I REALLY WANT A CROSSRAM, I have come to the realizlation I can not afford a crossram, even on E-gay they are going for 300.00 and up plus freight, then there are the 2 carbs linkage, $600.00 to 900.00 just for induction, I cannot justify...! But,.... I have a cross fire TBI intake from a camaro, (took out of the scrap bin at work) and the tbi top unbolts from the lower unit. I was thinking about making a new top and fitting it with a couple of 2 barrel ford holleys, that way I would have the gas milage/drivability of a 4 barrel with the looks, (at least looking at the front of the carbs) of 2, 4 barrel carbs. Plus they fit better on the top than 2 actual 4 barrel carbs. My biggest concern is the inside of the lower intake! The runners are unlike anything I have seen before...obviously it works, because it was on a motor, but everything is so OPEN inside there!!! This must work with fuel inj. But will it be the same with Carbs????? There are "runners that are about 3 inches long and then STOP, but they don't go to the top of the upper portion of the intake. To me it looks like it woud be a huge vacuum chamber with fuel/air getting to the cylinders closest to the carbs, and very little getting to the opposite cylinders. Maybe I am in over my head??? What do you guys think? It would all basically be free, I have the intake, the aluminum for the top, the carbs, I could even make the top to mount 4-94's. But if someone has tried this and "knows" some pointers or failures, I would be gratefull to hear from your experience, so as to NOT repeat the bad! Ken
It didn't work very well even with the computers driving it, thats why they switched to TPI not long after the Crossfire debued.
I guess that explains the "scrap bin"!!! well I think I will still make it, NOT to use BUT just to put on the display motor I have my 6 dueces on. Thanks for the tip!!
the cross fire engine was pretty crappy, low perf smog stuff mostly designed to put the 4 cyl EFI stuff onto a V8 using the existing injectors they had. I think you should try it, see if it works...shouldn't take too long to make it, and if it works, great, if not you can let us know that it doesn't work.
It's been tried before. It is vaguely similar to an old "Smokey Ram" intake in concept (converting it to carbs). It takes a HELL of a lot of accelerator pump shot in order to make it go. One other thing to keep in mind is that you will have a very large plenum full of fuel/air vapor...so try to avoid pesky backfires. The one I've personally seen didn't run all that well, but looked pretty good...probably make a neat display.
In the late 60s, AMC had an engine builder actually develop an engine that used a crossram with two Holley two barrels. I don't remember the reasoning, but it ran really well for Can Am racing. Obviously yours is designed for injection, but as you said, you have all the goods to make it happen. And if it doesn't, it might make some really good backfires. Nothing draws a crowd more that a good engine fire!
Years ago, I had an '84 Vette with cross fire and my daughter's first car was an '82 Z28 (305) with c/f. They were both temperamental, hard to keep balanced, etc. but they ran o.k. under WOT...not worth a shit otherwise. Their only saving grace was that they had a real nasty sounding idle. Made 'em sound like some of the 60s muscle cars with the radical cams. I would think it would be a terrible choice to put carbs on, unless you just wanted it to look cool.
Well...it WAS TBI which means it was designed to have wet flow unlike TPI, so why not? A backfire with TBI would be just as bad as with carbs due to the amount of fuel in the passageways. Your after looks NOT ultimate performance here right? I'd give it a shot...stranger things have been tried.
HOOOOOOOLDIT. Dont hrow it out. You are onto something. Crossrams 413 426 MaxWedge 426 Race hemi and as mentioned the Smokey ram. I have made tops for crosrams before. it will work and you can do it. Dont be diswaded. Your thinking is right on. I think a pair of 2gc double barrel rochestors (from say a 70 350) would work wonderful. You need to positon the carb as best you can centered over the runner box. Probably right where the injector bodies were on the stock top. Dont be afraid to do a little porting while you are in there on the manifold. Now lets take the worst case scenerio and say you do all this and you dont like it (which by the way is highly highly unlikely but not impossible) Next time someone asks you will KNOW the actual answers instead of the maybe answers and what if it works? What will you do then.? Me I am thinking you are thinking very well. try it . you might like it. At least you will have your crossram.Don
I've looked at the crossfire before and seems to me that its no different than the later TBI injection setups on conventional intakes,just has dual single throttle bodies instead of a single dual throttle body. Sure the intake is a throw-back to the old Smokey crossram and maybe not the most street friendly piece to ever come down the road,but you sure wouldn't be the only one here running an old school not real street friendly induction setup. I think if I had one layin around I might have to give it a try. Dont they have some kind of pinwheel lookin vortex generators on the top plate under the throttle bodies? If you decide to build it keep us posted.
I know a guy that a few years ago used a cross fire on a 400 sbc. He used the C /F because it was cheap ( free ) and he is good with fuel injection. That thing ran real good . Everyone said it wasnt worth his time and effort, well he proved them wrong. The point is , do it!!!!
Okay dude, I'll tell you what: I have the Crossfire intake, and have already done this conversion, with a top plate made to accept a pair of 500cfm Holley 2bbl carbs. The linkage is 95% done. It has the carbs, a pair of custom made spacers (to get the carbs up off the plate so the linkages clear), and two never-run 500cfm carbs. The carbs are spaced so they can each wear a 10-inch air cleaner, so they won't be restricted by dinky cleaner assemblies. I never got around to putting it on an engine, and it's been a door stop/shelf space waster/conversation piece ever since. Wanna save yourself some hassle and just buy mine? -Brad
My first reaction to you post was that it all hinges on execution. The cross-fire manifold was plagued with warpage and air leaks. I don't know that you could overcome that by making your own top. A dual carb set up is tough enough, why complicate it with a questionable manifold? I think a tubular cross ram built from scratch would be super trick and have better manners. Some creative bending would let you make up a high torque, long tube design with a sheet metal valley pan. Keep the dream, ditch the scrap.
Well this is what your top plate would look like - not sure what carbs this was made for. You soon run out of room once you start figuring out where to put the carb linkages.
Cross ram is a very effective way to improve either mid or top end torque. Chrysler were the American experts at this ( I say Amercian because Mercedes Benz were pretty knowlegible on this too) and they developed a formula which accurately plots the length required for what ever rev range you may want to run at. ".. Someone, I think a brilliant engineer by the name of Bob Graham, deduced that if we tuned our intake runner to the point where the resonance was greatest, it would give the maximum push to the air and fuel when the intake valve opened at any given speed. The theory proved correct in the tests on the single cylinder and the results were reduced to a formula that was used from that day forward for ram manifolds on Chrysler engines. The runner as measured from the valve seat to the plenum (the open area where they normally meet under the carburetor,) can be determined by dividing 84,000 by the length of the runner = the speed the runner will work the best. An example is: 84000 (constant) = 5250 rpm 16 (runner length) The formula worked with all camshaft designs tested, engine displacements, compression ratios, and bore and stroke combinations of the time. An exhaust tuning formula was also developed on the single cylinder test stand. An example is: 205000 (constant) = 5256 rpm 39 (length of exhaust runner to collector) On the exhaust tuning we found that we could flatten out the torque curve by adding length to the collector (the point where all the runners meet.) The collector on an engine with all cylinders operating was usually a tube measuring about 20% smaller than the total of all the exhaust runners...." this is a 1960 ish Sono ramic Commando. I've run one of these at 70+ mph and when you put your foot down at that speed thry really begin to haul the asses on board! I did have A 64' mAX wedge myself with the smaller manifold,a lot closer together and designed to work at a lot higher rev range for drag racing . You can still buy these new from MOPAR...as you do..
i have logged more miles behind a cross-fire than most. this is the deal. cross-fires are very sensitive to fuel pressure. they were very mysterious at the time because all fuel injection was very mysterious. they also have an electronic advance in the distributor that was over looked as a potential problem. once a year my car would start back-firing trough the injectors and running like shit. i would change the fuel filter, spark plugs, and pour in a can of injector cleaner and it ran like new again for another year. i did this to the tune of 275,000 miles. 83 Z-28. when i sold the car it looked like junk yard shit. but it ran like new. there's really no reason why the 2 carb deal won't work. with two good carbs and distributor in proper working order i see no problems. i have a complete cross-fire in the garage with the distributor. i'll put it on something some day. with no worrys.
Are they as port type injector ala 'Holley projection'? ,if they are all would be good but if they are injector type set up with injectors in the ports,then forget it.There is a world of difference between a wet carburetor manifold and a Dry type fuel injection manifold. The flow dynamics in a dry manifold will not allow a wet fuel mixture to work through the runners and you will in fact lose power.
Lets get to the root of the thread. You are bitching about a $300 INTAKE? WTF? i am not rich but $300 is a stupid night at the bar, a month without fast food lunches, ditching the freakin cable or satelite TV for a month or two...............so what was yer fuckin issue?!
I can see the point in saving $300. Maybe not to the point of building something that runs like crap & is un-drive-able, but I guess that's why he asked if anyone knew if it'd run like crap. Or maybe he just loves his cable TV. Later- John
haha did anyone notice this thread is over a year old? i bet he either already did it or ditched the ideal one. maybe he will come back and post and tell us what he did..........
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