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[alferr]

ok need some help in modifying or replacing my radiator, i have st my 33 up for racing and it is stuggling to keep cool, i was wondering on what mods i could do to the cooling system

do you think dual fans is possible?, one on outside, other on inside? bigger radiator?

etc

thanks in advance
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[Eddie W]

In nz Ihave seen it recommended to prop the rear of the bonnet open 12-15mm or so.This would venting in a relatively high pressure area though.I have wondered about using louvre vents a la Evo 1.These would have to exit in front of the strut firewall to be effective and have araised front edge so that there was an extraction effect from the airflow across the bonnet.
Regards Eddie

[lesthegringo]

Try putting in an oil cooler - this gives you more overall cooling efficiency, and also improves your oil pressure by keeping your oil working at the temperature it works best at. You can also stick it where you want it as you have flexible lines going to and from it. I put a thermostatic valve in as it's for street use, but for out and out racing that's probably not necessary

You can choose the size of oil cooler, but I used a 13 row job and it seems to be good for a 16v stuck in a sprint.

Obviously if the air cant flow through the rad in the first place, it won't help - making sure the air can get cleanly to and from the rad by putting louvres and ducts will help, as mentioned above

Good luck

[rallyboy77]

hey les,

where did you mount your oil cooler? I'm planning to install one but I'm not sure where to mount it. We are not allowed to make new holes in the bonnet under PRC rules, and there isn't really any room up front... ?

jez

[lesthegringo]

I stuck it between the radiator and the plasic grille that goes in front of it. It's a little tight, but with a bit of juggling goes in there. The hoses are more of an issue than the rad, as they are quite thick and the bend radius is wide. If I was to do it again, I'd go for tubes, bent to get around everything.

Les

[Eddie W]

Les
Where do you connect to the block (in and out)?
Eddie

[lesthegringo]

I would send a photo, but I don't know how

If you want, I can send an e-mail with a photo showing it

[rallyboy77]

hey les,

would also love to see the images... but it would be great to have a gallery which was easy to add images too. I'm sure it will come into handy quite often!

jez

[lesthegringo]

As usual I was being stupid - take a look at the photos on this page of my site

http://www.alfasprint16v.fws1.com/photo.html

It has a number of pics showing it intalled

Les

[Eddie W]

Les.
Thanks,I see the oil cooler adapter at the filter. Ishould have thought of the obvious. When visiting your site,I checked your brake and suspension sections, most informative. You queried about fitting vented in place of solid discs, I did this on my `87 SL 1500 and had to fit spacers on the front to clear my Lancia wheels with new pads. Not good! The vented caliper has a bigger piston and gives more even pressure as the pads wear as well as better effort. On the suspension front, there was a change around `87 to a different set up with lowered front pickup points and more castor . The change in the front pickup position reduces dive on braking .Be aware that this set up requires different length driveshafts as well as arms and front xmember.
Regards Eddie

[Matt Stolton]

Why did you go for the Jenvey throttle bodies? The 16V has not a bad set fitted as standard, all you need is the trumpets, and some filtration in place of the plenum based one. If it was down to bore size, do you find you have lost too much torque for BHP at top end revs, or is it drivable around town?

Did you find this set up suffered from drawing in hot air from the engine bay? I did a similar mod to an 8V (well, trumpets and ITG filters on 40mm IDFs) and found the hot air didn't help low speed running. Obviously not a problem when moving quickly as the engine bay is cooled by huge amounts of turbulent air, but always left me struggling in traffic.

I have a friend who is ftting/fabricating a plenum for his 145 with a 3.2 V6 (i jest not, the clovertech blue 145 now has a AHMotorsport 3.2 V6 in it!!). He has fitted the six throttle bodies and trumpets to the chromed intake runners, but is going to great lengths to generate a sealed, pressurised, cold air intake and plenum to fit over and around his trumpets.

Any way, your opinions on the conversion, and your experiences with living with it would be appreciated. I am in the middle of converting my P4 to around 180BHP (Lairy cams, chip, valve increase, serious headwork, etc) and wondered if you could recomend any cheats to keep driveability. I am keeping the plenum style similar to original, but using a 145/6 boxer plenum (better tract shape/length), through a CDA type filter, from a cold air intake, probably from in front of the window washer bottle, imbetween innner and outer wings.

I will be doing very similar things with the oil as yourself. Who supplied the thermostatic plate for the oil send/return, and is it a standard size/made for boxer 16V, or did you find something to fit? If so can you let me know what model it is ?
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Regards

Matt

Ex Alfa 33 'GTA' (P4 with Knobs On)
Now cruising in a 166 3.2 Ti!!

[lesthegringo]

I went for the throttle bodies at the time because of the desire to later on modify the engine, so it was a bit of 'future proofing'.

On the standard engine, the standard throttle bodies are perfectly good for the job, and now I have done it, in retrospect I would not go for the bigger throttle bodies again. It's not that you lose any drastic amount of torque, the injection sees that doesn't happen. The thing is, the 16v in a road going Sprint is a bit too much. We are talking MASSIVE torque steer, and remember it has new bushes, bearings and Koni shocks. It has really unbalanced the car. Before anyone asks, I had all the front suspension alignment and setup done by a professional who successfully races Alfa 33's.

The later 33's are able to deal with it better, I think, and certainly the P4 can.

As for the behavior of the engine, well all I can say is that it starts with no throttle, idles properly from cold, (though the addition of an idle air control valve would be better), pulls cleanly and well in the lower rpm range, idles very stably when warm (we are talking leaving it for more than 15 minutes no problem) and goes brilliantly at high rpm, even if you do have to be very ready for the torque steer. The sound though the two throttle bodies (even though covered by K&N's) is totally totally addictive, and the Ansa system I have in not loud at all, but sounds the part. The intake roar does get tiring when you have to sit at motorway speeds all day though.

The standard throttle bodies will probably end up going back on the Sprint, and the '45s will end up on the mid engined 16v boxer powered car I'm building, as the engine will be modified to extract a bit more go. As that will be rear wheel drive, the torque steer issue disappears.

As for getting more torque from the 16v, well remember that very large diameter exhaust manifolds sacrifice torque. Keeping the primary pipe diameters down to something reasonable (45mm) will help bolster the torque without any real top end loss. The manifold should also be of the crossover type, where the primaries of cylinders 1 and 2 meet, rather then 1 and 3.

By putting in the controlled vortex type manifold (see the www.alfaboxertuning.fws1.com exhaust details) you can also help pull the engine up on the cam a bit earlier.

A good three angle valve seat job is well worth it too. I'm going to assume that you are having the heads modified professionally, so they will do the port sizes and shapes - hopefully they won't make them too big, as that drops torque.

A compression hike is definately worth going for, especially if you are changing cams, and if you are going for aftermarket programmable injection and ignition setups, you can up the ratio a bit more still. Upping the ratio really does benefit both power and torque.

No idea what cams you are putting in, but if they are race cams, you will not get any decent torque below 4000 rpm, simple as that. A 'fast road' or 'mild rally' cam grind is what you should look at. Whatever, you may have to up the compresion ratio to make the best of the cams. You may have to change to solid lifters.

Hopefully you will junk the standard cam tensioners and put in turned Aluminium ones with good quality sealed bearings. It's a good insurance policy, and if you have skimmed the heads, you can make them slightly smaller diameter to help you regain the adjustment you lost by bringing the cam wheels closer to the crank.

The oil cooler kit came from Demon Tweeks, and was an off-the-shelf item, there is no problems getting hold of it.

Your comments on cold air are correct, apart from one thing - the injectio control 'brain' receives under bonnet temperature info from a temperature sensor mounted close to the intakes, so it is self correcting. All other observations about the benefits of cold air are correct. Do it, you won't lose anything.

Hope this helps!

[Matt Stolton]

Firstly thanks for your answers and observations.

The cam and chip are an autodelta (Forza Tuning) part, which I believe gave around 160BHP from standard 137. I have no reason to doubt that original claim, just we are doing a lot more.

An interesting point is we are enlarging both inlet and exhaust valves (being done very proffesionally, by a bloke called Peter, who seems to know a hell of a lot, including telling Mercedes how to lighten there F1 pistons even further, but thats another storey. He even had a valve seat milling machine given to him for helping the manufacturer evaluate/sort the software on it. Only worth 1/2 million!!!!!!!!!).

The exhausts are going a lot larger (within reason, another of Peter's observations was on an Aston Martin, V12, that by reducing the exhaust valve sizes 1.5mm, gave them an extra 43BHP!!!), as is one of the cylinder pair of inlets. If you look at the standard alfa 16V inlet cam, you will see that one valve/lobe opens a little before the second one. We are keeping this valve standard, for low end torque and gas speed. The second, 'slower' valve is going up 3mm to get top end breathing up. Along with some heavy grinding around in the heads, we hope to amplify the original effect, to retain bottom end pull, and general around town driving. However, at high revs, the second larger valve will allow more mix in, hopefully getting more power from top end, without too much loss of low end tractibility.

The exhaust manifold will be standard, until we can source/manufacture a crossover type. The backbox will be supersprint, and a simple fairly straight through mid box to quieten to non embarresing levels. None of this will be excessively diametered, as you loose gas speed....

The plenum is from a 145/6 boxer, which has D shaped legs, that are longer than the 33 boxer plenum. This will give us some more torque, bottom end, but still flow enough top end to not restrict the inlet charge too much, although it will not breath quite as easily as your trumpets. For filtration we are going for a ITG CDA in line filter. It has some interesting vortex and venturis built into it, which claim sensible improvemnets, which fitted to a 24V 164 Cloverleaf, did seem to bring around the claimed figures. The air inlet will be trumpeted as well, and be behind the bumper, imbetween the inner and outer wings, nice and cold, and away from the engine heat.

Most of the engine ideas are Peter's. He does a lot of sports bikes (motoGP, super bikes etc), and pointed out that a boxer is just two two cylinder bike engines!! He has also shown me a saab 16V head, which hasn't got the split cam inlet timing, but has got a flow/lump to achieve a swirl into one valve for low end torque. It isn't just the 16V 33 that uses the asymetric inlet geometry. He is also increasing the 'volume' in the inlet tract to help achieve greater gas speed and flow. However, he has proven that too much volume behind the valves actually looses power and torque, as he has seen another bike engine with too much volume. By reducing the inlet volume, the 950CC 2 pot, gained 20BHP!!!

He is an amazing engineer, with lots of pictures of his work before and after, with dynos before and after too. He does a lot of Jag straight six engines too, which he turns into complete works of art.

Getting back to the Mercedes bit, he was chatting in his local to a mate of his, that works on the Merc F1 engine team. He was trying to glean some extra ideas for his own improvements, as you would, but in return he gave them an idea to shave about a further 15gr off of each piston, without compromising strength. The proof was sitting on his desk, in the form of a paperweight, engraved with the Merc blokes signature, with Peter's drillings duly in place!! He does has some top flight mates.....
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Regards

Matt

Ex Alfa 33 'GTA' (P4 with Knobs On)
Now cruising in a 166 3.2 Ti!!

[Serpent33]

Dear guys, A stadard oil cooler off a 325 E30 fits nicely below the front axle. You'll have to find a way to create ducts. I cut a slot where the licence plate is and thinking of relocating the licenceplate. But if it's for race, shouldn't be a problem.
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Each time I speed I say, "Dear lord, make me fast and accurate..."