Alfa Romeo Owners Club of Australia Forum

Technical => 900 Series (Alfasud, Alfasud Sprint, 33) => Topic started by: amichie on March 14, 2015, 10:00:10 AM

Title: Tech questions cams and carbs
Post by: amichie on March 14, 2015, 10:00:10 AM
Hello all

Just curious about a couple of things.

1. Do the 40 IDF carbs bolt on to the 36IDF manifold from a 1.5 or do you need to get the 40IDF manifolds also?
2. What is the easiest way to convert a 1.7 from hydraulic lifters to mechanical?

Thanks in advance
Title: Re: Tech questions cams and carbs
Post by: colcol on March 14, 2015, 10:22:15 AM
The easiest way to convert a hydraulic cam setup to a solid lifter setup is to buy a 1.7.
The hydraulic cams are different to the solid cams, as they have a ramp to pump up the lifters.
The solid lifters are different to the hydraulic lifters.
Even the cam belts are different from the hydraulic to solid.
The hydraulic belts are 100 teeth, the solid belts are 98 teeth.
I think that 40 IDF's will bolt onto the 36IDF manifold.
Some people who purchased 1700 without carbs used the existing 36IDF's
33's with 1.7's are so cheap these days on ebay, people just buy the car for the motor.
The first 200 or so 1.7's imported into Australia had solid lifters.
Because Alfa Romeo had not got the hydraulic lifters into production yet.
I know because i spent 2 years waiting for a 1.7 with solid lifters to come up for sale for the Sud.
The 1.7 has a better looking combustion chamber than the 1.5.
The 1.7 has bucket loads more torque than the 1.5.
The 1.5 is more fun to drive, because it needs to be revved.
The fuel injection 1.7 uses less fuel than the 1.7 carby and even the 1.5 carby.
The 1.7 lasts longer as well because the more precise injection doesn't wash the oil of the cylinder bores.
Try a few wreckers and see what they have in stock.
Give Monza Motors a call in Bayswater in Victoria.
If anyone wants 2 new hydraulic cambelts, 100 tooth, contact uncle col, Colin, ha ha.
Title: Re: Tech questions cams and carbs
Post by: amichie on March 14, 2015, 02:55:01 PM
Hi Col
Your first line confused me. I thought it was the 1.7 that had hydraulic lifters.
Title: Re: Tech questions cams and carbs
Post by: colcol on March 14, 2015, 08:11:34 PM
The first 200 1.7's that came to Australia had solid lifters.
Just get the whole motor and don't muck around with conversions.
You need a hydraulic camshaft for hydraulic lifters.
The solid lifters need a solid cam.
The profiles are different.
Hydraulic lifters can work ok with performance cams.
As long as the performance cam has a Hydraulic profile on it.
It all depends on what you want to do with it, Colin.
Title: Re: Tech questions cams and carbs
Post by: Ray Pignataro on March 14, 2015, 09:21:55 PM
Col. I have taken all mechanical gear from 1.5 heads and converted them or retro fitted them to 1.7 heads . You would only do it if you were using extreme revs
Title: Re: Tech questions cams and carbs
Post by: colcol on March 14, 2015, 09:32:48 PM
Like i said, it all depends on what you want to do.
The cylinder heads for a 1.7 seem to have a bit more of a combustion chamber than the 1.5.
And it depends on what is available.
Do you want carbs or Fuel injection.
Colin.
Title: Re: Tech questions cams and carbs
Post by: amichie on March 15, 2015, 09:35:30 AM
I have heard some very positive reports about the 1700 8V twin carb motor and it would look stock in my 83 SUD TI QV. So if I can't find a complete motor then I guess I need to build one. I can get 40 IDFs. I have a 1500 86 Sprint donor motor that has shim over bucket mechanical lifters so I may be able to swap cams, housings lifters and valves to fit on a 1700 block.
Title: Re: Tech questions cams and carbs
Post by: colcol on March 15, 2015, 09:53:03 AM
The 1.7 would look like a standard 1.5, consider getting a 1.7 carby 33, with shims instead of hydraulic and scrapping the body, as they can be purchased for no much coin, Colin.
Title: Re: Tech questions cams and carbs
Post by: amichie on March 15, 2015, 08:02:36 PM
Thanks Col

Please Let me know if you here of a suitable donor car for sale.

Thanks Andrew
Title: Re: Tech questions cams and carbs
Post by: amichie on March 18, 2015, 06:50:44 PM
Just a bit of trivia

I looked over the twin carbs on the Sud and the sprint.

1983 Alfasud TI QV has twin 36 IDF carbs with 30mm chokes.

1986 Alfa Sprint QV has twin 36 IDF carbs with 32mm chokes and according to the specs makes 10 less horsepower than the SUD with bigger chokes. Must be the catalytic converter that causes it to lose 10 HP.


Title: Re: Tech questions cams and carbs
Post by: colcol on March 18, 2015, 09:30:49 PM
The 1983 twin carb Sud has 95 horsepower, the 1984 33 TI has 105 horsepower, the 1984 33 GCL has 95 horsepower, the European Suds have 105 horsepower.
Why?, i hear you ask, well in 1983 the 95 hp motor complied with Australia's pollution standards, the 105 hp motor didn't.
But in 1984 Australia rejigged its pollution laws to be the same as Sweden, and the 105 hp motor was sold in Australia.
The last Suds sold in Australia were the twin carb model, half were silver and the other half were red.
Except for 3 that made their way to Australia with 105 hp non compliance motors.
They were painted black, one ended up in Bendigo, the other one??? and the last one ended up at Nareen in Victoria to a farmer who happened to be Prime Minister at the time....or so the story goes, next time i see Mal, i will ask him, Colin.
Title: Re: Tech questions cams and carbs
Post by: amichie on March 19, 2015, 07:51:30 AM
I wonder how they detuned the 105 HP Alfasud to 95HP. Was it just carb settings or were the cam profiles different also?

Title: Re: Tech questions cams and carbs
Post by: colcol on March 19, 2015, 08:13:00 PM
The 105 hp motor had slightly higher lift cams, different carby jetting, most likely richer and pipes going into the exhaust to burn any fumes, the torque was also higher up in the rev range, Colin.
Title: Re: Tech questions cams and carbs
Post by: Ray Pignataro on March 19, 2015, 09:37:00 PM
geez no wonder im slow im shortchanged 10 hp
Title: Re: Tech questions cams and carbs
Post by: colcol on March 19, 2015, 09:48:48 PM
Hey Ray, isn't yours a Black twin carb Sud from Bendigo?, Colin.
Title: Re: Tech questions cams and carbs
Post by: Ray Pignataro on March 19, 2015, 10:33:49 PM
Mm coincidence I think not mine is black and now lives in Bendigo and only 95 hp