Alfa Pages

[Serpent33]

Mine is a 1.7 QV 8v. With raised cr and hot cams . Radiator is new. Nothing is choked. Car can cruise at 190km/h for an hour without heating problems.

But when on track. excessive red lining revs, the temp starts shooting up . The fan is working as well. My friend with a 16v had the same problem. Any suggestions? Guys?

I also have an oil cooler in my car.
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Each time I speed I say, "Dear lord, make me fast and accurate..."

[ricardo]

there are a few different water pump types, early ones are shorter i think
also some can cavitate at hi rpm, a larger pully can help
radiators ...best is the long version of the alloy type
headgaskets ..have heard that some makes have smaller water gallery holes
if you want i will send the email of a guy i know who searched 4 eva with this prob ,,,,,see what he says
your link to your web site aint workin
cheers
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alfa romeo trofeo series new zealand, video site .
http://alfa-racing.blip.tv/

alfatrofeo blog and interesting stuff .... unofficial ....
http://alfatrofeo.blogspot.com/

[Scott Sander]

Hi,

When the car is idling will the fan cycle on and off. This is a good indication that the thermostat is working and not blocked.

My series 1 had an issue with the thermostat. The car would only stay cool while moving. A blocked thermostat was the problem.

You may also consider permanently having the fan on while racing. Worth seeing if it has any effect.
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Scott Sander
'91 Alfa 33 Boxer 16V Monza - Awesome
http://www.sanderfamily.com

[ak863]

just have the car running idle and check at what temp the fan start working.

i have noticed mine comes in late (100C) but it does not seem to go higher during traffic. obviously the temp has an effect on the car because then it start rattles..

try fitting a switch so you can start the fan whenever you feel like.

[Serpent33]

I have given a thought about it but wasn't too sure. Thanks a lot. I've been rather upset not to be able to push the car. The car has effective rev range up to 7000 rpm, higher than the factory redline. I suppose I need to try harder. Any idea of the water pump maker? I have a wide selection here.

As for the fan switch, I've switched 6 times. Concluded that the termostat is not accurate coz no loss of water even when registering at 110 for prolong periods. Mine cuts in at 100 as well! Freaky.
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Each time I speed I say, "Dear lord, make me fast and accurate..."

[Matt C]

There always seems to be alot of focus on "cooling systems" and only a few parts of, Coolant, Fans, Radiator, thermostat.

Something which is over looked is "OIL"
the standard cooling system of a car is designed to function with a standard engine in mind. Increase your cp and lumpier cams will result in high temp, let alone adding high rpm into it.
(cooling system on a 33 has alot to be desired for!)
A quick fix would be to add a sandwich plate between the oil filter housing and oil filter. You will be surprised how cool your engine will run just by cooling the oil. This will also dramatically increase the life of your oil, providing better and longer protection for your engine and seals.

It doesn't need to be a large Oil cooler or this will Over cool your engine, causing damage at the other end of the scale! It is possible to get thermostatic sandwich adaptors, optimising the coolers performance, therfore increasing the engines performance.

It's worth while looking into

Have fun
Matt
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Molto Veloce!

[Serpent33]

[Gary UK]

My money is on either a leaky head gasket(s) which only occurs under the pressures of extreem engine stress or running a too lean fuel mixture. The fact that you have increased the compression ratio only adds weight to the first argument. Where the lumpy cams with standard ECU (or carb set-up) adds weight to the second.

What colour are you plugs after this happens as this may give you some clues. And what sort of pressure is in the cooling system when it happens (smell the gas given off from the filler bottle (can u smell exhaust gasses) and if it sounds like air is bubbling up from the engine when the pressure is released this lends weight to the head gasket theory)

If the fuel mixture is too weak watch you don't burn out the valves.

Also have you done any changes to the front of the car that would effect air flow into the radiator, is the oil cooler lessening air flow into the radiator? Have you fitted a sump guard? etc.

As a short term fix run with the heating set to max in the car and the fan on Full.

[Serpent33]

[Gary UK]

If the oil cooler is below the radiator then bugger all air will be going through it unless u have created new holes in the bumper, this may be your problem.

Cruising at high-speed airflow is high so no problems, revving the Kittens off it at lower speed when airflow is lower is causing the problems maybe.

My money is on a lean mixture though especially if you have not had the car set-up on a rolling road, changing the cam profile will have HUGE MASSIVE ENORMOUS impact on the way the engine operates(not one to over emphasize things).

[Jas]

It may not be of any help much, but when ever someone rolls in with overheating problems, the Alfa mechanic will fit after doing all the other obvious tests, a low temp switch. Can't remember when they turn on, lower than standard anyhow.
I have also leary cams in a 1.7 conversion on a 1.5 box. This gives a close ratio and i find my self often in the high revs. Temperature was a problem, so another fan was fitted to the outer side of the radiator, plus the low temp switch. Solved the overheating.
Around Melbourne with a close ratio can be close to a racing situation at rush hour times hehe (those from Melb. know what i'm saying). Especially when it reaches 40 odd degrees on the dirty old punt road......nah it aint racing. Dangerous though.
Sounds like a combination of things to me.

-jas

[Guest]

[Errol]

While we are on the topic of temperature, i just want to add that does any one notice a difference in performance when the car is around 90-100? I notice my series 3 16v is sluggish when the temp goes past 85, but when around 80 and just under it goes oh so much better! MY fan cuts in at 95 but really when i sit in traffic and the car is on 85...it just keeps going up..and only goes down when i start moving, and this happens in cold sydney weather. Hmmm realy strange those alfas...
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91 Alfa Romeo 33 16v * SOLD*
Lowered 45mm
15 x 7 inch advanti wheels
Falken 195 low profile
K&N Pod filter
Cannon 2inch exhaust from cat-back with 3inch tip.

[james]

I know i have't got a 33 but i have a 145 QV "96".

When i got the car 4 weeks ago it was running really hot. 90 on a cool night and 120 during the day. My friend siad it was the head, So i removed the themostat and it was running better but still would go up will in the red. So i had a better look at the rad and 90% of the fins where not there. So now i have replaced the Rad, Themostat and Fan switch, and now it runs so much better. the fan cuts in at 85-90 ish and when cruising about, not ragging it. the temp is below 80 and when i rag it it in only gos up to 80-83, So now im happy. Well worth £130 for the bits, and 3 hours of my time (note im a computer engineer, What the hell is a spanner.) All i need to do is put some anti frezze in later this week and see if it make any difference to the temp.

James
My 2 cents
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Umm thinking of getting a Alfa 33 P4 16v cloverleaf.

I would have done but i could not see any nice ones, so on the end i went for a 145 QV. Very happy with it

But still looking for a nice cheep 33 cloverleaf.

[Serpent33]

[Matt C]

There is an art to tunning carbs.
you may want to take a look at your emollsion tubes aswell, these are what come into force at high rpm introducing air into the fuel mixture before the fuel enters the venturi.

Have you checked your fuel bowl Levels? you may not have needed to adjust your main jet size but to fine tune your carbi to suit your driving style. Unfortunatly you will either compromise idle or high rpm depnding on what you are using your engine for. With high rpm you may find bottom end will be slightly dowy and high end superb.

So take into account your main jet size, Emollsion tube size and fuel bowl levels.
Your main jet is now delivering enough fuel but is your emollsion tubes a match for these jets? Dellortos have a range of sizes but are limited, you will find Webers have a bigger range of jets to offer (Not that there is anything wrong with dellortos )
As RPM increases the Level of fuel in the emollsion chamber will fall opening up more jets in the emollsion tube to allow more air to mix with fuel giving more efficient Atomisation.

Here is a Hint or a trick rather, to see what is going on in your carbi's Point a timming light down the barrel!!! this will reveal everything in snap shots! give it a go
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Molto Veloce!

[Serpent33]