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[knighty2]

Hi Folks, since I have installed my 1.7 hydraulic 8 valve boxer in my kit car (from a G plate 33) , fitted with 40 dellortos, I had a mobile tuning guy come round and set up the carbs, sure enough they were a mile out, but not are considered all ok.....but...... I must say I have been shocked by its fuel consumption in general, when compared to my 1.5 sud engine which i ran previously.....also the throttle response is not great, leading me to think a 40 size carb is too big for the 1.7 in general

before I scrapped the 1.5 engine I obviously stripped everything usefull off it, and I am thinking about putting my pair of weber 36IDF's onto my 1.7 8v engine, for two reasons, 1) better fuel consumption....2) better general engine response, as I dont exactly "red-line" it everywhere, I just want it to be drivalbe and pokey when I want it to be.

my main question is - will the 36 IDF's need a major re-jet?......or will I be able to install them onto my 1.7 engine with minimal fuss, I will obviously balance them to get them running in sync.....your experiences will be much appreciated, any jetting sizes will be greatly appreciated

I seem to remember someone telling me they used to do this on a 1.5 track car for better drivability on smaller twisty circuits.........I forget your name, but it was the Italian bloke who sold me a 1.5 exhaust front manifold, who lives in east london.......I'm sure I will remember the name later!!!!!

[paulhide]

I had 36s on a 1.7 years ago no problem, just changed the main and idle jets - very easy. But the 1.7 on 40s, because of the gearing should, if anything get better mileage than the 1.5. Okay figures vary depending upon type of carbs and how they are set up, but the original manuals stated that the 1.7 did better mpg than the 1.5. Mind you then it depends which 1.5 engine you had - 85hp, 95hp or 105hp. I have driven all types and have always found the 1.7s (carbed) to be the most driveable and best geared for standard driving. State of the carbs and floats may make a big difference.
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Owner's Club 33 Registrar. Now from P4 & S2 1.7 QV
http://www.alfa-pages.co.uk/viewtopic.php?t=5188

[knighty2]

Hi Paul, many thanks, do you remember what size you changed the main and idle jets to????........was this jet change from a dyno session or just an incremental up-size???.....my 36 IDF's were from a 95bhp 1.5 sud

[paulhide]

The jets were simply taken out of some knackered IDF 40s and the car ran fine. Not dyno-tested though.
_________________
Owner's Club 33 Registrar. Now from P4 & S2 1.7 QV
http://www.alfa-pages.co.uk/viewtopic.php?t=5188

[knighty2]

thanks Paul - thats just what I wanted to hear.....I notice the 40 IDF's run a 50 idle jet and a 140 main jet......my 36IDF's run a 52 idle jet (bigger???) and a 135 main jet (smaller).......so it looks like for starters I will get myself a set of 140 main jets, that works out at about 8% more flow area, so will do for now, I'm thinking the 36 IDF idle jets will probably be ok as they appear to be marginally bigger.

many thanks again, I will let you know how it goes

[paulhide]

Dellortos for a 1.7 run 52 idle jets. Webers should use 50s.
_________________
Owner's Club 33 Registrar. Now from P4 & S2 1.7 QV
http://www.alfa-pages.co.uk/viewtopic.php?t=5188