Weber downdraught question

wilf leek · #1 (**permalink**) 05-23-2003, 05:27 AM

Guys - acquaintance of mine is considering downdraught webers on his 351W, wants to know what he should consider before going that route.

My own thoughts are:

1/ Expense and difficulty of setting up (need to find someone who can set them up)

2/ Headroom under hood - the car he is considering can just squeeze a performer rpm and holley 4V carb with oval (shallow) Cobra air filter under the hood - are webers on their appropriate manifold taller than this?

3/ Potential need for custom cam grind?

4/ Difficulty in arranging vacuum take off for brake booster.

Anything else to be considered?? Thanks in advance.

wilf leek · #2 (**permalink**) 05-23-2003, 02:11 PM

walt347 · #3 (**permalink**) 05-23-2003, 02:33 PM

Wilf, some additional thoughts based on my experience/Weber project:

- fuel pump (pressure max. 3 psi - fuel pressure regulator needed ? )
- compression ratio (Webers like high comp engines)
- air filters needed ? (hood clearance)
- linkage
- max hp (rpm red line) vs. max torque
- distributor (I had to change mine - was too large)
- manifold (thermostat, heater, water temp gauge)
- 48 IDAs / 48 or 44 IDFs
- local regulations (emission control)

Hope this helps.

Regards,

Walter

Jim Holden · #4 (**permalink**) 05-23-2003, 02:48 PM

Wilf:

I've now used Webers on three cars; big block 428cj, Boss 302 and now Gurney 331. Each has been a bear to get right but once set up not bad and... they "shore due look pretty"

Enzo at Finish Line is my source of information Webers. Give him a call.

Jim

347 · #5 (**permalink**) 05-23-2003, 07:56 PM

wilf.........maybe all of the above except custom cam grind......if he has the money i wouldnt even worry about any of those things you mentioned......looks ,sound, performance out ways all of them by far !!!

Wild Thing · #6 (**permalink**) 05-25-2003, 12:04 AM

if you wanna know more about Webers, here's are great article:

inglese

Andy FIA · #7 (**permalink**) 05-26-2003, 02:46 AM

There is an old guy called Dave Bogg who owns a garage with a rolling road on the Yorkshire Wolds, he is one of the old school who sets Webers up by by feel and ear and he dosen't charge silly modern garage type prices. He re-jetted the 40DCNF's on my Dino and got me an extra 4mpg as well as removing a flat spot, he has set up the 44IDF's on a friends Hawk 289 and it runs perfectly. Dave Bogg will certainly be sorting my Webers when I get around to installing them. Gordon has 4 off K&N filters on his Hawk, but I think mine will be filterless.
I certainly wouldn't be put off by the rumours of Webers being difficult to set up, once jetted correctly and with a good linkage they should stay in tune for a good while.

Andy

Jack21 · #8 (**permalink**) 06-03-2003, 05:10 PM

Way back when. Had SU's on a TR4. Spent $$$ on Webers, never could get them tuned and put the SU's back on.

Question? Is this a drive it on weekends car, or a tinker with it on weekends car? If drive it, bolt on a Demon 650DP, and enjoy driving. If tinker with it, bolt on Webers, and enjoy tinkering.