
Would I do this all over again if I had the chance? Yes, I would. Again, I have a much better understanding of what needs to be done and the order in which things should happen. Having been a project manager at one time, I can honestly say that this was the hardest project to stay on top of. My advice to anyone thinking about doing this, is take some time and research what it is you want to do and how you think it needs be done. Spend time with the tech or person that is going to work on your car and ask questions! Be prepared for the worst case scenario and plan your time accordingly. Get all of your ducks lined up before you pull the trigger. Make sure you have all of the contact information for the various vendors, their hours of operation, and their process for solving issues if you have any. For me, getting in the office @ 8:00AM and only having an hour or two before Germany leaves for the day was a big hassle. If you decide to get your ECU flashed too, make sure you have all of the needed information so you only have to do it once. I could go on and on, but you get the point.
I think this will all work out for me. All of the research I’ve done on cams, the issues that I’ve had all appear normal. In fact, those cars that go through these little issues are the ones that end up making the most power. A drop in and drive cam will never make the power that a tuned cam will make, IMO. If the cam profile is so close that no other modifications are needed, then the gains will reflect that.
At any rate, I’m excited and I can’t wait to hit the Dyno!
Here is a picture of what I’m talking about.
After all of this, MB had the car working perfectly with the OEM cams and decided to move forward with the Schrick cams. Another day or two went by and I was informed that the Schrick cams were installed but the car is still not running at 100%. The car was misfiring at idle, and by the cars design, when it misfires the affected cylinder gets shut down until the codes are cleared and the car is restarted. The problem is that the cars idle is too low for the cam profile. After a few phone calls to Schrick in Germany, they suggested that the RPM be raised from our low 700 RPM to 820-830 RPM. I did a few searches on Google and this is normal for what I’m trying to accomplish. Please note: If you guys don’t port / polish the heads, there is a good chance you can drop in the cams and go. I don’t want to speak for Jgsx, but apparently his car ran fine with just dropping in the cams. My MB dealership only has the ability to raise the RPM from 700 to 760, so the remaining RPM difference will need to be taken care of by Renntech. I had MB FedEx my ECU yesterday to Renntech with hopes that they can get it shipped back out to me today for Saturday delivery. I was told the car was drivable and I attempted to find a local tuner that had the ability to raise the RPM, but I could not locate one that could do it same day. So, with my wife going to be out of town this weekend, I wouldn’t have an extra vehicle to drive, so I had no choice but to leave the car with MB and wait on the ECU from Renntech.
I’m glad things turned out the way they did, I now have a much better understanding of the internals of our car, and the way the mods affect the engine.
So far, MB has stuck to their original quote of 10.5 hours for labor and hopefully this continues until I get the car back.
Would I do this all over again if I had the chance? Yes, I would. Again, I have a much better understanding of what needs to be done and the order in which things should happen. Having been a project manager at one time, I can honestly say that this was the hardest project to stay on top of. My advice to anyone thinking about doing this, is take some time and research what it is you want to do and how you think it needs be done. Spend time with the tech or person that is going to work on your car and ask questions! Be prepared for the worst case scenario and plan your time accordingly. Get all of your ducks lined up before you pull the trigger. Make sure you have all of the contact information for the various vendors, their hours of operation, and their process for solving issues if you have any. For me, getting in the office @ 8:00AM and only having an hour or two before Germany leaves for the day was a big hassle. If you decide to get your ECU flashed too, make sure you have all of the needed information so you only have to do it once. I could go on and on, but you get the point.
I think this will all work out for me. All of the research I’ve done on cams, the issues that I’ve had all appear normal. In fact, those cars that go through these little issues are the ones that end up making the most power. A drop in and drive cam will never make the power that a tuned cam will make, IMO. If the cam profile is so close that no other modifications are needed, then the gains will reflect that.
At any rate, I’m excited and I can’t wait to hit the Dyno!
Last edited by sales@eurocharged.com; 04-20-2007 at 09:51 AM.
04-20-2007, 11:43 AM
#184
MBWorld Fanatic!
I do not have my car back either. I did not port my heads, but I installed the Schrick cams. The seem to have went in ok, but I had a large intake leak and an exhaust leak (before I even put the cams in).
My exhaust leak was caused by the evosport headers. Both headers cracked at the center of the collector. Because of the location, it isn't something that can easily be welded. Evosport is going to repair the headers, but that is more downtime.
It now appears that the intake leak was caused by the evosport phenolic spacers. My shop completely covered the throttle body opening, and the car was still getting air. It's too early to know if my head was warped by the strangely designed spacers (I have to wait to get my headers back before the car can be started again).
So far the car has been out for several weeks, and it looks like it is going to be at least one more week.
So much for the 3 hour install . . .
My exhaust leak was caused by the evosport headers. Both headers cracked at the center of the collector. Because of the location, it isn't something that can easily be welded. Evosport is going to repair the headers, but that is more downtime.
It now appears that the intake leak was caused by the evosport phenolic spacers. My shop completely covered the throttle body opening, and the car was still getting air. It's too early to know if my head was warped by the strangely designed spacers (I have to wait to get my headers back before the car can be started again).
So far the car has been out for several weeks, and it looks like it is going to be at least one more week.
So much for the 3 hour install . . .
04-20-2007, 01:29 PM
#186
SPONSOR
Thread Starter
04-20-2007, 04:46 PM
#187
SPONSOR
Thread Starter
No car this weekend. 
I'll get the ECU on Tuesday.
I'll get the ECU on Tuesday.
04-20-2007, 06:56 PM
#188
04-20-2007, 07:38 PM
#189
MBWorld Fanatic!
I thought I was dropping off the car and picking it up that evening!
04-20-2007, 07:44 PM
#190
MBWorld Fanatic!
Join Date: Dec 2005
Location: So Cal
Posts: 2,347
Likes: 0
Received 1 Like
on
1 Post
2006 Weistec 3.0L SC'd C55, 2006 MaxPsi PT6466 Turbo'd M3, 2019 Maserati GTS , 2020Alfa Quadrifoglio
Green with Envy
I truly envy you C32 guys with so many power upgrade options. The only choice C55 owners really have is blower or no blower which of course leads to the question...Warranty or no Warranty...
04-20-2007, 09:42 PM
#191
sorry joe, didn't mean to leave you out...i have just been talking to jerry on the phone alot about the progress on his car...
evosport should just ship you a new set of headers, i would not accept "fixed" headers...it is just a bad idea
04-21-2007, 02:24 AM
#192
MBWorld Fanatic!
I love what evo has done for the platform, so I'm pretty forgiving
04-21-2007, 02:33 PM
#194
SPONSOR
Thread Starter
04-22-2007, 10:04 PM
#195
Newbie
Join Date: Apr 2007
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
I was asked by a local AMG owner to take a peek in this thread. Looks like a nice build that's in progress. 
I've read through the majority of the thread and there is some good info and I'm sensing an air of confusion about heads and valvetrain upgrades and their impact on performance.
There was a comment about how bench flowing is not the only way to test a ported head. This comment couldn't be more accurate. It is a good tool to ensure that each cyl is balanced and has the same flow as the others, and provided that a bench flow was done prior to porting, it would be a way to show a % gain (flow-wise) after the work was done.
Now combine that with the right valvetrain upgrades, and how a person intends to drive (daily driver, roadcourse, all HP/Drag) and you have the components to design an appropriate head for your needs.
You shouldn't have a 'hogged' out head with no combustion chamber work but +2mm oversized valves, and only drive you car around town.... it will lack low end power and because no combustion chamber work was performed, you wouldn't be able to fully utilize the oversized valves. Make sense?
If you are after a bump in performance, the simplest way to go and see the most gains would be a head that has cleaned up intake and exhaust ports, a good blend in the bowl and seat, a 3 or 5 angle valve job done by carbide cutters NOT grinding stones, and upgraded valves that are swirl polished. Back-cutting the valves will also improve low-lift flow and is generally a good option to go with if available.
I saw a comment earlier stating that a 'tulip' valve and a back cut were the same. Not true. A tulip is a very gradual thickening of the valve from the stem to valve sealing surface. This is generally thicker than your stock or aftermarket valve. Back cutting is adding another angle, or cut to your valve, removing more material. You can think of it being similar to the cuts on the seat, but on the valve itself. So instead of just your 45 degree sealing angle, you would also have a 30 degree cut above that allowing increased flow at low lifts.
Other options that are out there are advanced coatings for the valves, combustion chambers, and exhaust ports. Some coatings (on valve stems) will be applied to help galling, reduce friction, and aid in heat dissipation resulting in a longer lasting valvetrain. The coatings on combustion chambers and exhaust ports will help keep the heat in the combustion process, instead of transfering itself to the head and valvetrain components. In some cases, as much as 2-6% increase in power can be had just by applying coatings.
So a few things to keep in mind when looking into headwork, know your goals (how you intend to drive), know what options are available in general (such as valvetrain options), and most importantly, know your porter. Make sure its someone who is reputable and knows their stuff. This should give your porter an idea of what port shape and valvetrain upgrades will suit your needs and give you peace of mind with your expensive (generally) upgrade.
So at any rate, I hope that helps clear up a few things with regards to portwork. I too do this for a living and would be more than happy to help answer any Q's you may have.
I've read through the majority of the thread and there is some good info and I'm sensing an air of confusion about heads and valvetrain upgrades and their impact on performance.
There was a comment about how bench flowing is not the only way to test a ported head. This comment couldn't be more accurate. It is a good tool to ensure that each cyl is balanced and has the same flow as the others, and provided that a bench flow was done prior to porting, it would be a way to show a % gain (flow-wise) after the work was done.
Now combine that with the right valvetrain upgrades, and how a person intends to drive (daily driver, roadcourse, all HP/Drag) and you have the components to design an appropriate head for your needs.
You shouldn't have a 'hogged' out head with no combustion chamber work but +2mm oversized valves, and only drive you car around town.... it will lack low end power and because no combustion chamber work was performed, you wouldn't be able to fully utilize the oversized valves. Make sense?
If you are after a bump in performance, the simplest way to go and see the most gains would be a head that has cleaned up intake and exhaust ports, a good blend in the bowl and seat, a 3 or 5 angle valve job done by carbide cutters NOT grinding stones, and upgraded valves that are swirl polished. Back-cutting the valves will also improve low-lift flow and is generally a good option to go with if available.
I saw a comment earlier stating that a 'tulip' valve and a back cut were the same. Not true. A tulip is a very gradual thickening of the valve from the stem to valve sealing surface. This is generally thicker than your stock or aftermarket valve. Back cutting is adding another angle, or cut to your valve, removing more material. You can think of it being similar to the cuts on the seat, but on the valve itself. So instead of just your 45 degree sealing angle, you would also have a 30 degree cut above that allowing increased flow at low lifts.
Other options that are out there are advanced coatings for the valves, combustion chambers, and exhaust ports. Some coatings (on valve stems) will be applied to help galling, reduce friction, and aid in heat dissipation resulting in a longer lasting valvetrain. The coatings on combustion chambers and exhaust ports will help keep the heat in the combustion process, instead of transfering itself to the head and valvetrain components. In some cases, as much as 2-6% increase in power can be had just by applying coatings.
So a few things to keep in mind when looking into headwork, know your goals (how you intend to drive), know what options are available in general (such as valvetrain options), and most importantly, know your porter. Make sure its someone who is reputable and knows their stuff. This should give your porter an idea of what port shape and valvetrain upgrades will suit your needs and give you peace of mind with your expensive (generally) upgrade.
So at any rate, I hope that helps clear up a few things with regards to portwork. I too do this for a living and would be more than happy to help answer any Q's you may have.
04-23-2007, 09:00 AM
#196
SPONSOR
Thread Starter
I was asked by a local AMG owner to take a peek in this thread. Looks like a nice build that's in progress.
I've read through the majority of the thread and there is some good info and I'm sensing an air of confusion about heads and valvetrain upgrades and their impact on performance.
There was a comment about how bench flowing is not the only way to test a ported head. This comment couldn't be more accurate. It is a good tool to ensure that each cyl is balanced and has the same flow as the others, and provided that a bench flow was done prior to porting, it would be a way to show a % gain (flow-wise) after the work was done.
Now combine that with the right valvetrain upgrades, and how a person intends to drive (daily driver, roadcourse, all HP/Drag) and you have the components to design an appropriate head for your needs.
You shouldn't have a 'hogged' out head with no combustion chamber work but +2mm oversized valves, and only drive you car around town.... it will lack low end power and because no combustion chamber work was performed, you wouldn't be able to fully utilize the oversized valves. Make sense?
If you are after a bump in performance, the simplest way to go and see the most gains would be a head that has cleaned up intake and exhaust ports, a good blend in the bowl and seat, a 3 or 5 angle valve job done by carbide cutters NOT grinding stones, and upgraded valves that are swirl polished. Back-cutting the valves will also improve low-lift flow and is generally a good option to go with if available.
I saw a comment earlier stating that a 'tulip' valve and a back cut were the same. Not true. A tulip is a very gradual thickening of the valve from the stem to valve sealing surface. This is generally thicker than your stock or aftermarket valve. Back cutting is adding another angle, or cut to your valve, removing more material. You can think of it being similar to the cuts on the seat, but on the valve itself. So instead of just your 45 degree sealing angle, you would also have a 30 degree cut above that allowing increased flow at low lifts.
Other options that are out there are advanced coatings for the valves, combustion chambers, and exhaust ports. Some coatings (on valve stems) will be applied to help galling, reduce friction, and aid in heat dissipation resulting in a longer lasting valvetrain. The coatings on combustion chambers and exhaust ports will help keep the heat in the combustion process, instead of transfering itself to the head and valvetrain components. In some cases, as much as 2-6% increase in power can be had just by applying coatings.
So a few things to keep in mind when looking into headwork, know your goals (how you intend to drive), know what options are available in general (such as valvetrain options), and most importantly, know your porter. Make sure its someone who is reputable and knows their stuff. This should give your porter an idea of what port shape and valvetrain upgrades will suit your needs and give you peace of mind with your expensive (generally) upgrade.
So at any rate, I hope that helps clear up a few things with regards to portwork. I too do this for a living and would be more than happy to help answer any Q's you may have.
I've read through the majority of the thread and there is some good info and I'm sensing an air of confusion about heads and valvetrain upgrades and their impact on performance.
There was a comment about how bench flowing is not the only way to test a ported head. This comment couldn't be more accurate. It is a good tool to ensure that each cyl is balanced and has the same flow as the others, and provided that a bench flow was done prior to porting, it would be a way to show a % gain (flow-wise) after the work was done.
Now combine that with the right valvetrain upgrades, and how a person intends to drive (daily driver, roadcourse, all HP/Drag) and you have the components to design an appropriate head for your needs.
You shouldn't have a 'hogged' out head with no combustion chamber work but +2mm oversized valves, and only drive you car around town.... it will lack low end power and because no combustion chamber work was performed, you wouldn't be able to fully utilize the oversized valves. Make sense?
If you are after a bump in performance, the simplest way to go and see the most gains would be a head that has cleaned up intake and exhaust ports, a good blend in the bowl and seat, a 3 or 5 angle valve job done by carbide cutters NOT grinding stones, and upgraded valves that are swirl polished. Back-cutting the valves will also improve low-lift flow and is generally a good option to go with if available.
I saw a comment earlier stating that a 'tulip' valve and a back cut were the same. Not true. A tulip is a very gradual thickening of the valve from the stem to valve sealing surface. This is generally thicker than your stock or aftermarket valve. Back cutting is adding another angle, or cut to your valve, removing more material. You can think of it being similar to the cuts on the seat, but on the valve itself. So instead of just your 45 degree sealing angle, you would also have a 30 degree cut above that allowing increased flow at low lifts.
Other options that are out there are advanced coatings for the valves, combustion chambers, and exhaust ports. Some coatings (on valve stems) will be applied to help galling, reduce friction, and aid in heat dissipation resulting in a longer lasting valvetrain. The coatings on combustion chambers and exhaust ports will help keep the heat in the combustion process, instead of transfering itself to the head and valvetrain components. In some cases, as much as 2-6% increase in power can be had just by applying coatings.
So a few things to keep in mind when looking into headwork, know your goals (how you intend to drive), know what options are available in general (such as valvetrain options), and most importantly, know your porter. Make sure its someone who is reputable and knows their stuff. This should give your porter an idea of what port shape and valvetrain upgrades will suit your needs and give you peace of mind with your expensive (generally) upgrade.
So at any rate, I hope that helps clear up a few things with regards to portwork. I too do this for a living and would be more than happy to help answer any Q's you may have.
I wish this thread was here when I started.
If I may ask, where are you located? Have you ever done head work on AMG's? If so, can you go into detail on some of the projects?
I think there are a few people still reluctant to move forward and someone like you will put their minds at rest.
Do you have any comments on any of the issues that I have faced and what I could have done differently?
Thanks for taking the time to post.
JT
04-23-2007, 11:23 AM
#197
Newbie
Join Date: Apr 2007
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
Awesome response!
I wish this thread was here when I started.
If I may ask, where are you located? Have you ever done head work on AMG's? If so, can you go into detail on some of the projects?
I think there are a few people still reluctant to move forward and someone like you will put their minds at rest.
Do you have any comments on any of the issues that I have faced and what I could have done differently?
Thanks for taking the time to post.
JT
I wish this thread was here when I started.
If I may ask, where are you located? Have you ever done head work on AMG's? If so, can you go into detail on some of the projects?
I think there are a few people still reluctant to move forward and someone like you will put their minds at rest.
Do you have any comments on any of the issues that I have faced and what I could have done differently?
Thanks for taking the time to post.
JT
Thank you for the compliment!
To date, I have done many heads but non on any AMG's. My main markets are the sport compacts (domestic and import) and some big block work. But some of the essentials, as I tried to explain without getting to complicated above, are the same from head to head.
I think there are too many that worry about saving the extra ~$200 by not going with a reputable shop and go with 'some local guy' that wields a dremel and knows enough to talk the talk, but not the experience or tooling to do an apporpriate job. Honestly I don't see that being too much of an issue with the AMG crowd, but the sport compact market I usually deal with is all about the wal-mart approach to upgrades.
For your issues, if you can elaborate on what specifically you ran into, I would be more than happy to provide some feedback. The only thing that came to mind was your misfiring issues which would make sense as you have a better flowing head. Generally adjusting the idle set screws on the throttle body (bodies) will be a possible solition for that.
Oh and I am located in St. Paul, MN.
Actually I'm not too far from you in the windy city.-Bob
04-23-2007, 12:42 PM
#198
SPONSOR
Thread Starter
Thank you for the compliment!
To date, I have done many heads but non on any AMG's. My main markets are the sport compacts (domestic and import) and some big block work. But some of the essentials, as I tried to explain without getting to complicated above, are the same from head to head.
I think there are too many that worry about saving the extra ~$200 by not going with a reputable shop and go with 'some local guy' that wields a dremel and knows enough to talk the talk, but not the experience or tooling to do an apporpriate job. Honestly I don't see that being too much of an issue with the AMG crowd, but the sport compact market I usually deal with is all about the wal-mart approach to upgrades.
For your issues, if you can elaborate on what specifically you ran into, I would be more than happy to provide some feedback. The only thing that came to mind was your misfiring issues which would make sense as you have a better flowing head. Generally adjusting the idle set screws on the throttle body (bodies) will be a possible solition for that.
Oh and I am located in St. Paul, MN. Actually I'm not too far from you in the windy city.
-Bob
To date, I have done many heads but non on any AMG's. My main markets are the sport compacts (domestic and import) and some big block work. But some of the essentials, as I tried to explain without getting to complicated above, are the same from head to head.
I think there are too many that worry about saving the extra ~$200 by not going with a reputable shop and go with 'some local guy' that wields a dremel and knows enough to talk the talk, but not the experience or tooling to do an apporpriate job. Honestly I don't see that being too much of an issue with the AMG crowd, but the sport compact market I usually deal with is all about the wal-mart approach to upgrades.
For your issues, if you can elaborate on what specifically you ran into, I would be more than happy to provide some feedback. The only thing that came to mind was your misfiring issues which would make sense as you have a better flowing head. Generally adjusting the idle set screws on the throttle body (bodies) will be a possible solition for that.
Oh and I am located in St. Paul, MN.
Actually I'm not too far from you in the windy city.-Bob
My ECU is currently at Renntech have the idle raised via programming, as our throttle body is sealed and to my knowledge can't be changed manually.
04-23-2007, 01:58 PM
#199
If you are after a bump in performance, the simplest way to go and see the most gains would be a head that has cleaned up intake and exhaust ports, a good blend in the bowl and seat, a 3 or 5 angle valve job done by carbide cutters NOT grinding stones, and upgraded valves that are swirl polished. Back-cutting the valves will also improve low-lift flow and is generally a good option to go with if available.
I saw a comment earlier stating that a 'tulip' valve and a back cut were the same. Not true. A tulip is a very gradual thickening of the valve from the stem to valve sealing surface. This is generally thicker than your stock or aftermarket valve. Back cutting is adding another angle, or cut to your valve, removing more material. You can think of it being similar to the cuts on the seat, but on the valve itself. So instead of just your 45 degree sealing angle, you would also have a 30 degree cut above that allowing increased flow at low lifts.
Other options that are out there are advanced coatings for the valves, combustion chambers, and exhaust ports. Some coatings (on valve stems) will be applied to help galling, reduce friction, and aid in heat dissipation resulting in a longer lasting valvetrain. The coatings on combustion chambers and exhaust ports will help keep the heat in the combustion process, instead of transfering itself to the head and valvetrain components. In some cases, as much as 2-6% increase in power can be had just by applying coatings.
Good info, thanks! I'm wondering however - if these are good modifications to do, why don't manufacturers produce engines that already have these features? Cost alone cannot be the answer, as some of them (BMW and M-B in particular) are in all out horsepower war with each other. Is there an associated loss of long-term reliability?
04-23-2007, 04:19 PM
#200
SPONSOR
Thread Starter
Good info, thanks! I'm wondering however - if these are good modifications to do, why don't manufacturers produce engines that already have these features? Cost alone cannot be the answer, as some of them (BMW and M-B in particular) are in all out horsepower war with each other. Is there an associated loss of long-term reliability?
I think that the question has multiple answers. I think that if MB had a more powerful C32, it might have impacted sells for other models. Granted, this is a shot in the dark.
Secondly, these mods will cause the car to have a rougher idle and could effect emissions to some degree. If the car didn't idle smooth or had any other "side effects", some drivers would think something is wrong with the car and bring it in.
Last but not least is the fact that the trq and hp numbers won't be so close together. MB might have wanted to car to have a smooth powerband and chose the setup they did because of this. The guy that did the heads said they were some of the best stock heads he had seen and it had a great valve job from the factory.
It could have been as simple as MB wanting a car to compete with the M3.
It's a good question and I would like to hear other opinions...
