Crossfire Injected 383

[Jims86]

Ahhh hah!
http://www.fullsizechevy.com/forum/...bd-i-ecm-pcm/449497-dual-tbi-getting-run.html

 

[bucket]

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.

This is what I don't understand. I've got several sets of heads sitting around and the ports in the heads are all much larger than the ports on this intake. Even the #450 casting 305 heads.

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 thought had crossed my mind, but I figured it would be costly. I guess it wouldn't hurt to look into it.

 

[Swims350]

that's the guy Jim.

but yea bucket it may be worth asking about, at least you'll know what it'd cost.

what about tracking down the heads that match it? then port and polish and have some work done to them? Maybe compare that cost, heads + machine work to the cost of having the intake worked.

 

[bucket]

that's the guy Jim.

but yea bucket it may be worth asking about, at least you'll know what it'd cost.

what about tracking down the heads that match it? then port and polish and have some work done to them? Maybe compare that cost, heads + machine work to the cost of having the intake worked.

The #450 heads are very close to what would have come on the Crossfire 305 to begin with, maybe even the same. I ran those heads on a 350 and they did OK, but nothing spectacular. They have been ported too. Might be a good choice if I go with my 283-307 idea.

 

[Jims86]

that's the guy Jim.

but yea bucket it may be worth asking about, at least you'll know what it'd cost.

what about tracking down the heads that match it? then port and polish and have some work done to them? Maybe compare that cost, heads + machine work to the cost of having the intake worked.

Or more important, try to find out why GM made the ports on the manifold 2/3rds the size of the head ports.
I think it was to bring the intake velocity up, to keep the fuel in suspention, and give favorable torque.
Might work good on a truck, but dont expect too much in the top end.

 

[bucket]

Or more important, try to find out why GM made the ports on the manifold 2/3rds the size of the head ports.
I think it was to bring the intake velocity up, to keep the fuel in suspention, and give favorable torque.
Might work good on a truck, but dont expect too much in the top end.

But those ports were designed to build velocity in a smaller engine. Wouldn't that design feature do a good job of choking a 383?

 

[Jims86]

But those ports were designed to build velocity in a smaller engine. Wouldn't that design feature do a good job of choking a 383?

In the top end, yes.
low end may be the **** though.
Crossfire may have been a stepping stone for TPI, considering the CF runner length is probably twice the length of a carb manifold....maybe it would have done better as an MPFI, instead of t body.
TPI Gave me over 400 ft lbs, but my hp was 230, but gave up between 4700 to 5000 rpm, not that I regularly went that high anyways.
Cam grind is also specific to the crossfire, from what I just read.
In my opinion, the stock crossfire manifold would be a bad choice, and I would probably scrap the project, Unless their wer resources to purchase the renegade manifold from crossfireinjection.net.
The Eddy MPFI manifold with a set of 30 pph injectors, and a nice large bore or 4bbl throttle body.

 

[bucket]

Bad choice completely, or just a bad choice for a larger engine? I really want to run this Crossfire on something.

 

[Jims86]

I personally would not even try it, unless i had the new manifold.
Its a risk, but if your money is funny, like everyone else, its not worth it.
I would spend towards an MPFI, TPI or Eddy, or even a Dual TBI with an Offy crossram, like on the FSC thread.

 

[bucket]

Alright. I guess it can be garage art hanging on the wall, it can look neat there rather than under a hood.