Hi all,

I had a c4 (1995) back a few years but life happened and I had to sell it. I am in better shape now and was able to lock down a 112,000 garage kept 84 with the crossfire(unfortunately but oh well)

i have a 4K budget and am looking to bump up the HP. Everything is currently stock , the motor is tired and smokes some at idle . I do plan on pulling it this winter.

I think the easiest route would be to keep the CFI . I am not familiar with porting but I see this likely needs done ( I’m sure I could find a machine shop)

I am seeking recommendations. As I am pulling out the motor for a refresh should I have it bored ? If so does the computer need updated?

if I keep the stock bore what are your recommendations on heads and cam?

thanks all!

 

Goals and budget?

I can't believe a 112k mile motor is burning oil. You sure it's not an intake gasket leak? If it's rings, that was a pretty poorly maintained car....

Watch out for folks giving "advice", who've never owned a CFI car, b/c they don't know WTF they're talking about. Any poster in this thread should clarify that. I'll start; I owned one for 12 years.

 

thanks for the advice! The CFI is certainly a niche. I have a $4k budget and goals are just to maybe get 280-290 horse? It is not a daily and will drive it 5,000 miles a year or less ( this also helps me avoid the emissions inspection in PA)Planned on pulling the motor to rebuild (pistons/rings/etc) . It could be an intake gasket. I plan on pulling the cfi apart and doing a rebuild kit as well.

 

If it was me I'd get a vortec 350 to do my build. The whole roller cam & great flowing heads deal is hard to beat.

 

not opposed to that. I actually have one laying around from a suburban. Not sure what I would need to do computer wise

 

Chances are it's more in the valve seals than the rings unless like was said it was poorly maintained.

If you were to do that vortec roller as it sits and install it with a ported intake I'd figure you'd be pretty darned happy with the results. And the fueling could mostly be compensated by the pressure. Those vortec cams are close enough to stock specs that it should be fine. But with the better heads and intake porting you'd be in a good place imo.

 

ok so port my cfi intake and bolt on vortec heads and insert vortec cam and call it a day?

 

We did a CFI intake on a Vortec long block in Jim's (CFI-EFI)'s car years ago. It requires new intake bolt holes, and double stacking intake gaskets to get the right intake runner "height"....it's worked great.

 

Yes and no. Understand that you want to keep the original short block which in that case you'll need to use a $retro roller lifter kit$. I'd like to see the CFI with double intake gaskets on vortec heads!!!

 

There are pics of it on this here forum, I think....

Let me look and see if I can find that thread.

 

awesome thank you. I’m very intrigued . Would be an easy build .

 

Just curious, where are you located?

 

I am in Levittown PA

 

Ah. You're actually not terribly far from me. I'm in jersey out over by six flags. Just a curiosity was all.

There is a gentleman in my town with another 84 thats almost exactly the same as mine but I never see it when I'm driving the car. I always wonder if he's on here or not so I always ask where everyone is from lol.

 

Well, I have 30+ years with CFI, but what do I know? Mine only runs 12s, which seemed to be a controversy on here lately. My experience is to include my own current 82 and the 84. Which also includes the 82/83 camaro, firbird and trans am. I would also vote on the heads may be at issue with the seals going bad, but it may not be the only thing, who knows until you take a closer look. Since you are in PA I would HIGHLY suggest looking into Dynamic EFI there in Phoenixville, PA. Get the EBL Flash II. That way if you really want to increase the power on your 84, you will have the capability to do so since the ECM would be 100% laptop tunable. If you go that route, I can give you a free tune for a stock 84, but you can customize it anyway you like to suite your needs. Good luck and post up what you find with the motor issue.

 

Sorry, but I can not find the pics. I was the one who installed them, though. This was forum member CFI-EFI's car -an '84. His original engine took a dump at something like 200k miles? It was his DD so a few of us (forum members, Ross Rosland, Wayne T Nelson and I) rallied. I got him the stock Vortec long block. Wayne, Ross, Jim and I all threw it into his car in my shop at work one weekend. We plugged the Vortec manifold bolt holes in the Vortec heads using bolts, heads chopped off, slotted so you could run them in flush w/a screw driver, and then coated with RTV to seal the coolant in the head. Then we drilled and tapped new bolt holes for the older gen I CFI intake. We could see the difference in runner height and knew we needed to raise the CFI intake...we felt stacked gaskets would do it...and they did, surprisingly well.

How did it all work? Damn well. Jim (CFI-EFI) lost some cam, going from the stock CFI long block and it's flat tappet cam, to the truck block and it's VERY lame roller cam, but gained head, of course. The "finished product" was as follows:
*STOCK, L31 Vortec long block
*Heavily ported, stock CFI intake.
*free CAI mod
*2" dual exhaust, no cats
*Stock ECM and chip (tune)
*FPR "modded" into an adjustable FPR...I think he was running 13-14 PSI?

*212 RWHP/270 RWTQ at 4200 and 3200 RPM. Car ran 14.10's at 4500' elevation @~95-96 mph, IIRC. Not like today's cars, but damn good for what it was, and the $ that was put into it.








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has anyone used these heads? has crossfire bolt pattern. flows 240cfm at .500 lift 191cfm at .300. . I'm guessing these are trick flow heads. does anyone know how much a ported crossfire manifold flows?
Summit Racing SUM-162109 Summit Racing® 62cc Aluminum Cylinder Heads for Small Chevy | Summit Racing

 

I don't think anyone knows what a ported CFI intake flows. First, IDK anyone who's flowed one. Second, "ported" means SO many different things. For most, porting out the last Inch or two of the runner, where it chokes down is "ported". It's better, but that is not a ported intake. Ported to me means floor, ceiling, walls....until they're paper thin, all the way through from mouth to flange. I've only seen one intake done like this....the one that I spoke of, above. I'd imagine that it'd flow close to well enough to feed that head.

 

They are close to Trick Flows, but TF are 175cc, 64cc chamber on the small end. I think the TF heads would be a better option IMO. I don't think anyone has ever put a stock or ported manifold on a flow bench that I'm aware of...We never did. I should dig out my ancient stock manifold out and throw it on a flow bench some time just for giggles.

 

I windowed mine in a couple places last time I worked it.