"Serial Renault Deviant" Adey's current Renault R8 adventure

[adey]

Here is a hilarious one...... took the car for a run, no issues, ran as well as it ever did. Did a compression check and all came in at around 8.5bar.....

With the spare gasket sat on the shelf I though I may as well pull the head for shits and giggles. I absolutely love this series of engine for its simplicity, and in an 8 there's loads of space to work.

What I found was a little shocking, but explain where the blow by was coming from.

Piston 1 to 3 all with damage, the top of the piston has gone to the top ring on cylinder 1, there are 2 holes down the side of piston 2 and 3 also has damage. Not sure what has gone through there but there was plenty of carbon build up before I cleaned it off. I'm wondering if a bit more of it came loose a few days ago causing more noise than normal. Either way its ruined inside and needs some hefty remedial work or a new lump throwing in. We will see what parts become available over the next week or 2 and go forward with a plan of action.

thanks for reading

[adey]

I may have a lead on a good 1108cc R8 engine. Should have more details in the next few days.

I'm still on the hunt for something bigger and better but ideally I want the time to build it all up properly. So if all goes well a replacement engine will go in and I will still be able to use the 8 until all the other bits I need become available to fit a 1390/1397cc.

[adey]

Had a chat with a guy called Brian Whiteside, who happens to have a good 1108cc engine (plus many other spares) so I will be picking that up on Sunday. I'm hoping to gain a few more ponies just by having and engine with no holes in the pistons

Have decided to make a weekend of the trip so the wife and kids will be coming along too, not that the weather is looking very good but still some fun to be had.

I decided to get cracking with the engine out job, this was more to check what gearbox and clutch setup I have. I'm not sure so hoping the gurus will chime in, but I think I have a mix mash of parts in there? could be normal though.

20 spline box but unguided release bearing (is that the right release bearing?)

Clutch looks like the carbon seal type that I had in my dauphine but I'm sure the release bearing was different

Anyway, engine is disconnected, its on the jack currently until I get my hoist back and either lift it out or lift the car over it (y)

 

[adey]

And we are home, and no messing, the engine is also pretty much in the hole.

Today saw us wrapping up our short family getaway, the route home was to now take us to Brian Whitesides house. Arrived to the engine loaded on a telehandler which made things nice and easy. Boot unloaded of all the holiday gear, engine slid into place and then the family and everything else reorganised on the inside. The trusty Clio doing its thing and plodding home, fully laden for a further 140miles. It surprisingly delivered 42.5mpg for the full trip (and to the annoyance of my Mrs, we put the hammer down a fair bit)

Once home I whipped the crane out, got the engine in the garage and started whipping some bits off. Spark plugs removed and some GT45 thrown down the holes. The clutch cover had some damage so I whipped the one off the old engine and threw it on this newer lump. I use the thicker of the friction plates. As I hadn't even unhooked it I slapped it straight in the car..... lined it up easy enough and is held onto the bellhousing with 4 bolts. Now its in there, I pulled the rocker cover off to be greeted with a clean top end. I've poured oil over everything and it spins nicely by hand. Fingers crossed its a good one. The engine plate suggests its a service exchange unit so no idea what the actual spec is.

I've got tomorrow off work so hopefully we will have it spinning on the starter and we can make sure the top end is getting oil before moving forward and getting it running. All being well I can have it wrapped up and ready for testing by the weekend 🤞

 

 

[adey]

Right, I think we are onto a winner.

Started the day by fitting up the engine cradle, this then bolts to the engine mounts and holds a everything steady. Next up was to get the starter motor in place so I could use it to spin the engine over and check for oil pressure and oil making its way to the rockers. This wasn't an issue and all went fine. Like for like engine means everything just goes back in as is.

Whilst at it I thought it'd be good to do a comp check... this is where things got a little odd. Compression was right down on 4 and 2.. (about 3 bar on each) I rotated everything over and found the inlet valve on 4 to be tight on the rocker. Adjusted it back to spec and comp jumped up a little. The other 2 were ok though still looking ropey (all low and the highest at about 6.5 bar) I'm not going to lie at this point I was very concerned, had I just picked up a duff engine.

In my head lack of comp could only really be a few things, more holes in the piston..... blown gasket, valves not seating or stuck piston rings. As it was already down I thought I may as well just crack on with what I had anyway. A bit of a run should highlight the issue. Slapped some ATF down the bores to help with the piston rings if it was them. Checked the dizzy drive gear to see it was out a tooth, so moved that around to spec. Fitted up my coil and the rest of the wiring. Sucked fuel through from tank to the carb top and poured some down the carb itself. Got to cranking it over and within a few turns she fired into life, and for an old hag that hasn't been ran for a while it sounded fantastic. Sprayed oil everywhere as I had the rocker off but still smooth, better than the old engine at least lol. I was shocked at how well it was running considering the previous results!

With no water pump hooked up I didn't run it for long, less than a minute at a guess. Out of curiosity I checked the comps again once. 10.5 to 11bar on all of them! 2 bar higher than my old engine. Ill take that

So next up is to drain the oil and fit the filter setup along with some fresh oil. I'm waiting on a water pump gasket, the old pump was knackered so I'm going to fit the "new" one from the old engine. Once that is done I will be able to refit the rad panel and get the system bled and working again. There's a few panels I need to refit but I want to clean them up a little first.

Once up and running I will make sure I set the timing properly (just in case it was det that contributed to the death of the last engine) maybe even a run on the dyno to make sure all is good. I'm hopeful that the better condition engine will have a few more ponies than the old engine had.

Cheers for reading

 

[Matty]

On 21/02/2026 at 03:39, adey said:

Here is a hilarious one...... took the car for a run, no issues, ran as well as it ever did. Did a compression check and all came in at around 8.5bar.....

With the spare gasket sat on the shelf I though I may as well pull the head for shits and giggles. I absolutely love this series of engine for its simplicity, and in an 8 there's loads of space to work.

What I found was a little shocking, but explain where the blow by was coming from.

Piston 1 to 3 all with damage, the top of the piston has gone to the top ring on cylinder 1, there are 2 holes down the side of piston 2 and 3 also has damage. Not sure what has gone through there but there was plenty of carbon build up before I cleaned it off. I'm wondering if a bit more of it came loose a few days ago causing more noise than normal. Either way its ruined inside and needs some hefty remedial work or a new lump throwing in. We will see what parts become available over the next week or 2 and go forward with a plan of action.

thanks for reading

To think that folk denounce old cars as crap. What they will do is take a rake of abuse that modern stuff wouldnt cope with and still somehow run. Seriously impressive that.

[delux]

Fantastic thread! I know nothing about these cars but I recognise the engine from other Renaults. Looks mean as fuck! 

Please keep fixing and updating.

[adey]

1 hour ago, Matty said:

To think that folk denounce old cars as crap. What they will do is take a rake of abuse that modern stuff wouldnt cope with and still somehow run. Seriously impressive that.

could have slapped it back together and it would have plodded along for sure

40 minutes ago, delux said:

Fantastic thread! I know nothing about these cars but I recognise the engine from other Renaults. Looks mean as fuck! 

Please keep fixing and updating.

thanks, this is only part way through where its up too currently. I will keep updating until you are all caught up 

[Brigsy]

Forgot about the damage to the pistons. Its crazy how well the old ohv renault engines run when basically totally knackered.

 

[Six-cylinder]

What a great project.

Reading it tonight has stopped me going out and vandalising any bus shelters!