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Alpine 1968 Renault R8

  • Thread starter Thread starter Adey
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Well done, tedious steps I think, we have been these in some form or other with these cars, regarding the idle have you considered a new 1397 Weber idle jet from Weber [ Fast Road Cars Ltd.] as the R8S 1108 one must be too small?
Cheers
Dave
 
I will defo look into jetting and such once I can run it for a while. It may well be too small though actually seemed very willing to run as is. The French team r8 forum has lots of jetting info for the carb on different engines so I should be able to find a very good base to go from. That said I'll hopefully check how it is as is. Essentially if it's pulling in more air from being a bigger cc it should also pull in more fuel. I don't think it'll be a million miles off.

I also have the 1397cc weber here so may be able to pillage parts from that

First is being able to idle and warm it up without making my ears bleed 😁
 
Engine specifications
- Displacement : 1108 cm³
- Engine origin : R8S
- Camshaft : Origin
- Additional details :

Weber 32 DIR
- Your assembly
: 32 DIR 4
- Filtration : R8S air box
- Centering device - Body 1 : 4.5
- Centering device - Body 2 : 4.5
- Diffuser - Body 1 : 23
- Diffuser - Body 2 : 24
- Emulsion tube - Body 1 : F9
- Emulsion tube - Body 2 : F9

- Main jet - Body 1 : 125
- Main jet - Body 2: 125 - Air jet - Body 1 : 160 - Air jet - Body 2 : 150 - Idle jet - Body 1 : 50 - Idle jet - Body 2 : 60 - Accelerator pump jet : 40

- Needle : 175
- Float weight : 11 gr
- Tank level : A = 7 mm
- Float stroke : B = 8 mm

Engine characteristics
- Displacement : 1397 cm³
- Engine origin : R18 GTL
- Camshaft : Original
- Additional details : Lightened and balanced connecting rods - Planed cylinder head

Weber 32 DIR
- Type : 32 DIR 21T
- Filtration : R8S air box
- Centering device - Body 1 : 3.0
- Centering device - Body 2 : 4.5
- Diffuser - Body 1 : 23
- Diffuser - Body 2 : 24
- Emulsion tube - Body 1 : F53
- Emulsion tube - Body 2 : F6

- Main jet - Body 1 : 117
- Main jet - Body 2 : 110
- Air jet - Body 1 : 135 - Air jet - Body 2 : 100 - Idle jet - Body 1 : 53 - Idle jet - Body 2 : 60 - Accelerator pump jet : 55
Engine characteristics
- Displacement : 1397 cm³
- Engine origin : R18
- Camshaft : Origin
- Additional details :

Weber 32 DIR
- Your assembly
: 32 DIR 21
- Filtration : Cobra head without air box
- Centering device - Body 1 : 4.5
- Centering device - Body 2 : 4.5
- Diffuser - Body 1 : 23
- Diffuser - Body 2 : 24
- Emulsion tube - Body 1 : F9
- Emulsion tube - Body 2 : F9

- Main jet - Body 1 : 125
- Main jet - Body 2: 125 - Air jet - Body 1 : 160 - Air jet - Body 2 : 150 - Idle jet - Body 1 : 50 - Idle jet - Body 2 : 60 - Accelerator pump jet : 40

- Needle : 175
- Float weight : 11 gr
- Tank level : A= 7 mm
- Float stroke : B= 8 mm

Engine specifications
- Displacement : 1397 cm³
- Engine origin : R12
- Camshaft : Original
- Additional details :

Weber 32 DIR
- Your assembly
: 32 DIR 21T
- Filtration : R8S air box
- Centering device - Body 1 : 3.5
- Centering device - Body 2 : 4.5
- Diffuser - Body 1 : 23
- Diffuser - Body 2 : 24
- Emulsion tube - Body 1 : F53
- Emulsion tube - Body 2 : F6

- Main jet - Body 1 : 117
- Main jet - Body 2 : 110
- Air jet - Body 1 : 135 - Air jet - Body 2 : 100 - Idle jet - Body 1 : 53 - Idle jet - Body 2 : 60 - Accelerator pump jet : 40


- Needle : 175
- Float weight : 11 gr
- Tank level : A= 7 mm
- Float stroke : B= 8 mm
 
What you're looking for is the choke size, they are calling it the Diffuser, they all appear to be 23/24 then the Emulsion tube/main jet/air jet/idle jet.
Changing the emulsion tubes changes the main jet/ air jet relationship considerably in some cases, so there is no pattern there.
The bigger motor will have a stronger signal (more pull) but depending on cam timing and loads of other details determines how the engine breathes through the range.
Leave it alone and go to your mates rollers, then see whats happening AFR wise and where about, before just changing things.
You can see what I'm on about if you look at the first 2 of your examples
The 18gtl used a slightly smaller main, with a much smaller air and different emulsion tube from the 8s. 23 choke 125/160 main/air F9 tube (8s1100) then 23 choke 117/135 main/air F53 tube.
The f numbers are not in any other order than when they were invented, just incase you were wondering. They alter the emulsion through the range and have characteristics rather than anything more definite.
Enjoy
 
Dyno is defo on the cards once running sweet (y)

And we are very close to being able to run up. I'm roughly measuring 2.5meters from head to tip. I decided to go the opposite way to most I've seen and then back on itself and then across the back of the car. Not going to look to closely at the welding, it will do, and with the exhaust wrap on it wont be seen. V-band connection to the manifold and then mounted the box to the engine brace so the whole thing moves as one and solid. Now its 2 bolts to drop the whole thing off.

cant wait to hear what it sounds like :D

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Solid work as usual mate. Suprisingly quiet for short exhaust and one silencer.

Afr gauge and sniffer clamp out for carb jetting ;)
 
Solid work as usual mate. Suprisingly quiet for short exhaust and one silencer.

Afr gauge and sniffer clamp out for carb jetting ;)
Cheers bud, I was shocked how quiet it was still sporty though, the 4-2-1 mani and extra loop of pipe has added a decent length to it.

Should be on the dyno this week after a few test miles (y)

Roll on 60bhp 🤣 🤣
 
Wrapped up a few bits after work today, fitted the right hand engine cowling, the left wont go due to the tubular manifold. Hopefully it doesn't cause issues with cooling... Oil and filter changed this afternoon. Spark plugs changed last week. Seems to idle nicely even without a working choke. Will put a few miles on it and bleed the coolant system ready for Friday. I've ordered a filter for it, no one seems to list one for the carb so I've got a "blank" one from ramair on its way. Hopefully its not too big. Plan on the dyno is to stick a probe up the exhaust, have a listen to it and tweak the timing a touch if it'll allow it. Being a dizzy and points its pretty fixed with the curve currently but we can get it in the best place possible.
 
@Adey see if you can find the total advance for the dizzy that's in it, from the manual for the car, that had the engine, that had that Dizzy. You are going to end up between 32-36 degrees advance at 5000 rpm, it might take more. It depends on loads of variables. Most likely Dizzy's give between 12 and 18 degrees advance, remember for Dizzy figures to multiply by 2. This means between 24-36 degrees at the crank. For example a 36 degree total advance Dizzy would be statically timed at tdc as it will give 36 deg of advance at full power/rpm. A tighter 24 degree Dizzy would be at 12 deg static to give 36 deg at Max. how it does it depends on the 2 springs controlling the weights. some are linear, some throw on a lot (soft spring) followed a steady increase (stiffer 2nd spring) You can weld the stops and change springs to get what you want, but a dizzy dyno is needed. Salv's yer man as this is a particular field he has experience in, as well as the kit. Done properly it is surprisingly good. The vacuum line has no input on high power throttle openings, it is used on light throttle medium rpm to give extra advance at lower power settings to give better economy when cruising.
This is why side draughts don't have a vac line as the cylinder filling on part throttle (light) is much better and there is much lower vacuum. The engines light throttle operation is much better, so it's economy is good without need for vacuum trickery devices. I always have a quiet laugh to myself when people talk about bad fuel economy on Sidedraughts. What that means is it is not set up properly, as done correctly it is excellent. All my race motors were capable of 30+ mpg cruising.
 
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