`90 switching to carb need advice

[bradley1ph]

could you help me with some advice on the pro`s and con`s of this swap? parts list and potientional road block. the car is a `90 6speed 383 nice cam longtube headers ect.... not worried about emissions or gas mileage. daily driver. tried the stock tpi and super ram now i want to try carbed. thanks.

 

[vetteboy86]

Is there any reasons why you want to go carb over fuel injection?

 

[bradley1ph]

Is there any reasons why you want to go carb over fuel injection?

lots of them. have you done this conversion?

 

[bradley1ph]

will who ever has done the switch let me know what parts you used? intake, carb, distributor. thanks

 

[Ripp 73]

Does seem like a backwards step in some regards. I think putting a Carb on these cars would be an interesting task. One thing I like about Fuel Injection over a Carb is that the fuel is always regulated. On a Carb the air that flows in and around the fuel can do some strange things sometimes depending on the air flow in the engine compartment. If you don't mind me asking Bradley, what makes you want to take this step with your 90? I see that it is now a 383, is it the original block or a Crate motor?

 

[bradley1ph]

original block stroked,factory heads, 224/230 cam, long tubes, gutted cat. all msd.

 

[Evolution1980]

(This is really contributing to the answer of your question, but...)
Carb is nice because: NO COMPUTERS to have to figure out! Check your jetting and your vacuum and yer done! :L

I happened to be talking to the guys at Mallett Performance since they are located right up the street from me. In the conversation he said that carburators are capable of producing (or handling?) higher HP requirements... or something like that...

Plus, I like the sound of a carb'd engine over an FI'ed engine. Has the more traditional 'muscle car' sound, IMHO... (Even on my motorcycle, coming off throttle I will actually modulate the throttle so it too sounds carb'd.. :L) I guess it's that POP POP POP POP sound that I like versus the smoother RRRRRRRRrrrrrrrrr burble burble burble

In this case, I'd be curious to see what kind of mods need to be done to the computer in order to remove the fuel delivery system from the monitoring of the whole package.

 

[bradley1ph]

"In this case, I'd be curious to see what kind of mods need to be done to the computer in order to remove the fuel delivery system from the monitoring of the whole package". i think iv already read up on that and the way i see it is the stock pump will work all we will need will be a regulator as the carb needs less pressure.

 

[Evolution1980]

"In this case, I'd be curious to see what kind of mods need to be done to the computer in order to remove the fuel delivery system from the monitoring of the whole package". i think iv already read up on that and the way i see it is the stock pump will work all we will need will be a regulator as the carb needs less pressure.

But what about all the computer instructions, sensors, and open wiring harnesses that go to the injectors, the MAF, etc...??? Don't all those things tie into the control of the engine, such as timing/ignition advance/retard and "all that other stuff", like the O-2 sensors which adjust the A/F ratio based on the mixture blah blah blah? All this stuff is all tied in to other pieces-parts, no?

 

[AdvancedAutoCC]

But what about all the computer instructions, sensors, and open wiring harnesses that go to the injectors, the MAF, etc...??? Don't all those things tie into the control of the engine, such as timing/ignition advance/retard and "all that other stuff", like the O-2 sensors which adjust the A/F ratio based on the mixture blah blah blah? All this stuff is all tied in to other pieces-parts, no?

All this is bypassed when switching to carburetion (unless you're using a feedback type carb which is a real perfromance killer). The air/fule mixture is controled by the carb jetting or by a combination of carb jets and metering rods (old school stuff)..there is no more automatic air/fuel monitoring. Of course, the "SES" light will be on, so pull the bulb if it really bothers you. Plug off the O2 sensor bung in the exhaust if you haven't already done so. For an accelerator cable, you'll need to replace it with a Lokar type cable (universal cut to fit), or find a way to loop up the original. It all depends on how clean or crude you want it.

 

[bradley1ph]

nice site advanced auto. i did read where the parts page is under construction that will nice when you finish. i dont think its going to be that big of deal to switch over. i do know this i will have about 5 less sensors to worry about plus my o2 has been unplugged for awhile now allready. i do have a breathless ram air set up that i really would like to make work as well.

 

[AdvancedAutoCC]

nice site advanced auto. i did read where the parts page is under construction that will nice when you finish. i dont think its going to be that big of deal to switch over. i do know this i will have about 5 less sensors to worry about plus my o2 has been unplugged for awhile now allready. i do have a breathless ram air set up that i really would like to make work as well.

Thanks... the parts page should be ready when our new site goes live next month.

With the Rammer setup, you'll likely have to fabricate some sort of airbox for the carburetor, which could get tricky. Just take your time.

 

[bossvette]

If its an auto the TV or kickdown cable will be too long but try one for a carbed camaro I used an 87 accelerator cable in my 76 so most likely an early carb cable will work for you; but those Lokars do look nice, I have one on my Ole Yellow truck

Me I sold off all my carb stuff and plan on staying with EFI

 

[bradley1ph]

If its an auto the TV or kickdown cable will be too long but try one for a carbed camaro I used an 87 accelerator cable in my 76 so most likely an early carb cable will work for you; but those Lokars do look nice, I have one on my Ole Yellow truck

Me I sold off all my carb stuff and plan on staying with EFI

its a 6speed

 

[redc4corvette]

I think on your 383 you might need a little more carb.
I would think a holley 850 vaccum secondaries and #81 jets in the primaries
should work out just fine.
You will need to go to jegs and purchase one of their throttle brackets and don't forget the holder for the trans cable if you have an auto,about $39.00,it also has the return springs,bolts right to the carb perferct fit.
You will need to purchase from jegs the hook ups for the carb throttle arm,I think $6.00.
You will also need a moroso low profile air cleaner.
The Aeromotive regulator will need to be purchased from jegs or where ever,I forget the # it knocks down 40 plus psi to 5 psi or more ,I would run about 7 or 8 lbs presure.The regulator has a vaccum line on it so the fuel presure will varry with enigne vaccum.
Remove all your injector electrical wiring, ball it up and wrap black electrical tape around them both sides of the engine and attach them to the fire wall with a tie wrap so they are out of the way.You will need a MSD distributor and a 6AL box with the 2 wire conector I think is green and purple to hook up the distributor comes from the box.
Hook the yellow wire to the ignitoin key and distributor is good to go.
Any low profile manifold should fit .I used a duel plane,you only lose about 10 hp but I think it rpm's better.
Fuel pump I went to the Warlboro 20000169 in tank to feed the engine 20 min change out ,but you can use the stock pump.
The egr not being hooked up will throw a check engine light,dump the bulb.
You can install a manule choke for the carb or you can hook up a wire from the ignition so it comes on when you turn the key.
I think that is it ,if you have anymore ?let me know?

You will need to purchase some #8 russell fittings and steel braded line,Sumett has the best price for that stuff.

 

[bradley1ph]

I think on your 383 you might need a little more carb.
I would think a holley 850 vaccum secondaries and #81 jets in the primaries
should work out just fine.
You will need to go to jegs and purchase one of their throttle brackets and don't forget the holder for the trans cable if you have an auto,about $39.00,it also has the return springs,bolts right to the carb perferct fit.
You will need to purchase from jegs the hook ups for the carb throttle arm,I think $6.00.
You will also need a moroso low profile air cleaner.
The Aeromotive regulator will need to be purchased from jegs or where ever,I forget the # it knocks down 40 plus psi to 5 psi or more ,I would run about 7 or 8 lbs presure.The regulator has a vaccum line on it so the fuel presure will varry with enigne vaccum.
Remove all your injector electrical wiring, ball it up and wrap black electrical tape around them both sides of the engine and attach them to the fire wall with a tie wrap so they are out of the way.You will need a MSD distributor and a 6AL box with the 2 wire conector I think is green and purple to hook up the distributor comes from the box.
Hook the yellow wire to the ignitoin key and distributor is good to go.
Any low profile manifold should fit .I used a duel plane,you only lose about 10 hp but I think it rpm's better.
Fuel pump I went to the Warlboro 20000169 in tank to feed the engine 20 min change out ,but you can use the stock pump.
The egr not being hooked up will throw a check engine light,dump the bulb.
You can install a manule choke for the carb or you can hook up a wire from the ignition so it comes on when you turn the key.
I think that is it ,if you have anymore ?let me know?

You will need to purchase some #8 russell fittings and steel braded line,Sumett has the best price for that stuff.

thanks. alot of stuff to cover here. im sure you have read my other post with pics. cant really change the parts list per your post as i have already bought them. holly classic double pumper with manual secondarys, torker 2 intake and areomotive regulator using the stock pump till it goes out. borrowed a hei and coil which i will replace with the msd unit with out a dought. for now i want to get it started. im with you on snugging all the tpi wiring harness out of the way. im not going to cut nothing incase the next person who owns this car wants to go back to injection. which brings me to my next point. i dont want to hack the fuel lines. i do want to move them around and still use them. my areomotive says not to use no smaller than an-08 1/2 on the return line. are the factory lines 3/8 or 1/2 are they an style or npt? do you have pics of your fuel reg set up as well as the carb linkage to the factory cable? steve1ph2@comcast.net

 

[redc4corvette]

I am going to try to take some pics fro another thread on the other form he is doing the same thing.
I did cut up my fuel lines .I made a dession to not save the front fuel lines and cut them off under the a/c box .I don't have an a/c box anymore the last nitrous explosen took care of that.I have a piece of tin where that was and I cut the fuel lines off at the frame just after the fuel filter.I just used 1/2 fuel line and #8an fittingssteerl brade.I looked around for a long time to see if I could find a fitting that would fit the pipe thread for the fule line but I gave up and cut the thing and used steel brade line and hose clamps ,after I flaired the lines and pushed the hose on.It aint pretty but it passes tech.The car should have 5/8 fuel comming in and 1/2 return but I am lazy .The new motor I am putting in will require the change in the fuel lines but Maybe I 'll fudge.
They lowered the speed for a shute to 135 mph and I will have to change the car around to slow the mph and lower the et.
Before I found out about the speed change I ordered a 687 hp 434 with 300 shot of nitrous.
Oh well Looks like a set of 4.56 rearend gears are due.

 

[bradley1ph]

got the fuel pressure regulator installed. heres the link. http://photobucket.com/albums/f333/steve1ph2/corvette/?sc=1

 

[redc4corvette]

Looks good!