Port injection or dual tbi???

[buddrow]

Hello everyone!

I am outlining my next project. It is a 1972 Buick Skylark with a built 455 and a 4L80E. My delima is this. Buy two affordable gm TBI units and use a 2x4 intake(low rise) or buy a relatively expensiv, by my standards ;), aftermarket throttle throttle body assemly and go port injected. This will be a totally custom setup although there is a port inj manifol available. I know you fine folks here are well versed in custom applications so i hope for some interesting commentary.

Thanks in advance,

Buddrow

[buddrow]

Would someone be interested in building a crank trigger set-up for a big block Buick? ;)

[dave w]

Would someone be interested in building a crank trigger set-up for a big block Buick? ;)

I would sell CAD drawings, so the parts could be made by a machine shop near you.

The prices for "one off" parts will "Stress a Budget"!

dave w

[buddrow]

Dave, the bb Buicks like a LOT of air, like 850+cfm when built, that i dont believe the 454 throttle body would supply. I would think dual 350 tbi's on an adapter plate on the dual quad manifold would be sufficient. I have a hard time paying what they want for an aftermarket 4bbl throttle body. Ya im cheap although you could t tell if you look at the cost of building a bb Buick lol. Did i mention I am also thinking DIS? I appreciate and value your input. I have no problem exchanging cash for your time so just lemme know when you get something drawn up for me. ;)

[buddrow]

Oh and I have TP5, a burner and have been tuning '7747s for about 6 months with a fair amount of success lol

[Six_Shooter]

In my friend's '71 Cutlass, he has a 46something (IIRC .60 over 455), with a 4L80E, and a home made 4 bbl TBI unit made from two GM TBI units, one is a 454 unit, the other side is a 350 unit. He bored out the 454 side a bit, and it flows over 1180 cfm dry (IIRC). The injectors have been modified to be adjustable.

We are using a 16147060 PCM to run the show. If I was starting from scratch I would use a 16197427 instead, since it has a little more support for tuning and home brewed modifications.

His car puts out over 500 HP and 600 ft/lbs to the wheels.

I'm attaching some pictures of revision #9 I think it is. There have been several of these made by the owner. He currently has two of them, this one on his Olds, and another with a different fuel system in his GF's Caprice that is also Olds powered.

[dave w]

The 454 throttle body could be bored to 54mm, for about 795 CFM.

The attached pictures are my 1st design for a 454 throttle body adapter mounted on a full bore (Holley) bolt pattern dual plane intake. My final design of the 454 throttle body full bore adapter has the volume matched to flow like the bores are 54mm diameter cylinders.

DIS, that would be challenging! Would need to a dual trigger cam / crank configuration.

dave w

[Six_Shooter]

The 454 throttle body could be bored to 54mm, for about 795 CFM.

The attached pictures are my 1st design for a 454 throttle body adapter mounted on a full bore (Holley) bolt pattern dual plane intake. My final design of the 454 throttle body full bore adapter has the volume matched to flow like the bores are 54mm diameter cylinders.

DIS, that would be challenging! Would need to a dual trigger cam / crank configuration.

dave w

DIS would not be that difficult. Using the Northstar DIS it would be a single wheel solution, with some tweaking of settings in the BIN.

[dave w]

Dave, the bb Buicks like a LOT of air, like 850+cfm when built, that i dont believe the 454 throttle body would supply. I would think dual 350 tbi's on an adapter plate on the dual quad manifold would be sufficient. I have a hard time paying what they want for an aftermarket 4bbl throttle body. Ya im cheap although you could t tell if you look at the cost of building a bb Buick lol. Did i mention I am also thinking DIS? I appreciate and value your input. I have no problem exchanging cash for your time so just lemme know when you get something drawn up for me. ;)

I went looking around EFI Connections for some ideas. I find it interesting that the SBC 24x system has the 1x signal machined from the upper timing chain sprocket. The 24x signal trigger wheel is on mounted in front of crankshaft timing chain sprocket. With some tig welding, maybe the 455 Pontiac timing cover could be modified to hold the cam sensor and crank sensor. Maybe a Pontiac 455 aftermarket camshaft timing sprocket could be modified for the 1x trigger.

The 24x trigger could be a larger diameter, and mounted on the harmonic balancer.

dave w

[bonnieclyde100]

i wouldnt mind seeing a write up on how to make the frankenbody. i was hoping to do something like that instead of getting a dual four barrel intake and run 2 tbis

[dave w]

My "Budget" choice would be the "Port Injection" system. I would use the 16197427 PCM, which can handle the 4L80E transmission controls (cost savings?). I would convert the 16197427 to MPFI mode (same mode as a TPI) (cost savings?). The 16197427 is OBDI with very low cost tuning software / hardware! If the aftermarket Buick port fuel injected intake has a carburetor style mounting for a throttle body, maybe an adapter plate for the Chevy 454 Throttle Body (670 CFM) could be used by removing the injector pod, instead of an aftermarket throttle body (cost savings?).

Depending on where you live, the prices for a used PCM, used wiring harness, and used 454 throttle body might be just what the "Budget" calls for? I'd look for a 1995 454 Suburban / Pickup to get the parts from.

dave w