83cfiz28

Hi, I am new to this forum and I was wondering about vortec heads on a 305 Chevy that has crossfire injection. I know i need an intake manifold and carb and i would like to put a cam in while it was apart. I'm not going for crazy amounts of power but 250 or more hp would be nice. I was wondering if it was worth trying to mod a crossfire injection one or better to look for a different engine because I also wanted a manual transmission anyway, but I'm not sure how much work the swap would be. Sorry if this has already been discussed I looked around for it but couldn't find anything.

five7kid

iTrader: (14)

Welcome aboard thirdgen.org.

The Crossfire engine is fine, but the Crossfire manifold is restrictive. And, the aftermarket didn't pick up on the configuration, so there really isn't anything out there significantly better than the factory pieces.

Converting to carb, along with cam and exhaust improvements, will make a significant change to performance. Having larger 1.94" intake valves installed in your stock heads would also help, and 1.60" exhaust valves would also be an improvement. Vortec heads would have to be shaved to work well with a 305, but your HP return for $'s spent would be much lower than just working with the heads you've got. Intake manifolds are also much less expensive than Vortec intakes, and there is a better selection for your stock configuration.

In fairness, though, the parts and machine work for installing 1.94"/1.60" valves will be close to what Vortec heads would cost. With the Vortecs, though, you'd still need to have them shaved, and you'd need a more expensive intake manifold.

Damon

Agreed- swap it over to a carbureted setup (and sell the CFI parts to pay for it!) and add headers and a full exhaust system. In other words, work on the OUTSIDE of the engine first since those parts can easily be swapped onto another small block later. If you want to have the heads ported and install a cam, go for it, but don't go crazy pouring money into a 305 when it would be better spent building a righteous 350 or larger small block down the road.

CFI stuff might be worth some money to the numbers-matching "restoration" crowd (although I'm not sure even those guys care about CFI stuff yet), but they definitely aren't worth spending time and money on it when it comes to making power.

8t2 z-chev

actually the C/F system does have a lot of potential to
raise the power way over stock-does take a lot of work
and some parts fabbing though-indeed the stock
manifold is where most of the work needs done....
Switching to carb is a far easier way to get a quick
boost in power and easier tuning-getting 250 hp out
of a 305 will be easy(if your short block is original,it will
have 9.5 C/R,making the goal that much easier)
Also,since the C/F fuel pump is a turbine style,fuel will
pull through it with it inactive-no need to remove-
been there,done that(when i had a q-jet on my C/F
while the modifications to the C/F were underway)
BTW if you want to know more details on what needs
done to wake up a C/F,just ask and i will tell.

mcm95403

iTrader: (1)

I guess you haven't seen anything about the Renegade intake from DCS. It's a 100% bolt-on direct replacement for the crossfire and it is amazing. That intake combined with the right parts will run great - 1 guy in New Zealand is running bottom 12's with his crossfire.

http://crossfireinjection.net/catalog.htm

There is NO REASON to remove the fuel injection and switch to a carb - that is a myth told by people who don't understand the crossfire system.

This is a shot of one batch being readied for shipment:

MC305SS

059 Vortec heads.
Will outflow his current heads and be close to the 350 vortec heads and don't require milling them down.

Damon

There have been companies offering upgrades to the CFI intake for quite some time. Yes, they have potential. But the cost of the parts is usually prohibitive. More importantly, like all EFI systems you won't get much out of the upgrades without custom tuning of the ECM (who knows how to custom tune a CFI computer??) or going with a stand-alone (aftermarket) system to run it (again, many more bucks).

Don't assume all us carb guys are just brainless knuckle-draggers. You have some of the sharpest and longest-tenured guys on the board replying to this thread and none of us has anything against EFI. It's just that the cost and complexity far outweigh the performance benefits in this case. The shortest route to victory here is ditching the CFI system and bolting a carb on top.

five7kid

iTrader: (14)

What engine is the New Zealand guy running? What platform?

Best I've seen a Crossfire run is 13's (in a Vette, highly modified - probably didn't have the manifold, though).

ray jr

iTrader: (2)

where do you find these 059 vortec haeds at ?

Javier

ttt
ttt
ttt


this would be a good option for me, any info on any 305's running this intake, and if so any numbers on those?

Air_Adam

The 059 have the same intake ports as the L31 heads, but not the same really good chamber design. They use the same basic chamber as most other 305 heads.

83 Crossfire TA

iTrader: (2)

I ran low 13's in my TA without it being that heavily modified with a mostly stock long block... In my case it was all worked original parts, including manifold and throttle bodies. It had to be making more than 250hp to run that fast, had _way_ more low end torque than my L98 or LT1 car making it MUCH more fun on the street than either, killer mpg, and honestly, it was the best sounding car I've ever owned (even the stock exhausts on them sound much better then any of the later 3rd and 4th gens, and aftermarket stuff sounds incredible on it).

I was happy enough with it that I saved the whole crossfire setup for use on my TBI truck.

Like mcm95403 suggested, you just need to know what you're doing with it and tune/build towards it's strengths.

aftermarket- it's been there all along, you just have to know where to look. Turbo City had all sorts of TBI upgrades for them from the beginning. Hypertech used to have every stage of chip they used to sell for them, and tons of stuff has come and gone for them, sure, not as much as for the TPI cars, but it's out there, that and a lot of the similar small block 3rd gen parts work (besides the intake) and later TBI f-body and truck stuff.

FWIW, if I was going to do it now I'd start by converting to a later TBI ecm (or ebl or even MS).

Complicated? Honestly, I don't know how, It's simpler then both a carb and a TPI setup, the only FI setup that is simpler is the standard TBI setup, which mostly is the same except where you run into the additional linkage and fuel lines... as far as reliability, mine was my daily driver for most of the 90's, automated or drag raced most weekend, and for a lot of that time it had to run and be cheap to maintain...

Let me put it this way... I was happy enough with it that I want to get a C3 vette as a toy and I've been looking for just the right '83 crossfire car...