TBI's and Big Blocks

[RedneckExpress]

Well, my project to locate a 440-3 and swap it in on my truck is still a ways off, but I remember seeing many mentions of doing TBI conversions onto the old motors for better performance and I got to wondering if the stock Holly TBI kit off of a later model 360-1 would fit and physically be able to produce enough fuel air flow for a big block motor or not...

I know Chrysler had issues with choking their big blocks for a number of years by putting those rather worthless 2-barrel Carters on them, so it got me to wondering. 

[ClydesdaleKevin]

My good friend Rick has a TBI on his late model Suburban with a 454, and he gets plenty of power, even with the huge big block.  I prefer carburators myself, and the conversion would require adding a computer and other sensors as well, so I'm not sure if the complete conversion would be worth the money and effort for you.  For the same or less money, you could buy a troublefree Edlebrock.

Kev

[RedneckExpress]

I already have the TBI system in my pickup on the 360-1 that's in there, it's a fairly early TBI, rather simplistic.  My curiosity is would it work on a 440-3 Big block engine if transferred over.  This is of course assuming that the distributor from a 360 would fit onto a 440, which is likely the big killer right there (The Holley TBI uses electronic advance vs vacuum). 

[DaveVA78Chieftain]

Far as I know no one has really figured out how to tune the Mopar setup.  You cannot use the stock small block 360 programming to run a big block 440.

360 is a LA small block - http://www.allpar.com/mopar/318.html - Distributor in rear


440 is a RB big Block - http://www.allpar.com/mopar/383.html - Distributor in front


Big blocks like a Mopar 440 or GM 454 need a larger 2" bore TBI rather than the smaller 1-13/16" bore used in the smaller engines.  (800 vs 650 CFM).  Additionally the injectors have to be larger (80lb vs 55lb) for a big block.  SB Mopar distributors rotate clock wise, BB Mopars (383/400/440) all rotate counter clockwise.

Most conversions either use one of the aftermarket setups (Holley [http://www.jonsteiger.com/www/barracuda/efi/] or Affordable TBI [http://www.affordable-fuel-injection.com/ixxocart/products/Mopar_Complete_TBI_System_w_Distributor-15-15.html]) or adapt a GM TBI system using a 1227747 ECM. 
ECM.  The TBI unit would need to come from a 454 and you need to wire the setup based on the 91 P30 MH version (larger injectors require more amperage to open).
http://www.binderplanet.com/forums/showthread.php?t=47254
http://www.diy-efi.org/gmecm/ecm_info/1227747/
http://www.ifsja.org/forums/vb/showthread.php?t=69362

Now that you have your parts you get to buy your tuning equipment.
http://carprogrammer.com/Z28/PCM/FAQ/
http://www.tunerpro.net/
http://www.moates.net/

Now modify your ECM so you can burn/tune your chips.
Will be retaining the stock distributor by removing the vacuum advance and locking up the centrifugal advance using the FBO Mopar Advance Limiter Kit (http://www.gofastmopars.net/mopar_ignition_service.htm).  The hall effect sensor will drive the GM ECM ok.

Study, study, study.

Actually not that hard   Hm?  but does represent an investment.  As you can see, a little research is in order   W%

Dave

[RedneckExpress]

Thanks, I figured from the getgo that there would be issues. 

So far, at least one big problem is closed, the A518 Bell housing matches up the same as the old 727.   Sounds like I'll still with the original concept, which was going back to Carb and adapting the remaining electronic components to work without the engine linkages.  (Transmission works like a 727, non-electronic). 

[jkilbert]

Dad had a Dodge P/U with a 360 TBI, it only a 2bbl set up so i think your problem would be finding the appropriate manifold to work with it. My '95 suburban with the 454 was also a 2bbl setup but ran very well. I wanted to get a little more out of it while i had it and found out that the GM system doesn't like being played with alot, Can't say much about the dodge. Personally, I'd save myself all of the headaches and go with one of the Holley standalone kits from Summit Racing. You can be up and running with a complete kit for just over $1K.

[RedneckExpress]

yeah, that up and running for $1k is why I think I'd likely go with an Eddie 4 barrel Carb instead.....