Looking for a new engine for my coup and just need abit of info about them performance wise and availiblity to get one ?

Cheers shaun

afh is cheaper and easier to find than a g40 engine.

afh with bike carbs puts out more power than a standard g40

g40 with some modding blows an afh away. but you need deep pockets!

AFH with bike carbs may put out more power than a standard G40, but a chip and pulley would more than redress the balance. And once you've taken the plunge with a G40 engine, you can keep upgrading and get up to real giant slaying power figures.

But there's no such thing as cheap and reliable power. Get a cheap G40 and you'll wish you didn't. Get a really powerful one and you'll spend serious cash on it. You don't need that much power in a G40 though to get a car that feels hilariously quick. In gear acceleration in a G is something to experience, but do it once and do it right.

My 150bhp G40 will do over 40 to the gallon, it's not too noisy on the motorway, has a wide power band with shit loads of torque, starts first time every time and is reliable enough to use every day no matter what the weather is like. Wring that sort of power out of an AFH and you'll have a stressed, thirsty engine with all the power at the top end, plus you'll probably have spent more and won't be able to take it much further.

Whereas with mine I could pump a few hundred more pounds into a turbo conversion and push the power further.

renegades is pushing 150 bhp though and i wouldnt say a set up afh would be any more thirsty than a g40. fair play to the rest of what you said though.

imo opinion it just depends on wether you want a cheap and stupidly quick polo, or a more expensive but insanely quick polo lol

Edited 24 February, 201214 yr by erixtar1992

I've never run a car on bike carbs, personally, so I couldn't comment.

Incidentally, I get the attraction to the AFH and it's a good conversion in a Mk1/2/3. But for me it just lacks the moron factor of a G40.

yeah, if i could afford a g40 lump, id 100% do it. but for the money an afh conversion is great and deffinately put a smile on my face! mine wasnt set up properly and i ran it a little rich but it was still doing over 30mpg. i hear of people getting over 40 when set up

You cant have AFH smiles G smiles ftw :)

I have no idea what bhp i have but needless to say i'll annoy anything on the road easily. even in the snow the car worked as it should. like Alex tho, i have no experience lsof bike carbs so cant comment.

It's not really like comparing apples with apples, one is a cheap way of making a polo quick and the other is an expensive way to make a polo quick The g40 has much more scope for tunning but again your looking at even more money

Guess it all depends on your budget really. Tbh I'd go for a hybrid 16v on injection over an afh on bike carbs but then I'm biased. Mines got a nice amount of torque, good on fuel, reliable, comes with a factory immobiliser, great as a daily, as near as it matters to 140 brake and cost about £400 which included full cam belt kit and water pump and full head gasket kit. Plus no extra cost or pissing about of getting carbs set up.

You cant have AFH smiles G smiles ftw :)

I have no idea what bhp i have but needless to say i'll annoy anything on the road easily. even in the snow the car worked as it should. like Alex tho, i have no experience lsof bike carbs so cant comment.

yes you can, bike carb smiles!

you should try them. chavs hate them. wich makes them great.

My first drive in my bike carbed GT gave me a BIG smile. The sound was awsome...

But NOTHING a polo produces can sound better that a raspy g40 hitting boost, then utilizing the boost return mod

I love the noise of mine even if I'm being overtaken by a mobility scooter

I've got the budget for the g40 engine but its just getting hold of one .... Interested in the afh hybrid engine got any more info on it mate

I prefer the sound of bike carbs than G-lader, and on the 1600's the bike carbs are so hooligan it can be almost embarrassing in the wrong place. Plus they sound great when driving on a light throttle, so the noise is as good in town as on the by-pass. Never driven a G, so i can't comment on the driving experience. But the carbs..?

Throttle response actually sends shudders up my spine, it's tantalising.

Torque on the AEE meant i could spin up the wheels at 2k rpm in 3rd in the dry (built that engine for £150). The 1.6 AFH had less but it was more tractable.

My MK2 has always been more economical with 1.4/1.6 bike carb'd engines than it ever was with it's healthy 1.3 pierburg, though the AFH cams don't help out on either capacity if you nail it..

8v for best sound, torque and economy - 16v for sheer speed.

All i know about the G40 - if you're gonna run one, might as well run big power, as they can take it. Personally i can't see why anyone would choose to run a standard one over a bike carb'd 6n/2 lump, apart from the G40 being stock and 'out of the box'.

Personally i can't see why anyone would choose to run a standard one over a bike carb'd 6n/2 lump, apart from the G40 being stock and 'out of the box'.

Not for a conversion no, but I can see the appeal of an original spec G40 run as standard because none of them are these days. It's quite nice seeing one in factory spec. But I think that's what you meant anyway.

I chose a G40 because it was the easiest way to get good power under the bonnet and the way it delivers the power it has is out of this world - I guess because not only is power to weight good but the weight itself is tiny.

That's not to say a high powered valver in a light pre-94 car wouldn't be fun, though. I've not driven one.

Personal preference though.

I dont think this is a good comparison. If you can afford to get a G40 conversion then thats probably what you should get.

If you want to get the most form a small budget then a AFH with carbs is a great choice and some nice sounds.

But in all cases - get them set up properly, its the difference between an ok car with some annoying bits to a great car.

I'm going for a afh on carbs because i wanted a cheap fun car that was light and I could give it some beans and not be endangering my licence. I also like instant throttle response which you would need a twin throttle set up for on a G or maybe a coldside conversion if it was possible.

I have been driving FI'd cars pretty much exclusively for the last 10 years and what the bhp figures cant tell you is the delivery of the power and the torque they give in gear that a NA car cant hope to match.

However I've been missing a free reving car that I can blip in tunnel without doing 120mph though.

My resto car cost £250 and I'm hoping to complete the initial build for about £1k (including wheels and tyres, and replacing the interior and a full body respray). Ill be going megajolt and getting it all set up on a rolling road. I'm lucky i have one 3 miles away and they are brilliant.

The G might be a more reliable car to start with but the conversion is just too much money (has to be a mk2 loon for me) and ill defy anyone who claims that you can modify a FI car to loads more power and it wont cost a fortune. I get mates rates on a lot of stuff, and can do many things for free but FI gear costs more as its under more stress etc etc.

You have heard " Fast, Reliable, Cheap - pick two" many times but its so true.

A mildly warmed up G has a lot of those attributes but the temptation to take it further is going to cost a lot to retain the factory reliability.

Also forgive my ignorance here, but dont they need servicing/rebuilding every 40k or so?

Finally i didnt go for a G as it would (dont mean to piss the G guys off here) pale in comparison to a lot of other FI machinery you can get for that money as a drivers car. Dont get me wrong I like the G40 and its a great little car but if you are chasing big power you should start somewhere else. If you want a surprisingly quick car with semi retro looks and factory attributes in mpg and reliability they are a good choice.

This was my diy mp45 conversion to my mx-5 - it has a twin throttle set up to maintain boosted air of throttle to give the instant torque and power that and FI car cant normally do and will even better some IRTB'd cars.

I'm wondering why nobody has done a twin throttle on a G? I'm sure it would be obvious if I knew more about them. Here is a short vid where you can see the twin throttle working.

This was my old coldside m45 on my previous mx-5 - it was not as powerful as the diy job but the setup drove and sounded like factory - it cost a lot more.

sorry for the non polo references.

Edited 24 February, 201214 yr by Retrotub

Yes and no on the driver's car front. Yes you'll get something decent for the same cash, but the G40 offers a lot of bang for buck which more than makes up for its lack of finesse on the handling front.

Like I say, I've been fortunate enough to try a lot of 'proper' cars through work and I still get goosebumps giving the G40 a good thrashing. It'll never make evo's list of best hot hatches, but that doesn't stop it being a LOT of fun to drive about in. Regardless of the simplistic throttle body it's quite happy to take off like a rocket when you give the throttle a squeeze.

And yes the G-chargers do require a rebuild every 40,000 miles. But it's not difficult to switch to a turbo if you want to avoid that, you'd still get that lairiness too.

Edited 25 February, 201214 yr by Alex

(good post otherwise though)

Personally i can't see why anyone would choose to run a standard one over a bike carb'd 6n/2 lump, apart from the G40 being stock and 'out of the box'.

Not for a conversion no, but I can see the appeal of an original spec G40 run as standard because none of them are these days. It's quite nice seeing one in factory spec. But I think that's what you meant anyway.

I chose a G40 because it was the easiest way to get good power under the bonnet and the way it delivers the power it has is out of this world - I guess because not only is power to weight good but the weight itself is tiny.

That's not to say a high powered valver in a light pre-94 car wouldn't be fun, though. I've not driven one.

Personal preference though.

one of the reasons to run a stock g40 (as a conversion) is decent power and reliability. Seen stock bottom ends do 160,000 miles and still be usable. AFH - well they seem to be a little long in the tooth before then.

I run a stock g40 and power is good more progressive than chip/pullied and insurance is silly cheap. As a garaged second car you can get classic with unlimited mileage insurance for under £200.

Yep I was very impressed with how it drove. Don't think I could leave one standard though, if it was an original G40.

That said I've never wanted huge power figures out of mine. Just enough to make it a quick and tractable road car. Wouldn't be too difficult to get more but as you say reliability and driveability can suffer.

This was my diy mp45 conversion to my mx-5 - it has a twin throttle set up to maintain boosted air of throttle to give the instant torque and power that and FI car cant normally do and will even better some IRTB'd cars.

I'm wondering why nobody has done a twin throttle on a G? I'm sure it would be obvious if I knew more about them.

They have a boost return valve instead, which opens as the throttle closes. Charge air is then recirculated through all the boost pipes and 'charger.

Way I see the AFH vs PY debate is that if you want 120bhp then an AFH on stock injection is the cheapest way of doing it. If you want 150bhp, excellent flat torque curve and decent economy - with the scope for even more power, then a chipped n pulley'd PY is the way forward. You need cams in a 1.6 AFH hybrid to get that power with the naturally aspirated lump, which don't come cheap.

You need cams in a 1.6 AFH hybrid to get that power with the naturally aspirated lump, which don't come cheap.

They may not be cheap but a 1.6 hybrid with cams would probably still be cheaper than a G40 conversion + chip and pulley and every thing else needed to get it to a reliable 150bhp

Tbh tho its pretty pointless debating which is best as so much depends on personal preference. For me personally I love the set up I have atm (not that that's going to stop me trying to improve on it), it was cheap to build, cheap to run while still being able to take pure abuse and put a grin on my face. I've never bought a G40 because I know for a fact I'd kill it, either through ragging it or not looking after it as it needs, or both. So for me a G40 is out of the question, I'd rather leave them to the sort of people that believe in preventive maintenance and regular services

My Polo is nearly 100kgs lighter than a stock G40 Alex, so i can certainly relate to that element. Not an entirely fair point given it's a tin roof MK2 but it makes me wonder which is the lightest conversion..?

I've yet to find a reliability issue, i melted a piston being silly and running very lean, but it's not like a G40 piston has never been melted.

Charger rebuilds are off-putting, bike carbs don't stay balanced forever but they're relatively quick and simple to sort.

The 1.6 has a more expensive tax disc. Both can run a catalyst (mine does). I think it comes down to a matter of preference, really.

But the price i'm a little stuck on. It's the reason i ran bike carbs seven years ago, but today it's purely choice. So is a G really worth 4,5,6 times the price?!

But then if they were cheap, would they be treasured and kept as much..?

Liking the sound of the 1.6 ... What would I need from the 1.6 lump as afh convos are quite cheap and what can I use from a mk3 GT engine ?? Cheers Shaun

There's a full guide of how to build the engine in the FAQ section above mate