Crossfire Injected 383

[bucket]

Yep, I have yet another crazy idea for my '88 4x4 Burb. Future plans involve a mild 4 bolt main 383 with full roller valvetrain. Heads have not been decided yet, kinda depends on the induction. I was thinking about running a Crossfire setup but retaining the stock TBI wiring harness and ecm. The goal would be excellent low and mid range power, a little more power upstairs than stock TBI, and keeping mileage about what it is with the stock 350.

Am I asking too much? I also have to admit, a big reason for wanting Crossfire injection is because it's different. When's the last time you saw anything with Crossfire swapped in?

Another option is just a basic 4bbl intake with a 454 throttle body on top. However, that's ordinary and boring... plus I only have two 454 TB's and I'd like to use both of them on the crew cab.

 

[RetroC10Sport]

I saw a Cross-fire Camaro at the junkyard and had one of those brainstorms...But then decided to stick with the TPI.

I'm sure a chip could be burned to run the two TBIs...

 

[bucket]

I'm not sure, hoping Jim knows. They are single barrel TB's and Painless I think it was sells a wiring splitter. Either way, I was planning on a mail order tune from TBI Chips.

 

[Jims86]

I say why not.
Last time I looked, Painless did have a harness available.
The nice thing is that you can use any size TBI injector you want....no bastardized ****.
I would suggest using 454 injectors from the get go, and installing adjustable regulators on the throttle bodies.
The manifold design looks a little questionable to me, and looks like fuel puddling may be an issue. There is a company that specializes to the crossfire enthusiast: http://www.crossfireinjection.net/index.htm
They have a really nice manifold of their own design, and they also bore the throttle bodies to 2"

 

[bucket]

Well, this idea might fizzle out. I knew the stock intake isn't the best design, but I wanted to use it since I already have it. I was starting to lean towards vortec heads that have been drilled to accept the old intake bolt pattern. But I also knew that the vortec ports are a little too tall to use with some intakes, so a mock-up was in order. The results were disappointing.

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Here you can see the gap where the manifold is not tall enough. There are no gaskets installed so it may look worse than it is, but there would be no sealing surface, at best.

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Here you can compare the difference in port size and shape.

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No matter how you slice it, those ports are just too small for a 383 even with standard heads. Mid 70's smogger heads have ports almost as tall as the vortec.

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Now I'm curious, did the Crossfire setup on the Corvette 350 use a different intake? This intake is from an '83 Z28 305.

 

[Jims86]

Well, this idea might fizzle out. I knew the stock intake isn't the best design, but I wanted to use it since I already have it. I was starting to lean towards vortec heads that have been drilled to accept the old intake bolt pattern. But I also knew that the vortec ports are a little too tall to use with some intakes, so a mock-up was in order. The results were disappointing.

Here you can see the gap where the manifold is not tall enough. There are no gaskets installed so it may look worse than it is, but there would be no sealing surface, at best.

Here you can compare the difference in port size and shape.

No matter how you slice it, those ports are just too small for a 383 even with standard heads. Mid 70's smogger heads have ports almost as tall as the vortec.


Now I'm curious, did the Crossfire setup on the Corvette 350 use a different intake? This intake is from an '83 Z28 305.

Nope, they were the same. I wish you would have mentioned vortec heads...i could have saved you some research.
What do you think about multiport?

 

[bucket]

Nope, they were the same. I wish you would have mentioned vortec heads...i could have saved you some research.
What do you think about multiport?

I already figured it wouldn't work with the vortec heads, I just wanted to check and make sure. However, I was not aware just how restrictive the crossfire manifold seems to be.

 

[bucket]

I like the simplicity and reliability of the TBI, as well as the low cost. I don't think I want to go to the trouble of TPI or similar.

 

[Jims86]

I like the simplicity and reliability of the TBI, as well as the low cost. I don't think I want to go to the trouble of TPI or similar.

I was thinking of a non emissions system on the edelbrock MPFI manifold, using the large 454 throttle body you have, sans injectors of course, and a TPI ecm.
Kinda like a home brewed pro flo setup.

 

[bucket]

I was thing of a non emissions system on the edelbrock MPFI manifold, using the large 454 throttle body you have, sans injectors of course, and a TPI ecm.
Kinda like a home brewed pro flo setup.

Let me ask you this, what would be the benefits of going that route over a basic TPI setup?

I still want to use the crossfire on something, I just don't know what. After looking at the manifold, it would be best suited for a smaller motor. Perhaps on top of a 283 or 307, in my stepside, with a 700r4 and 3.42 rear.

 

[Jims86]

Let me ask you this, what would be the benefits of going that route over a basic TPI setup?

I still want to use the crossfire on something, I just don't know what. After looking at the manifold, it would be best suited for a smaller motor. Perhaps on top of a 283 or 307, in my stepside, with a 700r4 and 3.42 rear.

Well, for starters, the edelbrock intake for vortec heads is $100 cheaper than the TPI lower manifold. And if you have to service the injectors, you dont have to unbolt the runners and upper plenum to get to them. You can use a top mounted throttle body that you could use a regular air cleaner on(provided you use a speed density ecm) or an LSx throttle body. with an adaptor, you could run the 454 throttle body too.
Edit:Oh yeah, and it breaths like a ************.
As far as the crossfire, dont be fooled by the smaller ports...they could make a lot of torque where you want it for a truck. Maybe port them a little to match the head ports. Should work fine on a 350, which has the same size ports in the heads as a 305, just make sure the fueling is correct.

 

[Swims350]

I saw a guy on FSC who has a crossram/crossfire dual tbi setup and he said it works well. I forget the guys name and such tho, pretty cool and definately different IMO.

As for your intake what about having someone to weld up the tops and then machine it down flat? I saw them do it on tv on american hotrod once.

 

[Jims86]

I saw a guy on FSC who has a crossram/crossfire dual tbi setup and he said it works well. I forget the guys name and such tho, pretty cool and definately different IMO.

As for your intake what about having someone to weld up the tops and then machine it down flat? I saw them do it on tv on american hotrod once.

That is also an option, gotta find someone reeaaly good at aluminum welding though.
Chris, I think I remember who you are talking about, but I think it was just dual TBI, not crossfire.

 

[Swims350]

well it had the tbi's one beside the other to the best of my knowledge I could be wrong though. Seems like there was 2 guys had it, one dual quad setup like one behind the other, and then crossfire across from one another.

 

[Jims86]

well it had the tbi's one beside the other to the best of my knowledge I could be wrong though. Seems like there was 2 guys had it, one dual quad setup like one behind the other, and then crossfire across from one another.

Hmmm... I will take a look, very interesting.