A Cars forum. AutoBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AutoBanter forum » Auto makers » Corvette
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

'84 crossfire to carburator conversion



 
 
Thread Tools Display Modes
  #11  
Old December 19th 07, 06:07 AM posted to alt.autos.corvette
'Key
external usenet poster
 
Posts: 548
Default '84 crossfire to carburator conversion

"Billy Ryman" > wrote in message
...
---snip---
> Bypassing emmision controls? Might as well tear out the
> ECM, and all the wiring that goes with it. You can't
> cherry-pick with the ECM. You did plan on rewiring the
> car, didn't you? Your digital dash?... I guess you'll
> replace everything with analog gages, 'cause non of the
> electronics will work.


the ECM can be left in the car and continue to controll the
digital dash among other things.
I didn't have to get analog gages..

---snip---

> And you better consider what you're going to do with the
> fuel pump/delivery system. That carb you spec'd WILL NOT
> handle the pressure from that electronic pump!


fuel pressure regulator.

--
'Key
=====



Ads
  #12  
Old December 19th 07, 06:19 AM posted to alt.autos.corvette
'Key
external usenet poster
 
Posts: 548
Default '84 crossfire to carburator conversion

"Fixitman" <fixitman333-at-yahoo.com> wrote in message
...
> I've been restoring a 82,000 mile 1984 Corvette for over a
> year now. During
> this process, I've made it a point to know how everything
> works. The
> electrical system was hacked up pretty bad, so this was my
> primary concern.
> Unfortunately, the car ran very poorly, so I had to fix
> that first. I
> initially wanted to convert to carburation, but found the
> price-to-benefit
> ratio to be a negative value.
>
> On the plus side:
> 1. The cluster only needs the ECM for fuel economy
> information. The rest of
> it will perform perfectly without the ECM.
>
> On the negative (note that the ECM will be effectively
> dead):
> 1. The transmission TV cable (throttle valve system) can
> be adapted to a
> carb, but will be difficult to syncronise properly.
> Result- shift points and
> kickdown are never quite right.
>
> 2. The TCC (torque converter clutch: overdrive) is
> controlled electrically
> by the ECM. Most aftermarket TCC kits are designed for
> off-road use, and can
> be a real PITA on the street. Leaving the TCC disabled
> means reducing fuel
> economy considerably above 45 MPH. Top speed will also be
> reduced.
>
> 3. The stock distributor will not advance timing properly
> without the ECM.
> Improper timing advance = extremely poor performance.
> Early
> centrifugal+vacuum advance distributors will work, but not
> as well as the
> original system. Once again, it would lose some
> streetability.
>
> 4. Emissions will be higher, because affordable carbs just
> aren't as
> effecient as fuel injection PERIOD. Emissions go up and
> fuel economy goes
> down, resulting in a loss of performance and "fun factor".
>
> I've been working on cars proffessionally for over a
> decade now. Once I
> realized just how much work was involved, and what I would
> lose, the
> decision was easy..... Fix The Crossfire. I later found
> that the fuel lines
> were severely corroded inside, severe enough to plug the
> fuel filter within
> a few days of replacement. I spent about $50 and about 5
> hours bending and
> installing new fuel lines, and couldn't be happier. The
> '84 runs great, and
> gets 18-20 MPG (if I keep the pedal off the floor).



my conversion and engine overhaul gets
"18-20 MPG (if I keep the pedal off the floor)".
has 375 to 400 HP and is very fun to drive..

my2
--
'Key
=====


  #13  
Old December 19th 07, 06:28 AM posted to alt.autos.corvette
Elbert
external usenet poster
 
Posts: 22
Default '84 crossfire to carburator conversion

On Tue, 18 Dec 2007 20:17:24 -0500, "Fixitman"
<fixitman333-at-yahoo.com> wrote:

>I've been restoring a 82,000 mile 1984 Corvette for over a year now. During
>this process, I've made it a point to know how everything works. The
>electrical system was hacked up pretty bad, so this was my primary concern.
>Unfortunately, the car ran very poorly, so I had to fix that first. I
>initially wanted to convert to carburation, but found the price-to-benefit
>ratio to be a negative value.
>
>On the plus side:
>1. The cluster only needs the ECM for fuel economy information. The rest of
>it will perform perfectly without the ECM.
>
>On the negative (note that the ECM will be effectively dead):
>1. The transmission TV cable (throttle valve system) can be adapted to a
>carb, but will be difficult to syncronise properly. Result- shift points and
>kickdown are never quite right.
>
>2. The TCC (torque converter clutch: overdrive) is controlled electrically
>by the ECM. Most aftermarket TCC kits are designed for off-road use, and can
>be a real PITA on the street. Leaving the TCC disabled means reducing fuel
>economy considerably above 45 MPH. Top speed will also be reduced.
>
>3. The stock distributor will not advance timing properly without the ECM.
>Improper timing advance = extremely poor performance. Early
>centrifugal+vacuum advance distributors will work, but not as well as the
>original system. Once again, it would lose some streetability.
>
>4. Emissions will be higher, because affordable carbs just aren't as
>effecient as fuel injection PERIOD. Emissions go up and fuel economy goes
>down, resulting in a loss of performance and "fun factor".
>
>I've been working on cars proffessionally for over a decade now. Once I
>realized just how much work was involved, and what I would lose, the
>decision was easy..... Fix The Crossfire. I later found that the fuel lines
>were severely corroded inside, severe enough to plug the fuel filter within
>a few days of replacement. I spent about $50 and about 5 hours bending and
>installing new fuel lines, and couldn't be happier. The '84 runs great, and
>gets 18-20 MPG (if I keep the pedal off the floor).
>
>If the only reason you're bent on starting this project is a cracked
>manifold, here is a cheap alternative:
>http://cgi.ebay.com/ebaymotors/Corve...spagenameZWDVW
>If it's still available Friday night, I'm going to buy it for a porting
>project.....
>
>Fixitman
>
> "Art" > wrote in message
. net...
>> Hello All Again,
>>
>> After doing tremendous research I think the conversion is not very

>difficult
>> as long as certain things are compromised. Please allow me to run these
>> things by everyone for comment.
>>

>



None of you guys have mentioned that there are a number of engine swap
harnesses out there that would allow you to swap something like a
modern tuned port or Vortec style engine over into this car, which
would include a new ECM. IF you determine which cars don't have
electronic shift and only have to deal with TCC control then that
would solve the shift business.

I realize that you have to know a great deal about car work to really
tackle one of these jobs, so that's a given.

As far as a TV cable with a Carb. The principle of the TV cable
adjustment is the same, whether its on a carb or fuel injected
car. The brackets are very similar. I don't see it being a problem to
adapt a bracket , or I believe B&M and others make one that would
work.

Don't have first hand knowledge of the TCC kits...they may suck don't
know. As stated there are kits out there. As I related swapping over
a 700R4 into an older car (ie older than an 84 vette) is real common.
I suspect there are a number of proven combinations for brackets and
TCC control.

If you run a carb, you throw the electronic distributor in the garbage
and get an old school HEI distributor (non ECM controlled)

I don't equate to emissions going up and performance going down.

You don't go down the road of a hybrid. You either go all the way with
a carb or go all the way fuel injection. Its also clearly a given that
fuel injection is by far cleaner, and more fuel efficient. Potentially
more power depending on the system, due to fuel control.
Meeting emissions requirements does not equal more power.

Yes its clear that fuel economy will not be improved by going to a
carb, but I'm not sure the guy cares about that.



So the idea is that the ECM only drives the mileage "computer" on the
dash. I personally don't think those things are accurate, and I could
do without that. Don't know what the initial poster's preference is on
this.

You can swap the intake, and install a carb, plus a non ECM
distributor and have a very decent performing car. Look into what
all the hot-rod guys are doing to make this happen.

Intake max $200.00
Carb $350
distributor $100
TCC control $75 ?

I don't agree with making this happen for $500 even if you
do the work yourself. But its very clear that this is somewhat
simple modification if one has basic mechanical skills.

So if you eliminate the distributor, and the fuel injection,
and if you don't care if the fuel mileage display works, what's
left that the ECM controls... just TCC? Which you can address.

I believe you could just remove the ECM all together, along with the
stock intake and fuel injection. Install an aftermarket carb and
matching intake, along with a old school HEI distributor and you would
be in business. Yeah its a given there may be some like issues, like
ign on at the distributor and TCC control. But these things are old
school issues that have been out in the hot-rod community
for some time.

Of course if you go old school, that opens the box to all kind of
proven engine combinations that make good streetable power and run
a carb, or even getting a Vortec 350 long block and use a carb for
power.

Like I said... I think a tune port setup is the ticket here, but it
depends on the owners ability and how much $$ he wants to apply.

If were to go to the trouble of going to a carb, I would change the
cylinder heads to something like a Dart Iron Eagle setup, run a
performer style dual plane if it will clear the hood or one of the GM
LT1 old school dual plane intakes, and a matching carb. I would put
that combination up against any cross fire. Carb setups are plenty
"streetable" .

There are any number of vehicle setups that one could replicate with a
GM 5.7 engine assembly. To be honest it would be near impossible to do
this even simply for under around $700. And that's someone who knows
how to do this work on their own.

I think you can easily get a clean running, very smooth drivable car
by going carburetor. Will it pass emission for that year model
vehicle...simply no!, will it outperform a cross-fire setup? maybe,
Will it be more fuel efficient, no! Can someone do this with basic
mechanical skills? yes. Is there value lost...yes if you want the car
to be stock. Will your accessories function, yes. Are there many
sources for modifications such as this, yes.

If I had a more modern vette would I change from fuel injection...no.
Would I consider moving to a more modern fuel injection system over
carb, yes. Why.. power. Are there plenty of parts available for such
a swap over to a carb, yes.

If you want a stock vette, then of course you would not want to do
this. You could easily make a swap like this work out and have a nice
drivable car that performs very well.

Does a 84 vette run a mechanical fuel pump, if not then that would
have to factor into a carb swap. I don't know what the fuel pressure
requirements for a crossfire is but I would guess around 13 or lbs
similar to a TBI. Of course with a carb you have to reduce that down
to somewhere around 7lbs.

Of course I would make some other adjustments related to emission
controls if I were to go carb setup. Yes you can make adjustments
that actually make the car run better.

If you have pass emissions then you had better play the fuel injection
game and see what your options are. If not then there exists a whole
panacea of options.


Does doing a modification like this increase the value or even
maintain the value, no. Unless you can repair the intake,you have a
dead car on your hands, then something that runs sales better than
something that does not.
-----------
Elbert


  #14  
Old December 21st 07, 01:22 PM posted to alt.autos.corvette
Ralph Snart
external usenet poster
 
Posts: 1
Default '84 crossfire to carburator conversion

Yeah, the C-4 is the red-head stepchild of the Vette family. I have a '95
Base Coupe. It has great 'AWE' factor with anybody out of the Corvette
family but it's treated with much discrimination within the Corvette family.

That said, prices for C-4's are low. So if you're modding a C-4 that's not
a Grand Sport or ZR-1 then you're not really doing any damage to the Vette
family.

My '95 LT-1 will outrun almost any stock C-3 and deliver over 20 mpg. Name
any C-3 that can do both. As for the C-5's, their prices are starting to
soften and in a couple of years they will bottom out - then maybe they will
be treated as badly as they treated the C-4's.

You should look at some of the Corvette forum message boards for ideas. As
much as I hate to say it, Usenet is dying.

Try these message boards:

http://forums.corvetteforum.com/

http://www.digitalcorvettes.com/forums/




"Art" > wrote in message
et...
> Thank You, that is my sentiments exactly, with only driving this car less
> than 5k/yr max it is a fun toy like a '32 roadster with a 350, the intake
> and carb combination is street legal in all 50 states, the catalytic
> converters were off this car when I bought it 7 years ago, if this were a
> day driver I might feel different, to be slammed about emissions when I
> look
> at the trucks on the interstate smoking so black for thousands of miles
> each
> day. To try to sell this car for even near what I paid for it is
> impossible. But to take the top out on a Saturday morning and drive it to
> the golf course is what toys are for.
>
> Thanks
> "Elbert" > wrote in message
> ...
>> On Mon, 17 Dec 2007 15:53:54 GMT, "Art" > wrote:
>>
>> >Hello All Again,
>> >
>> >After doing tremendous research I think the conversion is not very

> difficult
>> >as long as certain things are compromised. Please allow me to run these
>> >things by everyone for comment.
>> >
>> >1. Emissions - 1984 was a very early stage of emission control and the
>> >components can be easily bypassed or disconnected completely and be

> similiar
>> >to the '79 'vette, as strictly a toy car for me I feel the emmissions

> issue
>> >is non existant as I dirve the car less than 5000/yrs tops and there are

> no
>> >emision controls where I live and if I must bypass those laws it can be

> done
>> >by either reregistering th ecar as a street rod or an antique.
>> >
>> >2. Intake and Carb - Edelbrock has a combination that will fit under the
>> >hood and not force outside body alterations,so on the street it is
>> >invisible.
>> >
>> >3.Valuation - the value of an '84 C4 with 128,000 miles is very limited

> as
>> >it now stands probably the maximum value is less than $5,000 a very
>> >inexpensive toy for a play car. With the conversion I know I could sell

> it
>> >for around $3500.00 a $1,500 loss but much less than a new toy.
>> >
>> >4. Distributor - this is kinda up in the air some say it has to be
>> >replac

> ed
>> >with a vac advance distributaor and some say t does not, i will have to

> try
>> >the original first and if it don't work then replace it.
>> >
>> >5. The biggest issue is the transmission with the kickdown, most
>> >information is split 50/50 but it appears the the computer does not

> control
>> >the transmission and is controlled by a cable that may have to custom

> made
>> >but certainly doable I think.
>> >
>> >6. Digital dash - the digital (as another very attempt) will still be
>> >controlled by the ECM.
>> >
>> >The total expenditures from Jegs (with the exception of the
>> >distributator
>> >and transmission) is less that $500.00
>> >
>> >Please give me any comments or knowledge from your experiences.
>> >
>> >Thanks in advance.
>> >
>> >Art
>> >'84 red/red
>> >soon to be carburated
>> >

>>
>>
>> (1) who cares about the value of the car. It's your car do what you
>> will.
>> If is of value to you to keep it stock then get it fixed. If you want
>> to hot rod it or modify it, then do so. You can post a simple
>> question and you'll always get different answers. If you live in an
>> emissions strict state then it has to matter to you in order to get it
>> to pass. Otherwise its your car.
>>
>> (2) I guarantee you that there are a number of manifold and carb
>> setups
>> that will fit under the hood. I'm sure a tune port setup would fit
>> under the hood too.
>>
>> (3) the Value is in your eyes....
>>
>> (4) If you go with a carb setup then you don't use an electronically
>> controlled distributor (ECM controlled).
>>
>> (5) I'm sure a 1984 car uses a TV / kick down cable for trans
>> control.
>> this is easily modified to work on any number of combinations. You
>> need to start looking at some hot rod magazines, online resources. Its
>> very common to swap out 700R4 transmissions into old cars ... IF you
>> are going to run a carb setup for fuel then you stay with a 700R4
>> transmission. This is not a big issue at all, most any shop can get
>> something to work here. I suspect that a TV cable out of a 92K1500
>> would almost work fine.
>>
>> (6) I think the dash could be the biggest issue if its ECM controlled,
>> but in 1984 there were very few cars that had any type of ECM control
>> much less control over the dash. This should be very easy to call
>> and find out about, as there are any number of shops that just do
>> corvette work. I just don't think that in 1984 the ECM controlled
>> very much at all, beyond maybe timing, fuel to some degree, and may
>> have read engine temp and or O2 level to adjust for fuel.
>>
>>
>> Get over the hurdle and go buy the shop manuals for your car. Make
>> some phone calls, ask around where you live.
>>
>> A 79 Corvette would have a carb and distributor setup you could
>> replicate. A TV cable for your transmission would be easy to do.
>> You might make some real gains in power by going with a tuned port
>> setup, but that's your call.
>>
>> Once again your project cars value is what it worth to you. IF you
>> have fun with it and it serves your interest then who cars what other
>> do. There are plenty of people who $hit-canned the early fuel
>> injection crap and went with a carb setup on various GM cars, because
>> a number of them plain sucked. Now with hindsight its known that the
>> tuned ports are good performers, and not to hard to setup, or even
>> entire engine swaps...LT1 for an example would be great candidate for
>> a vette. Most any of the 5.7 engines out of Z-28 or trans-am would
>> also be good (fuel injected).
>>
>> If that were my car, my only two concerns would be. (1) can I pass
>> emissions if required (2) what kind of crap would I have to deal with
>> to get the dash to work.
>>
>> Outside of that everything else is just how
>> you want to proceed. Either old school with a carb, or something new
>> with a modern fuel injection setup.
>> -----------
>> Elbert
>>
>>

>
>


  #15  
Old December 29th 07, 10:32 AM posted to alt.autos.corvette
[email protected]
external usenet poster
 
Posts: 1
Default '84 crossfire to carburator conversion

On Dec 17, 10:53 am, "Art" > wrote:
> Hello All Again,
>
> After doing tremendous research I think the conversion is not very difficult
> as long as certain things are compromised. Please allow me to run these
> things by everyone for comment.
>
> 1. Emissions - 1984 was a very early stage of emission control and the
> components can be easily bypassed or disconnected completely and be similiar
> to the '79 'vette, as strictly a toy car for me I feel the emmissions issue
> is non existant as I dirve the car less than 5000/yrs tops and there are no
> emision controls where I live and if I must bypass those laws it can be done
> by either reregistering th ecar as a street rod or an antique.
>
> 2. Intake and Carb - Edelbrock has a combination that will fit under the
> hood and not force outside body alterations,so on the street it is
> invisible.
>
> 3.Valuation - the value of an '84 C4 with 128,000 miles is very limited as
> it now stands probably the maximum value is less than $5,000 a very
> inexpensive toy for a play car. With the conversion I know I could sell it
> for around $3500.00 a $1,500 loss but much less than a new toy.
>
> 4. Distributor - this is kinda up in the air some say it has to be replaced
> with a vac advance distributaor and some say t does not, i will have to try
> the original first and if it don't work then replace it.
>
> 5. The biggest issue is the transmission with the kickdown, most
> information is split 50/50 but it appears the the computer does not control
> the transmission and is controlled by a cable that may have to custom made
> but certainly doable I think.
>
> 6. Digital dash - the digital (as another very attempt) will still be
> controlled by the ECM.
>
> The total expenditures from Jegs (with the exception of the distributator
> and transmission) is less that $500.00
>
> Please give me any comments or knowledge from your experiences.
>
> Thanks in advance.
>
> Art
> '84 red/red
> soon to be carburated


Hi Art,
Hey, I wouldn't listen to the Corvette Nazi's too much. I have done
exactly what you want to do (an 84 as well) and I love it. I don't
know about emisions (exempt where I am) or resale value (don't care
either) but I can tell it is very easy and relatively inexpensive too.

I have a performer rpm intake and speed demon carb and it all fits
under the stock hood perfectly. I even fabed an air box that connects
to the old hood ducts.

Any old HEI dizzy will work fine. I use a crank trigger set up though.

Yes, lots of brackets are available to adapt the existing TV cable
("kick down") and adjusting it perfectly is not an issue at all. To
have torque converter lock-up and overdrive in 4'th gear (all thats
needed) you just jumper 2 pins on the 700r4 connector.

My digital dash works just fine without the computer.

I had to change engines anyway so maybe not a "good idea" for you. Who
is to say . . ? I'm extremely happy with mine anyway. It's 406ci with
GMPP fast burn heads and their "hot" roller cam and the acceleration
is just brutal now in comparison.

Ray
  #16  
Old August 9th 17, 02:01 AM posted to alt.autos.corvette
[email protected]
external usenet poster
 
Posts: 1
Default '84 crossfire to carburator conversion

I realize this is an old discussion but if anyone wants info on x fire to carb conversion, ive done it and i did it on a budget and am a year later still loving it. 13.66 1/4 mile, daily driver and still get 21 mpg highway. I still have the car and can supply part numbers and information to make your conversion go smoother. .
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Brasilian Carburator 34 pict-3 equivalent Macsoft VW air cooled 1 October 18th 07 11:30 AM
Dies at idle...do I need I new carburator? Manuel Macedo VW air cooled 8 October 13th 07 02:06 PM
Cleaning a lawn mower carburator Gaetan Mailloux Technology 6 June 26th 06 03:44 AM
Dual Carburator Kits Typ-1 EMPI HPMX Joao Eliseu VW air cooled 0 October 30th 05 10:48 PM
Fish Carburator Landen Schooler Technology 1 April 19th 05 02:01 PM


All times are GMT +1. The time now is 08:06 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright 2004-2017 AutoBanter.
The comments are property of their posters.