ok well my cousins 305 crossfire engine just plain out sucks. So the plan is to swap it with a high 90's 350 thats out of a tbi caprice. We are gonna be the crossfire on it. WIll it run correctly or run like ****? there will be no tuning because its not for power purposes

 

You will be lucky to get it out of the driveway. Not to mention that centerbolt valve covered heads will not bolt to a crossfire intake in stock form.

 

A lot of guys have ditched their CFI for a plain old carburetor and gotten fair bit of performance out of it, even on the stock engine. And, of course, you can then stick a 350 under it later with maybe only mild retuning of the carb (or none at all). Carbs are high-tech in an old-school kind of way: they don't know what engine is underneath them- they only know how much airflow is going through them and to match it with the right amount of fuel.

Switching from CFI to a carb would be basically the same procedure as switching from TBI to a carb- there is a tech article on this board about how to do it. Just another alternative, FYI.

CFIs are tough to work on- nobody knows much about how to tune them (although it would probably be similar to tuning a TBI application), not many parts available, etc.

 

so putting that 350 in wont go so well?
crappy news for him
this sucks

thanks a lot

 

ok well project 305 crossfire to 350 crossfire begins tomorrow!!!
games on

 

To do this right, you will need to take the injectors from the 350 TBI and install them into the Crossfire manifold. They will fit.

You should also use the Caprice ECM rather than the (much older) ECM used for the Crossfire.

Crossfire is TBI, it used 2 fuel injectors though each was housed in its own throttle body unlike the F and Bcars. So if you use the 350 injectors, and if you repin the Fcar harness to the Caprice ECM connectors, then it should run ok.... especially if it's not for big power purposes. CFI will do a very nice job on a street 350 because it's a manifold better suited for torque production than for power.

There is a lot more info on Crossfires on the Crossfire Vault web pages, so I suggest you go there for help especially for tuning tips and "what to avoid."

The Crossfire was saddled with small runners (even smaller than on TPI) so airflow at high speeds is hard to obtain, but porting can relieve some of that. There are a number of people that have modified CFI (Crossfire Injection) cars and had "performance" gains, incl Tom 400 CFI here on TGO; he installed a CFI unit atop a 400 sbc and ran an altitude-corrected 13.3 if memory serves. HTH.

 

well its just to make the car run possibly in the future up to my cousin if he wants it to be better he can tune and upgrade for now we are just trying to get over the ****ty motor and broken cam.

 

I think the problem you are going to have is manifold fitment to the newer style head. There is not exactly alot of room to grind on the center 4 bolt holes on the crossfire manifold. The newer heads have the 4 center bolts that hold the intake down at a different angle.

 

ive heard but ive heard the worst that comes out of it is air being sucked in causing pinging. Its better than an engine that barely runs am i right? the motor was in a carbed car before and the intake manifold on that had the same problem and it pinged thats why it was changed. so the pinging is the least of the problems if this thing has more power and runs better than the old crappy 305 we are golden

 

http://www.crossfire.webhop.net/

IIRC the issue that Fast355 mentioned is not that much of a problem, as many others have used 87+ heads with the 82-84 CFI intake manifold after suitable modification to the intake to handle the angled bolts. Search at the above webiste for more detail. HTH.

 

thanks well the motor is out and what a sludge monster it is antifreeze was trapped behind all the sludge dunno how it ran dirty as hell too

its gonna be 100x better

tomorrow is the cleaning and swapping to the 350 part and possibly starting to install it back

 

Do a quick porting job on the intake before you bolt it on. Here's the thread (it has pix):

http://www.crossfire.homeip.net/cfte...ID=18&CAT_ID=1

The L-83 Crossfire Corvette 350 engine was rated at 205 fwhp, but that was without roller lifters (worth 5 hp), and without low-restriction cats (5-10 hp). So given the stock cam, the early 80s heads, and the contemporary (poor) exhaust of the era, the engine wasn't bad -- it put the Vette back into the 15s in the quarter mile (mid 15s) and upped the fuel economy by 2 mpg, both much better than the 16.0 L-82 carb engine it replaced.

Crossfire 350 owners have gone into the low 14s with intake porting and exhaust mods, so an Fcar should be able to do the same. And the torque will make it a fun driver. HTH.

 

I dont think anyone mentioned that the corvette crossfire was a 350. Maybe some parts off one could be handy? Including the ECM and what not.

 

i was debating on porting it since i was polishing the area for the gaskets getting it all nice and clean. I saw how it matched up and was wondering i even mentioned it but prob wont happen.

Well today didnt go so good. Our new 350 looks as if the head gaskets were going so the heads came off and the old 305 heads are being sent out to be machined tomorrow. Come back all nice and clean with new valve guides, seals, etc. Everything is off the old block and nice and cleaned up now. Everything is just all over the floor waiting for reassembly once the heads come back.

Tomorrow the outter block of the new engine will be cleaned and possibly painted unless i wait for the heads. I also have to shine the block where the gasket goes to make it work like a charm.

Looking good looking good so far

 

ok today was a little slow and not much happened. The heads went to the machine shop nice and early in the morning and didn't get them back yet . Although the inside and outside of the block today was all cleaned and polished in certain areas. All parts taken off the car were also cleaned to make this car look new and just look better and less disguisting.

 

I've already been down this road so let me help you out. There's really not much you can do to the cfi manifold to get it to perform without cutting it up, but for starters cut the egr channel off, then smooth out all contours on the manifold walls and ports, then grind back the runner inlets until they're at a 45* angle (this helps smooth the transition from the throttle into the runners) and round off all edges. Then remove the swirl inserts from the lid by gently tapping them out with a hammer and port match the intake ports. You can port the runners out some, but don't over do it because there's a water jacket right below the runners. Then polish the whole thing, beyond that there's not much you can do. You could drill dimples into the runner walls to cut down on drag, but I doubt anyone would have the patience to drill hundreds of dimples into each runner.

 

well ive been told im not good enough to port and polish this **** so i cant port anything unless i send it out to the machine shop so it isnt going to happen.

well didnt make any progress at all today. Called the machine shop on the heads and we were told 1 head was completely done and the other had a crack so tomorrow the new one gets done over by the man and guess its another boring day maybe ill rip out those ****ty white face gauge layovers.

 

ever consider selling the CF in total and use a Edelbrock or (better yet) Holley TBI manifold? with a 7.4L TBI unit on top?

advantages? i think so !

 

I agree, a 454 tbi is the way to go but if you insist on using the cfi manifold you can learn to port it yourself with some practice on a junk manifold. It's not as difficult as it's made out to be once you develop a feel for it.

 

o no i bet i could do the porting without messing up but its not up to me. The motor is gonna stick with crossfire for now since we dont want to do any wiring as of yet as this car was all hacked so we are doing it properly as it should be done. Still waiting on the heads at the machine shop he now has both

 

I'd tell your cousin that he should still consider having it ported because with the caprice injectors and ecm it'll run a little rich (until it gets into closed loop anyway). He might be a little disapointed with the stock performance especially after what he spent rebuilding the 350.

 

this wont even cost as much as your thinking. The only charge mainly will be for the machining of the heads and thats it so..... and the ecm is staying the same cause he wants his hood to "flap" as he calls it. ans the injectors are going to stay stock from before once again im saying not going for performance just running better than stock.

 

BTW, I would look into the EBL when it comes out, it lets the "FLAP" open.

 

first off sorry but what does EBL stand for?

and we just got back the nicely done heads today look like they are brand new out of the box. The heads are now on with the intake manifold(bottom) cause only i now how the top goes on. Tomorrow the engine should be built and friday is the big day and moment of truth.

 

well today the motor was all put back together painted and is laying in the car not in solidly yet. flywheel is in backwards so that has to be flipped tomorrow and hopefully this bastard should be running by noon time ill let you know how it goes.

 

All i have to say is WHO IS THE MAN. 305-350 crossfire swap is finally complete. Yesterday bolted the whole motor up in less than one day and got the biotch driving by 5. Runs very nice but a little rough for now cause the valves may need to be adjusted but well see in about a week cause the heads were redone. Otherwise it runs very well and kicks ***. It is also a speedy **** if i may say.

 

Imagine if you had moded the CFI assembly, and were feeding it the correct amount of fuel.

305HO heads+350+fuel injection=fair power, great mileage, great torque.

Good to hear that it is running well.

 

you mean like this?

 

thankyou so far the car is still running very very well. the total of this job thats being charges is in the 1400 range. Good huh? yea its nice to know people and be a mechanic helps a lot.

 

vipershark,

Don't let anybody BS you that a Xfire manifold can't be made to run. They respond to go fast stuff just like any other SBC

 

Dom: is that still a 350 or is it now a 383? did you swap cam in past year? i thought i read you did?

 

Ron,

Stock short block 350. Did swap cams with WB tuning. I think its faster than indicated because this was on street radials, so the 60' is in the 2.1s. Also, the Spark curve was conservative, (36d in at 3600rpm) and I had forgotten about the fuel cutoff, so motor was shutting down through the traps. I'm very curious to see what it does with EBL.

 

fuel cutoff ? as you know i have the 7747. what ecu are you running?