Welcome to the Corvette Forums at the Corvette Action Center!

Question: Crossfire Intake Manifolds

AussieCorvetteNut

Well-known member
Joined
Dec 19, 2010
Messages
189
Location
Gold Coast Australia
Corvette
1984 Two-tone Blue Coupe
Ok, I know this topic has been flogged to death, but from what I see, the postings are a few years old, meaning there may or may not be new technology out there.

My issue is that I am starting the process of removing my matching numbers engine and DNE 4+3, and rebuilding the engine and boat anchoring the 4+3.
i have spent that last couple of days starting the process of disassembly and tagging wiring harness connections, I am getting ready to pull the transmission, only have two torque arm bolts and the four on the bell housing and the trans is out. The engine is next.
while removing the inspection plate on the bell housing, I noticed a drop of coolant where it shouldn't have been. My guess is maybe a rear welch plug, although the others in the block seem fine, old, but fine. The only other thing it could be is the inlet manifold.

Here is my issue, my engine shop will want to know induction requirements for recommending the appropriate cam, intake valve train etc, set up.
Question is, as there aren't too many replacement crossfire intake manifolds on the market, in fact from what I can see the last one Renegade has just shut up shop and Ecklers and Summit have the last few in stock...what do I use? It is 2015, what upgrades are there?

I would like to rebuild the engine, enhance it a little and use the TBI set up, I just want a cruiser that is more reliable and just a little better than it was when it was new. With no crossfire intakes on the market, I only have a few options left.

Edelbrock do a great 4V bolt on injection system, but I would need to go back to an old school looking manifold. The system is plug and play and can learn as it burns.

Renegade have a crossfire intake that is the same as the OEM with improvements, but I know by the time I get around to rebuilding this L83, that option will be out.

Edelbrock also have a Ram Air type, but it may not fit under the 84 bonnet.

I could put a TPI on it, but then I think I should change the heads....besides that upgrade has been done before. I don't really like seeing crossfire injection on the fender panels and seeing TPI. TPI is great though don't get me wrong.

i would love to keep it stock looking but the options are drying up, I like the ram air Edelbrock set up, but it may not fit, I wouldn't want to install the TPI unless I changed the heads.

i know some fellas have got some serious power out of tweaking their TBI's, my issue is that if my intake has water jacket issues, then to replace it I would need to install a second hand crossfire intake...bit like putting brand new tyres on wheels that are rusted out.

I dunno which way to go, would appreciate any help.

cheers

Tony
 
Last edited:

xfirez51

Well-known member
Joined
Jun 2, 2007
Messages
280
Location
Chicagoland
Corvette
1992 Black Rose ZR-1
Whatever changes you make, an ECM swap will be required. There's no support for the stock ECM, and cam timing, porting etc. will necessitate re-doing the fuel and spark maps. I went down this road 15 years ago w my Xfire. I port matched and Extrude Hone'd the manifold. Used bored out TBs.
You need more fuel to make more power so bigger injectors. But the Xfire uses staggered injectors and those can't be replicated with a set of larger ones. That means parallel plumbing the throttle bodies to use 2 of the same injectors and then a Variable Adjustable Fuel Pressure Regulator to provide enough fuel for WOT, but back it down for idle. I did all this and more and got a motor that put down 283rwhp/347rwtq. Ran low 13's at 104mph on street tires.
i think I would either swap the top end for LT4 heads, a hot cam, and a Mini-Ram, or look at an LSx conversion. Either way, the 4+3 won't handle it, and an ECM swap is needed.
look at thirdgen.org and dynamicefi.com.
 

AussieCorvetteNut

Well-known member
Joined
Dec 19, 2010
Messages
189
Location
Gold Coast Australia
Corvette
1984 Two-tone Blue Coupe
Whatever changes you make, an ECM swap will be required. There's no support for the stock ECM, and cam timing, porting etc. will necessitate re-doing the fuel and spark maps. I went down this road 15 years ago w my Xfire. I port matched and Extrude Hone'd the manifold. Used bored out TBs.
You need more fuel to make more power so bigger injectors. But the Xfire uses staggered injectors and those can't be replicated with a set of larger ones. That means parallel plumbing the throttle bodies to use 2 of the same injectors and then a Variable Adjustable Fuel Pressure Regulator to provide enough fuel for WOT, but back it down for idle. I did all this and more and got a motor that put down 283rwhp/347rwtq. Ran low 13's at 104mph on street tires.
i think I would either swap the top end for LT4 heads, a hot cam, and a Mini-Ram, or look at an LSx conversion. Either way, the 4+3 won't handle it, and an ECM swap is needed.
look at thirdgen.org and dynamicefi.com.

Hey thanks for your help.

It looks like the LT4 heads option, opens up the doors for better/ later technology.
I am a stock look, but try to enhance fella, but with the limited options available now for the L83, looks like an upgrade of the heads to LT4 will open up availability to better induction, better valve train etc.

Doing an upgrade on the heads, valve train, cam and induction and mating this to a Tremec, I am wondering if my little DANA 36 is up to the job?

I can now see why some blokes have opted for a complete engine swap, ie they have gone crate or TPI or even LSx.

I purchased a parts 84 and the previous guys swapped the L83 for an LS1 in that car.

:beer

Tony
 

AussieCorvetteNut

Well-known member
Joined
Dec 19, 2010
Messages
189
Location
Gold Coast Australia
Corvette
1984 Two-tone Blue Coupe
I suppose the question is now, what are the differences between the L83, L98, LT1 and LT4 blocks.

As far as I can research, not much, they have the same bore and stroke (correct me if I am wrong here).
Maybe some differences around reverse watering?

So this pretty much means that the L83 2 bolt main block, has the same DNA as the later engines.
Strip away the heads, cam and intake and the platform is the same.

Mmmm, maybe the shopping list just got bigger...don't tell the Wife :eyerole
 

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors

Dealers:

MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Parts/Accessories:

Vetteskins

Advertise with the Corvette Action Center!

Double Your Chances!

Partners

Top Bottom