ALFAGTV6.COM

[MD]

Engine niceties aside, would you please note that FINALLY somebody has got the engine bay bracing right !!

[Giuliettaevo2]

Please note this is a very much altered enginebay... the engine lays further back as normal, just look at the steering rack... engine had 452 HP on an enginedyno, i was told by someone who would know.

this is an IMSA 'wannabee', extensive cagework can be expected in such a car, the cage and strenghtening alone would have cost thousands of euros. Not a real option for the most of us i'm afraid.

[strat24v]

Those are the pics that i have. Thanks for posting them up.

I know timing belts are very good but four cams with stronger springs take some turning, that setup would, i think cure one weak point. Very nice piece of work and i'd love some more info and detail, maybe to replicate that setup on my engine.

[Giuliettaevo2]

You can contact them on their website. The link is in the post with the pictures.

Please share with us if they tell you more.

[strat24v]

I did send an email, maybe three months ago? I politely asked about their belt setup and if they would be prepared to perhaps sell me a copy of their specs, parts supply and eng drawings but didn't hear anything back, Oh well, guess i'll have to tackle it from scratch at some point.

[kterkkila]

Interesting pics indeed! If those hp numbers are real and it's 3.0, then it really must rev. If someone knows ANY more details what's done to that engine, it would be great if that info could been shared.

[Giuliettaevo2]

Maybe it helps if i send them an email in Dutch? I will give it a try tomorrow at work.

[strat24v]

If you could manage to contact them, that would be great. Any info would be much appreciated.

As good as those 3.7 big bore engines are, i would really prefer to up the RPM's and keep my stock capacity.

[Giuliettaevo2]

Today i got a replie from the guy mentioned before who has knowledge about this car. I mailed him to ask him some details about the car. this was his replie;

Wagen van michiel. Motor gebouwd door Willem Pauw. 3.5V6 24V . Dry Sump. Motor staat 20 cm lager en 30 cm verder naar achter. Schutbord verbouwd. Carbon aandrijfas uit een stuk, met gelijmde Alu verbindingstukken. Motor staat vast in chassis. V-bak van een 575 Maranello, 6 bak sequentieel, Hewland. Eigen oliekoeler, tractie controle, launch control etc.
Aandrijfas kun je op je vingers leggen, zo licht is die.
Motor: Is als gezegd dry sump. Onderste carterpan is tegelijk de lagerkappen van de big ends van de krukas. anders gezegd, als je onder de auto staat zie je de moeren van de krukaslagerkappen zitten. de Alu onderpan heeft de lagerkappen geintegreerd erin zitten. Waanzinnig! Geeft heel veel sterkte. ik heb de eerste uitdraai op de vermogensbank, (zal zijn geweest '04) gezien: 452 PK op de waterrem. De tweede run liep de Distrisnaar stuk. GEEN kromme kleppen!!! Snaar was verkeerd, die had een draairichting. er stond echter geen pijl oid op en de fabrikant heeft de schade vergoed. Ik heb er ook nog wat fotos van, die moet ik opzoeken. LLD heeft de megagrote carbon airbox gefabriekt, na vier of vijf pogingen. Machtig mooi ding. Sliding throttle assy heb ik nog goede foto's van . Programmeerbaar alles.
Onderstel is geen IMSA maar eigenbouw. 100 liter tank op bijrijdersplek, met sneltanksysteem. 15 liter Dry sump tank achterin. Airjacks.
De meest mega 75 EVER dit. Lang verhaal, Willem had wat andere dingen aan zijn hoofd, wat problemen met michiel enz. Doet er verder niet toe, maar hij heeft het projekt niet afgemaakt. Zo stond de auto een tijd, Michiel kocht een 155 STW en nog later een 156STW, en deze kwam in de hoek terecht. Rolkooi etc Ad Verkuilen. Wagen is veel breder dan een standaard IMSA, carbon deuren enz op bestuurdersdeur na. Rijder zit zowat op achterbank. Voorschijven zijn 320 mm. Zeszuigertangen. Heeft voor zover ik dat weet tot dusver nog niet geracet. Gebouwd voor oa Belcar enz.


I'll give a translation for you guys;
-3,5 24v dry sump engine, bottom of sump also acts as a girdle plate for the main bearingcaps, gives massive strenght to them.you can see the nuts that hold the main bearingcaps in place from underneeth.
- there is also a huge carbonfibre airbox that goes around the trumpets.
-electronically programmable everything.
-engine is 20 cm lower and 30cm more backwards as the original engine. firewall seriously modified for this. engine is mounted solid to the chassis.
-one piece carbon-fibre propshaft with glued-on aluminium endcaps. serious lightweight, you can pick it up with one finger.
-Ferrari 575 Maranello gearbox, 6-speed sequential Hewland.
-traction control, launch control, electronic everything.
-Not an original IMSA, selfmade suspension, much wider car, carbon fibre doors and stuff. 320mm discs with 6 pots up front. driver is far backwards, almost on the rear seat. 100 liter tank in the passengerplace 15 liter dry-sump tank in the back. airjacks on all corners.

He also told me the engine had 452 hp on the waterjet the first run, the second run the belt snapped... No bent valves and the producer of the belt payed the damage, the belt turned in the wrong direction but there was no arrow or anything on it...

The 75 was never really finished or raced due to some different factors and the owner bought a 155 STW and later a 156STW so it got neglected in the corner of the workshop. It was build for the Belcar championship in Belgium amongst others.

[Giuliettaevo2]

Still no replie from the company...

[kterkkila]

Time is going fast. At last spring I had some discussion with that company. Very capable shop indeed. They said they will look for drawings of the triple belt system and make an offer about most critical parts, but I never got it. Maybe they couldn't find them.

So the belt is still a problem. It seems that 24V's original is quite uncommon type. Pitch is 3/8" or 9.5mm and the profile is HTD -like curvilinear type. Does someone know what's the right type for the belt? HTD's are metric, so it's something else..

Maybe two separated belts would work, but is there any hope to use original pulleys, meaning are there belts in different lenghts available? If no, then all must be replaced.

It's still unclear how the belts fail and the cure isn't clear either. For this point I wouldn't like to believe it's about torsion vibrations, but who knows.

[Giuliettaevo2]

The belts tend to skip teeth. The older 164 engines are more affected by this as the newer 24v engines.

the area of pulley actually covered by the belt is not very large on some of the pulleys. Lowering the middle guidebearing(? the one between both heads) would improve this.

[kterkkila]

Maybe two guide bearings between banks? The right block exhaust belt contact needs some modification too. Would it be so simple? Just add some more contact area and that's it? If the slipping is the only problem, then there's some hope.

Other experiences? SA guys??

[kevin]

Nothing really to add but an observation, is that its alway been the left bank intake that jumps a tooth when there is an belt issue. This has happend three times on my 164's(dfferent ones) with standard set up and once on my GTA based 164 in GTV. The valve touches slightly but never gets damaged thank goodness. Sounds like light machine gunfire.(very light)

[kterkkila]

These small pieces of information might be more valuable than you could imagine. I've started modeling double belt cam drive configuration, thinking internal engine balancing and some other mods related to this belt issue.. It would turn out quite costly for sure..

If the belt is slipping, then it's about routing, not unbeatable physical challenges for the belt itself.