"Ram Jet" injection to 383 & Fast Burn heads

[HotRod4PaPa]

I am new to EFI, but it is something I think is worth installing on a street rod project of mine. I have a complete "Ram Jet" unit that I want to use on a 383 with the GM "Fast Burn" heads and a Crane hydraulic roller cam(224/230 @ .050 and .509/.528 lift). I have a Commander 950 ECM with GM multi point injection harness (950-101) that I want to use rather than reprogramming the MEFI3 unit. I have a carbureted, 15 gal. gas tank(baffled, but no "in tank" pump reservoir tray). I can retrofit an "in tank" pump.
Are adapters available to adapt to the Ram Jet IAC and TPS?
Will not having a reservoir tray in the tank cause serious problems beyond the hesitation created from the pump momentarily starving for fuel when cornering?
What size rigid inlet and return lines, and fittings should I use and where can I get them? I guess I should also ask what size pump to run. Tanks offers two sizes (155 lph & 190 lph) and two brands (Walbro and AC). Is one better than the other? I think this has the same injector as the LT1.
Does the fast burn head have too large an intake runner (210 cc)to make a good, responsive engine for street driving when using an 700R4 automatic?
Any help you guys can give me will be greatly appreciated. Thanks

[Fuelie Fan]

I don't know where to get adaptors, but you should be able to find the connectors in the junkyard. I thought the IAC connector was the same.
If the car is not a track car, all you have to do is keep the fuel level up and you'll be fine without baffling.
3/8 supply, 5/16 or 3/8 return
I assume you mean Walbro, not Waldo? Walbro produces very good pumps. I would think that AC does also, but i've never used them. fuel pumps is one of those industries where there's probably 20 different name brands, but maybe 3 or 4 actual pump manufacturers. The rest is just fancy cases and different name stamps.
You need to find out what injectors you have, and also try to determine what size you need. See the FAQ, you will need to estimate your engine's hp.
I will let someone else answer the head question.

[HotRod4PaPa]

Thanks for the reply! Yes that is a "Walbro" brand of pump I was referring to. I will look for an injector part number in the service manual. I did look at the FAQ posting, which I thought was great info.

[PhillipM]

This is an engine that I happen to know a little bit about. I'd say about 8 months ago I built this motor. I used a GM performance parts 383, fastburn heads and and MEFI 4 Ram-Jet. The cam that I went with is the 525 lift GM hot cam. The real problem with the whole set up is not the fuel but getting the air through the ram-jet. We eneded up sending ours to California and had it extrude honed after portmatching the ports to the ported fastburns. I feel that this is what made the whole package work because the initial flow ratings of the stock ram-jet hardley covered the stock 350 it was designed for. As for the fuel I went with like a 190 lph intank pump and used bosch 30lb/h injectors off of a supercharged Cobra motor. If you are worried about tuning the MEFI Arizona speed& marine now has the exact program for my motor on file. All of this got us 434 HP and 503 TQ to the wheels through a Richmond 6 and a 12 bolt.

[HotRod4PaPa]

Wow! Great HP & Torque numbers. I guess the fast burn heads are ok. Can you tell me where to have the manifold extrude honed? I'm sure I will also have to go with the 30# injectors to get this thing right. I e-mailed Arizona S & M a few months back, but got no response. That's when I went with the Holley setup. Thanks for the reply. Great information! I appreciate it.

[PhillipM]

I don't remember the exact name of the company that we went with but I do remember that you must be a regestered technition because they don't work with the general public. This is probably because we met them at SEMA. I will try and find the name of the company that we used though because they were awesome. They had me scribe exactly where the head met up with the intake on the intake and then I port matched it to with in 10 thousands my self by hand and then send it to them to finish the rest off. I went from flowing 210 and the runners to over 270 cfm's at the runners which matched my newly done heads perfectly. As for the boys over at AS&M I guess you would just have to meet them to understand how they operate. Since I live here in Phoenix I sent the car over there and they spent about 3 days tuning it in. I do have to say that it runs just about perfect in every environment I have had it in from low desert to high mountains so... And the best part is that the MEFI was built for the ram-jet, there was no modifiying it to make it fit.

[HotRod4PaPa]

Yeah. I understand that the guys at AS&M are busy trying to make a living leaning over a fender with a wrench in one hand and an oily rag in the other. My dad did that for years. But times are changing. The internet is a huge resource for individuals and businesses if used correctly. That is why I appreciate these forums. Great people with good information learned the hard way, as you did with this engine combination, are out there. Thanks again

[Reckn8]

Sorry, I logged in under a different name on accident.



Thank you for the compliment. I think that you took my comment about AS&M wrong. I think those guys are jack ass's, well not all of them but about 90 percent of them over there are. If you try to email nothing happens, you either need to call and ask for somebody else than the bimbo that answers the phone or go in and ask to talk to somebody. I completly agree with you that they need to be more on top of their online stuff but... oh well. What ya gunna do. My dad also was a mechanic for years. He worked for Pontiac in the muscle car era. He sure does have some good stories from back then.

Phillip M.