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husky430 · Posted: Mon Sep 27, 2004 12:34 am Post subject: 1.7 8-valve:carbs vs injection

Gidday all,
I'm repowering an 87 sprint with a 1.7 8-valve. The 1.7 is currently injected and out of an 89 S2 33. The books say that the carbed 1.7 makes a little extra power than the IE. Did the carbed 1.7 come with 36 or 40mm carbs? Is anyone able to comment on the option of injection vs 36mm carbs and suggest pros and cons of each. I am thinking of fitting the 36mm carbs(unleaded) off the 1.5 Sprint engine.

Also, I like the ratios of the 1.7IE S2 gearbox but feel that the 3.89 diff is a little tall. How differcult is it to change diff ratios with 4.11 gears out of a S1 33.

Thanks for any feedback.

Mick

alexj · Posted: Mon Sep 27, 2004 1:35 am Post subject:

The 1.7 came with 40mm carbs with 32mm main venturi while the 36mm carbs probably have 30mm main venturi so will restrict the airflow a little when compared to the correct 40mm carb setup.

I'm not 100% sure on this, but you would need to make sure the carbs (and manifolds) match up to your 1.7 head. This is not something you should assume and may require some work to match... if they can match.

On the other hand, with injection you might have to consider swapping the entire fuel system.... tank/pump etc from injected 33.

If it were me, I'd be searching for a 1.7 8-valve twin carb engine and make my life a lot easier and for the diff ratio easiest way is swap entire gearbox.

Regards
Lex Jenner

Serpent33 · Posted: Tue Sep 28, 2004 1:29 pm Post subject:

I have converted my ie to twin carbs. Little more power comes from the wilder QV cams and individual throttle body.
_________________
Each time I speed I say, "Dear lord, make me fast and accurate..."

husky430 · Posted: Tue Sep 28, 2004 11:05 pm Post subject: carb fitting

Serpent33,

Could you tell me what carbs you used and if it was a straight bolt on or if you encountered any problems.

Thanks
Mick

GaryUK · Guest

Go for the carbed 1.7 loads more torque and extra power at the top end. Plus you can just simply drop in a 1.7 carb motor with no mechanical/electrical changes the injected one would be a right chew on.

rallyboy77 · Alfasud Joined: 08 Apr 2003 Posts: 76 Location: Sydney

Did the 1.7 carb engine have hydralic tappets? If so can they be changed simply by changing the cam housing and tappets?

j

Guest · Posted: Thu Sep 30, 2004 7:12 am Post subject:

The 1.7QV is twin carbed with hydraulic tappets. And yes you can change simply the cam housing to mech tappets.

Serpent33 · Posted: Thu Sep 30, 2004 7:16 am Post subject:

Sorry forgot to log on. And Gary are you missing out on the fuel pump? Coz the QV has mechanical pump and replaced by power steering on the ie. But it's easy to just fit in an electric pump but just make sure the pressure is right.
_________________
Each time I speed I say, "Dear lord, make me fast and accurate..."

rallyboy77 · Alfasud Joined: 08 Apr 2003 Posts: 76 Location: Sydney

Do you know of any issues with the cam profile (of this particular cam) as designed for the hydralic tappets as opposed to the mechanical ones? Eddie W raised this as a general issue which could effect the QV cam.

serpent--33 · Guest

Yes. I BLEW my engine! Those drunkard manufacturers will tell you it's bolt on when it's not! Safest bet is mechanical shims. If to use hydraulic, special shim might be needed on top of it. And the manufacturer were both bulduzzi and colombo. Again if unsure please use mechanical shim.

I made the greatest mistake by trusting the reputable manufacturers. How can I not? They sounded so sure. Confused

Serpent33 · Posted: Wed Oct 06, 2004 12:49 pm Post subject:

Serpent33 · Posted: Wed Oct 06, 2004 12:50 pm Post subject: Re: carb fitting