MSefi.com read only forum (Jan.15,2018)

I am working with a friend on his hot rod project. He is running a old Chevy 4 cylinder 181 ci motor that is currently setup with a hilborn/kinsler constant flow style fuel injection.

I don't have pictures of setup but here is picture of the same setup on a different car I found so you have an idea of what I am talking about:


He would like to go with EFI but still wants to keep the old constant flow look to the system. I am thinking of remotely mounting 2 EFI injectors is a fuel distribution block that would feed the old constant flow injectors. I would work to hide the injector wiring and make them look like fuel lines. We would use a EFI fuel pump and not the front mounted pressure pump so the pressure would stay the same. We may turn the current front mount pump into an idler pulley just to keep the old style look.

He wants the system hidden as much as we can. I told him we could mount the injectors on the bottom side of the manifolds and use the constant flow injects for MAP sensing but he was not too keen on that idea and we may have issues with heat soak due to the location of the exhaust. So the more hidden the better.

Another option is to use the EFI injectors to bleed off pressure from the constant flow injection system at the higher RPMs but this does not deal with cold start and drive-ability issues.

Like most hot rodders, he is using the car mainly for cruses and poker runs so drive-ability is important. He does not want to have to worry about cold start issues and tuning which can be a problem with the constant flow injectors.

I've seen a similar injector-as-valve strategy used with a guy who converted a Bosch mechanical fuel injection to EFI. I think in his case it was done to get around the racing rulebook, which did not allow any changes to the intake manifold or the injector nozzles, but had no rules about what was done upstream of them.

I have done some more searching and reading and I forgot GM did something like this back in the mid 90's into the early 2000's. It was called: GM Central Port Injection. I just need to figure out what size injector and spray tip to use. I worry that the spray tip will cause issues with the fuel being directed to one of the cylinder ports more the others. I think we could use one 90 to 100 lb/hr injector and up the pressure to meet the needs. Horsepower is going to be about 175 HP.

Also looking to see if we could use some other type of fast acting valve like from a nitrous setup that we really would not have to hide to get the "look". Most of the nitrous valves I have found look like slow acting OFF/ON solenoids.

If you don't want to alter the manifold ,make yourself a portfueler.
But put the injectors on the bottom.
http://www.turbosystem.com/auto/engine/Portfueler.htm