Rochester efi conversion. (HELP)
08-29-2016, 02:28 PM
#1
Rochester efi conversion. (HELP)
I am planning on doing a efi conversion on a 1960 Rochester plenum.
I have read some articles on doing the conversion, but nothing is very detailed as to what parts would be the best/ easiest to use. I would like to keep it as simple as possible, upgrade distributor with Pertronics ignition. an aftermarket ecm, without msd 6al if possible. If anyone has done the conversion, or has any input into how I should proceed, it will be greatly appreciated.
I have read some articles on doing the conversion, but nothing is very detailed as to what parts would be the best/ easiest to use. I would like to keep it as simple as possible, upgrade distributor with Pertronics ignition. an aftermarket ecm, without msd 6al if possible. If anyone has done the conversion, or has any input into how I should proceed, it will be greatly appreciated.
08-29-2016, 02:29 PM
#2
Team Owner
Contact wmf62 on here; he's done it; it works and works well; including a 10,000 mile trip a while back....
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Moleyman (08-29-2016)
08-29-2016, 03:21 PM
#3
Arizona Speed and Marine could do this conversion for you, with your choice of either the FAST or MEFI 4 controller. The FAST costs more but you could self-tune. ASM would need to program the MEFI for you.
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Moleyman (08-29-2016)
08-30-2016, 04:55 PM
#4
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St. Jude Donor '07
Pat
it has been since August 2009 since I did my conversion so I have no idea what advances may have been made in EFI management systems that would be compatible with mounting on a Rochester plenum. I can say that mine has worked flawlessly (except where I managed to shoot myself in the foot...) and is fully tunable by computer to parameters that I have no clue as to what they are... there are times that if I could have found a tall building I would have been tempted to jump off....
you say you want to use your current distributor with a Pertronics; I don't know if that is possible, but there may be an ECM that can use that as a triggering device.
I used an ACCEL Thruster 'kit' that consisted of a new distributor, a wide range O2 sensor computer, a ignition computer, and a main ECM computer, along with all sensors, wiring harness, coil pack, etc
sensors used were a knock sensor, IAT sensor, TPS sensor, MAP sensor, IAC sensor. a long wiring harness was included that had to be shortened for convenience and location of the electronics and injectors.
injectors are LS2 injectors mounted in nozzle blocks similar to the original Rochester blocks custom made to fit the LS2 injectors; I have seen pictures where people have simply bored out the doghouse injector holes to fit the injectors). the fuel manifold was fabricated to serve as the retainer for the nozzles and has a return to the fuel tank (which has an in-tank fuel pump).
any throttle body of approximately 600CFM that you can adapt should work.
the BIGGIE is cost... at the time I figure I had about $5000 invested in parts and some machine work; and I already had the old Rochester parts. I have no idea what electronics are available now and their cost....
speaking of those, is your doghouse a finned or smooth top plenum. the finned has smaller intake runners along with a smaller matching port in the adapter plate but will still work; I've used both and presently am using the smooth top.
back before I started this I considered the AS&M but had 2 problems with them: their unit was only for Vortec Heads, and it was expensive.
at this point, I would be tempted to contact AS&M and see if they will give you a materials list of the components they use; fat chance, but worth trying...
Bill
it has been since August 2009 since I did my conversion so I have no idea what advances may have been made in EFI management systems that would be compatible with mounting on a Rochester plenum. I can say that mine has worked flawlessly (except where I managed to shoot myself in the foot...) and is fully tunable by computer to parameters that I have no clue as to what they are... there are times that if I could have found a tall building I would have been tempted to jump off....
you say you want to use your current distributor with a Pertronics; I don't know if that is possible, but there may be an ECM that can use that as a triggering device.
I used an ACCEL Thruster 'kit' that consisted of a new distributor, a wide range O2 sensor computer, a ignition computer, and a main ECM computer, along with all sensors, wiring harness, coil pack, etc
sensors used were a knock sensor, IAT sensor, TPS sensor, MAP sensor, IAC sensor. a long wiring harness was included that had to be shortened for convenience and location of the electronics and injectors.
injectors are LS2 injectors mounted in nozzle blocks similar to the original Rochester blocks custom made to fit the LS2 injectors; I have seen pictures where people have simply bored out the doghouse injector holes to fit the injectors). the fuel manifold was fabricated to serve as the retainer for the nozzles and has a return to the fuel tank (which has an in-tank fuel pump).
any throttle body of approximately 600CFM that you can adapt should work.
the BIGGIE is cost... at the time I figure I had about $5000 invested in parts and some machine work; and I already had the old Rochester parts. I have no idea what electronics are available now and their cost....
speaking of those, is your doghouse a finned or smooth top plenum. the finned has smaller intake runners along with a smaller matching port in the adapter plate but will still work; I've used both and presently am using the smooth top.
back before I started this I considered the AS&M but had 2 problems with them: their unit was only for Vortec Heads, and it was expensive.
at this point, I would be tempted to contact AS&M and see if they will give you a materials list of the components they use; fat chance, but worth trying...
Bill
Last edited by wmf62; 08-30-2016 at 04:59 PM.
08-30-2016, 08:51 PM
#5
Safety Car
Charles
08-30-2016, 11:17 PM
#6
Le Mans Master
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Don't forget the general, GMPP, sells the Ram Jet 350 injection system as a bolt on kit designed for the small block Chevy. I expect less difficult for someone new to EFI.
08-31-2016, 04:31 AM
#7
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St. Jude Donor '07
we have discussed this, and it is possible he could just swap the electronics.
Bill
08-31-2016, 06:54 AM
#8
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Charles
08-31-2016, 03:43 PM
#9
Melting Slicks
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My conversion of a Hilborn 8 stack mechanical injection was not to difficult and I started with a MegaSquirt ECU. I did the initial tuning using a laptop then they came out with a self tuning program for around $50.00 and it worked fine.
I decided I wanted something a little better and bought a FAST EZ EFI 2.0.
It is a very friendly and efficient setup.
As wmf62 said you will need the complete Rochester setup not just the manifold, although you can do without he fuel side of the actual unit. If you just have the manifold some sort of custom throttle bodies will be required.
Bruce B
I decided I wanted something a little better and bought a FAST EZ EFI 2.0.
It is a very friendly and efficient setup.
As wmf62 said you will need the complete Rochester setup not just the manifold, although you can do without he fuel side of the actual unit. If you just have the manifold some sort of custom throttle bodies will be required.
Bruce B
Last edited by ohiovet; 08-31-2016 at 03:45 PM.
08-31-2016, 04:34 PM
#10
converting Rochester fi to efi
My conversion of a Hilborn 8 stack mechanical injection was not to difficult and I started with a MegaSquirt ECU. I did the initial tuning using a laptop then they came out with a self tuning program for around $50.00 and it worked fine.
I decided I wanted something a little better and bought a FAST EZ EFI 2.0.
It is a very friendly and efficient setup.
As wmf62 said you will need the complete Rochester setup not just the manifold, although you can do without he fuel side of the actual unit. If you just have the manifold some sort of custom throttle bodies will be required.
Bruce B
I decided I wanted something a little better and bought a FAST EZ EFI 2.0.
It is a very friendly and efficient setup.
As wmf62 said you will need the complete Rochester setup not just the manifold, although you can do without he fuel side of the actual unit. If you just have the manifold some sort of custom throttle bodies will be required.
Bruce B
thanks for the input, I am on a steep learning curve.
I have the manifold and the Rochester doghouse (plenum). I intend to adapt a late Camaro or ls1 throttle body to the plenum. I will then either mill out or weld in fuel injector bungs to the plenum. the plumbing for the injectors is pretty straight forward.
I am intending on using a Fast multi-port retro-fit EZ-EFI kit for control. It can be used either for sequential or batch injection. I will most likely go batch injection because I want to use my stock distributor with a Pertronic module. I want to keep it looking as stock as possible.
do you think I am on the right track.
Thanks,
Pat
08-31-2016, 09:12 PM
#11
Melting Slicks
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Pat,
You are going in the right direction and your idea of using the base plate and the plenum is good.
I used the FAST EFI 2.0 KIT which is batch injection and it works fine.
Since you are using the plenum (versus 8 stacks) you can utilize the IAC (idle air control) which is resident in the FAST 2.0. As far as using the stock distributor I started out that way and used the FAST RPM MODULE. The module is pretty unreliable and I ended up going with a MSD box and distributor which performs flawlessly and also does a excellent job controlling timing.
If you would like to discuss this subject give me a call.
Bruce B
You are going in the right direction and your idea of using the base plate and the plenum is good.
I used the FAST EFI 2.0 KIT which is batch injection and it works fine.
Since you are using the plenum (versus 8 stacks) you can utilize the IAC (idle air control) which is resident in the FAST 2.0. As far as using the stock distributor I started out that way and used the FAST RPM MODULE. The module is pretty unreliable and I ended up going with a MSD box and distributor which performs flawlessly and also does a excellent job controlling timing.
If you would like to discuss this subject give me a call.
Bruce B
09-02-2016, 03:03 AM
#12
Hi,
Much of what you will need can be bought off the shelf but some important pieces are not commercially available and will have to be designed and made.
You will have to increase the size of the injector bores in the dog house by about 1/32 to 0.531. I used a specially ground pilot reamer. The bore finish must be fine enough for the injector o-ring to seal. These bores also need to be back chamfered to prevent cutting the injector o-rings. The back chamfer tool isn't commercially available so you'll need a tool maker.
You can use an LS throttle body but you will need to design and build an adaptor to mate it with the dog house. The LS throttle body is cable drive and the stock system uses a bell crank so you will have to design and build a new throttle linkage.
You must devise and build the fuel system. The major pieces are high pressure pump, fuel pressure regulator and filter which can be bought from many suppliers. The injector manifold or fuel rail is not available commercially and must be designed and built along with any brackets. Care must be taken so that fuel delivery is continuous at low fuel levels. You cannot uncover the fuel pick up or the car stops. There are numerous threads on the trials of running the regulator return line.
The sensor suite is typically from the LS series. You will need to design and build mounts for and plumb the MAP sensor and IAT sensors. You will most likely need exhaust oxygen sensors added to your pipes.
You can use an aftermarket ECU. The big names all offer self learning and have a support network. You could also use an OEM ECU but will need aftermarket software and pretty advanced computer skills to defeat the things you don't need/want like the factory vehicle security codes.
This isn't a kit so you'll have to tune it or find a local tuner.
One of the benefits of EFI is better engine management. All the EFI systems allow sequential fueling and complete control of engine timing. You are going through all the effort to install a complete system you should use it to it's fullest. I suggest you might reconsider your position on batch fire and external timing control. You are leaving chips on the table.
Best wishes with you project. It feels great when you are done and it fires up.
Grampy
Much of what you will need can be bought off the shelf but some important pieces are not commercially available and will have to be designed and made.
You will have to increase the size of the injector bores in the dog house by about 1/32 to 0.531. I used a specially ground pilot reamer. The bore finish must be fine enough for the injector o-ring to seal. These bores also need to be back chamfered to prevent cutting the injector o-rings. The back chamfer tool isn't commercially available so you'll need a tool maker.
You can use an LS throttle body but you will need to design and build an adaptor to mate it with the dog house. The LS throttle body is cable drive and the stock system uses a bell crank so you will have to design and build a new throttle linkage.
You must devise and build the fuel system. The major pieces are high pressure pump, fuel pressure regulator and filter which can be bought from many suppliers. The injector manifold or fuel rail is not available commercially and must be designed and built along with any brackets. Care must be taken so that fuel delivery is continuous at low fuel levels. You cannot uncover the fuel pick up or the car stops. There are numerous threads on the trials of running the regulator return line.
The sensor suite is typically from the LS series. You will need to design and build mounts for and plumb the MAP sensor and IAT sensors. You will most likely need exhaust oxygen sensors added to your pipes.
You can use an aftermarket ECU. The big names all offer self learning and have a support network. You could also use an OEM ECU but will need aftermarket software and pretty advanced computer skills to defeat the things you don't need/want like the factory vehicle security codes.
This isn't a kit so you'll have to tune it or find a local tuner.
One of the benefits of EFI is better engine management. All the EFI systems allow sequential fueling and complete control of engine timing. You are going through all the effort to install a complete system you should use it to it's fullest. I suggest you might reconsider your position on batch fire and external timing control. You are leaving chips on the table.
Best wishes with you project. It feels great when you are done and it fires up.
Grampy
09-02-2016, 11:49 AM
#13
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St. Jude Donor '07
considering the Rochester is 'puddle' injection, batch will work; but it makes no sense if sequential is available...
the BIG advantage is essentially no more perc problems.... if it wasn't for perc problems I never would never have gone to the dark side
1st picture is of the original installation on 70 LT1 crate engine, 2nd is on a ZZ4 crate engine
Bill
the BIG advantage is essentially no more perc problems.... if it wasn't for perc problems I never would never have gone to the dark side
1st picture is of the original installation on 70 LT1 crate engine, 2nd is on a ZZ4 crate engine
Bill
Last edited by wmf62; 09-02-2016 at 11:50 AM.
09-02-2016, 12:22 PM
#14
converting Rochester fi to efi
Hi,
Much of what you will need can be bought off the shelf but some important pieces are not commercially available and will have to be designed and made.
You will have to increase the size of the injector bores in the dog house by about 1/32 to 0.531. I used a specially ground pilot reamer. The bore finish must be fine enough for the injector o-ring to seal. These bores also need to be back chamfered to prevent cutting the injector o-rings. The back chamfer tool isn't commercially available so you'll need a tool maker.
You can use an LS throttle body but you will need to design and build an adaptor to mate it with the dog house. The LS throttle body is cable drive and the stock system uses a bell crank so you will have to design and build a new throttle linkage.
You must devise and build the fuel system. The major pieces are high pressure pump, fuel pressure regulator and filter which can be bought from many suppliers. The injector manifold or fuel rail is not available commercially and must be designed and built along with any brackets. Care must be taken so that fuel delivery is continuous at low fuel levels. You cannot uncover the fuel pick up or the car stops. There are numerous threads on the trials of running the regulator return line.
The sensor suite is typically from the LS series. You will need to design and build mounts for and plumb the MAP sensor and IAT sensors. You will most likely need exhaust oxygen sensors added to your pipes.
You can use an aftermarket ECU. The big names all offer self learning and have a support network. You could also use an OEM ECU but will need aftermarket software and pretty advanced computer skills to defeat the things you don't need/want like the factory vehicle security codes.
This isn't a kit so you'll have to tune it or find a local tuner.
One of the benefits of EFI is better engine management. All the EFI systems allow sequential fueling and complete control of engine timing. You are going through all the effort to install a complete system you should use it to it's fullest. I suggest you might reconsider your position on batch fire and external timing control. You are leaving chips on the table.
Best wishes with you project. It feels great when you are done and it fires up.
Grampy
Much of what you will need can be bought off the shelf but some important pieces are not commercially available and will have to be designed and made.
You will have to increase the size of the injector bores in the dog house by about 1/32 to 0.531. I used a specially ground pilot reamer. The bore finish must be fine enough for the injector o-ring to seal. These bores also need to be back chamfered to prevent cutting the injector o-rings. The back chamfer tool isn't commercially available so you'll need a tool maker.
You can use an LS throttle body but you will need to design and build an adaptor to mate it with the dog house. The LS throttle body is cable drive and the stock system uses a bell crank so you will have to design and build a new throttle linkage.
You must devise and build the fuel system. The major pieces are high pressure pump, fuel pressure regulator and filter which can be bought from many suppliers. The injector manifold or fuel rail is not available commercially and must be designed and built along with any brackets. Care must be taken so that fuel delivery is continuous at low fuel levels. You cannot uncover the fuel pick up or the car stops. There are numerous threads on the trials of running the regulator return line.
The sensor suite is typically from the LS series. You will need to design and build mounts for and plumb the MAP sensor and IAT sensors. You will most likely need exhaust oxygen sensors added to your pipes.
You can use an aftermarket ECU. The big names all offer self learning and have a support network. You could also use an OEM ECU but will need aftermarket software and pretty advanced computer skills to defeat the things you don't need/want like the factory vehicle security codes.
This isn't a kit so you'll have to tune it or find a local tuner.
One of the benefits of EFI is better engine management. All the EFI systems allow sequential fueling and complete control of engine timing. You are going through all the effort to install a complete system you should use it to it's fullest. I suggest you might reconsider your position on batch fire and external timing control. You are leaving chips on the table.
Best wishes with you project. It feels great when you are done and it fires up.
Grampy
My idea is to mill the doghouse and use ls2 injectors. option 2 would be to bore the doghouse injector holes out and tig weld in injector bungs.
The hold down for the injectors is not a problem. I want to run individual hard lines to the injectors, and mount a fuel distribution block under the doghouse. I am having a hard time finding the individual cap/clip for the top of the injectors to convert to hard lines. Please let me know if you have a source. I was thinking of using the FAST multi-port retro-fit EZ-EFI kit. for control of fuel and spark. I could run the FAST crank trigger or FAST dual sync distributor. Either system would support sequential injection and timing control. with the crank trigger I could use my existing distributor less guts for spark distribution only. The fuel can be handled by either installing a return line in my fuel tank, and using an external in-line fuel pump, or changing out my tank and using an internal fuel pump. The benefit of the internal pump is that the tank has special baffles that help in low fuel conditions. I was planning on using a corvette ls2 type in line fuel filter/ pressure regulator. I have used this filter/pressure regulator before and it works well. It would be mounted close to the fuel tank.
Please let me know what you think.
Your fi setup looks great.
can you tell me the exact cross section profile of the injector seats. are I have access to a milling machine, lathe, and tig welding equipment, so I would be doing the modifications myself. Care to rent your bit.
Thanks for your help,
Pat
09-02-2016, 12:26 PM
#15
converting Rochester fi to efi
considering the Rochester is 'puddle' injection, batch will work; but it makes no sense if sequential is available...
the BIG advantage is essentially no more perc problems.... if it wasn't for perc problems I never would never have gone to the dark side
1st picture is of the original installation on 70 LT1 crate engine, 2nd is on a ZZ4 crate engine
Bill
the BIG advantage is essentially no more perc problems.... if it wasn't for perc problems I never would never have gone to the dark side
1st picture is of the original installation on 70 LT1 crate engine, 2nd is on a ZZ4 crate engine
Bill
Your engine looks great. Stock looking. I responded to Grampy with my plans for the moment, have a look and see what you think.
Thanks,
Pat
09-02-2016, 12:30 PM
#16
Race Director
Stay AWAY from the MEFI. It is so outdated it isn't funny. Just about anybodies ECU is better. I am sure the newer ones are better than my 7-8 year old Accel which is light years ahead of the MEFI.
The MEFI strikes me as useful for say a boat that does nothing but run at a constant RPM most of the time, with no altitude changes.
And you definitely want sequential port vs batch fire (MEFI), the sequential runs so much better at low RPM. You will need some sort of dizzy trigger for sequential, the Accel dual sync dizzy does that for the Accel ECU, it may work with other ECUs, or they may have their own crank position trigger, ask around.
Doug
The MEFI strikes me as useful for say a boat that does nothing but run at a constant RPM most of the time, with no altitude changes.
And you definitely want sequential port vs batch fire (MEFI), the sequential runs so much better at low RPM. You will need some sort of dizzy trigger for sequential, the Accel dual sync dizzy does that for the Accel ECU, it may work with other ECUs, or they may have their own crank position trigger, ask around.
Doug
Last edited by AZDoug; 09-02-2016 at 12:33 PM.
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Moleyman (09-02-2016)
09-03-2016, 09:06 AM
#17
Pat,
I have this system available if you're interested.
https://www.corvetteforum.com/forums...1&d=1472907871
https://www.corvetteforum.com/forums...1&d=1472907871
I have this system available if you're interested.
https://www.corvetteforum.com/forums...1&d=1472907871
https://www.corvetteforum.com/forums...1&d=1472907871
09-03-2016, 09:10 AM
#18
More details:
I have a F.A.S.T. XFI 2.0 computer, Dual Synch distributor and wiring harnesses.
The system was put together by Carl Reisbach at BDS before he retired and sold the business. I never installed the system as I recently purchased a 1965 and am looking for a reasonable priced second generation Rochester to build an EFI around.
Good Luck with your project;
Geoffrey
I have a F.A.S.T. XFI 2.0 computer, Dual Synch distributor and wiring harnesses.
The system was put together by Carl Reisbach at BDS before he retired and sold the business. I never installed the system as I recently purchased a 1965 and am looking for a reasonable priced second generation Rochester to build an EFI around.
Good Luck with your project;
Geoffrey
09-03-2016, 03:43 PM
#19
Melting Slicks
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EFI, fuel rails vs no fuel rails.
2 Hilborn units I have, the one on my car has no fuel rails the other has fuel rails.
I prefer the fuel lines as compared to the rails.
I like Geoffreys setup with the hard lines, mine uses braided flexible lines with AN fittings.
Geoffrey, what did you use for fuel line adapters on the injectors?
I use the same type retainer clips you used.
Do you use a IAC?
Bruce
I prefer the fuel lines as compared to the rails.
I like Geoffreys setup with the hard lines, mine uses braided flexible lines with AN fittings.
Geoffrey, what did you use for fuel line adapters on the injectors?
I use the same type retainer clips you used.
Do you use a IAC?
Bruce
Last edited by ohiovet; 09-03-2016 at 03:44 PM.
