vettespd20

I am having my locked up 1984 Crossfire rebuilt with some tweaks done to it. The guy is going to do the following to it

Speed Pro Flat top pistons and Sealed Power rings.
cam with 450, 460 lift and 224 degrees duration at 050 lift and lifters.
Clevite rod and main bearings.
Durabond HD cam bearings,
Cloyes double roller timing set,
Melling Hi Volume oil pump,
Brass freeze plugs
and a full Fel pro gasket set.
with PORTED (1989) L98 heads and PORTED intake.
Ok my question is about how much HP would this rebuild give me????? And will my engine with the ported crossfire be able to flow this rebuild, and if this engine doesnt get me to 350 HP if i did more to it could my PORTED intake with ported L98 heads be able to flow 350HP???? thanks

Goody

A ported crossfire intake? I have limited knowledge of the Crossfire system, but my gut says NO. The intake system just wont support it.

Alcee1

Just curious, why did you choose to port the crossfire manifold instead of going with, o say the X-Ram manifold?
http://www.x-ram.com :confused:

bogus

sadly, not alot of people know about the X-Ram...

Jedi

I think with a stock manifold(but ported and extrude honed) it can support 300+ ish (im told) but i would think thats its limit.
A big improvement, but for better gains on a cross-fire, an X-ram will allow much more.
Or buy an old SY-1 manifold and try that.(although this requires a custom top plate to mount the throttle bodies)
The X-ram is a bolt on job, much easier.

But, also think of the throttle bodies, they have a limited CFM capacity.
I dont Know their max HP pontential, But im not sure they will quite handle 350hp. But these can be bored out to flow up to 850 cfm.
So with the right work, YES the cross-fire can go to 350.




[Modified by Jedi, 6:52 PM 8/28/2003]

84Coyote

I just did similar modifications and my car feels a LOT more powerful. It really takes off now. My intake is ported aswell. I also went with 454 injectors off a 91 454 SS truck. But the car has been running really rich with the combination of the smaller combustion chambers on the L98 heads, and the 280/280 duration on my cam, so I'll be swapping them out for the stock and see how it runs. I do want to get my tb's bored over to 2.2 inches. Have you been to the crossfire injection forum?

crossfire.homeip.net, check it out, my sn there is California_Corvette. Hope to see you around.

Jim85IROC

the x-ram is kinda neat, but unless you really want to say you have a ceasefire car that actually performs, why not just pitch it and carb it instead?

Alcee1

Lets not put the crossfire down, The way I see it, if you are looking for HP and can get the crossfire to produce it, then who cares if you have CFI, TBI, TPI, FBI, IRS whatever :lol: to me what matters is, you can now say I have a CFI that has 350hp :thumbs:

jefft84

:iagree: I love my cross fire

fixit

I have an '84 and feel this year is vastly underated for potential. I've done a number of mod's and can annihilate any stock '85 thru '89. What you're going to do is good. As mentioned you've got to get more air into it, have the throttle bodies bored and injectors recalibrated (I had Corvette Clinic do this 15 yrs ago), port the heads, and open up the manifold ports as much as possible, add good long length headers (got mine from Corvette Clinic), don't forget roller rocker arms! Ditch the OEM radiator, it's too thin, get a heavy duty from Modine (about $200), lastly, and this made the biggest single improvement get a high performance chip for the ECM, I used an ADS (now out of business), don't settle for a stage 1, go for a stage 2 or better. One more, put in an '87 or newer transmission, it'll stand up to the added power better. Show them what an '84 can do!

Dominic Sorresso

Vettespeed,

I don't think you'll do it with just a ported manifold and L98 heads. Not sure about the cam. You should be in the high 200hp range. I think you'll need bigger TB's and larger injectors to get there. Not sure the heads and cam wil support that either.
Right now, mine is sitting close to 350hp. Its port matched but also Extrude Honed. The strength of the Xfire is really the torque it produces. When its built right it is a very fun street car.
BTW, you should be ready to tune the ECM. :seeya


[Modified by Dominic Sorresso, 6:17 PM 8/28/2003]

Jim85IROC

My point isn't to be critical of crossfire, but I think before anybody spends a lot of time investigating crossfire options, he needs to examine his goals.

If horsepower is your goal, there are cheaper, easier, vastly more effective means to reach your goal than to keep working with the crossfire. If you really have a strong desire to make horsepower with the crossfire, and don't mind spending a bunch of extra cash to do it, then fine. You have a few (very limited) options. But if your goal is bang for the buck, or bang for the effort, pitch the crossfire.

Dominic Sorresso

I think we've dealt with something like this before. In actuality, the Xfire is no more expensive to mod than any other small block. And that's what it is.
A small block. It may be cheaper because much of the modifications aren't of the "off the shelf" type. They're very much DIY. The motor responds to exactly the same kinds of mods any other SBC does. Dan Plett has recently demonstrated that a Xfire induction system on a an L98 block turns low 14's.
Hope springs eternal.

Alcee1

Vettespd20, I'm also getting ready to rebuild my 84CFI. I'm going to go with a Comp Cam, Edlebrock performer heads, Comp 1.6 R/R, X-Ram w/EGR adapter, Bored TB's, Injectors, and a custom chip from exotic muscle. With these I should hit 300+ HP, won't know how much over until I get it dyno'd. I forgot to mention I'm also getting 3.73 in the rear with a transgo shift kit. It should hook-up pretty good. :D :D :D

tobijohn

bogus wrote:
"sadly, not alot of people know about the X-Ram..."

Assuming you've got long tube headers/catback, performance heads and a cam suitable for a daily driver, how much HP can the X-Ram support and are there throttle bodies or mods that can provide all the flow that it does support? And what kind of displacement will it support (i.e stroker)?
Thanks

vettespd20

Well, I hope to get atleast 300 HP with only what I got listed on my orignal post. Any one have any idea of how much HP will have with the parts listed above???????????

CFI-EFI

Or my factory cast Crossfire (ported) manifold on a stock,worn out L83, Crossfire engine, running high 13's. 'Scuse me. Time to fill the oil and check the gas.

RACE ON!!!

Jim85IROC

so after you do all the DIY you can think of, you get performance close to what anything with a carb will do right away. Then you start trying to climb up the brick wall you just hit.

84s have a few obstacles to overcome. The induction is extremely restrictive, extremely primitive from a computer control point of view, and the heads suck. Generally the long block isn't a heck of a lot different from the 85, yet after a whole bunch of "DIY", you're lucky to see times that are a couple tenths better than a stock 85. The biggest problem is that the manifold can't flow any air, and the computer is too stupid to figure out what's going on after you mod it. Can this be solved? Yeah. You can buy the x-ram and aftermarket tbi control, or you can slap a carb on. Dollar for dollar, carb still wins.

I swear the cfi posts on corvetteforum are just like the 305 posts on thirdgen.org. There are so many 305 owners who are hell bent on spending money to make their car fast, and for the select few who achieve their goals, they've spent well beyond what it would have cost them to build a 350 and get better results.

All I'm saying is that for any particular horsepower level, there are a million ways to get there, but each way costs a different amount of money. Modding CFI might be cost effective up to a certain point, but anywhere beyond it is going to be a whole different story.

scorp508

The D-Port L98 Heads (1988-1991) will flow 350hp without any work done to them. So yes your HEADS will flow 350.

fixit

You might try Corvette Clinic, they did a make-over for the '84 back in 1987 or 1988 that was featured in, I think, Corvette Magazine. Turned some respectable e.t. times. Sold me, I had them do their thing on my TBs and used their headers. It was well worth it.


[Modified by fixit, 3:51 AM 8/29/2003]