A110 Group 4/5

I'll do some research!

Something for your research.

A couple of pages from 'Berlinettes Alpine' by Christian Descombes.

IMG_5549.jpg

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that's in French, what use is that?

[johnb]

that's in French, what use is that?

Not a great deal actually I think books in English on this subject could be a bit thin on the ground. Google Translate can be useful.

The text doesn’t mention Group 5 much but there’s a couple of sentences just above the ‘1975, 1976’ section on the second page that roughly read:-

‘In Group 5, we can still work the undercarriage and lightening to compensate for its too bourgeois conception; but in Group 4, the A310 actually weighs 100 kg more than the berlinette. Its career will be very pale next to that of the berlinette Tour de France.’

The caption to the photo on the first page reads:
‘Finished for the 1974 season, a berlinette 1800 Group 5 awaits quietly waiting in the courtyard of Viry-Chatillon.’

The second page photo caption reads:
‘In Dieppe, this time, this Group 5 has 16 valves and was prepared for the Tour de France automobile in which it did not eventually compete. In the background, the Sport-prototypes A210 and A220 of the 24 Hours of Le Mans.’

The car photographed on the second page has the same registration as the yellow car in the photo added by stephen. Coincidence or maybe not many were produced.

thanks for that, looking like a project that never actually raced then?

Thing about Group 5 that there was a lack of cars... all races I attended would comprise of 5-10 Porsche 935's racing against each other. The odd BMW 320T usually with superstar Stuck/ Petersen driver line up would be fast but fragile, as were the Lancia Beta's when they arrived a few years later. Albeit in a lower capacity class to the Porsches but would still be competitive overall.
With Renault putting all resources behind the Group 6 cars and the forthcoming F1 project its no wonder this got shelved as the car would have been pretty much out of production by then so no sense to be marketing it.
German Group 5 had the capris and a good mix of other cars. Must admit forgot about tour de France, will have to research it.

[johnb]

Came across this yesterday, which you might have seen. The Group 5 gets mentioned on pages 20, 22 & 24. Already translated as a bonus.

https://en.renaultclassic.com/wp-conten ... t-A110.pdf

[stephendell]

Also found pics of a couple of groupe 6 cars that look more like Porsche 935s.

Will post up when I get a chance.

Also found pics of a couple of groupe 6 cars that look more like Porsche 935s.

Will post up when I get a chance.

Group 6 were open top prototypes, how can they look like a 935?

Came across this yesterday, which you might have seen. The Group 5 gets mentioned on pages 20, 22 & 24. Already translated as a bonus.

https://en.renaultclassic.com/wp-conten ... t-A110.pdf

guessing this is the car in question... although no group 5 mentioned.

In preparation for the 1975 Tour de
France Automobile, a rally it did not
normally take part in, one last A 110
was made. It was a one-off prototype
whose special, one-piece rear panel
afforded direct access to the mechanical
assembly. However, the
originality of the last of the A 110s
resided mainly in its engine, a
16-valve, 1800 cc, double-camshaft
version developed by Bernard Dudot.
Entered in the 1976 Ronde Limousine
for Bruno Saby, until 1978 it took
part in various races and hill climbs.
It pursed a successful career in
Belgium before returning to France
where, in the hands of Alain
Serpaggi, it was among the frontrunners
in VHC* rallies.

[johnb]

guessing this is the car in question... although no group 5 mentioned.

Although pages 20 & 22 do mention other Group 5 cars. No doubt Stephen will do the necessary research.

guessing this is the car in question... although no group 5 mentioned.

Although pages 20 & 22 do mention other Group 5 cars. No doubt Stephen will do the necessary research.

yes but those are previous era group 5 regs John.

[johnb]

guessing this is the car in question... although no group 5 mentioned.

Although pages 20 & 22 do mention other Group 5 cars. No doubt Stephen will do the necessary research.

yes but those are previous era group 5 regs John.

Ah, OK.

[stephendell]

Also found pics of a couple of groupe 6 cars that look more like Porsche 935s.

Will post up when I get a chance.

Group 6 were open top prototypes, how can they look like a 935?

Maybe the earlier pre '76 group 6 redesignated as group 5.

[stephendell]

Spent some time stripping the engine for inspection:

A110 Engine Rings.JPG

First surprise was to see that the liners had been ringed. Presumably to improve the sealing of the copper head gasket.

A110 Engine Head Gasket.JPG

Trial fitting laser cut flange for new aluminium dry sump. Block will be vapour bead blasted.

A110 Engine Block.JPG

Crank looks rather special. Knife edged and balanced.

A110 Engine Crank.JPG

A110 Engine Piston Rod.JPG

Conrods standard looking I beam but polished so will probably replace these with H beam.

A110 Engine Piston.JPG

Pistons are Arias forged items.

A110 Engine Cam 2.JPG

A110 Engine Rings Cam.JPG

Cam unknown but KC marking means possibly Kent Cams?

A110 Engine Tappets.JPG

Tappets and pushrods etc stored.

A110 Engine Valves.JPG

Valves only 1mm larger than standard Gordini so some scope to go larger.

A110 Engine Pulleys.JPG

Vernier cam pulley.

Next step is to dismantle the head.

.
Stephen,

Very nice indeed, and thank you for sharing... who ever built it I recon was an old Fiat man... but anyway, why take it apart?? Looks like, you could have just primed it when you were ready to go, and just used it... why change anything?? what are you trying to "improve"?? I get the dry sump, and I presume you are going to get a pro driver to drive it and compete, otherwise why bother with that.. unless some sort of value thing, in which case you need the setup it ran...

I get I'm a victim of trying to progress engine tuning, so a self confessed serial addict, so kettle black and all that, but some times it's worth valuing the beauty of things as they are, limitations they may have, that is if we actually reach them, than meddle and simply enjoy. Having said that it is great seeing the photos

I would plug it in and give it a run...

Martin

[stephendell]

Hi Martin,

Disassembly mainly due to the engine being a complete unknown and having stood for a while.

Some of the nylon spacers on the rockers had broken up so they will need to changed in any event.

Engine was already running a dry sump but reckon design could be improved a little as was previously using what looks like a modified OEM sump.

Pretty sure I'll change the rods from i to h if the length is avaiable as the old ones whilst looking ok are heavy and just polished OEM as far as I can tell.

Block is away having pattern made for new head gaskets at the moment. When back it will go off to be vapour blasted prior to reassembly.

New head gasket, likely alloy rocker spacers instead of nylon, maybe new rods, new oil seals and gaskets all round, some fresh paint, otherwise will probably stay as it.

What makes you think a fiat man?

[stephendell]

While the engine is being rebuilt have been working on the windows and glass.

Old front screen was original Saint Gobain and whilst chip and crack free had some scratches that were too deep to polish out.

Original plan was to fit a heated front screen and poly or heated rear but this has changed for following reasons.

Had a problem with a heated front screen from the usual UK supplier where a customer complained/noticed it had tiny delamination bubbles. They looked to the customer like they were from production. Supplier said no they must be from storage but talking to pilkington they said it was not uncommon with small run heated screens due to wires in the lamination which makes sense I guess.

New UK heated screen bubbles:

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Having had enough of delaminated screens and headlamp glasses in GTA's didn't want this again so had a change of plan.

The Dieppe parts list had A110 screens so bought one of those to try with a poly rear and new front and rear seals.

I fitted the Dieppe screen with the new seal which was a nightmare getting the seal to stay on the glass and it didn't fit very well in the aperture. The old seal appears to be moulded to the aperture shape or has moulded itself over time and the new seal is just a stretchy rubber circle. Like an big elastic band.

Front Aperture

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Front Old Seal

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New French glass + new seal

IMG_6758.JPG

In any event the new screen came out again and was fitted again with the old seal. Better this time but not quite as good as the original combination. This is how I have left it for now.

New French glass + old seal

IMG_6775.JPG

Delamination of the heated front put me off the heated rear. Also presumably the heated rear is laminated glass so heavier. Poly rear was probably ok but the previous one was terribly scuffed cracked and crazed over time. It didn't seem worth the weight saving but I know they have problems blowing out at speed and I guess the poly is easy to drill to secure and for cooling.

New poly rear

IMG_6781.JPG

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I remembered having a old OEM glass rear screen in storage that I had never opened so unpacked that. Having scrapped off all the stickers and old sealant it looked ok and wasn't really that heavy as it's just thin toughened glass so thought I'd give it a go.

After fighting with the new rear seal for a couple of hours (yes really) I managed to get it to stay on the glass long enough to rest it in place.

Rear aperture

IMG_6776.JPG

Second hand rear glass with new seal

IMG_6778.JPG

And that was as far as I got.

So plan A was:

New Heated UK front and rear screens (or poly) with new seals all round.

And this changed to Plan B:

Standard French front screen with S/h seal and S/h rear screen with new seal!

Getting slightly disillusioned with new replacement part quality both at home and abroad compared to new old stock or good OEM s/h.

The new front seal was around £150!

Anyone else had any experience with A110 screens?