11's on the Motor, 9's on the Nitrous
08-10-2010, 11:23 PM
#41
Elite Member
Thread Starter
iTrader: (2)
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
Cylinder Head
Well, it is time I got back to work on the car.
I decided to work on the cylinder head first. I cleaned it up and reattached the intake manifold. When I looked down the intake into the head, it looks like there are a few problems with the port work. I want to find as much power as I can, so I am going to have the big boys have a stab at it. Don't get me wrong, the port work is not bad, but I think there is more to be had.
It is going out to Rebello tomorrow. Once the head is complete, I will have him make or source out the camshafts. I planned to have Integral build the cam, but they are no longer in business.
I decided to work on the cylinder head first. I cleaned it up and reattached the intake manifold. When I looked down the intake into the head, it looks like there are a few problems with the port work. I want to find as much power as I can, so I am going to have the big boys have a stab at it. Don't get me wrong, the port work is not bad, but I think there is more to be had.
It is going out to Rebello tomorrow. Once the head is complete, I will have him make or source out the camshafts. I planned to have Integral build the cam, but they are no longer in business.
Reply
0
0
10-27-2010, 09:46 PM
#48
Elite Member
Thread Starter
iTrader: (2)
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
Awesome Brakes
Sixshooter called me up and suggested that I use the 1.6 brakes from the car that he was parting out. At first I thought that he lost his mind. It eventually occured to me that the idea was brilliant, so we proceeded to do the..... uh hmmm......upgrade.
I thought if we are going to do this, might as well go all the way. Why not try to install a rear rotor on the front, but still use the existing front calipers. We did a few test fits, and made sure that the pads would not fall out of the calipers, and what do you know, it looks like it is going to work.
The only problem, is that if the pads wear significantly, there is a possibility they can fall out. I am either going to have to make sure the pads are fresh, or I will have to fab something up to keep them from falling out. I also had to shim the caliper so it fits center on the rotor. I will not be able to test the brakes until I get a motor in the car. If it does not work, I will simply put the 1.6 front rotors back on.
The reason for this is simple less rotating mass makes the car quicker in the quarter mile. Most pro built drag cars have just enough brake to stop them in the quarter, and are tiny compared to road race or street brakes.
Pics on the way.
I thought if we are going to do this, might as well go all the way. Why not try to install a rear rotor on the front, but still use the existing front calipers. We did a few test fits, and made sure that the pads would not fall out of the calipers, and what do you know, it looks like it is going to work.
The only problem, is that if the pads wear significantly, there is a possibility they can fall out. I am either going to have to make sure the pads are fresh, or I will have to fab something up to keep them from falling out. I also had to shim the caliper so it fits center on the rotor. I will not be able to test the brakes until I get a motor in the car. If it does not work, I will simply put the 1.6 front rotors back on.
The reason for this is simple less rotating mass makes the car quicker in the quarter mile. Most pro built drag cars have just enough brake to stop them in the quarter, and are tiny compared to road race or street brakes.
Pics on the way.
Reply
0
0
11-02-2010, 04:57 PM
#50
Elite Member
Thread Starter
iTrader: (2)
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
Finally got some news on the cylinder head. Rebello tested it to .450 inch lift, and my head was flowing around 230 cfm. Apparantly when he tested a head that he had ported, it flowed around the same at .450 inch. However, he says that my head is not flowing as much as one he ported at lower lift. I am not sure I know what is going on there.
What phenomenon is going on that my head catches up at the higher lift? Would it be that my ports are bigger (big in the wrong places), and there are velocity problems, or is it because my ports are smaller, and that a higher lift is what it takes to maximize the port flow potential?
I have never seen flow charts on a 99 BP head, and do not know how this compares to the average ported head.
my head @ .300" 196 cfm
Rebello @ .300" 210 cfm
my head@ .400" 218 cfm
Rebello@ .400" 222 cfm
my head@ .450" 230 cfm
Rebello@ .450" 230 cfm
above data is on the intake side.
Rebello also mentioned that my head was a little weak on the exhaust side, and that more work needs to be done.
I found a post by ctdrftna that his head flowed @.500", 246 cfm.
That makes me think that Rebello needs to test it at a higher lift. He is proceeding with a little more port work on both intake and exhaust to get the lower lift numbers up, and improve the exhaust side.
What phenomenon is going on that my head catches up at the higher lift? Would it be that my ports are bigger (big in the wrong places), and there are velocity problems, or is it because my ports are smaller, and that a higher lift is what it takes to maximize the port flow potential?
I have never seen flow charts on a 99 BP head, and do not know how this compares to the average ported head.
my head @ .300" 196 cfm
Rebello @ .300" 210 cfm
my head@ .400" 218 cfm
Rebello@ .400" 222 cfm
my head@ .450" 230 cfm
Rebello@ .450" 230 cfm
above data is on the intake side.
Rebello also mentioned that my head was a little weak on the exhaust side, and that more work needs to be done.
I found a post by ctdrftna that his head flowed @.500", 246 cfm.
That makes me think that Rebello needs to test it at a higher lift. He is proceeding with a little more port work on both intake and exhaust to get the lower lift numbers up, and improve the exhaust side.
Reply
0
0
11-03-2010, 09:47 AM
#51
Moderator
iTrader: (12)
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 20,652
Total Cats: 3,011
I would say that the low lift numbers being too low is probably a result of less than optimal velocity at low lifts as you first proposed. I agree that could be due to oversize or misshapen ports. But, to my understanding, it is also commonly caused by less than perfect shaping of the transition from the port to the back of the valve seat. It has been a few years since I did any reading on head porting so...
If your ports were too small you would probably be bottlenecking at high lift.
The bad news is that the low and medium valve lift numbers are almost always more important because your valves spend more time transitioning through those values than they do at absolute peak lift. Not that flow at peak isn't important, but if I could pick up 30 cfm at .200 and .300, be even at .400, and be down 30cfm at .500, I would chose that option in a heartbeat. That is unless I had a very long duration flat-nose cam with roller followers and very steep ramps, and I don't.
That is a very nice lightweight brake setup you have there.
Did you go to the Street Car Nationals on Sunday? I ended up going there almost by accident on Saturday. Gary and I went riding and he got a call from Mark Mazurowski who was trying to qualify his car in Extreme Import class, so we went over. I have a few pictures I will post up when I get them loaded into photobucket.
If your ports were too small you would probably be bottlenecking at high lift.
The bad news is that the low and medium valve lift numbers are almost always more important because your valves spend more time transitioning through those values than they do at absolute peak lift. Not that flow at peak isn't important, but if I could pick up 30 cfm at .200 and .300, be even at .400, and be down 30cfm at .500, I would chose that option in a heartbeat. That is unless I had a very long duration flat-nose cam with roller followers and very steep ramps, and I don't.
That is a very nice lightweight brake setup you have there.
Did you go to the Street Car Nationals on Sunday? I ended up going there almost by accident on Saturday. Gary and I went riding and he got a call from Mark Mazurowski who was trying to qualify his car in Extreme Import class, so we went over. I have a few pictures I will post up when I get them loaded into photobucket.
Reply
0
0
01-25-2011, 07:48 PM
#52
Elite Member
Thread Starter
iTrader: (2)
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
Made dismal progress on my project, but at least the cylinder head porting is done.
Here are the numbers I got off of the flow sheet Rebello sent me. These are before and after Rebello ported the head. Keep in mind that the head was already ported by my local cylinder head guy.
Intake
0.05" lift
before 39.8 after 41.4
0.1"
before 83.0 after 84.2
0.2"
before 158.0 after 159.3
0.3"
before 196.7 after 205.0
0.4"
before 218.0 after 230.0
0.5"
before 230.4 after 235.00
Not a whole lot better on the low lift like he said there would be, but an improvement never the less. Also,no where near what ctdrftna posted, but it could be at a different test preasure. Rebello tested at 25".
The big gains are in the exhaust side.
0.05"
before 28.7 after 31.0
0.1"
before 63.7 after 65.9
0.2"
before 124.4 after 130.7
0.3"
before 149.3 after 164.0
0.4"
before 163.3 after 184.6
0.5"
before 169.6 after 187.1
That is one hell of an improvement. My guy obviously did not do much on the exhaust side.
I am interested to know how my flow numbers compare to others out there that has done some head testing. Maybe we should start a thread on it.
Here are the numbers I got off of the flow sheet Rebello sent me. These are before and after Rebello ported the head. Keep in mind that the head was already ported by my local cylinder head guy.
Intake
0.05" lift
before 39.8 after 41.4
0.1"
before 83.0 after 84.2
0.2"
before 158.0 after 159.3
0.3"
before 196.7 after 205.0
0.4"
before 218.0 after 230.0
0.5"
before 230.4 after 235.00
Not a whole lot better on the low lift like he said there would be, but an improvement never the less. Also,no where near what ctdrftna posted, but it could be at a different test preasure. Rebello tested at 25".
The big gains are in the exhaust side.
0.05"
before 28.7 after 31.0
0.1"
before 63.7 after 65.9
0.2"
before 124.4 after 130.7
0.3"
before 149.3 after 164.0
0.4"
before 163.3 after 184.6
0.5"
before 169.6 after 187.1
That is one hell of an improvement. My guy obviously did not do much on the exhaust side.
I am interested to know how my flow numbers compare to others out there that has done some head testing. Maybe we should start a thread on it.
Reply
0
0
01-26-2011, 07:34 AM
#53
Moderator
iTrader: (12)
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 20,652
Total Cats: 3,011
I'm sure those big exhaust side increases are going to be much more critical for you since you can't just add two more lbs of boost pressure to get there like a turbo car could. You are going to need that exhaust flow capacity to be able to spin the RPMs you will need to make the N/A power to hit your goal. Thinking about it makes me want a ported head.
Does anyone know offhand what a good flowing stock Honda 1.8 head flows for comparison?
Does anyone know offhand what a good flowing stock Honda 1.8 head flows for comparison?
Reply
0
0
01-26-2011, 08:31 AM
#54
Elite Member
Thread Starter
iTrader: (2)
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
I did a quick search. All numbers are at 28" of H20. Mine was tested at 25".
Stock miata 1.8, did not specify what head.
201.82 @ 0.5" intake
158.68 " exhaust
Stock B16
252.0 @ 0.5" intake
186 " exhaust
Stock S2000
295.0 @ 0.5" intake
Stock miata 1.8, did not specify what head.
201.82 @ 0.5" intake
158.68 " exhaust
Stock B16
252.0 @ 0.5" intake
186 " exhaust
Stock S2000
295.0 @ 0.5" intake
Reply
0
0
12-10-2011, 07:24 PM
#58
Elite Member
Thread Starter
iTrader: (2)
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
I had to really concentrate on work for a while. I also have one big commitment I have to get past before I get too involved with racing again. I will be free at last at the end of May.
I will be putting a shortblock together hopefully in January, and have gotten quite a few details done on the car since I last posted. When I really get into it again, I will start posting all of the details.
I will say this, I am not likely to put the car in driving condition until I get past this commitment. I am afraid I will get distracted and lose focus on this project. People are counting on me.
I will be putting a shortblock together hopefully in January, and have gotten quite a few details done on the car since I last posted. When I really get into it again, I will start posting all of the details.
I will say this, I am not likely to put the car in driving condition until I get past this commitment. I am afraid I will get distracted and lose focus on this project. People are counting on me.
Reply
1
1
03-01-2013, 03:17 PM
#59
Elite Member
Thread Starter
iTrader: (2)
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
Remember this old thread?
This project got seriously derailed, but now I am back on track to building my car. At the begining of the year, I moved the car from my house to my office to begin work.
I decided to achieve my goal, I need to do some serious chassis development, so I got to work stripping as much weight out of the car as I could. The car is now pretty much a bare shell.
Some things were done last year, most importantly gutting the doors.
I am going to leave the motor pretty much as I had it before I tore it apart. I am interested to see how much improvement the chassis work will give me, and also hook the nitrous up and start seeing what parts start to break.
This project got seriously derailed, but now I am back on track to building my car. At the begining of the year, I moved the car from my house to my office to begin work.
I decided to achieve my goal, I need to do some serious chassis development, so I got to work stripping as much weight out of the car as I could. The car is now pretty much a bare shell.
Some things were done last year, most importantly gutting the doors.
I am going to leave the motor pretty much as I had it before I tore it apart. I am interested to see how much improvement the chassis work will give me, and also hook the nitrous up and start seeing what parts start to break.
Reply
0
0
03-01-2013, 03:32 PM
#60
Elite Member
Thread Starter
iTrader: (2)
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
I went to the dragstrip with a friend who has a very fast all motor Mustang. He had the cleanest engine compartment, and it inspired me to do a mild engine bay smoothing. This is what I have been working on for about 2 weeks.
Last edited by miata2fast; 03-01-2013 at 04:24 PM.
Reply
0
0
