V6 powered E30 (Finished!)

[tari]

I would stick with a straight six lump...

[e30_singh]

nice work on the bell housing and conversion looks like its well on its way!!

[tailoutcharlie]

I would stick with a straight six lump...

with that kind of thinking we'd still all be driving around in mk1 cortinas. lol

deserves respect for trying something different, we cant all be the same









my two cents

[tari]

I retract my previous statement... I just heard that "the straight six is possible the best balanced engine ever made"

Unsure how true this is though...

Looking at the work you've done, I do envy you and would love to see the final outcome.

Good luck with your project matey. Tee

[x-works]

Quick question for anyone who might have tried it before or seen it been
done. With the original airflow to throttle body rubber elbow fitted the
airflow meter ends up in an undesirable position. Can a longer pipe be
fitted (3 or 4 inches) without upsetting the engine management or
running of the engine, i.e. will the engine notice that the airflow meter
is now a couple of inches further away from the throttle butterfly.

[HairyScreech]

shouldnt make a huge difference. may change the pulse tuning of the system but it doubt thats at
the optimum anyay.

[Ritchie]

I would say it would be fine locating the airflow meter a bit further away. This is looking very good, its a great feeling when you turn the key for the first time and it bursts into life! You guys cant be far away from it now.

[fozzymandeus]

Lots of people (esp towards the front of this thread) talk about 'balance' of the inline six. Balance is great if you want to remove NVH, but I don't think a whisper quiet cabin and comfy ride are the priorities of this conversion!

Alfa engines are distinctive enough for me to understand the motivation behind the work!

Whatever you come out with, it's truly ingenious work so best of luck with it! (I am a little worried about the exhaust bolting directly onto the bellhousing without anything to decouple it... but this probably speaks of my lack of automotive understanding rather than a potential problem!)

[Andyboy]

there are much better engines out there and also arent they fwd

that would mean causing problems mating it with rwd

Such as? Alfa V6 is one of the best engines ever made. Compact, light (all alloy) and they sound the bollocks. 188 bhp standard on LE Jet with a lot more to come. RWD in the 75 3l but the gearboxes were all in the back. The only V6 RWD Alfa to have a conventional box is the manual Alfa 6 2.5 which was never sold here.

Personally I'd keep the engine in the 75 it came from and mod that. They're great cars.

[Andyboy]

But V6 engines are just SO inferior to I6 engines!

They're inherently rough running

What a load of bollocks. Maybe the V6 in your Dad's Granada, not one of these or a Dino V6. I've never found a BMW six that revs (or sounds) like this. But an Alfa V6 is a somewhat higher quality engine anyway, an example of what a V6 should be. In fact, the only V6 I can think of that's any good although the Audi V6 was okayish.

Alfa V6's aren't 90 degrees though, they're 60. The only 90 degree V6 I can think of is the PRV (Peugeot Renault Volvo) which started life as an all alloy V8 but got chopped into a V6. It was a horrible bastard engine, utter crap. Early Volvo 264 on a single SU carburettor...........

[buster]

I wouldn't have thought it would cause a problem.

[tristan325]

Personally I'd keep the engine in the 75 it came from and mod that. They're great cars.

I couldn't agree more with you Andy, but having had several Alfas of that era and earlier, including a V6 75, I'm guessing it's a pile of orangey brown dust!

[Demlotcrew]

Guys i think this one should live in engine swaps section, i would hate for a great thread like this to be lost down the tech help hole of wonders

Andrew

[Turbo-Brown]

But V6 engines are just SO inferior to I6 engines!

They're inherently rough running

What a load of bollocks. Maybe the V6 in your Dad's Granada, not one of these or a Dino V6. I've never found a BMW six that revs (or sounds) like this. But an Alfa V6 is a somewhat higher quality engine anyway, an example of what a V6 should be. In fact, the only V6 I can think of that's any good although the Audi V6 was okayish.

Alfa V6's aren't 90 degrees though, they're 60. The only 90 degree V6 I can think of is the PRV (Peugeot Renault Volvo) which started life as an all alloy V8 but got chopped into a V6. It was a horrible bastard engine, utter crap. Early Volvo 264 on a single SU carburettor...........

you're entitled to your opinion Andy, but you're not arguing against me, you're trying to argue with physics which dictate that V6 engines cannot be inherantly balanced and must wobble from end to end. The only way to prevent the user from noticing is to fit balance shafts and they consume lots of energy.

There have been loads of 90 degree V6 engines over the years, the PRV was on as you say (incidentally my 264 had fuel injection :p ) Buick used to have one and, most notably, Mazerati used a 90degree V6 in the Bi-Turbo. The fact that the Alfa has a 60 degree V angle doesn't make it well balanced, it just gives it even firing intervals.

[deian]

Maseratti used the PRV one when Citroen owned Maseratti. I nearly bought a series one XM with that PRV engine, one of mate has one and fair play it goes well. Another mate offered me one for my xantia 2.1td, i jibbed out last minute... something didn't quite feel right. I wonder what it was. I know own a Xantia V6 (the later 60degree one) and it is surprisingly swift and sounds the dogs bits from citroen. Who'd have thought huh.

Personally I want to sell it to get another I6 (M20/M30) from BMW (or the M60 V8). You just can't beat it. As for BMW being better than other marques... my brother has a Saab 9-5 3.0TiD, how slow and boring, my brother said the BMW would blow it away in all ways. He referred to BMW as slimy (and thats a 523 estate). Thats a good thing!

As for Alfa Romeo engines, i'd have one, when I bought my first BMW it was a choice between an Alfa 75 V6 (which i heard near a bus stop near london, the guy floored it away and i fell for the sound), or a BMW 325. I went for the BMW. No regrets since then. But sure, I like the idea of an Alfa engine in a BMW, but personally there is something nice and unique in BMW's 6cyl inline engines, how many other car companies make car with them more or less standard, it's exclusive to BMW. It gives the BMW soul, but the Alfa engine would give it a character unknown to anyone else.

Good luck with this interesting feat of engineering and original idea!!

[Toby_Unna]

the SM/merak engine was a maserati design derived from an earlier maserati V8, unrelated to the PRV...



citroen was nothing to do with the PRV group

[Andyboy]

But V6 engines are just SO inferior to I6 engines!

They're inherently rough running

What a load of bollocks. Maybe the V6 in your Dad's Granada, not one of these or a Dino V6. I've never found a BMW six that revs (or sounds) like this. But an Alfa V6 is a somewhat higher quality engine anyway, an example of what a V6 should be. In fact, the only V6 I can think of that's any good although the Audi V6 was okayish.

Alfa V6's aren't 90 degrees though, they're 60. The only 90 degree V6 I can think of is the PRV (Peugeot Renault Volvo) which started life as an all alloy V8 but got chopped into a V6. It was a horrible bastard engine, utter crap. Early Volvo 264 on a single SU carburettor...........

you're entitled to your opinion Andy, but you're not arguing against me, you're trying to argue with physics which dictate that V6 engines cannot be inherantly balanced and must wobble from end to end. The only way to prevent the user from noticing is to fit balance shafts and they consume lots of energy.

There have been loads of 90 degree V6 engines over the years, the PRV was on as you say (incidentally my 264 had fuel injection :p ) Buick used to have one and, most notably, Mazerati used a 90degree V6 in the Bi-Turbo. The fact that the Alfa has a 60 degree V angle doesn't make it well balanced, it just gives it even firing intervals.

Yaaaaawn........

Sadly this is living proof that reading lots of text books doesn't teach you everything. Go and drive a GTV6 2.5 and tell me that a V6 cannot be smoother than an i6. Real world experience tells me that a V6 with a properly made (i.e stiff) alloy block and a perfectly counterweighted forged steel crank doesn't need balance shafts. Again; we aren't talking about old Volvo junk but a proper engine!

Only an utter anorak could discuss an Alfa or Ferrari V6 engine in pure technical terms - you clearly don't appreciate a really nice engine, the way it feels on the road or the sound it makes. Yes, I know all about 60 and 90 degree V6 engines having different firing intervals which is why the PRV had such a weird off beat sound to it. Do we actually care? No, not really - it's either a nice engine or it isn't. M20? It's not bad but no marvel. It's not made from particularly great materials and it's heavy. About the most charitable you could be is to say it's strong and easy to fix.

[Demlotcrew]

The maserati engine which has two turbos on each bank is a work of art! Very cool design

[Toby_Unna]

not a very charitable person though are you Andy

M20s are about as smooth and silky running as anything I've owned. or, they are when they're running right anyway

[Toby_Unna]

The maserati engine which has two turbos on each bank is a work of art! Very cool design

which engine is that

[Andyboy]

the SM/merak engine was a maserati design derived from an earlier maserati V8, unrelated to the PRV...



citroen was nothing to do with the PRV group

Unfortunately it was horribly unreliable. As for the PRV engine, the CX very nearly got it when Peugeot and Citroen joined in the seventies to form PSA but Citroen refused it (clever guys) and developed the CX Turbo which was a lot better.
The PRV wasn't all bad but it was a nothing engine. It was thirsty, not very powerful (144 brake from a K Jet 2.7 604 and 136 bhp in the Volvo) and not that reliable with timing chain issues. As a boat anchor to pull along a Renault 30 Auto or a Pug 604 it was sort of okay.

[Andyboy]

not a very charitable person though are you Andy

M20s are about as smooth and silky running as anything I've owned. or, they are when they're running right anyway

Nice, but just a bit characterless. They certainly don't howl like a good old Eytie V6.

[Andyboy]

The maserati engine which has two turbos on each bank is a work of art! Very cool design

which engine is that

Biturbo Ghibli. 2 litre V6 with more then one blower. That's a ******* weapon.

[Toby_Unna]

yeah i know about that one

but Andy said 2 turbos per bank?

[Andyboy]

Typo I expect.

Best BMW straight six - early L Jet 3.5 (E12 M535i) with the six branch inlet manifold. F**k me they sounded horny and were just really grunty. Much more so than the later E34 motors.

A few years ago I met this guy who had restored a 1979 Capri 3.0S. He converted the 3 litre Essex (fuelled by a 38DGAS Weber with simultaneous chokes) to Bosch K jet by seriously modding a 2.8i inlet manifold. With a 285 cam it did over 200 bhp and it sounded glorious and really flew.

[Turbo-Brown]

I've driven a reasonable number of V6 powered cars in my short time, one of which was an Alfa 156 2.5 V6, the Mondeo V6, Mercedes C-Class and (of all things) Ford Explorer, not to mention the venerable ol' Volv in both 2.7 and 2.8 forms.

Almost without exception, they rattled the car ever so slightly. It's one of those things you don't think about untill you find something demonstrably different. Good examples of the 'something different' being the I6 or, two examples I found striking, the difference between your average I4 (sure we've all driven cars with boggo I4 engines) and then driving something like a Honda Civic Type-R or a Porsche 944 with their counterbalanced I4 engines. You don't necessarily notice how shaky the bog standard I4 is until you drive something which removes the vibration from you attention.

Incidentally, the imbalance isn't down to how well the engine's made so a well balanced crank can't cancel out the inherant wobble.

Don't think either of us is going to convince the other, but I do have both practical experience on the comparison between I6 and V6 engines of a few different types (including the Alfa) and theory on my side.

There are reasons companies make V6 engines. They're cheap, easily modularised and they fit neatly in FWD packages. There's also a reason that companies like BMW will continue to use I6 engines: They're better than V6 engines.

[fozzymandeus]

Why is a V6 cheaper than an I6?

This is an odd argument, one where I think both parties have very good points. V6 engines are unbalanced by design. It's a fact - covered in uni... I6s aren't, which is why my M52 engine is incredibly refined. BMW still makes them because they see them as an important part of their brand, however what percentage of new BMWs these days actually have an I6? All I see are 116i,320d and 520d models, or expensive V8 things. Ok they are in the lineup but BMW is moving away from them. The reason I think is because they are awful to package. Such an unnecessary long bonnet is needed, which is why the 1 series looks so daft.

Remember, we are comparing two very different brands here. Alfa engines (especially the current lineup) are all very high specific output, which brings with it reliability issues. (new variator please?) Our BMWs have engines engineered for reliability.

I don't think the project being discussed in this thread is that bothered about reliability, but wants something with buckets of character, which it will undoubtedly achieve. Remember what kind of engine the E30 M3 has? I don't think that had balance as a priority!

[chrisr29]

Having owned a variety of straight six Beemers and v6 Alfas (currently have one of each at the moment) I'd say the only point the I6 was smoother is at idle. The v6 does make car wobble ever so slightly at tick over. The rest of the time the Alfa lump has it pretty well beat....especially at high revs where you can almost wind it off the clock without a trace of harshness. Though sound wise I actualy preffer the sound of the bm straight six....the transition from mid-range growl to top end howl is unbeatable.

[Morat]

Horses for courses, but the I6 does leave a serious amount of room in the engine bay for turbos, intercoolers or even a V-12 Yes, this is a bad thing if you are a car manufacturer but its great news for us!
And anyone who has worked on an Italian car knows that you either need the hands of a gynaecologist or shares in elastoplast.

[chrisr29]

Italian cars are a piece of cake to work on......well, compared to French anyway!

[Morat]

You can come and change the belts on my Fiat Coupe any time you like

[DRIFTBOY]

anyone who has worked on an Italian car knows that you either need the hands of a gynaecologist or shares in elastoplast.

Do you mean contortionist ?

[fozzymandeus]

You can come and change the belts on my Fiat Coupe any time you like

Fiat developed that engine/car combo so you could sent the engine away for easy cambelt replacement ;)

[chrisr29]

Ouch!

Was reffering to the older, rear wheel drive stuff.

Would that be the 20v? Heard it's an engine out job on those.

[Andyboy]

I do have both practical experience on the comparison between I6 and V6 engines of a few different types (including the Alfa) and theory on my side.

As I said - text books versus 'Christ, listen to that!'. Alfa V6 - alloy block with studs and nuts for the head, main bearings and big ends, forged steel crank. M20 - nicely made with cheap stretch bolts for everything. If you like a cheaply made engine, the M20 is just fine.

BMW reliability? Alfa V6's don't crack heads...........................