Going from EFi to carb, what goes where?

[Risky]

Hi
Initially it was going to be Efi, that's how the donor came but as usual things change!
What may be easy to some seems a bit harder to others, ie me!! so bear with me on my struggle to fit this together.

I need to know how and where to join the hoses. I've read a fair few threads on here and now it seems just a bit more tricky. I want to get it right and the best set up I can.
Pictures should help with descriptions so here goes. Any advice greatly appreciated.


Thermostat housing and I take it Top hose goes to top of Radiator. The small pipe off bottom is differant/not there on the Efi one? What is it, where does it go?
Connection coming up out of the inlet (between the looped rubber hose) what and where to run it?



2 connections out the rear of water pump. These connected to a pipe that ran under the EFi manifold and out the back to what I assume fed the heater? What and where to connect to now? There appears to be nothing to remount the pipe that runs underneath the inlet manifold?


Rear of manifold...obviously something missing, what and where does it go to?



These hoses are running under the Efi manifold, do I re-use them or is it a case of re plumbing. I read that the steel tube can rust away so best change it/mod it?


What gets used from here?

Apologees for what to you guys may be easy but i've never attempted anything like this before so i'm learning as I go. THANKYOU.
Phil.

[ChrisJC]

Connection under top hose outlet = thermostat bypass. Connect to rear of water pump.

Connection 'in rubber loop' = brake servo vacuum feed.

You are missing a plate from the rear of the manifold. That will give you a feed for the heater.
The heater return you will have to improvise to connect to the other connection on the rear of the water pump.
Later EFi engines used a steel pipe that ran above the rocker cover with a nice bleed port.

Chris.

[Risky]

Connection under top hose outlet = thermostat bypass. Connect to rear of water pump.

Connection 'in rubber loop' = brake servo vacuum feed.

You are missing a plate from the rear of the manifold. That will give you a feed for the heater.
The heater return you will have to improvise to connect to the other connection on the rear of the water pump.
Later EFi engines used a steel pipe that ran above the rocker cover with a nice bleed port.

Chris.

EXACTLY WHAT I THOUGHT!!

Cheers Chris, thanks for that.
I'm now have the dilemma of what system to go with...Carbs or back to the original Efi?

The guys on here that know these motors inside out seem to agree that the carb route will not be the 'easy' option that at first it seems.
I'm a novice and by no means a mechanic, I'm told various things in favour of both.
Efi seems more wires, but then It's only 5 wires?...plug and play I believe is the term for the system I have.

Carbs...surely they too can be set up with what has previously been used on a basic 3.5 motor?

I'm going off topic here, sorry.
Just a bit confused...easily done at my age!
Cheers again for info/advice.

[ChrisJC]

Flapper EFi is only 5 wires, and it's self contained.

The problem comes when an an EFi system doesn't work. Although I have never been unable to diagnose a problem, some people find it more difficult than others. I suspect me having a degree in electronics helps understand how it works.

Personally I would go EFi, but if 'lectrics scares you, carbs are better.

Carbs run well enough all the time, EFi runs perfectly or not at all!

Chris.

[Risky]

Flapper EFi is only 5 wires, and it's self contained.

The problem comes when an an EFi system doesn't work. Although I have never been unable to diagnose a problem, some people find it more difficult than others. I suspect me having a degree in electronics helps understand how it works.

Personally I would go EFi, but if 'lectrics scares you, carbs are better.

Carbs run well enough all the time, EFi runs perfectly or not at all!

Chris.

Cheers Chris... I'm right torn between the 2 now. I respect the guys on here with the knowledge and experience in the systems.

Efi system is not really scary, it's just that I kinda like the look of the traditional carb and shiney air cleaner. I know the EFi is way more precise and no doubt smooth all the way through the rev range and more economical...BUT..... It's my toy, I won't be using it as a daily drive, It wont be going up the quarter mile, nor doing flat out on the motorway, not interested in any of that.

All I want is.
Bimble around.
Easy tinkering about with a bit of setting it up. I have a guy that can do carbs, builds big yanks and motors, well on the ball.
I'm not worried about economy.

I can always put the Efi system on it at a later date.
Thanks again, I'm just trying to convince myself that carbs are more than adequate for my motor and that all the other motors that run carbs seem to do so well enough, why should mine not?

[DaveEFI]

Snag with the early EFI systems is they can't practically be re-mapped for a modified engine.

Also, the flapper is a precision built bit of gear which needs to be on spec to do its job. As does the ECU. Both can give problems with age. Injectors too.

But then a carb wears out too. And can be difficult to set up perfectly on a modified engine. Just the same as a dizzy.

The answer is a MegaSquirt which is an easier fit to the RV8 using the original injection parts than to some other engines. You can then alter both fuel and ignition maps from inside the car on a laptop with just a few keystrokes - rather than messing about with jets and springs.

[kiwicar]

Hi
I've posted about this before, but if you decide to go 4 barrel they need to be pretty much brand new to work well, they are built down to a price in a way that makes even a stromberg look engineered for life, the materials are very cheep low grade alluminiun/zinc alloys that rot if fuel is left in them to dry out, the dies they are injection cast into are used until they are well past worn out and if any part will fit in it's given hole it is used. They are designed to last for the warrenty life of a US car of the 1980s, fir at the factory, run every day for 75k miles, then buy a new car, most US cars of that generation were chuched out by 5 years/ 100k miles old, this is why the manufacturers could offer 5 and even 8 year warentys, they knew that no one kept a car that long so (the warenties offered are only first owner) so they would never have to be honoured.
Best regards
Mike

[Risky]

Snag with the early EFI systems is they can't practically be re-mapped for a modified engine.

Also, the flapper is a precision built bit of gear which needs to be on spec to do its job. As does the ECU. Both can give problems with age. Injectors too.

But then a carb wears out too. And can be difficult to set up perfectly on a modified engine. Just the same as a dizzy.

The answer is a MegaSquirt which is an easier fit to the RV8 using the original injection parts than to some other engines. You can then alter both fuel and ignition maps from inside the car on a laptop with just a few keystrokes - rather than messing about with jets and springs.

Hi Dave
Thanks for your input.

I have a bog standard old 3.5 V8 motor. it is and will never be tuned or highly modified.
It is going in an old Toyota Hilux that will bimble around at probably no more than 30 to 40 or maximum 70mph on a motorway in 5th gear...probably slower with the window down just listening to the exhaust note.

The Carbs are BRAND NEW. I will probably cover less than 3000 miles a year...if that.

I'm sure a carb set up the best as reasonably can be will give me no major hassles and the occasional bit of fine tuning if needs be, or am I missing something?

[DaveEFI]

Well, Rover fitted EFI on the Vitesse long before emission regs made it necessary. And since they already owned a carb maker, I'd say that speaks for itself.

If you insist on sticking with carbs and it's for a standard engine which will only potter around, I'd go for the standard SU set-up. They're a much better carb - apart from perhaps maximum power.

[kiwicar]

Mike

[ChrisJC]

I bet you wish you'd never asked!!

If you like the look of the yank carb, and have all the bits, then fit it. It'll work well enough for what you want, and there are plenty of places that can set it up for you (I'm sure a few folk on here have one and can advise on jets etc).

It does fit the Keep It Simple philosophy.

You can always then put together an EFi kit over time to suit any longer term goals, and lots of people on here have tried the various systems.

Chris.