My daughter has a 1.4 R12 and its got all the pollution stuff on it and it runs OK but... I'm sure it could run better and use less fuel with a bit of the crap removed. Any ideas where to start or should I just leave it?
How to make a 1.4 R12 go faster
- Thread starter markm
- Start date
Mark,
Without overstating the obvious, small to medium size cars, with engines of 1.5 litre or less, need to be in a good state of tune to maintain economy and performance.
The R1.3 & 1.4 engines are no exception. However, they are renowned for long term reliability, ruggedness, and usually good economy (38-40 MPG) for open road driving.
If all the obvious items have been attended to (tappets, points, condenser, plugs, breather and vacuum hoses, air filter etc), then there is one other item which you can check.
The air filter uses a thermostatically controlled flapper valve to direct heated air from the exhaust manifold to the air filter. This device operates on induced ambient air temperature, and should be fully open with air temperatures above approx 15 degrees C (from memory). Don't forget this will include the under bonnet air temperature, and the rapidly rising heated air from the exhaust shroud.
The purpose of the air pre-heating is to eliminate carburettor throttle icing, which the Weber carburettor is susceptible to, given the right atmospheric conditions. Symptoms include progressively worsening rough running during open road cruising, gradual power loss, and finally, engine stoppage. The ice will melt after a minute or two, and the engine can be restarted.
The reason for mentioning this device, is that I have yet to see one which is not either seized, or simply not functioning. This means that the engines is breathing air which is extremely hot, causing a drop in volumetric efficiency (similar to driving up to a high altitude mountain in a non turbo car). It also means that the less dense air has less Oxygen, and therfore the fuel air ratio is richer, hence poor economy.
The simple solution is to remove the air filter, and permanently lock wire the flap to the cold air position. Then, replace the filter, and discard the flexible heat hose (if still fitted) joining the exhaust manifold to the filter intake.
A better solution is to manufacture a good cold air box, or get an after market sports filter. However, I would be wary of that option if you drive on dusty roads.
You may have seen other models of cars which have a manually operated valve on the filter, with positions marked Summer and Winter. Much more reliable, provided you remember to re-set at the appropriate time!!
The chances of carburettor icing occuring cannot be accurately predicted, as even a mild morning in foggy conditions may produce this condition. However, it nearly always needs, firstly, constant throttle, low power cruising for icing to occur. I can explain this further if you wish.
Similarly, for piston engined aircraft (with carburettors), this incident remains a concern for all pilots.
Hope this information is useful.
Cheers,
Kim.
Without overstating the obvious, small to medium size cars, with engines of 1.5 litre or less, need to be in a good state of tune to maintain economy and performance.
The R1.3 & 1.4 engines are no exception. However, they are renowned for long term reliability, ruggedness, and usually good economy (38-40 MPG) for open road driving.
If all the obvious items have been attended to (tappets, points, condenser, plugs, breather and vacuum hoses, air filter etc), then there is one other item which you can check.
The air filter uses a thermostatically controlled flapper valve to direct heated air from the exhaust manifold to the air filter. This device operates on induced ambient air temperature, and should be fully open with air temperatures above approx 15 degrees C (from memory). Don't forget this will include the under bonnet air temperature, and the rapidly rising heated air from the exhaust shroud.
The purpose of the air pre-heating is to eliminate carburettor throttle icing, which the Weber carburettor is susceptible to, given the right atmospheric conditions. Symptoms include progressively worsening rough running during open road cruising, gradual power loss, and finally, engine stoppage. The ice will melt after a minute or two, and the engine can be restarted.
The reason for mentioning this device, is that I have yet to see one which is not either seized, or simply not functioning. This means that the engines is breathing air which is extremely hot, causing a drop in volumetric efficiency (similar to driving up to a high altitude mountain in a non turbo car). It also means that the less dense air has less Oxygen, and therfore the fuel air ratio is richer, hence poor economy.
The simple solution is to remove the air filter, and permanently lock wire the flap to the cold air position. Then, replace the filter, and discard the flexible heat hose (if still fitted) joining the exhaust manifold to the filter intake.
A better solution is to manufacture a good cold air box, or get an after market sports filter. However, I would be wary of that option if you drive on dusty roads.
You may have seen other models of cars which have a manually operated valve on the filter, with positions marked Summer and Winter. Much more reliable, provided you remember to re-set at the appropriate time!!
The chances of carburettor icing occuring cannot be accurately predicted, as even a mild morning in foggy conditions may produce this condition. However, it nearly always needs, firstly, constant throttle, low power cruising for icing to occur. I can explain this further if you wish.
Similarly, for piston engined aircraft (with carburettors), this incident remains a concern for all pilots.
Hope this information is useful.
Cheers,
Kim.
Thanks Kim, After I posted my question I did just that and jammed the flap on cold it was stuck sucking hot air. It runs much better, I also pulled the carby apart and blew all the jets out and that seems to has had a likewise good effect. Checking the points after the "mechanic" set them showed them to be 15 degrees of dwell out although he did have the timing right. The car seems to run quite sweetly now the only thing left which every 12 I've owned has had is mushy steering but I don't think that will be that easy to fix.
Hi Mark,
Glad you have got a few tuning problems sorted out. A common mistake with the dwell setting is not correctly identifying the distributor type. The Bosch distributor has a different dwell setting to the Ducelier.
Whilst the 1.4 engine should have had a Ducelier as standard, over the years some of those have been replaced with a Bosch equivalent.
Regarding the handling and steering, I can say that the fitting of R15 / 17 sway bars front and rear make a huge difference, especially to body roll. The bars are interchangeable, needing only the larger clamp rubbers for the front bar, which may in good condition when you acquire the 15 / 17 bar anyway.
R18 steel or mag rims will also help, giving another .5 inch rim width. Just be sure that you do not have the R1.4 wagon rear axle, otherwise the track will be too wide with the R18 rims, causing tyre rubbing.
Cheers,
Kim.
Glad you have got a few tuning problems sorted out. A common mistake with the dwell setting is not correctly identifying the distributor type. The Bosch distributor has a different dwell setting to the Ducelier.
Whilst the 1.4 engine should have had a Ducelier as standard, over the years some of those have been replaced with a Bosch equivalent.
Regarding the handling and steering, I can say that the fitting of R15 / 17 sway bars front and rear make a huge difference, especially to body roll. The bars are interchangeable, needing only the larger clamp rubbers for the front bar, which may in good condition when you acquire the 15 / 17 bar anyway.
R18 steel or mag rims will also help, giving another .5 inch rim width. Just be sure that you do not have the R1.4 wagon rear axle, otherwise the track will be too wide with the R18 rims, causing tyre rubbing.
Cheers,
Kim.
Mark, the steering should definitely not be mushy; check the rubber bushes in the end of the rack where the tie rods connect. Critically, also check the uni joint inside the car about 25 cm up from the floor. I have new bushes on the rack and a new uni joint (Caravelle has them) on mine and the steering is pin sharp. Oh, and I run 32psi front cold, 29 back, but I have hard springs on the back (wagon). With stock springs I ran 32 all round.
Stuey
Stuey
THanks Guys I will check the bushes and the uni and the tyre pressures are already about 30 (funny how that is the one thing I can't do in Metric)
Or, replace the air filter housing with one that doesn't have the heat control flap. There appear to be plenty of the simpler air filters around.
Say, does anyone know why the air filer housings are so large. The filter element itself is less than half the length of the housing.
Is there some technical reason to make them that big or was Renault simply trying to fill up the space under the bonnet.
Ren cheers!
The Renault 16TS has the manually operated summer/winter flap. Works nicely. And since the R16TS filter system is designed to fit a two barrel Weber, it may even fit straight on to the R12 carby. That's only a wild guess, though, since I don't know what the top of the R12 1.4 carby looks like.
As for the steering problem, the above suggestions are good, but there is one more which I would like to add, and that is to check the top wishbone's inner bushes. The top wishbone is on the same plane as the steering rack, so any wear in its bushes will have the same effect as having worn steering arm bushes or a worn rack. This is a common problem on R16's and it makes a huge difference to the steering.
<small>[ 25 February 2003, 11:29 AM: Message edited by: frogs4ever ]</small>