| Author |
Message |
Russ Turner (Snj5)
Junior Member
Username: Snj5
Post Number: 73
Registered: 2-2003
| | Posted on Wednesday, April 09, 2003 - 7:26 am: | |
Hey - new idea.
Just got the specs off of a Jalpa 3.5 (2V, 9.1 CR, 250hp)with 42 webers (darn close).
Two sets of data:
Choke:
34 - or - 36
Main jet:
135- or - 140
A/C:
180- or - 170
Idle:
50 - or - 60
pump:
45 - or - 50
Based on this, initial settings before do look a bit rich. But, the Lambo makes up for smaller main jets with smaller A/Cs, which as I understand it affect the mixture at higher flows. I know many 308 folks use 140 main jets with the original 210 or so AC's.
Any Lambo Jalpa guys out there that can tell me what that engine is like or altermate jettings?
So, now will look at:
choke 34
main 150
a/c 190
idle 60
Reticent to go much leaner based on not sure of effect of increased flow due to 4V.
Other ideas??
thanks |
John_Miles (John_miles)
New member
Username: John_miles
Post Number: 49
Registered: 7-2001
| | Posted on Wednesday, April 09, 2003 - 4:06 am: | |
My guess is it'll be pretty rich, but I can't wait to hear what kind of results you get! |
Russ Turner (Snj5)
Junior Member
Username: Snj5
Post Number: 72
Registered: 2-2003
| | Posted on Wednesday, April 09, 2003 - 12:16 am: | |
I have the manifolds and am about to order the carbs, so need ideas on initial jetting. Pierce calculated the venturi size at 33.5, so went with 34.
Many say the 4 valve heads flow way significantly more air, and have been following Kermit and Paul Sloan's 3.0 liter QV development with the 48 IDAs(!), but they have not started jetting yet.
I know competition Dinos had 36 venturis, 160 main, 175AC and 60 idles.
Have only heard of one guy who did this and he is unreachable in Austrailia. Have read the Weber books and FChat threads. Appreciate all suggestions and rationale.
Many thanks
rt |
Hans E. Hansen (4re_gt4)
Intermediate Member
Username: 4re_gt4
Post Number: 1075
Registered: 4-2002
| | Posted on Tuesday, April 08, 2003 - 11:59 pm: | |
Have you actually tried this yet? I'm curious, as it's considerably richer than 308 settings. I'm wondering what kind of A/F ratios you end up with, considering you probably will be flowing more air than the rest of us. |
Russ Turner (Snj5)
Junior Member
Username: Snj5
Post Number: 71
Registered: 2-2003
| | Posted on Tuesday, April 08, 2003 - 8:52 pm: | |
Will soon be getting the Weber 40DCNFs on my 3.2 daily driver. Read the excellent previous threads- request suggestions on a good initial ante for jetting, especially if you have done this before.
Spoke with the great folks at Pierce Manifolds and compared notes with many of you: here is the initial setting for a 3.2 liter 4 valve with stock 244 duration cams, exhaust cam retarded 4 degrees from stock:
40 dcnf
34 mm choke
155 main jets
190 A/C
65 idle
60 accel
F36 emulsion
Your experience and advice appreciated.
best
rt |