I'm going with port injection on my 250 - the Clifford manifold I have has the injector bosses cast into it, so proper injector alignment should be easy. What's confusing me is the decision on which throttle body to use, and how to get it properly connected. I'd rather use a vintage-style round air cleaner than a modern cone-type that would normally connect to a throttle body. Has anyone figured out an adapter for that?

All advice is appriciated!

Holley makes throttle bodies that fit the standard square bore flanges.

http://store.summitracing.com/default.as...t=egnsearch.asp

What kind of a distributor are you planning to use to get to sequential fuel injection? The siamesed intake ports would seem to be a problem for batch fire FI. Based on the firing order and the batch fire scheme (multiple injector pulses before the compression stroke), the cylinders will alternately run rich or lean. TBI or Sequential MPFI would solve this.

Gene

I've been thinking about that. As long as six injectors are used, firing in two batches, I think it will work. 1-5-3-6-2-4. First batch fires the 1, 3 and 5 injectors, second batch fires 2, 4 and 6. My manifold is set up to be machined for 6 injectors, anyway. I'm converting my old mechanical HEI to computer control (unless someone can show me a computer-controlled L22 distributor...). First plan was to go TBI, but having the manifold set up for PFI is very tempting.

On the throttle body issue, I'm hoping for some sort of clever junkyard solution. I know there have to be some PFI L22s out there...

No one has run PFI on an L22?

What are you planning on running for a EFI controller?

GM 7727 weather-tight computer.

just go down to your local parts supplier and order a cardone hei for a computer controlled 80-82 chevy truck w/ california emissions. turn in any regular hei as the core. this is the only application that used the computer timing control. could you get a pic of your intake. i am using a throttle body from a 2000 vortec 5.3? it is a big monoblade with iac and throttle position. you would just need to make a adaptor. i turned mine sideways toward the driver fender. tom

Tom, thanks for the suggestions. I'll try to find one of those TBs and HEI distributors. I have a few HEIs that I've snagged from the boneyard, so I have an extra to exchange. Worst case scenario, I can still convert a mechanical HEI to computer control.

What did you do for the air cleaner?

This isn't my manifold, but it looks like this one: http://cgi.ebay.com/ebaymotors/Clifford-...sspagenameZWDVW

i am running aturbo will end up with a remote filter. i've tried converting the dist. just get the cardone one. if you need a tb like mine i have extras. they are on ebay all the time. tom

if you have not machined you injector holes yet i have a jig that you bolt the intake to and then fasten in the mill for maching. my local machinist can do it for you. tom

I'll hit up the boneyards to see what I can turn up on the TB - I know of a few good pick-n-pulls. How much would the machining cost at your local shop? I might be up for that. I'm planning to run standard Chevrolet injectors (probably from a TPI 350 or something like that) - but from what I've seen, injectors are fairly standardized.

What kind of computer are you using? What did you do to get around the problems with the siamesed intake ports? How did you set up the fuel rail? I've thought of doing it with two three-injector rails, but I'd have to tap the inlets or returns off at a weird angle rather than simply taking them out of the ends. I'm afraid if I ran a 1-piece rail the injectors at the far end might get a lot less fuel than those by the inlet.

Looking at that monoblade TB, I can probably rig up an aluminum collar with a crossbar and stud for a carburetor/TBI style air cleaner.

you could easily do the cross bar for the aircleaner. i have a common long fuel rail. the regulator goes after the rail so no starving of any of the injectors. the rail was bought with no injector holes and my machinist did the injector holes in it also. i bet he would do both the rail and intake for around 100.00. i don't think there will be any problem with the shared port for fuel dist. if there is i will stage my injectors by using two separate banks. i am using a holley c950 computer. you'll find almost all injectors have the same dimensions.

Have you considered running a megasquirt for you EFI controller? Save burning chips as its fully programable from a laptop.

Yes, I considered megasquirt - for about 20 seconds.

Cost of my eprom programmer - about $40.
Cost of a good used 7727 with v6 memcal - about $40.
Cost of a pile of eprom chips and ZIF socket - about $10.
Taking advantage of the millions of dollars GM spent on R&D - priceless.

Megasquirt might be the right option for some people, but my engine-bay-mountable 7727 is just fine for me.

Taking advantage of the millions of dollars GM spent on R&D - priceless.


No dought that GM put a lot of effort into getting the base code correct.

Once you have it running please post your results.

Thanks

It will be a while, but I'll be happy to post pictures and results when it's done.

tlowe,
I tried one parts store that didn't have that distributor listed in their computer system. Where did you get yours? I was thinking about trying NAPA and O'Rielly's later in the week. Also, I'm interested in having your machinist work on my mainfold and fuel rail. Can you send me an email through here to discuss it further?

i got my computer controlled hei thru orielly. i'll send you a pm. tom