Weber IDF Main jet help |
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Weber IDF Main jet help |
tornik550 |
Aug 11 2010, 07:29 PM
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#1
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Senior Member Group: Members Posts: 1,248 Joined: 29-January 07 From: Ohio Member No.: 7,486 Region Association: None |
I am in the process of tuning my car after a rebuild. I have dual weber 40's. My engine is a 2.27L. Everything is going pretty well. I am slowly getting the jetting closer and closer. I was driving around at about 60mph yesterday. The head were hotter than I like (325 degrees). I checked the spark plugs and they were bone white. The main jets were at 160. I increased them to 170 (above 160 I only have increments of 10). With the increase to 170, the car is running very well and the temp at around 60mph cruising is around 275. I sped home, tuned off the car and took out the plugs- bone white. I was quite surprised.
The main jet size sounds high too me. Does it sound high to everyone else? Is it possible that I am needing a high main jet size because of the float level? I have my floats set at 10.5 with the gasket. Any opinions would be greatly appreciated |
tornik550 |
Aug 12 2010, 08:25 PM
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#2
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Senior Member Group: Members Posts: 1,248 Joined: 29-January 07 From: Ohio Member No.: 7,486 Region Association: None |
Here is an update. I drove my car to work today. I have 180 mains and 220 AC jets. The car ran well and the CHT cruising was around 275. The plugs were bone white. Before heading home, I changed to 190 AC jets. The car ran well and the CHT when cruising was around 275, maybe a little less. Plugs were still bone white.
I changed a few things. I changed the fuel filter (which only had 100 miles or so). The fuel pressure now can reach around 3.5. I changed to the 34mm venturis. I kept the mains at 180 and AC at 190. I adjusted the float heights to 10mm with the gasket (the floats were previously at 11 with the gasket-i thought they were at 10.5). I drove the car around. I drove it quite hard. There was a noticeable increase in power however if I floored it, it seemed a little sluggish. Something that I was not expecting was that there was a deeper, throatier sound from the exhaust. It sounded great. I sped around and then did a quick shut down. Of coarse, when I pulled the plugs they were carbon fouled. I was quite pleased. I was afraid that I was going to be super lean still with the increase in vent size. I was quite happy to see the carbon fouling. I can work with this. Does this sound reasonable- I plan on putting 210 AC jets and leaving the 180 mains. Drive around- if still fouled then start lowering the mains one step at a time until I get it right. To address a few posts saying that I should get a o2 sensor and A/F gauge. I would love to however my wife is a bit pissed off at me for spending so much money. I have put one on my Christmas list (I can't wait 4 months!!!) |
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