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CAD 500/4L80E advice needed

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77crewcab

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Okay I have been thinking here and that usually means trouble. But since getting my Caddy 500 and 4L80E, I have been thinking of the best way to run them. Here is what I have come up with, please offer any opinions or advice.

1. Buy adapter plate to mate 500/4L80E
2. Buy everything for 454 TBI swap from a truck that had 454/4L80E
3. Tune ecm for 500

Now here is what I am thinking on this. I would have a great motor and OD trans combo, fuel injection, and ecm controls for the trans.

Now I know that the 502HT used to be available as a direct replacement for the 454/4L80E combo and the kit came with a new chip for the computer. It seems it is no longer offered this way. But if the stock 454 TB would work for a 502 with tuning, why couldn't it do the same for the 500. And the TB mounts to a standard q-jet manifold with the help of an adapter so I could mount it the same way to the 500. From looking at the specs on the 502HT, they are almost the same as what a stock 500 is, so anyone see a problem with this idea? Thanks for any advice.
 
The CID isn't necessarily the problem, as fueling and timing are different based on how the engine is built. Heads, exhaust, cam, etc. As long as the fueling is sufficient, based on the "hard parts" (fuel pump, lines, injectors) then the PROM can simply be tuned to work with your particular combo.

I'd be careful and make SURE the 454 injectors can handle 500+ CID. burts4x4(?) had a post about running lean with his engine, can't recall what the donor was vs. what he was running. Basically, you just need to know that whatever injectors you intend to use, are capable of meeting the fueling demands of the engine at PEAK demand. That's not something the ECM can "override".

The other obstacle may or may not be the distributor. If there is a Cadillac distributor out there that will fit a 500 that already has an electronically controlled distributor, you are fine. If not, may need to make something up. I suspect this has already been done by numerous people, it shouldn't be that difficult in my mind.
 
Based on the part numbers from Napa, PartsAmerica, Autozone, the HEI distributor is the the same as SBC/BBC, so no problem on that. From my old Scoggin-Dickey catalog, the 502HT conversion kit only came with and new ecm chip, and fuel pump. It lists other things not related to engine controls i.e. trans cooler, exhaust, and just says and more. It never says anything about different injectors. But even so larger TBI injectors are available right?
 
I have always been under the impression that the 454 throttle body could not feed a slightly modded 454 much less a 500 inch engine. I could be wrong.

I know I would like to inject mine, but I have not figured out how to do it on the cheap. Mine has been modded heavily though.
 
77crewcab said:
Based on the part numbers from Napa, PartsAmerica, Autozone, the HEI distributor is the the same as SBC/BBC, so no problem on that. From my old Scoggin-Dickey catalog, the 502HT conversion kit only came with and new ecm chip, and fuel pump. It lists other things not related to engine controls i.e. trans cooler, exhaust, and just says and more. It never says anything about different injectors. But even so larger TBI injectors are available right?
Click to expand...

That not even close to right on the dizzy. the cad dizzy is aboutan inch and a half shorter. I could measure the 2 but thats close enough. but if you find the dizzy out of a 82-84 368 and put the guts from a newer unit into it you'll have what you want
 
Wouldn't the best way be an aftermarket EFI set up? The easiest way would probably be a throttle body injection, and the easiest one of them, I think would be the Powerjection 1 kit from www.professional-products.com. They say it does not require a return line, so you can just bolt it in place of your carb and go. The computer tunes itself as you drive, so you don't even need a laptop to tune it. This is the set up I want to go with when I switch to EFI. I saw them install one of these on Horsepower on Spike Tv and it looked real easy.


You can also go multiport EFI. Cad Company sells everything you need. A quote from their site:


Bulldog Single Plane Intake @ $495
From the makers of the aluminum heads. Available with standard or Dominator carb flange. Cast-in injector bungs for fuel injection (or port-nitrous). Available pre-drilled ($50).
Fuel rail setups ($50) to complete port injection systems also available - call for more information.




http://www.mtscadparts.com/



http://cad500parts.com/
 
Easier and usually far cheaper to do GM parts (if you've got a donor), aftermarket would like you to believe otherwise. :)

Availability of spares is better, and it's a known quantity. The injection system really doesn't care what it's on, you just need the right hard parts (which in this case should be) and the right tune. As long as there is an easy way to get the distributor to work with the Chev ECM, this is a fairly easy job.

Especially when talking about a 4L80E, in which case you'd simply start with a 454/4L80
PCM and be done with it.
 
You're right on the dist. I rechecked the numbers and had them way wrong. How hard would it be to swap the top end parts from a FI large body dist to the caddy one? Still working on figuring out the injector issue. Anyone have any ideas where to look for bigger injectors for the 454 tbi?
 
You might check summit.

Have you talked with Brian over at TBIcips.com? He probably knows a fair amount about the injectors, and since 502 chev's are fairly common, may have dealt with this same issue.

I could be mistaken on the distributors, but it doesn't seem like the basic design changed from non-ECM control to ECM control, at least when talking large cap vs large cap. If the above is correct about the 368 being '82-84, then that would be the easiest solution, as all GM V8 US-destined gas engines installed in cars were computer controlled by then.

Going to need to do some discovery on this, but wrecking yards are great places to compare parts, if you can't find anything online. I think I'd start with tbichips and see if Brian has any input. Also Cadillac forums. I will probably inject my Oldsmobile at some point, and it's plainly obvious that Chev TBI is going to be the easiest way to do it.
 
Well after looking around some it seems that the 368 dist, a 54mm TB, stock 454 injectors with pressure cranked up, and higher rated fuel pump is the way to go.
 
77crewcab said:
Well after looking around some it seems that the 368 dist, a 54mm TB, stock 454 injectors with pressure cranked up, and higher rated fuel pump is the way to go.
Click to expand...

Make any progress on this? I'm running a 472/4L80e and have thought about the same setup many times.

Anyone know the 4l80e/454 ECM part number?
 
Not really I sold all the 454 tbi/4l80e parts. I decided to go with a BOP 400 with an aftermarket overdrive (usgear or gearvendors) and I am currently looking at some other options to allow sequential multiport injection. I am not sure it will work though. The engine still needs to be rebuilt and installed in the truck. The fuel injection will come later down the line after some more research.
 
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