A6 TAU - Atmo

[johnb]

.........reliable and easy servicing is the way to go so you can just jump in and go.
.........

I'm in agreement with that.

[johnb]

If you have a second manifold, it's a simpler choice. Weber conversion is less metal hacking than the Holley.
There was a lengthy thread about all this on one of the facebook forums recently with the Guru's - Martin F, Dave G, Stephen and Lee C. There are quite a few differing views... !

How do you access that forum, could be worth a read?

Is your engine/exhaust standard otherwise? Bear that in mind as some of the examples have free flow exhausts and polished heads and or cam work too.

The previous owner had a UK made stainless steel exhaust system fitted. Tubular headers and the two transverse, stacked boxes. Presumably giving a bit more power than the original system.
At the time I was rebuilding the engine Martin F providedI useful and helpful advice. A recommendation he made was to try and get hold of the camshafts, rocker assemblies and timing chain guides from a GTA. Fortunately I was able to obtain the items from a GTA being broken for parts at the time. Presumably this change has also added some additional power. I can't tell you what differences the camshaft change has made because, in my ownership, the engine has not run with the original camshaft/rocker arrangement.
A word of caution if anyone follows this recommendation is that some rework to the stiffening ribs inside the cast aluminium rocker covers is required. When I first put the rocker covers in place they wouldn't sit down on the head joint faces. Not by much but sufficient to find out why. The stiffening ribs were being contacted by the top of the rocker arms near the adjusters. Comparing the original steel rocker arms with the GTA aluminium arms showed that the GTA arms had more material, and higher, in the areas where contact with the cover stiffening ribs was made. Fortunately there was plenty of depth in the cover stiffening ribs to allow localised grinding at the contact points to provide plenty of clearance for the arms. So that was a relatively easy fix. The rocker cover castings are quite substantial so I would think the rib grinding would have minimal, if any, effect on their stiffness.
The only other thing I did to the engine was to polish the intake and exhaust tracts but not reshape them in any way.[/quote]

[mettersl]

Unfortunately you need to be on facebook and join the renault alpine owners club and find it there- (unless you are lucky and its a public group and post)
https://www.facebook.com/groups/801407303683897
https://www.facebook.com/groups/8014073 ... 336520859/ (takes you to the post, once you have got into the group)
Started by Andrew mark brakespeare- 74 comments in the thread .

Happy hunting...

[johnb]

Thanks for that Lee. I’ll take a look.

Sounds like you have a good engine, I am still running the original cam which I should have had done but I have removed the big restrictions in the exhaust ports. With the new carb and not talking over inflated pub HP you should achieve a true 165 to 175 but more importantly a much better torque improvement and flatter curve.

[johnb]

Sounds like you have a good engine, I am still running the original cam which I should have had done but I have removed the big restrictions in the exhaust ports. With the new carb and not talking over inflated pub HP you should achieve a true 165 to 175 but more importantly a much better torque improvement and flatter curve.

Sounds like it might be worth some more investigation.

However I am taking about an Atmo engine not the smaller 310 engine, although you can get them up to good power as well. I would love to put a set of 6 down drafts on if I could ever find some the induction noise would be epic.
But I will be probably be building my 610 engine and putting in my Lemans build as the car Renault should have offered alongside the 610, I’m not a big fan of Tubo stuff because of the lag on instantaneous power delivery, but the 610 lump had some decent lower down grunt but the 610 was a heavy car so I’m hoping that in 1100kg it might be faster on the pickup.
Things to do to pass the time during all this stuff that’s going on at the moment, over the past few years I have accumulated most of the parts to do it and you can still get any thing supplied you just have to wait for it to be delivered.

Sounds like you have a good engine, I am still running the original cam which I should have had done but I have removed the big restrictions in the exhaust ports. With the new carb and not talking over inflated pub HP you should achieve a true 165 to 175 but more importantly a much better torque improvement and flatter curve.

I'm doing a rollers session for a couple of Weber DGAS conversions early December, want to pitch up and join in the fun, can then directly overlay your Holley conversion? Always good fun what ever happens

Sounds like fun would be up for that the old thing hasn’t been on the rollers for 4 years now, all I have done is drive it haven’t done a thing to it since then, I know it’s running a bit rich lower down as I had a job to get it through the Mot this year and all my time has been spent on the Ds.
So it would be interesting to see how it has fared over the years I will get out my old test results, it seems to still feel good.
Can’t do the weekend of the 4 December also where are the rollers I am down south so a mega trip North in December is not that appealing.

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Planned in for mid-week 2nd week in December, won't be a weekend I'm afraid this time, but agree needs to be worth the effort. I'm planning on spending some time changing the break points on the OE ignition controller, so that's going to take a fair bit of time I think, and the hours evaporate under pressure. I'm sure there will be other opportunities next year in better weather, sort something out then.

Martin

Ok something to look forward to.
Are you saying you are planning to sort out the crappie ignition curve on the Atmo distributor, that I would be interested in as I’ve tried all sorts of things to get it sorted as it gives you that annoying flat spot. But being odd fire unless you spend a fortune on a top end ignition system that can cope with odd fire which isn’t really worth it just to get a smoother power curve money spent for a small gain.

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Crappie curve - yes

Martin

So is this the temptation game, I may be having a go at sorting the distributor watch this space or something else.
Having spent now 2 and a bit years doing my short wheel base Ds Rally I am burnt out on working on cars and I still have probably another 2/3 months left doing all the complaints stuff which is adding so much Wt to the car, I cannot get enthusiastic about anything really.
The only thing keeping me working on the bloody thing is it is pretty quirky and something special to drive, never driven anything like it, one of the things that make you smile is it’s immune to speed humps what ever size.
I will at some point build my 2 Prv engines which one will end up in the Alpine, I am thinking of building a low pressure Turbo engine for the road not chasing Hp but Torque so keeping the best of normally aspirated low down quick response with a massive progressive torque surge but with only slightly longer legs at the top.
At the moment I just want to finish what I have started and have a brake.

Hi all!

First post for me, but just to let you know I've just bought A6 TAU off Phil and am really looking forward to completing the excellent work he's started on the car. I even plan on getting it resprayed once all of the other little niggly jobs are complete.

Thanks in advance for the good reading material!

Ben

How is this coming along.
Martin how did you get on re doing the timing on the rollers with the Atmo.
Just started driving the GTA again and forgot how good it is a lot of adrenaline was pumping around me yesterday, it would be nice to get rid of the tiny flat spot which is definitely timing.