Switch From F.i To Carbs?

[johnkennedy]

HAS ANYONE SWITCHED FROM F.I TO CARBS AND SEEN A PERFORMANCE DIFFRENCE?

IF SO WHAT IS THE RIGHT SIZE CARBS TO GO WITH?

I HAVE A STOCK 75' 2.O LITRE AND THE F.I WORKS WELL, I WOULD LIKE TO GO THROUGH THE F.I FOR RELIABILTY REASONS BUT IF I CAN GET MORE PONIES OUT OF CARBS I'LL SWITCH.

[Kenny Powell]

Originally posted by johnkennedy


I HAVE A STOCK 75' 2.O LITRE AND THE F.I WORKS WELL

[Barber Dave]

What kind and size of carb are you switching to? Dave

[ruddyboys]

Taking a working easy to use FI to put on carbs. Doesnt make sense to me, it FI was completly shot then maybe. If you put on dual carbs (I have Webber 40IDF, PO installed) you should put in a new cam that is made for carbs. For more power I dont think so.

[skline]

Ruddyboys is right, if your FI is working and working good, leave it. The FI is far more efficient and will get you better gas milage. To run carbs, you really should run a different cam designed for carbs. I run 45 Dellorto's and would not even try to run them with a stock cam as it would just flood it out. I am running a 295 duration with a 498 lift cam as opposed to the stock FI cam. I am not sure of what the stock lift and duration are. I know from experience the the gas milage drops dramatically. The horsepower is also increased but cost wise, it is not a wise choice. New carb kits for 44 Webers would cost you at least $500 and up and the cam and lifters would cost you another $250 and up. Since you will be replacing the cam, that means splitting the case and you may as well go ahead and do a rebuild. That gets into a lot more money. If the car is running good now, why would you want to change it? I have almost $3000.00 into my 2270 rebuild and it is not even in the car yet. The whole thing has got me depressed. Why put yourself through all that? Good luck.

[woodman]

Scott - so whats going on with the 2270? Did you get the interference problem worked out? I want to see that thing fired up! Not that you don't.

[Joe Bob]

No performance increase with the addition of carbs. You WILL see an increase if you take down the whole engine and put in another cam suited to carbs.

[skline]

I have not had the time to put it in yet. The interference problem turned out not to be a problem after all. Not knowing what to expect was the problem. Straight cut cam gears make noise, at low RPM's it clicks. At high RPM's the clicks turn to a whine. Now I just need some cheese to go with it. Once the valves were adjusted correctly, I get the click on every cylinder. It makes sense now. It's been too cold at night to work on it. Anything under about 68 and I get cold. I am dying to hear it run and drive it. Soon, very soon.

[pbanders]

As everyone says, with head work, different cam, and hell, while you're at it, bump up the displacement - carbs get more HP. Jake Raby's motors are more than proof of that. But it isn't cheap, and there are other disadvantages - higher fuel consumption, higher emissions, difficult or impossible to pass smog visual tests, loss of low-end torque, cold start problems, increased susceptibility to vapor lock, and general durability issues. When you add up all the up front and hidden costs, it's often much cheaper to repair your existing FI system (check my web pages below for information). Make sure to understand all of the issues before going to carbs. I've owned both carbed and FI motors, both are great, but different.

[Barber Dave]

Well this is my story; 1.7 L. 30,000 to 35,000 miles since compleat rebuild by a P.O. F.I. cam. and the infamous 2bl. progressive Carb. Runs like **** up to 3.500 R.P.M. then O.K.
Just don,t pull out in traffic unless on comming traffic is at least a block away. All ready have got a good F.I. sysstem and that will be in it shortly.
On the other hand I had the chance to ride in a great running weber carbed, and Isky camed 2.0 l at MSUR . My feeling is to keep the F.I. fix it ,or pull the engine, split the case and do it right.
Good luck eather way Dave

[jurhip]

I wouldn't change the FI system to carbs. Though the system in your car is dated compared to modern systems, in actuality nothnig really changed. The only real difference, is that yours is mechanical and new cars use electronic sensors to measure air flow and dispense fuel.

A stock Fi car will produce more power than a stock carbed car because the FI system has the ability to adjust to many changes and meter out the fuel accordingly. The only problem is, all your hoses, seal, and mechanicals of the FI system must be working correctly.

[jkeyzer]

What's the difference between the FI cam and the one for carbs? What do carbs need that the FI doesn't?

I can understand it not working the other way around.
I can also understand that you would want to change cams because you CAN with carbs and not be limited by the stock FI system.

But what is the fundamental problem with just sticking carbs onto an FI cammed engine?

[SGB]

I've got 40 IDF webers, and after I changed the cam it changed the power band and increased hp and torque ( some...). If stock cam is retained, stick with FI. When it runs right, It is smoother (sounds like a Porsche!), probably less stressfull on the components, and follows the factory's perception of what the car should be like. My two pesos....

[Dave at Pelican Parts]

The stock FI cam does indeed work with carbs. The car runs fine. The carbs themselves introduce a few problems (e.g., they don't meter fuel as well) which often but not always lose you some performance under most circumstances.

However, you leave a whole lot of performance on the table if you keep the very mild stock FI cam. With an aggressive cam, a carbed motor will make significantly more power than the stock injected motor. So if you're looking for more power, carbs and cam are the way to go. Just carbs aren't.

--DD

[Joe Bob]

D-Jet FI does not work very with a (carb type) cam that has overlap....i.e. a cam that will have partial openings on more than one valve. So the cam for FI is very mild. Modified cams for FI are available but tend to need FI tweaking and will cause the engine to fail the sniffer test for smog....ask me how I know.....%^B

No one ever said that carbs won't work, just that there is no performance advantage of simply adding carbs to a stock cammed T-4 motor. which was your original question.

BTW....NEVER let anyone talk you into converting to hydraulic lifter/cams....do a search on the subject.

[DDS]

>Anything under about 68 and I get cold. .

Unbelievable.... ;-)

On cams and carbs, I'm in with the others. Don't do it. FI'd cars tend to be smoother and I did change to a cam and carbs etc. and while the car is way more fun to drive it sucks fuel. Carbs with the FI cam will give the worst of both worlds.

[skline]

It's 66 in my garage right now and I have a huge coat on. I cant work in this kind of cold. I could never live again in a place where it snows. I did that for 2 years and moved back here to California. I think it is even cold here in the winter. That is why I always go to Hawaii or Mexico in the winter. Someplace where it is warm.

[Joe Bob]

Originally posted by DDS
>Anything under about 68 and I get cold. .

Unbelievable.... ;-)

On cams and carbs, I'm in with the others. Don't do it. FI'd cars tend to be smoother and I did change to a cam and carbs etc. and while the car is way more fun to drive it sucks fuel. Carbs with the FI cam will give the worst of both worlds.

Yeah...it ain't like yer Daddy's Buick no more.....

A six conversion is pretty smooth.....

[DDS]

Now, don't start with me son. Mom sends her regards. You should visit sometime. Her I mean. And remember, she's a bit old fashioned - try not to talk about your 'stiffy' if you can help it. Yes, I know, she used to think it was cute, but it that was when you were five. ;-)

I'm patiently waiting for that six... Car's ready!

Cold!?! 66? I have to work naked when its that warm! (Supress that visual Mikey) Skline - check your thermostat! I was travelling last week out West and dropped into Calgary Alberta for a day. From the air, you could see ... white, everthing covered with snow. Got off the plane and the air had that really clean crisp feel and smell - not really cold - maybe 25deg F. Felt really nice and invigorating, I was kind of looking forward to it. Winter can be beautiful.
Got to the rental car booth and they warned me that the driving was bad and to be careful - Whaddaya think I am - Californian? - No sir, its REALLY bad. Ahh , first storm, everyone re-learning how to drive. Paid five extra bucks for a trailblazer and was glad I did. Flipped cars in the ditch, kids trying to push their slick-tired ricers stuck on level ground, and the worst - folks stopped going up a long hill and can go no further. The only way out is to make a U turn in front of the oncoming DOWNHILL traffic which of course can't stop...
Not looking forward to when it hits here and stays for four months and am getting really tired of trying to glass my Lotus in the cold.
Hawaii sounds good, except for the hockey.

[Joe Bob]

Rose to the bait didya???

Mom still dating the ex-con...wasshis named Bubba or was it Cornbread, can't ever keep them straight....speaking of straight...they should really NOT take that jacket off of her......%^B

As to a carbed version versus FI....try and and find an example of what you are interested in and drive it.....