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Renault/Continental R engine 839-46

Laurie

Enthusiast
Messages
26
Location
Australia
Hello, As i explained in the introduction section, I have a Toro Groundmaster 72 lawnmower with a continental R engine. I would appreciate any advice you Renault enthusiasts may be able to give me.

A couple of years ago I picked up this old mower fairly cheap, it was great at the time after recently having a horse die and needing something fairly sizable to cover a few acres.

When i purchased it i expected to have to do some maintenance work. I actually checked under oil filler cap and spotted condensation and thought it wouldn't be long before it needed a head gasket...either way it was cheap enough that i would be happy if it just got me through the next year..

So its done a couple of years now and i'm very happy with it as a mower and would like too do some resto work on the machine.

I started having some problems with it running right a few months ago with various symptoms that led me to believe its time i done the head gasket...got to the point where even after new points, cap and rotor I just couldn't get it to run right, particularly under load where it would blow some white smoke.

Now i began disassemble today, with the intent of removing the head and cleaning and preping everything, after inspecting for any major problems..i intended to then order a full gasket kit...

The first thing i removed was the manifold and noted as well as badly worn inlet/outlet gasket, a small pool of water sitting inside one of the inlets of the head...

Now the machine was sitting outside for a few weeks with the engine uncovered during some pretty heavy showers, so i'm wondering if there is a chance that water has found its way in through the bad inlet gasket, though it really only looked like the exhaust sides of both gaskets were damaged..

I'm wondering if white smoke under load could mean the engine was sucking condensation out of the air rather then water leaking through head gasket...

Ive done a cold comp test and found cylinders all to be between 110 and 120 psi. As i said i had intended to do the full job but i know there is a little more to these that a simple cast iron block and don't want to go that way if i don't have too...

At the moment i'm thinking i should just start with replacing inlet/outlet gasket and see how i get on from there, but if i go the full head gasket change what em i up for?...would it be a good idea to replace or rebuild water pump whilst i am in there?...

So yes...I hope i have included enough information and look forward to any advice you guys may have..thanks.
 

Geoff in the Gully

Getting it together
Messages
281
My last engine gasket kit was around $55 a year or so ago. That includes manifold, head, waterpump, sump etc.
In case you're wondering, big end and main bearing sets around $25-30 each.
Piston, rings, liner kit - $330 odd. Though that was for an 845cc kit rather than the 782 higher compression used on the 839 engine. And a 'get this waste of shelf space out of here' price.
All this from Caravelle Imports in Box Hill - they might not have any left though now (change of management and 'business direction').

I concur with your idea of trying a replacement manifold gasket - I'm not hopeful of success but it's a cheap easy trial and you never know your luck.

'Under load' is a key point. If it was condensation you're seeing in the inlets, I would expect to see the white smoke mainly on start up and then disappear.
Under load suggests the water is being sucked into the cylinder with some force. It doesn't take much if a hole between water channel and cylinder to let water in.

The compression figures you're getting seem rather good but I'm used to those for the engines with 8:1 compression ratio rather than the 839's 8.5:1 ratio. So they might be down a bit.
The more important factor is whether one cylinder (or two adjacent ones) are markedly lower than the rest. If so there's a head gasket issue. If not there could still be a small leak enough to suck water in but not make much difference to compression. A 'leak down' test is what's needed for this.

These engines can experience corrosion in the water channels in the head. My guess is that this is the case and that the head gasket has given way, first, between water channel and ports. This then progress to gap between water channel and cylinder. Actually, writing makes me think it could just be a leak between water channel and inlet port as that would put water into cylinder also. The head gasket is clamped most tightly around the cylinders and there's a metal seam around the cylinder bore hole. It seems to me that the gaskets tend to give way around water channels first.

Now about the water pump. There's only ever been two things that have given me grief in stripping these engines and that's the water pump and the water pump.
It's held on by long thin (7mm?) studs with little nuts on them. The combination of alloy and steel and water tends to lead to corrosion of the stud and nut. It's common for a frozen nut to break the stud. Lots of WD40 or equivalent and time - a long soak to start with. Even when the nuts are off, or broken, the hole through the water pump body fills up with corrosion - some sort of salty mineral - and jams the pump body so it won't lift off. It can take a lot of time and care to get the bugger off. My last effort was my worst and I eventually resorted to the help of Mr Angle Grinder, not so fatal as I knew the pump body was already cactus which was why it was coming off. You can still get new ones from various places (assuming the mower has the same pump as car ...).

And don't believe the manual, you can recondition the water pump. There's secret tricks to this of course...

I don't suppose you have a workshop manual for the beast?

Bon Chance
 

Laurie

Enthusiast
Messages
26
Location
Australia
Thanks for your reply mate, I know it seems like a long shot just replacing manifold gasket, but as you know the weather here is quite lovely at the moment so wont hurt to spend a day messing around with it...I picked up some gasket material from supercheap this morning , i will make up some new gaskets and see how i get on from there..
If it was an old holden block i would have no hesitation in replacing head gasket just for good measure, but i can see after scanning a few threads here its not that straight forward...I have found a workshop in sydney i have been able to get some parts from though i suspect he probably sources them from someone here anyway...

I dont quite understand the way the liner seals work in relation to the head gasket...they are just a fine adjustment to insure head gasket is properly sealed? the head gasket sits directly on top of them?
I have found a workshop manual for this engine which i have downloaded...I am the type of bloke that likes to do things right, but i am on a bit of a budget at the moment so hopefully there is nothing major wrong with this engine....I will see how i go today and possibly get some photos for you all.
 

Laurie

Enthusiast
Messages
26
Location
Australia
Got it all back together today, spent most of the afternoon going round in circles with electrical system...I gave up in the end, she just wouldn't fire..Ive got good spark...checked firing order, cant work it out...will have another go in the morning
 

mojobaby

Enthusiast
Messages
1,280
I dont quite understand the way the liner seals work in relation to the head gasket...they are just a fine adjustment to insure head gasket is properly sealed? the head gasket sits directly on top of them?
I have found a workshop manual for this engine which i have downloaded...I am the type of bloke that likes to do things right, but i am on a bit of a budget at the moment so hopefully there is nothing major wrong with this engine....I will see how i go today and possibly get some photos for you all.

Hi Laurie
My photo was probably quite deceptive as it shows the liner seals on top of the liner. I only placed them there for measurement purposes.
The liners themselves are loose fitting and can be removed from the block

The liner seals are positioned into the block first and then the liners are placed on top of them.

The liners have to protrude between ,04mm and 0,12mm above the block surface, which is why the liners seals come in 3 different tthicknesses. They are marked with red, or black or plain white.

The head gasket will therefore rest directly onto the liner itself.

The following photo shows the seals resting on top of the liner, but in reality they should be underneath.
The second photo shows the seal (with black stripe) placed in position in the block, before the liner is placed on top of them
I hope that is clearer explanation

DSCF6549.JPG DSCF6563.JPG
 

Laurie

Enthusiast
Messages
26
Location
Australia
that makes a lot more sense now, thanks Mojo!..I thought that this was the more likely scenario, though as you have picked up...your pictures led me astray! absolutely no experience with cylinder liners..the engineering makes sense..for the diy workshop....
 

Laurie

Enthusiast
Messages
26
Location
Australia
now i understand why you have clamped cylinders in before fitting head to check tolerance
 

Laurie

Enthusiast
Messages
26
Location
Australia
also thinking that its par for the course that these seals are doomed to fail the head gasket overtime...hmmm
 

Laurie

Enthusiast
Messages
26
Location
Australia
I will say though, that my oil is ok...not ideal, the machine has been treated like a lawn mower the last 20 odd years..no love...so its dirty...but not gummy...no mayo...the water in radiator is a little oily between the fingers..but not enough to concern me..this could be residue from a coolant.
 

mojobaby

Enthusiast
Messages
1,280
If you do decide to replace the head gasket, once the head is off, the pistons have to remain absolutely stationary.

If they move just 1mm, they could dislodge the liners and break the seal at the bottom. You're correct, that is the reason why I clamped the liners- to stop movement
 

Laurie

Enthusiast
Messages
26
Location
Australia
Good advice that, thanks..Ive actually found my engine manual that i have downloaded from somewhere, its a very good service manual but is specific to the mower..i think it would be very helpful to this forum and wonder if you guys have it..i will see if i can chase up a link for it as its a free download
 

Laurie

Enthusiast
Messages
26
Location
Australia
Had a little success today, seems the condenser is the problem...can anyone give me correct capacitance of stock condenser? I have replaced with another but isn't the right part..still running a bit rough but big improvement, I have many high voltage BP caps in my workshop as i mess around with vintage electronics..
 

Gsim

New Member
Messages
1
Location
USA
Laurie,
I just stumbled across this forum today. I too have a Groundsmaster 72 and I suspect it does have a leaky head gasket. Compression was 130-80-130-130 this spring. No gasket sets for my R08 Renault continental engine anywhere, including eBay. So reluctantly, I poured in a pint of Bars Leaks head gasket leak repair fluid. I ran it at idle for 15 min. Repeated a day later. It improved the running dramatically, not totally smooth, but very usable. However I had to clean radiator afterwards due to it running too hot. :laughing: Got that fixed, and it is definitely going to cut my grass ok as it is for now. I will make another compression test to see if or how much it improved. I still want to pull head and install new head gasket and cyl seating gaskets. I'm 75 yrs old, and I figure it might last me another 15 yrs if I just get it properly repaired. I won't be mowing grass that long!:laughing:

Wondering if you know of any source for a gasket set for my Continental R08? I'm in USA.

Oh, by the way, the water pump for a Renault Rodeo Hatchback 4, 5, or 6 fits our Continental R08 engines. I found two vendors. One is in Latvia, Europe. Ordered one and total is $100 USA, half for shipping. Exact same pump/gaskets and even comes with hub/pulleys. An aftermarket distributor that works perfectly can be bought from Northern Eqpt in Minnesota, USA. About $300 USA. Alternator is GM/Chevy USA, can easily be found at any parts store in USA.
 

harbourseal

Renault R4 Lunatic
Messages
1,023
Location
Breda The Netherlands
I happen to have a headgasket lating around for a billancourt engine. Can you post the engine number to make dure it fits.
Regards, Robert
 

mauromj

New Member
Messages
1
Location
Pullman, WA - U.S.A
Laurie,
I just stumbled across this forum today. I too have a Groundsmaster 72 and I suspect it does have a leaky head gasket. Compression was 130-80-130-130 this spring. No gasket sets for my R08 Renault continental engine anywhere, including eBay. So reluctantly, I poured in a pint of Bars Leaks head gasket leak repair fluid. I ran it at idle for 15 min. Repeated a day later. It improved the running dramatically, not totally smooth, but very usable. However I had to clean radiator afterwards due to it running too hot. :laughing: Got that fixed, and it is definitely going to cut my grass ok as it is for now. I will make another compression test to see if or how much it improved. I still want to pull head and install new head gasket and cyl seating gaskets. I'm 75 yrs old, and I figure it might last me another 15 yrs if I just get it properly repaired. I won't be mowing grass that long!:laughing:

Wondering if you know of any source for a gasket set for my Continental R08? I'm in USA.

Oh, by the way, the water pump for a Renault Rodeo Hatchback 4, 5, or 6 fits our Continental R08 engines. I found two vendors. One is in Latvia, Europe. Ordered one and total is $100 USA, half for shipping. Exact same pump/gaskets and even comes with hub/pulleys. An aftermarket distributor that works perfectly can be bought from Northern Eqpt in Minnesota, USA. About $300 USA. Alternator is GM/Chevy USA, can easily be found at any parts store in USA.
Adding this information for others.

It appears this is the gasket kit we need for the Continental R08 839-46 engine in Toro Groundsmaster 72 / 327 mowers. The head gasket looks the same based off images I have seen online.


If the link is dead in the future, search for "renault r4 845 gasket" on Google.

If anyone can confirm, that would be great.
 
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