LS400 replace injection with a Carby

[Ian Neville]

I am using an LS400 motor and Trany in a sports car I am building. I would like to get rid of the injection and the ECU and use manual timing and a carby. has any one had any experance? I am Australian living in Bangkok Thailand . Ayn advide would be most welcome. many thanks Ian

 

[XR8tt]

Check the New Zealand guys...
They fit these engines to stock cars there..
The rules are ONE carb...They get very good power from them also...

 

[rms]

Why would you want to do this ????

 

[jibbby]

Again why in the hell would you want to do that?...Carb over fuel injection that makes no sense to me...

It's an interesting thought to consider though, I am trying to picture a 850cfm carb worked onto the top of an 1uz-fe motor...hmmmm? You would definetely need a custom intake manifold and carb setup, run the fuel lines to carb... Seal off and remove all the fuel injection and plumbing connections... Hook up the throttle manually and I guess you can have your wish....

No MAF or MAP, no ECU...Well it would be a simple operation from that point on...Wonder if the 1uz-fe would still idle as smoothly with a carb setup?????

I am sure you would lose power and reliability in the end....

 

[cribbj]

Like this?





I'm preparing my 1UZ for an engine dyno breakin with this 390cfm Holley and a distributorless ignition setup using the Ford EDIS8, controlled by a Megajolt Lt Jr. I'm hoping to finish it and get it on the dyno before the 15th of this month.

There's the Richwood manifold, with an adaptor plate and a 2" spacer for the Holley. I have no idea how the fuel/air distribution will be. Probably the middle cylinders will be a bit rich and the four corners a bit lean.

I'll either have the stock injectors or some rubber plugs in the manifold to seal it during breakin.

This setup will only be used for the motor breakin, then it's coming off and the Opcon-Autorotor SC, fuel injection, and EMS will be going on, then back to the dyno for some power runs.

 

[V8Datto]

Why do you do this?

Is it because it's easer to run-in a "Built" engine on carbs rather than EFI?

I've herd people say before, you can destroy a new "Built" engine while trying to tune it on the dyno

The engine's I'm talking about here are 600+hp so there are no standard ECU's
and normally run above or below standard compression

Am I close to the money? Or miles off

 

[cribbj]

Yep; I've already had a 2JZ-GTE ruined while the tuner was trying to dial in the EMS. It was a freshly built motor, new fuel system, new ignition system, new EMS, etc. None of these major systems had ever been run together before, so the guy was trying to keep track of 4-5 different things and they simply got away from him. AFR was waaaaaay less than 10:1 for the breakin (which was 20 minutes of idling), and by then, the excess fuel had washed the cylinders, and the rings were glazed (as diagnosed by Total Seal's engineers).

So this time, I'm keeping it as simple as possible. A smallish carb to keep the air velocity through the venturis high, and an EDIS8 ignition with a proven ignition map.

We're even going to heat the coolant and oil and circulate them through the motor to bring it up to operating temperature prior to firing it, then we're going to load it up as quickly as practical after starting.

The guy whose dyno I'm using thinks all this is OTT, but when I asked him if he wanted to take responsibility for dialing in a new EMS on a new motor, with a new fuel system and new ignition system, as the motor was being broken in, he saw my point.

 

[rms]

cribbj is doing this for a specific purpose. Without someone who is familiar with the specific ecu and the 1uz, and can write a base fuel and timing map that will be close for breakin, his carby option is probably the way to go based on a previous bad experience. There is a lot of expertise in the USA re jetting Holley carbs for various capacity engines.

I asked Ian Neville that question because there are a lot of issues involved.
Regulations, suitable ECU's, control of auto gearbox, ignition, manifolds, retro look for hot rod etc.

 

[lexplay]

looks good to me man a carby tuned right can run just as good as fuel injection in my mind. i got a mk2 escort wich i was thinking of putting a 1uz in and run twin 4 barrel holleys, a port job and raise the compression a little. i think it would be a cheap way of pulling a lot of horse power. and have a good burnout car.

 

[XR8tt]

looks good to me man a carby tuned right can run just as good as fuel injection in my mind. i got a mk2 escort wich i was thinking of putting a 1uz in and run twin 4 barrel holleys, a port job and raise the compression a little. i think it would be a cheap way of pulling a lot of horse power. and have a good burnout car.

Or four IDA Webbers ??? Even two of them????
8 motor bike carbs ??? Hmmm??
Its not so much the carb as I can see an issue ?? Its the even fuel distribution when going from efi to carb...
I'm sure there are manifolds for carb made for them in New Zealand

 

[jibbby]

Ha Ha Ha, Ok, people carb them out to break them in safely..Now that makes sense... I would think an experienced tuner would be able to dial in a stand alone ECU to break in a new built motor...Hmmm? Carb is the safest for sure though.....

390cfm carb is an eye dropper that's hillarious.... Is that a 4.0L 1uz you got there Cribbs?

A correctly made and fitted manifold should alow the Carb to distrubute the fuel evenly to each cylinder... Never thought I would see a carb setup on the 1uz-fe... This brings back fond and frusterating memories of backfires, rebuilding the carbs, jetting carbs, vacume assistant problems, choke problems, turning tiny carb screws to adjust the fuel mix, Eccel distrubutors, Holley and Edelbrock maniflods, etc... Oh the good ole days of the Carb'd SBC's...

 

[cribbj]

I would think an experienced tuner would be able to dial in a stand alone ECU to break in a new built motor...Hmmm?

Yeah, I thought so too; that was a $3500 mistake.

390cfm carb is an eye dropper that's hillarious.... Is that a 4.0L 1uz you got there Cribbs?

The one thing I don't want to do is overfuel this motor; been there and done that already. And remember, this is for breakin only - I'm not going to go WOT @ 7200 with it, so 390CFM should be enough for my purposes. There's no way I'm going to be trying for power with this manifold setup.

 

[XR8tt]

Yeah, I thought so too; that was a $3500 mistake.



The one thing I don't want to do is overfuel this motor; been there and done that already. And remember, this is for breakin only - I'm not going to go WOT @ 7200 with it, so 390CFM should be enough for my purposes. There's no way I'm going to be trying for power with this manifold setup.

Gulp..... Yea well?? Forget Webber's then Lol...

 

[Ian Neville]

Thanks guys for all your comments and inputs. The reason I want to change to a carby and non electronic ignition is very simple. I am in Thailand doing this sports car project and as the motor I have does not have an ECU I would like to make the car simple to work on as there are not a lot of motor parts here in Thailand for the 400 motor. I have an engineering business here so parts are not hard for me to make. The iginition system, any one got any thoughts on turning this back to a non electronic system ? The guys who use the motor in the stock car racing, does any one have a contact who I could talk to please. Thanks Ian

 

[rms]

Ian,
Have a talk to andrew K, he is in Thailand also and has an Autronic SM4. http://lextreme.com/forums/member.php?u=3864

An Autronic SMC stand alone only requires the crank trigger wheel to be modified (remove 4 teeth), a reluctor interface for the triggers, and 2 igniter modules to trigger the std coils, plus fit air temp sensor. The MAF is removed.

Wiring is pretty basic, and I can supply a map for a std 1uz.

To retain the auto gearbox you will need an electronic selector module to make it Tiptronic. It will not change gears without this control.
Kdog did make a batch and may be able to help

I think you would find an Autronic would be cheaper in the end and give better results.
You can download the software from the Autronic site. (SMC Autotune)
http://www.autronic.com/

Erol

 

[andrew k.]

Ian,
I believe we spoke on the phone before. Please contact me by PM if you wish. I happened to see a non-VVT-i engine in Pattaya last week. My twin turbo project is still a struggle to get completed. Slow but sure. Welcome to the site and let me know if you neeed anything.
Andrew k.

 

[lexplay]

i would be interested to know how this goes in the end as im keen to do a carby(or carbies)1uz conversions in one of my cars. after someone does it maybe they could do a thread on how they went about it.

 

[Ian Neville]

Hi Andrew, Sorry for the late reply. The motor you are talking about I purchased. Currently I am building a bench for it so I can set it up and run it. The problem is that the wiring is a bit of a mess so i thought that by having it on a test bench it would be easer to set up. I am also thinking about going with a carby and normal ingition to make things a bit simpler. The ignition has got me a bit worried but I am sure It can be worked out. My email is [email protected] if you want to talk out side this forum. Take care, Ian

 

[Ian Neville]

Thanks Erol, Thanks mate (I can supply a map for a std 1uz.) That would be good to have. I have finished my bench today and tomorrow I will mount the motor and start sorting out the wiring and generaly tidy the unit up. Have a great week end, Ian.