Fuel octane rating + timing
Drifting
Joined: Oct 2020
Posts: 1,567
Likes: 576
From: Wisconsin
There seems to be this strange tug-of-war right now with high octane gas. As availability of premium (93) is dropping, manufacturers are introducing more performance cars that can take advantage of it.
Back in the 80's, if you told me someday we could buy a daily driver off the showroom floor with 11.5:1 compression ratio, I'd have said you were nuts. But with modern cc design and the computers can compensate, when I can't find 93 and have to put 91 in my '17 Camaro, it's pulling timing and losing a smidge of power.
Back in the 80's, if you told me someday we could buy a daily driver off the showroom floor with 11.5:1 compression ratio, I'd have said you were nuts. But with modern cc design and the computers can compensate, when I can't find 93 and have to put 91 in my '17 Camaro, it's pulling timing and losing a smidge of power.
Tech Contributor
Joined: Jun 2004
Posts: 20,905
Likes: 962
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
You pose an interesting observation.
And are correct in that I can find no specific evidence scientifically supporting a faster burn rate other than it's simply stated that higher octane is more resistant to ignition and has a slower burn rate and that lower octane is more volatile and burns easier, hence faster. I would like to find a graph of some sort showing the faster rate of burn and the slower rate of burning of various octanes. Have not found that yet.
The energy contained in various octanes is identical if they are all pure gasoline vs the ethanol enhanced octane rated fuels which in fact do contain less energy due to the lower energy density of ethanol.
As resdoggie points out higher octane allows for us to take advantage of earlier ignition netting higher pressures to produce more power. However with diminishing returns once you have ignited the fuel so early that peak cylinder pressure is reached too soon (prior to approx 15 ATDC) thus creating more negative work.
So although higher octane allows for higher cylinder pressures and earlier ignition it cannot be lit too early despite it's ability to function under those higher pressures without detonation.
Thus a lower octane fuel may be of at least financial benefit if peak cylinder pressure is low enough due to air density, CR or cam dynamics.
I'm gonna try to find a test or graph that does in fact show the burn rates if I can. I would like to see some hard evidence of that as well now that you bring it up.
And are correct in that I can find no specific evidence scientifically supporting a faster burn rate other than it's simply stated that higher octane is more resistant to ignition and has a slower burn rate and that lower octane is more volatile and burns easier, hence faster. I would like to find a graph of some sort showing the faster rate of burn and the slower rate of burning of various octanes. Have not found that yet.
The energy contained in various octanes is identical if they are all pure gasoline vs the ethanol enhanced octane rated fuels which in fact do contain less energy due to the lower energy density of ethanol.
As resdoggie points out higher octane allows for us to take advantage of earlier ignition netting higher pressures to produce more power. However with diminishing returns once you have ignited the fuel so early that peak cylinder pressure is reached too soon (prior to approx 15 ATDC) thus creating more negative work.
So although higher octane allows for higher cylinder pressures and earlier ignition it cannot be lit too early despite it's ability to function under those higher pressures without detonation.
Thus a lower octane fuel may be of at least financial benefit if peak cylinder pressure is low enough due to air density, CR or cam dynamics.
I'm gonna try to find a test or graph that does in fact show the burn rates if I can. I would like to see some hard evidence of that as well now that you bring it up.
)The core question is still unanswered: octane vs burn rate. It almost seems a national security secret given the difficulty finding a straightforward answer. SUNOCO was the only place I could find some meaningful information, and I have to combine a couple of their write-ups to get a hopefully meaningful answer.
The first link below gives the specific gravity of their Premium (93) and Regular (87) grades of fuel. The Premium fuel has a lower specific gravity compared to their Regular. A comment in the link says that for most race fuels, a lower specific gravity suggests a faster burning fuel, and a higher specific gravity fuel suggests a slower burning fuel. Does that also apply to their street fuels? IDK.
https://www.sunocoracefuels.com/tag/specific-gravity
This second link mentions, among other things, the same tendency of lighter fuels burning faster. Neither link specifically gives any actual burn rate numbers (at any conditions), and it's up to interpretation whether their street fuels follow the same "tendencies" as their race fuels. They don't say they don't, but they also don't say they do.
https://www.sunocoracefuels.com/tech.../beyond-octane
It's been a frustrating exercise trying to get clear useful information from the oil companies, and so far SUNOCO has been the only site I've found that will offer up anything remotely useful.
Le Mans Master
Joined: Jun 2019
Posts: 5,481
Likes: 2,190
From: Loveland
There seems to be this strange tug-of-war right now with high octane gas. As availability of premium (93) is dropping, manufacturers are introducing more performance cars that can take advantage of it.
Back in the 80's, if you told me someday we could buy a daily driver off the showroom floor with 11.5:1 compression ratio, I'd have said you were nuts. But with modern cc design and the computers can compensate, when I can't find 93 and have to put 91 in my '17 Camaro, it's pulling timing and losing a smidge of power.
Back in the 80's, if you told me someday we could buy a daily driver off the showroom floor with 11.5:1 compression ratio, I'd have said you were nuts. But with modern cc design and the computers can compensate, when I can't find 93 and have to put 91 in my '17 Camaro, it's pulling timing and losing a smidge of power.
I'm trying to understand why anybody cares about burn rate. If it was a deciding factor in what octane fuel you put in your engine I think the experts would talk about it.
Melting Slicks
Joined: May 2002
Posts: 2,717
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
A gallon of regular (87) contains around 125,000 BTU's of energy where a gallon of premium gasoline contains around 120,400 BTU's due to the components used today to raise the octane rating (Isomerate, Alkylate, reformate, etc...) not much difference but there is a difference.
The difference in energy can be overcome by adding compression to the engine to take advantage of the higher octane fuels.
The end result is to get the highest pressure in the cylinder at the right time.
I've never seen a chart showing the joules needed to ignite regular gasoline vs premium at a given pressure so not sure if premium is any more resistant to ignition by a spark then regular. The additives used to raise octane rating do have slightly higher auto-ignition temps but not by much usually within a couple hundred degrees.
The higher octane fuels have a resistance to ignite due to the higher heat of compression caused by higher cylinder compression.
Neal
The difference in energy can be overcome by adding compression to the engine to take advantage of the higher octane fuels.
The end result is to get the highest pressure in the cylinder at the right time.
I've never seen a chart showing the joules needed to ignite regular gasoline vs premium at a given pressure so not sure if premium is any more resistant to ignition by a spark then regular. The additives used to raise octane rating do have slightly higher auto-ignition temps but not by much usually within a couple hundred degrees.
The higher octane fuels have a resistance to ignite due to the higher heat of compression caused by higher cylinder compression.
Neal
Safety Car
Joined: May 2001
Posts: 4,759
Likes: 1,647
From: Fairfax Virginia
I use Higher Compression in the engine to make more power. I currently have a 1968 C3 with it's 427 running 12.25-1 compression ratio using the Cast Iron Closed Chamber cylinder heads and L88 pistons. It does not have a detonation problem with 93 octane fuel until you hit the summer heat and then it gets hotter.
We added a Snow Performance Water/Methanol Injection System to help protect the engine. It helps get rid of the excess heat with the water and the methanol increases the octane which is a two way winner for my engine. Adding the windshield washer fluid "all the time" could get expensive so I have it come on after the engine reaches operating temperatures. I am experimenting with the Holley EFI Software to see how I can have the EFI system take control the injection system for me. With windshield Washer Fluid I can get the equivalent of 116 octane and I have a half Gallon tank/reservoir behind the passengers seat where the Jack used to live. I am working on ways of covering up the sound of the Pressure pump for the water/methanol as it is a bit loud yet. My system uses 150 psi where the new ones use a 300 psi pump. They work great if you have some compression like a 1970 LT1 engine.
My engine needs more octane than is currently available in my area so the water/Methanol seemed like the next best solution for my high Compression. I have L88 pistons and the heads I am using match the valve pockets perfectly despite being made of cast iron instead of Aluminum. I wish I had a control system that could identify each detonation and fix it right away like the newer cars do. I do have an old MSD Knock Sensor that allows me to listen and make sure that nothing is happening that I don't know about. I have the ultimate Cold Air Intake in my L88 Hood with wedding cake assembly, the air is ambient temp when entering the intake system. Cooler air helps keep down detonation or pinging al by itself. The Closed Chamber Heads were known for not knocking/pinging sensitivity like the later Open Chamber Heads were.
We added a Snow Performance Water/Methanol Injection System to help protect the engine. It helps get rid of the excess heat with the water and the methanol increases the octane which is a two way winner for my engine. Adding the windshield washer fluid "all the time" could get expensive so I have it come on after the engine reaches operating temperatures. I am experimenting with the Holley EFI Software to see how I can have the EFI system take control the injection system for me. With windshield Washer Fluid I can get the equivalent of 116 octane and I have a half Gallon tank/reservoir behind the passengers seat where the Jack used to live. I am working on ways of covering up the sound of the Pressure pump for the water/methanol as it is a bit loud yet. My system uses 150 psi where the new ones use a 300 psi pump. They work great if you have some compression like a 1970 LT1 engine.
My engine needs more octane than is currently available in my area so the water/Methanol seemed like the next best solution for my high Compression. I have L88 pistons and the heads I am using match the valve pockets perfectly despite being made of cast iron instead of Aluminum. I wish I had a control system that could identify each detonation and fix it right away like the newer cars do. I do have an old MSD Knock Sensor that allows me to listen and make sure that nothing is happening that I don't know about. I have the ultimate Cold Air Intake in my L88 Hood with wedding cake assembly, the air is ambient temp when entering the intake system. Cooler air helps keep down detonation or pinging al by itself. The Closed Chamber Heads were known for not knocking/pinging sensitivity like the later Open Chamber Heads were.
Last edited by ctmccloskey; Aug 1, 2021 at 04:42 PM.
Drifting
Joined: Oct 2020
Posts: 1,567
Likes: 576
From: Wisconsin
What does the manufacturer recommend for minimum octane in your 17. How can you tell the timing is being pulled?
I'm trying to understand why anybody cares about burn rate. If it was a deciding factor in what octane fuel you put in your engine I think the experts would talk about it.
I'm trying to understand why anybody cares about burn rate. If it was a deciding factor in what octane fuel you put in your engine I think the experts would talk about it.
Racer
Joined: Jul 2013
Posts: 294
Likes: 10
From: Palmer Alaska
I use Higher Compression in the engine to make more power. I currently have a 1968 C3 with it's 427 running 12.25-1 compression ratio using the Cast Iron Closed Chamber cylinder heads and L88 pistons. It does not have a detonation problem with 93 octane fuel until you hit the summer heat and then it gets hotter.
We added a Snow Performance Water/Methanol Injection System to help protect the engine. It helps get rid of the excess heat with the water and the methanol increases the octane which is a two way winner for my engine. Adding the windshield washer fluid "all the time" could get expensive so I have it come on after the engine reaches operating temperatures. I am experimenting with the Holley EFI Software to see how I can have the EFI system take control the injection system for me. With windshield Washer Fluid I can get the equivalent of 116 octane and I have a half Gallon tank/reservoir behind the passengers seat where the Jack used to live. I am working on ways of covering up the sound of the Pressure pump for the water/methanol as it is a bit loud yet. My system uses 150 psi where the new ones use a 300 psi pump. They work great if you have some compression like a 1970 LT1 engine.
My engine needs more octane than is currently available in my area so the water/Methanol seemed like the next best solution for my high Compression. I have L88 pistons and the heads I am using match the valve pockets perfectly despite being made of cast iron instead of Aluminum. I wish I had a control system that could identify each detonation and fix it right away like the newer cars do. I do have an old MSD Knock Sensor that allows me to listen and make sure that nothing is happening that I don't know about. I have the ultimate Cold Air Intake in my L88 Hood with wedding cake assembly, the air is ambient temp when entering the intake system. Cooler air helps keep down detonation or pinging al by itself. The Closed Chamber Heads were known for not knocking/pinging sensitivity like the later Open Chamber Heads were.
We added a Snow Performance Water/Methanol Injection System to help protect the engine. It helps get rid of the excess heat with the water and the methanol increases the octane which is a two way winner for my engine. Adding the windshield washer fluid "all the time" could get expensive so I have it come on after the engine reaches operating temperatures. I am experimenting with the Holley EFI Software to see how I can have the EFI system take control the injection system for me. With windshield Washer Fluid I can get the equivalent of 116 octane and I have a half Gallon tank/reservoir behind the passengers seat where the Jack used to live. I am working on ways of covering up the sound of the Pressure pump for the water/methanol as it is a bit loud yet. My system uses 150 psi where the new ones use a 300 psi pump. They work great if you have some compression like a 1970 LT1 engine.
My engine needs more octane than is currently available in my area so the water/Methanol seemed like the next best solution for my high Compression. I have L88 pistons and the heads I am using match the valve pockets perfectly despite being made of cast iron instead of Aluminum. I wish I had a control system that could identify each detonation and fix it right away like the newer cars do. I do have an old MSD Knock Sensor that allows me to listen and make sure that nothing is happening that I don't know about. I have the ultimate Cold Air Intake in my L88 Hood with wedding cake assembly, the air is ambient temp when entering the intake system. Cooler air helps keep down detonation or pinging al by itself. The Closed Chamber Heads were known for not knocking/pinging sensitivity like the later Open Chamber Heads were.
Safety Car
Joined: May 2001
Posts: 4,759
Likes: 1,647
From: Fairfax Virginia
AV gas has Lead in it, lot of lead in it. I used Av gas for a couple years and I started to see deposits forming on the plugs and upon using a bore scope I saw large deposits on the valves. I yanked the heads off and redid the valves before re-installing everything. I stopped using leaded gas at that point. My engine will run on 93 octane as long as you don't push it too hard, It can even run okay on 91 octane in a pinch. I will not pay for Race Gas so the Water/methanol idea made sense.
If you are careful with your timing and the advance curve you use high compression. With the Water/methanol system you can run 12.25-1 without any detonation. Are you still using a 427 or what motor? If I had to use the water/methanol all the time I would use a larger reservoir. I have driven back and forth 100+ miles in the summer with no issues down here in Virginia without the Water/Methanol Injection system even.
The Water/Methanol injection system injects into my Edlebrock RPM Air Gap Intake manifold just below the Holley Sniper Stealth EFI System. On my engine since I have a dual plane manifold I inject the water/methanol from both sides of the intake. This means I use smaller nozzles since I have two of them working. The guys at Snow Performance have been very helpful. I have to get it adjusted to the EFI system now that I have added that to my engine. I installed an air/fuel monitor for the other Oxygen sensor so I can watch the A/F ratio on either side to be sure I get it balanced.
Tell us about your engine, what is it? What have you done to it? They didn't come with scoops sticking out of the hood like that in the picture so you must have some work in it.
I am using a factory L88 Hood and wedding cake assembly to help my engine get COLD air into the throttle body. My engine is basically a L88 Clone with Closed Chamber Cast iron heads in a C3 that started life as an L71.
If you are careful with your timing and the advance curve you use high compression. With the Water/methanol system you can run 12.25-1 without any detonation. Are you still using a 427 or what motor? If I had to use the water/methanol all the time I would use a larger reservoir. I have driven back and forth 100+ miles in the summer with no issues down here in Virginia without the Water/Methanol Injection system even.
The Water/Methanol injection system injects into my Edlebrock RPM Air Gap Intake manifold just below the Holley Sniper Stealth EFI System. On my engine since I have a dual plane manifold I inject the water/methanol from both sides of the intake. This means I use smaller nozzles since I have two of them working. The guys at Snow Performance have been very helpful. I have to get it adjusted to the EFI system now that I have added that to my engine. I installed an air/fuel monitor for the other Oxygen sensor so I can watch the A/F ratio on either side to be sure I get it balanced.
Tell us about your engine, what is it? What have you done to it? They didn't come with scoops sticking out of the hood like that in the picture so you must have some work in it.
I am using a factory L88 Hood and wedding cake assembly to help my engine get COLD air into the throttle body. My engine is basically a L88 Clone with Closed Chamber Cast iron heads in a C3 that started life as an L71.
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Burning Brakes
Joined: Aug 2013
Posts: 1,071
Likes: 322
From: palm springs ca
I always used compression for power. I could advance more. Had to mix av gas to stop pinging, then installed water injection to see if that would work. It did a great job (no pinging). I could tell when the water ran out when I was driving. the engine would start pinging. I kept a jug in the car and would fill the water system back up. Also the water system keeps the pistons clean.
Dom
Dom
Melting Slicks
Joined: Oct 2012
Posts: 2,156
Likes: 273
From: Dunedin NZ.
Hi everyone
I've got two questions regarding the timing setting on my 1977 L48 (no emissions and true dual exhaust):
1) Here in Belgium the standard fuel is rated at 95 ('EURO 95'). The premium fuel is rated at 98 (SUPER 98).
I read that my L48 was made to run on 88... So will the 95 fuel allow me to set the timing for better performance, or won't the octane rating have any effect on the timing?
2) What would be the best timing to run an engine as cool as possible? Retarding or advancing?
A friend of mine said: "The more horsepower you create, the hotter the engine will get." I'm confused... Is this correct?
I've got two questions regarding the timing setting on my 1977 L48 (no emissions and true dual exhaust):
1) Here in Belgium the standard fuel is rated at 95 ('EURO 95'). The premium fuel is rated at 98 (SUPER 98).
I read that my L48 was made to run on 88... So will the 95 fuel allow me to set the timing for better performance, or won't the octane rating have any effect on the timing?
2) What would be the best timing to run an engine as cool as possible? Retarding or advancing?
A friend of mine said: "The more horsepower you create, the hotter the engine will get." I'm confused... Is this correct?
Racer
Joined: Jul 2013
Posts: 294
Likes: 10
From: Palmer Alaska
AV gas has Lead in it, lot of lead in it. I used Av gas for a couple years and I started to see deposits forming on the plugs and upon using a bore scope I saw large deposits on the valves. I yanked the heads off and redid the valves before re-installing everything. I stopped using leaded gas at that point. My engine will run on 93 octane as long as you don't push it too hard, It can even run okay on 91 octane in a pinch. I will not pay for Race Gas so the Water/methanol idea made sense.
If you are careful with your timing and the advance curve you use high compression. With the Water/methanol system you can run 12.25-1 without any detonation. Are you still using a 427 or what motor? If I had to use the water/methanol all the time I would use a larger reservoir. I have driven back and forth 100+ miles in the summer with no issues down here in Virginia without the Water/Methanol Injection system even.
The Water/Methanol injection system injects into my Edlebrock RPM Air Gap Intake manifold just below the Holley Sniper Stealth EFI System. On my engine since I have a dual plane manifold I inject the water/methanol from both sides of the intake. This means I use smaller nozzles since I have two of them working. The guys at Snow Performance have been very helpful. I have to get it adjusted to the EFI system now that I have added that to my engine. I installed an air/fuel monitor for the other Oxygen sensor so I can watch the A/F ratio on either side to be sure I get it balanced.
Tell us about your engine, what is it? What have you done to it? They didn't come with scoops sticking out of the hood like that in the picture so you must have some work in it.
I am using a factory L88 Hood and wedding cake assembly to help my engine get COLD air into the throttle body. My engine is basically a L88 Clone with Closed Chamber Cast iron heads in a C3 that started life as an L71.
If you are careful with your timing and the advance curve you use high compression. With the Water/methanol system you can run 12.25-1 without any detonation. Are you still using a 427 or what motor? If I had to use the water/methanol all the time I would use a larger reservoir. I have driven back and forth 100+ miles in the summer with no issues down here in Virginia without the Water/Methanol Injection system even.
The Water/Methanol injection system injects into my Edlebrock RPM Air Gap Intake manifold just below the Holley Sniper Stealth EFI System. On my engine since I have a dual plane manifold I inject the water/methanol from both sides of the intake. This means I use smaller nozzles since I have two of them working. The guys at Snow Performance have been very helpful. I have to get it adjusted to the EFI system now that I have added that to my engine. I installed an air/fuel monitor for the other Oxygen sensor so I can watch the A/F ratio on either side to be sure I get it balanced.
Tell us about your engine, what is it? What have you done to it? They didn't come with scoops sticking out of the hood like that in the picture so you must have some work in it.
I am using a factory L88 Hood and wedding cake assembly to help my engine get COLD air into the throttle body. My engine is basically a L88 Clone with Closed Chamber Cast iron heads in a C3 that started life as an L71.
Safety Car
Joined: May 2001
Posts: 4,759
Likes: 1,647
From: Fairfax Virginia
That sounds like some serious fun! I also have an AED carburetor that was built for my unique application. Those guys are good! That is a lot of carburetor for a 350 with a Blower. Running high compression is fun but it makes a LOT of Heat! My headers are missing the first 5 inches or so of the ceramic coating as the high heat from the Compression related issues. The heat from the headers has started damaging the paint on the hood of my C3 and now I need to re-paint the poor Corvette.
I have gone to a Holley Sniper Stealth EFI system on my 1968 and have been very happy so far. The Corvette was pretty strong with a carburetor and I am anxious to get the EFI system finished. I am now connecting the ignition to the Sniper EFI system as it will control both the fueling and the timing. Fortunately the people I bought my system from offer incredible help when I have any issues. I don't know if you have any experience with the Holley Software package they have online. Take a look at it some time, it can do a lot of stuff for you regarding the injection system. It has the ability to run a second fuel pump when you need it so I am setting up the injection system to work off of temperature and vacuum readings. Unfortunately this means I have to disable and replace the MSD ignition system I have as well. I have a Mechanical tachometer MSD Billet Distributor along with a MSD Ignition controller and an MSD Retard box that I use to pull 20* of timing to help the engine start up. It is put back as soon as the engine goes over 800 rpm. This was one lesson that I learned, How to start a HOT 427 with 12.25-1 compression in warm weather. I have a gear drive starter that makes it sound like a Chrysler when cranking and with the timing pulled back she starts right up. The Holley Software also can control a wet or dry Nitrous system for you. They just don't have anything to stop detonation automatically like they do on their more expensive systems
What motivated you to put a Blower on your engine? That must be fun but I know little of pressurized air systems. My brother had a Merkur XR4Ti that had a turbo in it. When the turbo spun up it felt like you were being rear ended by a truck and when I installed a larger Turbo along with a manual waste gate he was the happiest. I never did understand why the engine dies when you open a vacuum line on that engine. For this reason I stuck with the old tried and trued method of making power using lots of Compression. Was the blower expensive? Did you source it as a kit or buy the parts and build it yourself?
Being a private pilot I have always wanted to install an engine monitoring hardware like they use in light aircraft to monitor all eight of my 8 cylinders. I have been thinking about installing the threads for the thermo-couples to monitor individual cylinders Exhaust heat. I would feel better with something monitoring the engine while I am enjoying the drive.
One day at a speed shop I had my hood open and there were four Police Officers looking over my entire C3. Finally one of them looked up and told me that my 427 would outrun any of their Police Cars, he said they could never catch you driving something like my C3. I smiled and agreed with them, then I told them that I was smart enough not to try to outrun any Police cars and they all looked relieved. They loved the detailed 427 sitting there shining and looking like it was made for business. Now when I open the hood they can't even tell that it is fuel injected and that is what I was looking for.
I have gone to a Holley Sniper Stealth EFI system on my 1968 and have been very happy so far. The Corvette was pretty strong with a carburetor and I am anxious to get the EFI system finished. I am now connecting the ignition to the Sniper EFI system as it will control both the fueling and the timing. Fortunately the people I bought my system from offer incredible help when I have any issues. I don't know if you have any experience with the Holley Software package they have online. Take a look at it some time, it can do a lot of stuff for you regarding the injection system. It has the ability to run a second fuel pump when you need it so I am setting up the injection system to work off of temperature and vacuum readings. Unfortunately this means I have to disable and replace the MSD ignition system I have as well. I have a Mechanical tachometer MSD Billet Distributor along with a MSD Ignition controller and an MSD Retard box that I use to pull 20* of timing to help the engine start up. It is put back as soon as the engine goes over 800 rpm. This was one lesson that I learned, How to start a HOT 427 with 12.25-1 compression in warm weather. I have a gear drive starter that makes it sound like a Chrysler when cranking and with the timing pulled back she starts right up. The Holley Software also can control a wet or dry Nitrous system for you. They just don't have anything to stop detonation automatically like they do on their more expensive systems
What motivated you to put a Blower on your engine? That must be fun but I know little of pressurized air systems. My brother had a Merkur XR4Ti that had a turbo in it. When the turbo spun up it felt like you were being rear ended by a truck and when I installed a larger Turbo along with a manual waste gate he was the happiest. I never did understand why the engine dies when you open a vacuum line on that engine. For this reason I stuck with the old tried and trued method of making power using lots of Compression. Was the blower expensive? Did you source it as a kit or buy the parts and build it yourself?
Being a private pilot I have always wanted to install an engine monitoring hardware like they use in light aircraft to monitor all eight of my 8 cylinders. I have been thinking about installing the threads for the thermo-couples to monitor individual cylinders Exhaust heat. I would feel better with something monitoring the engine while I am enjoying the drive.
One day at a speed shop I had my hood open and there were four Police Officers looking over my entire C3. Finally one of them looked up and told me that my 427 would outrun any of their Police Cars, he said they could never catch you driving something like my C3. I smiled and agreed with them, then I told them that I was smart enough not to try to outrun any Police cars and they all looked relieved. They loved the detailed 427 sitting there shining and looking like it was made for business. Now when I open the hood they can't even tell that it is fuel injected and that is what I was looking for.
Tech Contributor
Joined: Jun 2004
Posts: 20,905
Likes: 962
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
That sounds like some serious fun! I also have an AED carburetor that was built for my unique application. Those guys are good! That is a lot of carburetor for a 350 with a Blower. Running high compression is fun but it makes a LOT of Heat! My headers are missing the first 5 inches or so of the ceramic coating as the high heat from the Compression related issues. The heat from the headers has started damaging the paint on the hood of my C3 and now I need to re-paint the poor Corvette.
I have gone to a Holley Sniper Stealth EFI system on my 1968 and have been very happy so far. The Corvette was pretty strong with a carburetor and I am anxious to get the EFI system finished. I am now connecting the ignition to the Sniper EFI system as it will control both the fueling and the timing. Fortunately the people I bought my system from offer incredible help when I have any issues. I don't know if you have any experience with the Holley Software package they have online. Take a look at it some time, it can do a lot of stuff for you regarding the injection system. It has the ability to run a second fuel pump when you need it so I am setting up the injection system to work off of temperature and vacuum readings. Unfortunately this means I have to disable and replace the MSD ignition system I have as well. I have a Mechanical tachometer MSD Billet Distributor along with a MSD Ignition controller and an MSD Retard box that I use to pull 20* of timing to help the engine start up. It is put back as soon as the engine goes over 800 rpm. This was one lesson that I learned, How to start a HOT 427 with 12.25-1 compression in warm weather. I have a gear drive starter that makes it sound like a Chrysler when cranking and with the timing pulled back she starts right up. The Holley Software also can control a wet or dry Nitrous system for you. They just don't have anything to stop detonation automatically like they do on their more expensive systems
What motivated you to put a Blower on your engine? That must be fun but I know little of pressurized air systems. My brother had a Merkur XR4Ti that had a turbo in it. When the turbo spun up it felt like you were being rear ended by a truck and when I installed a larger Turbo along with a manual waste gate he was the happiest. I never did understand why the engine dies when you open a vacuum line on that engine. For this reason I stuck with the old tried and trued method of making power using lots of Compression. Was the blower expensive? Did you source it as a kit or buy the parts and build it yourself?
Being a private pilot I have always wanted to install an engine monitoring hardware like they use in light aircraft to monitor all eight of my 8 cylinders. I have been thinking about installing the threads for the thermo-couples to monitor individual cylinders Exhaust heat. I would feel better with something monitoring the engine while I am enjoying the drive.
One day at a speed shop I had my hood open and there were four Police Officers looking over my entire C3. Finally one of them looked up and told me that my 427 would outrun any of their Police Cars, he said they could never catch you driving something like my C3. I smiled and agreed with them, then I told them that I was smart enough not to try to outrun any Police cars and they all looked relieved. They loved the detailed 427 sitting there shining and looking like it was made for business. Now when I open the hood they can't even tell that it is fuel injected and that is what I was looking for.
I have gone to a Holley Sniper Stealth EFI system on my 1968 and have been very happy so far. The Corvette was pretty strong with a carburetor and I am anxious to get the EFI system finished. I am now connecting the ignition to the Sniper EFI system as it will control both the fueling and the timing. Fortunately the people I bought my system from offer incredible help when I have any issues. I don't know if you have any experience with the Holley Software package they have online. Take a look at it some time, it can do a lot of stuff for you regarding the injection system. It has the ability to run a second fuel pump when you need it so I am setting up the injection system to work off of temperature and vacuum readings. Unfortunately this means I have to disable and replace the MSD ignition system I have as well. I have a Mechanical tachometer MSD Billet Distributor along with a MSD Ignition controller and an MSD Retard box that I use to pull 20* of timing to help the engine start up. It is put back as soon as the engine goes over 800 rpm. This was one lesson that I learned, How to start a HOT 427 with 12.25-1 compression in warm weather. I have a gear drive starter that makes it sound like a Chrysler when cranking and with the timing pulled back she starts right up. The Holley Software also can control a wet or dry Nitrous system for you. They just don't have anything to stop detonation automatically like they do on their more expensive systems
What motivated you to put a Blower on your engine? That must be fun but I know little of pressurized air systems. My brother had a Merkur XR4Ti that had a turbo in it. When the turbo spun up it felt like you were being rear ended by a truck and when I installed a larger Turbo along with a manual waste gate he was the happiest. I never did understand why the engine dies when you open a vacuum line on that engine. For this reason I stuck with the old tried and trued method of making power using lots of Compression. Was the blower expensive? Did you source it as a kit or buy the parts and build it yourself?
Being a private pilot I have always wanted to install an engine monitoring hardware like they use in light aircraft to monitor all eight of my 8 cylinders. I have been thinking about installing the threads for the thermo-couples to monitor individual cylinders Exhaust heat. I would feel better with something monitoring the engine while I am enjoying the drive.
One day at a speed shop I had my hood open and there were four Police Officers looking over my entire C3. Finally one of them looked up and told me that my 427 would outrun any of their Police Cars, he said they could never catch you driving something like my C3. I smiled and agreed with them, then I told them that I was smart enough not to try to outrun any Police cars and they all looked relieved. They loved the detailed 427 sitting there shining and looking like it was made for business. Now when I open the hood they can't even tell that it is fuel injected and that is what I was looking for.
Racer
Joined: Jul 2013
Posts: 294
Likes: 10
From: Palmer Alaska
That sounds like some serious fun! I also have an AED carburetor that was built for my unique application. Those guys are good! That is a lot of carburetor for a 350 with a Blower. Running high compression is fun but it makes a LOT of Heat! My headers are missing the first 5 inches or so of the ceramic coating as the high heat from the Compression related issues. The heat from the headers has started damaging the paint on the hood of my C3 and now I need to re-paint the poor Corvette.
I have gone to a Holley Sniper Stealth EFI system on my 1968 and have been very happy so far. The Corvette was pretty strong with a carburetor and I am anxious to get the EFI system finished. I am now connecting the ignition to the Sniper EFI system as it will control both the fueling and the timing. Fortunately the people I bought my system from offer incredible help when I have any issues. I don't know if you have any experience with the Holley Software package they have online. Take a look at it some time, it can do a lot of stuff for you regarding the injection system. It has the ability to run a second fuel pump when you need it so I am setting up the injection system to work off of temperature and vacuum readings. Unfortunately this means I have to disable and replace the MSD ignition system I have as well. I have a Mechanical tachometer MSD Billet Distributor along with a MSD Ignition controller and an MSD Retard box that I use to pull 20* of timing to help the engine start up. It is put back as soon as the engine goes over 800 rpm. This was one lesson that I learned, How to start a HOT 427 with 12.25-1 compression in warm weather. I have a gear drive starter that makes it sound like a Chrysler when cranking and with the timing pulled back she starts right up. The Holley Software also can control a wet or dry Nitrous system for you. They just don't have anything to stop detonation automatically like they do on their more expensive systems
What motivated you to put a Blower on your engine? That must be fun but I know little of pressurized air systems. My brother had a Merkur XR4Ti that had a turbo in it. When the turbo spun up it felt like you were being rear ended by a truck and when I installed a larger Turbo along with a manual waste gate he was the happiest. I never did understand why the engine dies when you open a vacuum line on that engine. For this reason I stuck with the old tried and trued method of making power using lots of Compression. Was the blower expensive? Did you source it as a kit or buy the parts and build it yourself?
Being a private pilot I have always wanted to install an engine monitoring hardware like they use in light aircraft to monitor all eight of my 8 cylinders. I have been thinking about installing the threads for the thermo-couples to monitor individual cylinders Exhaust heat. I would feel better with something monitoring the engine while I am enjoying the drive.
One day at a speed shop I had my hood open and there were four Police Officers looking over my entire C3. Finally one of them looked up and told me that my 427 would outrun any of their Police Cars, he said they could never catch you driving something like my C3. I smiled and agreed with them, then I told them that I was smart enough not to try to outrun any Police cars and they all looked relieved. They loved the detailed 427 sitting there shining and looking like it was made for business. Now when I open the hood they can't even tell that it is fuel injected and that is what I was looking for.
I have gone to a Holley Sniper Stealth EFI system on my 1968 and have been very happy so far. The Corvette was pretty strong with a carburetor and I am anxious to get the EFI system finished. I am now connecting the ignition to the Sniper EFI system as it will control both the fueling and the timing. Fortunately the people I bought my system from offer incredible help when I have any issues. I don't know if you have any experience with the Holley Software package they have online. Take a look at it some time, it can do a lot of stuff for you regarding the injection system. It has the ability to run a second fuel pump when you need it so I am setting up the injection system to work off of temperature and vacuum readings. Unfortunately this means I have to disable and replace the MSD ignition system I have as well. I have a Mechanical tachometer MSD Billet Distributor along with a MSD Ignition controller and an MSD Retard box that I use to pull 20* of timing to help the engine start up. It is put back as soon as the engine goes over 800 rpm. This was one lesson that I learned, How to start a HOT 427 with 12.25-1 compression in warm weather. I have a gear drive starter that makes it sound like a Chrysler when cranking and with the timing pulled back she starts right up. The Holley Software also can control a wet or dry Nitrous system for you. They just don't have anything to stop detonation automatically like they do on their more expensive systems
What motivated you to put a Blower on your engine? That must be fun but I know little of pressurized air systems. My brother had a Merkur XR4Ti that had a turbo in it. When the turbo spun up it felt like you were being rear ended by a truck and when I installed a larger Turbo along with a manual waste gate he was the happiest. I never did understand why the engine dies when you open a vacuum line on that engine. For this reason I stuck with the old tried and trued method of making power using lots of Compression. Was the blower expensive? Did you source it as a kit or buy the parts and build it yourself?
Being a private pilot I have always wanted to install an engine monitoring hardware like they use in light aircraft to monitor all eight of my 8 cylinders. I have been thinking about installing the threads for the thermo-couples to monitor individual cylinders Exhaust heat. I would feel better with something monitoring the engine while I am enjoying the drive.
One day at a speed shop I had my hood open and there were four Police Officers looking over my entire C3. Finally one of them looked up and told me that my 427 would outrun any of their Police Cars, he said they could never catch you driving something like my C3. I smiled and agreed with them, then I told them that I was smart enough not to try to outrun any Police cars and they all looked relieved. They loved the detailed 427 sitting there shining and looking like it was made for business. Now when I open the hood they can't even tell that it is fuel injected and that is what I was looking for.