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845cc R6

DFigueira

Enthusiast
Messages
10
Location
Portugal
#1
Hey guy's,

I've recovered a fully restored 845cc engine from a R6 that was in a junkyard (couldn't bring the car but it was fully restored... don't know why would someone do that).
I've heard that these engines are peppy compared to other R4 engines and the R4/R5 845cc and considering that my original 852cc engine on my R4 is completly dead I'm going to put this on it.
My question is - since this is the sturdiest engine on the ventoux family, can it take a little more power/abuse? Are there bolt ons that I could put without hurting it? I'm going to do some work on the car to take some of its weight out to help too.
I've considered a double barrel carb with a larger admission (R5?) and probably some kind of air filter (if there is any?) and custom headers and exhaust with a resonator.

This is for a Barn Find 73 R4 to drive daily.
 

harbourseal

Renault R4 Lunatic
Messages
731
Location
Breda The Netherlands
#2
You can put an oversized carb on the small engine, but if you don't do something with inlet valves it won't do any good.

A 32mm carb will give you some more power without having to do something about camshaft and valves.

The 845cc engine is a long stroke engine with good torque at low revs. It’s not a powerhouse.

I don’t think that you will be able to find an manifold that fits a 845 engine with the inlets for a double barrel carb.

But maybe someone has made one.

Good luck with the modifications.

Robert
 
Messages
10
Location
Portugal
#3
You can put an oversized carb on the small engine, but if you don't do something with inlet valves it won't do any good.

A 32mm carb will give you some more power without having to do something about camshaft and valves.

The 845cc engine is a long stroke engine with good torque at low revs. It’s not a powerhouse.

I don’t think that you will be able to find an manifold that fits a 845 engine with the inlets for a double barrel carb.

But maybe someone has made one.

Good luck with the modifications.

Robert
I feared that. Double carbs were just an idea since I saw a couple of them being sold so cheap but I feared that they would just sent more gas for nothing.

So the best thing would be a 32mm carb. If the engine comes with a Solex, should it be a Solex 32? The 852cc had a Zenith 28iF so I'm deducting those changes... and would I need a different manifold?

This is mostly as a daily project. I know its no powerhouse but I kinda like to go fast in a slow car and it will carry a few things to camp around the country so it needs to climb :D

Btw, 845cc engine would have a 'redline' of what? 5.5/6k? Maximum power is rated at 5k but I will be setting a limiter to be at its 'redline' in order to not go over and damage any internals.

Thanks!
 

harbourseal

Renault R4 Lunatic
Messages
731
Location
Breda The Netherlands
#4
If the Engine is from a R6 it probably has a Solex 32 carburetor with a matching manifold.
You can ad some power though. I raised the compression a bit by shaving a little off the cilinderhead.
I also shaved about 900 grams of the flywheel and had it balanced to the crankshaft.
By putting on a spaghetti manifold en polishing the outlet ports you'll be able to coax some more power out of the engine.
 

mr-reno-139

AKA Paul Cunningham
Messages
1,888
Location
lancing west sussex england
#5
Don't forget this engine was designed in 1950 with a 3 bearing crankshaft when pottering along was the aim of the game although the Dauphine Gordini modifications did improve matters by the time the 70s arrived the Renault 6 version was probably the most reliable version people have put superchargers on these if you're feeling really adventurous but it may not last long
 
Messages
10
Location
Portugal
#6
Things are rare around here, so my idea was only to have bolt ons and when the engine decided to die on me for any reason, I would swap for a stronger version.

How much agressive is the gordini engine on the dauphine compared to the R6 if they have +/- the same hp?
 

mr-reno-139

AKA Paul Cunningham
Messages
1,888
Location
lancing west sussex england
#7
Although the Dauphine engine is very similar it runs in the opposite direction so camshaft etc can't be used I'm definitely not an expert on this as I would always have converted to the 5 bearing crank engine used in the later 1100 which gives you options to then change to Gordini if you're feeling really silly
 
Messages
10
Location
Portugal
#8
Although the Dauphine engine is very similar it runs in the opposite direction so camshaft etc can't be used I'm definitely not an expert on this as I would always have converted to the 5 bearing crank engine used in the later 1100 which gives you options to then change to Gordini if you're feeling really silly
Ill stay with the one I have for now :P

As long it sounds fast, it will be fun :drunk:
 
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