I was searching around google, looking for info over the 454 TBI units and trying to see how hard it would be to set one up on the 425. I'm thinking you could use the TBI setup and a megasquirt box, but what else would need to be done? Also, I came across this while searching. They sell a complete TBI kit for the 401's. http://www.affordable-fuel-injection.com/store.php?crn=209&rn=437&action=show_detail
Brian, for a time holley was making a kit that could be used on any v8 that was a 4 bbl unit....I just never did try one.... it really looked good... they may still make it....
the holley unit he is talking about may be listed in summit catalog . $1599.95 . can go to www.summitracing.com and in the search area type in "HLY-950-24S" . that is the part number for the commander 950 tbi system , 900cfm , 375-525 hp . there are 3 other choices listed also . if ya look around a little in there it will list parts etc ( which will give you an idea of things that need to be done ) and you can also look at/print out instructions usually . you can also click on "brands" at the top of the home page and go to "H" , then go to holley and then on the right it will probably let you go to the holley web site to check out info . there have also been a couple other similar systems that have become available ( one from F.A.S.T. i think ) that would be worth researching i'm sure . i always thought this for a nailhead would be an interesting idea . del
Check out this link for a TBI swap using existing GM parts. Mike hasn't done it on a GM yet (he has done it to a Ford,) but he's done all of the ground work for it. www.rowand.net/Shop/Tech/GMTBISwap.htm
This conversion can be done, i did a jeep straight 6 by swapping all the stuff from a 4.0 .....the biggest thing was setting up the crank position sensor and then the wire loom had to be hand built......
It's funny that nearly all of the aftermarket systems are TBI since the nail is relatively obscure. I've considered doing this too but I am hesitant because I have always been under the impression that the factory TBI systems were pretty limited powerwise. I realize the heads sucked etc too. Hotrod did a bunch of articles on doing EFI conversions last year in one issue that showed the same or more power in some instances by going from carb to a TBI based system so I don't know. I would like to do a dual quad system but I am cheap too so I will probably just rebuild what I have.
I found a site (of course website is on work puter) and they make a wiring system for the TBI set-up. They said that the distributor must be made to use as a timing set-up for it though. So, the stock distributor cannot be made for that. BUT, the new billet HEI units out there can! What I wanted to do was instead of running 2 4bbl's, I wanted to run dual TBI's like the vette's in the 80's. It can be done, but you need the ECM from a dual TBI which i think was from 84-86 only. After that, the guys sell you a single TBI wiring kit, then sell you a splitter to split the signal from one TBI to another. What sucks too is you need to install an oxygen sensor to read the tailpipe emissions so the TBI can see what the thing needs to do to regulate proper fuel mixture. The more I looked itnto it, the more I decided to go simple... twin stock AFB carbs. IF I was going to run a nailhead in a street rod and had to install a wiring harness anyway, I would do the dual TBI's. Otherwise, I really don't want to install an aftermarket TBI capable fuelpump, new wiring harness, ECM, TBI's, and more.... too much of a pain in the *ss. Thats why we own older cars, to get rid of the insanity and to be able to work on our own cars.
looks ok but id rather run a carb looking tb with a mpfi system. the hard parts arent that expensive for mpfi its the 1000 bucks for a ecm that kills you. that and you got to know how to tune it.
To me, it's not the TPFI stuff, it's the puter and wiring. You can buy a TPFI injector from a camero for 50 a piece, then the ecm, another 50 bucks form the u-pull it... then you have the triggers (cam and crank sensors) thats why the guy is selling it. He realized that it was too diffcult to make it work and cost prohibitive. I would use the nozzles for the injectors for Nitrous foggers, and cap off the throttle body end and cut 2 large holes on the top for 2 4 bbl carbs!
Well, it is correct that when you add all the sensors, ect, that it takes and the wires that you ugly up the engine a bunch and the difference in the power is not much from my experience.....and add to it that I personally had the problem that the cam was not compatible with the computer program and that caused a high gear ''stutter'' that you could not tune out.... that was enough that after several years, that I went to a 4 bbl carb and intake..... much simpler and easier.....:Smarty: every thing that you add to a system is just one more part that can fail......:Brow:
Here is my set up.Old Hilborn has converted to Efi system,i go with Haltech GM6EX box. I try to hide all wiring stuff and others " not so good looking" parts as well i can for the old school touch. Linkages arent ready yet,those are only test pieces and i will do heat risers between to heads and manifolds(or whatever them calling in english :Smarty: :idea2 Those wood pieces are for the test only,and seems like risers work.When the heads heat rising up,butterfly shafts start twisting show and idle was about 1600rpm.But those risers keep it down. Anyway,it run already,and tune up sessions starts soon.Final tunes we dig out in engine dyno. This project is little diffucult,because in Finland nobody hasnt do this before to nailheads. The car is 1930 roadster Hudson with rumble seat +TH700R4 + Mopar 8 1/4" 4.10 gears. And sorry for my bad english...
I have two complete, running TPI systems on two of my Nailhead cars, and they work excellent. The setup for both was done by Dave Ray (IgnitionMan), and uses the Holley Commander 950 system. I also have a number of non-Nialhead TPI systems running on some of my other vehicles, all set up by Dave, and they all run great. For the individual port nozzles, Dave set up two one inch spacers for under the manifold, with the EFI nozzles sitting sideways, under the manifold, nozzles having a "pintal" that feeds the fuel 90 degrees down the inlet ports. He said a single plane manifold would work better for EFI, but the dual plane stock ones have worked well so far. After trying to work with a few other systems, including the "MegaJunk" (way, way too complicated, too many inputs to get dead on right, or the thing runs like dog guano), we came away with the impression, from our own working with the various systems, there are only two systems that are worth a darned, the Holley Commander 950, and one called "Affordable". Since I had the best luck with the Holley systems, that is the one I personally favor now. If the Holley weren't around, I'd go with the Affordable. Regards, Milton
ford_jj was bounced for being a spam bot. He will not be back to you for this reason. That is a great project you have there. When I was going to the tracks in the 60s, Hillborn injection (the mechanical type) on the the Gasser class cars were top dogs.
About converted FI to EFI, Dave did a couple of Hilborn injectors, one a two port, the other a 4 port, for blown applications, NON-electronic. Both run on a 6/71 GMC blower, on small block Chevies. With a piece that Dave built, there is no starting problems, and his barrel valve cut makes the transition from idle to off idle civilized. I have seen both these conversions, they are both in Willys vehicles, both are street driven and both perform very nicely. One is a 1941 pickup that used to be a gasser, now, commuter vehicle, the owner lives in Norwalk, Ca., and travels to the street drags at Pomona in it every week, he is a tech inspector at the drags. The other is a completely new car, fiberglass body, etc. I haven't seen any of them, but I understand he has done the same with the port injectors, the type shown in the pictures above. I like the EFI, but, those Hilborn injectors on those two engines are really striking, and when people realize they are NOT electronic, and hear/see the cars run, they are always impressed. Regards, Milton
Ok, so I decided to give this idea a shot. It's been stuck in the back of my head since I started this thread. I'm still collecting parts, but here's the parts I have collected so far from a 454 Chevy truck. All from the same truck. complete TBI throttle body complete uncut wire harness ECM distributor all sensors for reference, though I will be replacing them with new sensors. I'm going to run it with the stock truck ECM. 454 vs 425 shouldn't make too much of a difference. I know that I cannot use the distributor from the truck, but got it just in case there was something on it that I would need, or in case parts of it can be swapped over to my distributor to make some sort of conversion. Anyways, it's there if I need it. I also read somewhere that the MSD HEI distributor for nailheads can be used with this TBI setup as it has something that you can use to let the computer control it. Either way, I am sure there is a solution for the distributor. I still need to get a fuel pump and lines. I still need to figure out what to do about the knock sensor. I was reading somewhere on the 3rd gen board that you can drill the fuel pump blockoff plate and put the knock sensor there, but something tells me that with it being so close to the timing chain, this wouldnt be a good idea. Any suggestions?
