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 Post subject: From carbs to efi
PostPosted: June 26, 2019, 8:32 am 
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Joined: June 4, 2007, 5:49 pm
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Location: morin heights north of montreal qc
I have a engine from a lotus Europa its a Renault engine 1645 cc
it as twin delortos 45 with 38 venturies no ignition system i found a distributor with points that fits but the setup of the carbs is more for high revs usually 30 or 32 venturies it was tuned for high revs so probably wouldn’t be drivable a dayly i would need to change venturies and the jets wich is trial and error and i don’t have any so it ads up if i would have spare jets and venturies it would be nice but i don’t
So here’s what i thought i have a 4age engine wich is similar 1.6 4 cylinder ithought of using the the efi component and using them on the Europa engine
The distributor for the signal and injectors, tps, o2 sensor and stock ecu
Of course i would need to modify the distributor to fit the Renault engine and fabricate an intake
and since the toyota ecu ajusts the fuel by the inputs it should adjust itself
Please give me your thoughts or advice it would be appreciated
Also whe i got the engine there is a pulley on the cam with four magnets that where generating a signal for sparks there is no crank pulley to get signal from and i know the crank turns twice while cam turns once there were no sensors for the pulley when i got it
I am sort of stuck and need advice


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 Post subject: Re: From carbs to efi
PostPosted: June 26, 2019, 3:37 pm 
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Quote:
and since the toyota ecu ajusts the fuel by the inputs it should adjust itself


OEM ECUs have a verrrry narrow window they're allowed to operate in. Even something as simple as a change in cam timing can cause the ECU to get confused and give up.

If you're already fabricating an intake and ignition system, and if you'll need to modify the stock ECU program, you're probably better off going with a standalone ECU like a Megasquirt in the first place.

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 Post subject: Re: From carbs to efi
PostPosted: June 26, 2019, 5:02 pm 
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Joined: June 4, 2007, 5:49 pm
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Location: morin heights north of montreal qc
It was just an idea because i think it would be more reliable and less maintenance to go efi
I just got a distributor that fits this engine so im gonna try starting it to see how it runs but
I figured to buy all the parts would cost a lot especially if i have to try different jets chokes venturies

So the plan would be to sell the Dellortos and buy jenvey throttle bodies that fit my intake manifold with megasquirt
and used the aluminium pulley that runs off the cam with the magnets for the signal then i could
get it programmed to my needs


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 Post subject: Re: From carbs to efi
PostPosted: June 26, 2019, 6:39 pm 
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Joined: June 20, 2019, 12:34 pm
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The megasquirt can even handle distributorless ignition. It can use one of those sensors on the motor for timing. You would use a ED module, like used on a Ford motor, for the coil pack. There is a large user group out there for support.

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 Post subject: Re: From carbs to efi
PostPosted: June 26, 2019, 9:18 pm 
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Location: morin heights north of montreal qc
Attachment:
C721865B-E98A-4566-8EBC-6FBD7B44D7B0.jpeg
I did a little research i want to use my distributor that came with the engine it only distributes the sparks i wanna keep the original look of the engine with distributor and wires the only difference will be itb’s instead of carbs
I was looking at microsquirt wich is simular to ms2 but very affordable
The picture is of my distributor it came off a Renault Fuego wich had everything remote even vacuum
and the aluminium pulley with magnets that runs directly on the end of the cam


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 Post subject: Re: From carbs to efi
PostPosted: June 27, 2019, 2:32 am 
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Location: Under the weather. (Seattle)
If you're wanting to maintain the look of the engine enough to keep the distributor, as well as keep it more 'locost', have you considered using the existing Dellorto's as your throttle bodies?

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 Post subject: Re: From carbs to efi
PostPosted: June 27, 2019, 5:11 am 
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Joined: June 4, 2007, 5:49 pm
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Location: morin heights north of montreal qc
I did think about it
i heard of people doing it but i cant find any info on how to transform them
And they are 45 with 38 venturies so pretty big i would have gone with 40
my delortos have been rebuilt for vintage racing so they are like new never had fuel in them since rebuild so by selling them it would cover the cost of the itb’s and still have a few bucks leftover
I like the look of this engine so it would keep its original look except for itb’s instead of carbs


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 Post subject: Re: From carbs to efi
PostPosted: June 27, 2019, 9:56 pm 
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Your simple answer would be to just change the 45's to 40's and stay with carbs.
Also MUCH less expensive.
With so many guys going to EFI a set of 40 DCOE Webers can be gotten pretty cheap.
There are still enough guys looking for 45's it would probably end up about a even swap for cost.
Webers have better support than Dellorto, I learned that for certain when I rebuilt a set for one of my Alfa's and had to make a couple of parts.

As an aside, you wouldn't happen to have the five speed trans out of that Fuego? :mrgreen:
I've been looking for one a long time.

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 Post subject: Re: From carbs to efi
PostPosted: June 28, 2019, 6:04 am 
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Location: morin heights north of montreal qc
The problem with going from 45 to 40 is that first my carbs are freshly rebuilt the only problem would be to get the right size choke venturies and jets if i trade i might have to rebuild and doesn’t garanti that they won’t need new jets witch means i would end up at the same place or worst

To go with sidedraft the best solution woul be to find someone who as a box of jet choke and venturies for sale then i could find the right set up for the carbs

I need chokes 30 or 32 and they would fit my 45 dell
In the picture it shows what size choke fits on the 40 and 45
and my 45 could be detune very easily

It did not come with a tranny i know the ng3
Is a popular upgrade to the 336 if i see one ill let you know


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 Post subject: Re: From carbs to efi
PostPosted: June 28, 2019, 11:50 am 
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https://www.ebay.com/itm/Dellorto-40-DH ... SwRWZcNNn7

https://www.dellortoshop.com/contents/e ... loads.html

Start with the jet that comes with the venturi you want to use.

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 Post subject: Re: From carbs to efi
PostPosted: June 28, 2019, 4:11 pm 
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Joined: June 4, 2007, 5:49 pm
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Location: morin heights north of montreal qc
Do you mean start with what i have or
Get 32 venturies with jets to match

Choke 38 + auxiliary venturi
Idle jet 45
Main jet 150
Air corrector 170

But according to what i read
4x choke = main jet
Main jet + 50 = air corrector

according to this if i would put 30
chokes with 120 main the rest would be ok
Idle goes by cylinder size and air corrector is 50
More than main so 170

I was thinking more like 32 chokes and 128 mains


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 Post subject: Re: From carbs to efi
PostPosted: June 28, 2019, 7:18 pm 
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Unless you are doing a full-on race car 45's are just wrong for your engine.
You could try to tame them but getting them to work throughout the full rev range will be a chore and ultimately unlikely to make you truly happy.
ALFA GTA got away with 45's, and 30mm chokes with 4.50 aux venturi's, but they were race cars.
Alfa 1750 used two 40's, and 32mm chokes with 4.50 aux venturi's on thousands of street cars.

Going EFI will cost more and be much more complex than NEW Webers which can be ordered already choked and jetted for your engine.

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 Post subject: Re: From carbs to efi
PostPosted: June 28, 2019, 7:44 pm 
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Location: morin heights north of montreal qc
I didn’t think it would make a difference 40’s or 45’s from what i was reading
the difference is in what you put in as choke venturies and jets
I figured if its got the same setup inside it should produce the same output
and i can get 28 chokes for my 45’s so they can be detune
Usually this engine as 32 chokes
and came in the lotus Europa with weber45 sidedraft or 2 dhla 45 Dellorto ‘s


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 Post subject: Re: From carbs to efi
PostPosted: June 28, 2019, 9:48 pm 
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califkid_66 wrote:
Do you mean start with what i have or
Get 32 venturies with jets to match

Choke 38 + auxiliary venturi
Idle jet 45
Main jet 150
Air corrector 170

But according to what i read
4x choke = main jet
Main jet + 50 = air corrector

according to this if i would put 30
chokes with 120 main the rest would be ok
Idle goes by cylinder size and air corrector is 50
More than main so 170

I was thinking more like 32 chokes and 128 mains


I suggest matching similar applications with the same venturi. For example, a Lotus Seven 1500 with A2 cam and 40 DCOE uses 33 venturi, f16 emulsion tube, 115 main, 160 air corrector, 45 idle jet, 35 pump jet, light pump spring with the short rod, 8.5 float level, and 200 needle.

There is a chart for determining venturi size based on a single cylinders cc and rpm range. In this case, 1565/4 for about 400cc and max power at 6000, is about 33v. I think 33v, 160ac and 115m would work well or at least get you in the park.

I suggest getting a book for tuning webers or dellortos like Brooklands, ISBN 10: 1855207591

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Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12


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 Post subject: Re: From carbs to efi
PostPosted: June 29, 2019, 10:21 am 
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Joined: June 4, 2007, 5:49 pm
Posts: 44
Location: morin heights north of montreal qc
I read that chart and i know that engine was built to use in vintage racing but i didn’t know what was inside so my first step was to see how the carbs were setup then i removed the intake and saw it was ported and polished then removed the head to know exactly what pistons
and according to the chart this engine is setup to rev at 7000 rpm the block is cleon alu all the internals come from a r17 the head is a Renault Gordini head
I want to use this engine on the street
So im gonna order the chokes and jets you mentioned i found a place called eurocarbs would cost me about 99 pounds delivered at my door four chokes and four main jets and I’ll start with that
My kid is more efi so i can use is wideband to help tuning it but that’s another story


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