WEBER 40 IDF COnversion Part 3 of 3
 

PART 3 of 3
Install the air cleaner bases for your nice new K&N type Chrome air cleaners! Install the 4 velocity stacks. You will need 8 spacers to go over the studs of the velocity stacks so that you can seat the nut that tightens the cleaners & stacks down. You can cut pieces of the left over new fuel line setup. Once all is cinched down…. its Showtime!

Crank it over and it should start right up and idle down nicely...even though it may run like an old tractor for a bit with a few pops and snorts for @30 seconds. Initially for the first minute or so, just be checking this whole time visually, and by feeling around, all gas line connections for leaks, and for anything rubbing or vibrating. No leaks or other untoward things-great! So far so good.
Used the synchrometer (I use 2) and run up the idle evenly to @ 2 to 2.5k rpm and let the car get to operating temp – when there, pop off the throttle rods, then do the mixture adjustment turning screws in until engine runs fastest and smoothest. Web site had great, detailed, instructions on how to do this part.
Idle it back down evenly, always adjusting higher air pull down to the lower throat pull number, adjusting left & right idle screw until desired equal side to side balance/idle is reached. I always used #3 throat for the baseline balance point. Pop throttle rods back on. Check side to side balance again. Nothing SHOULD change if you had it all setup right. If it changes, it’s likely your rods were not adjusted properly. Remember, they don’t necessarily need to be even lengths. Re-adjust.
If all is right, you should have the identical air flow/pull on all 4 stacks, so when you put the tops of the air cleaners on your idle, rev, and back to idle, should not change one iota. If it does, and the 3 rods are adjusted right, you most likely have an air leak. Spray a little carb cleaner around the mating surfaces…a little at a time. If idle picks up for a brief moment-there is the leak. It may even be at the base of the manifold at the head. Good news is you can change & fix that one too with the engine in the car, bad news is its about a 3 beer project….not hard, just takes a little time removing sheet metal etc. But you gotta do it or the money spent on the Weber’s was wasted.

OK, no gas or air leaks or other observed problems. At this point I rechecked the dynamic timing to make sure it was happy. Made sure all tools, rags, etc out of the engine bay, and went for a drive (with screwdriver, a few wrenches & a rag, & fire extinguisher & cell phone- see I figger if you take the stuff with you, you wont need it). MAN, what a RUN! A little stumble off transition from idle and a little, little, bit of flat @2.8- 3k rpm.
Came back and just "diddled a teeny bit" with mixture and checked balance again. Changed to the 130 main jets (sooooo easy on Webers), and rechecking balance again and also for any gas leaks.
A quick drop to a fine idle @ 650 rpm & no more minor stumble transitioning off idle ,and NO flat spots (up to & a little past red line) during the second run…..& I mean I poked it on that second run. The exhaust was "cool", and no rich or exhaust "smell".

Back in the garage & dang it’s MILLER TIME …AGAIN & a shower!! Well 912 friends, there it is. I am not a mechanic just a regular 53 year old goober with average tools and skills, even thought I fooled around on & off with the cars for a while.
The kit vendor, Eric, has a good setup & Redline has a great website to download carb data, pics, and tuning specs.
With the jets I selected, my mixture screws ended up just about 1 full turn out, just like the book said it should. I hope this story is of some use to you.
The Redline web site is excellent.

The cost of my kit, venturis, stacks, other jets, 5/16th lines, T, fuel hose, breather, clamps et al (and overnight shipping) was $812 and about 3-4 hours of my time. IMHO it’s WORTH EVERY PENNY for how well the car runs now.

NOTES:
1. Get a nice thick piece of carpet or some knee pads as you will be spending more time on your knees than at a looong church service with a revved up Preacher.
2. There is no stubby screwdriver I have found that fits nicely, or at all, between the carbs & the body so I made one out of a ½” diameter plastic knob and a flat tip bit from my cordless drill. Jammed that bit into the hole of the knob for a tight fit and viola! I ended up with a 1&1/4” long, wide tip screwdriver that worked great for the adjustments. Use your imagination on this “special tool” if you need one. Fingers work well too on Weber’s since they have the nice knurled knobs. I prefer to “see” ¼ turns as I make mixture adjustments.
3. DON’T rush to hear your baby purr. Take your time, do it right, and especially don’t rush the mixture & idle adjustment turns on the screws. Make ¼ turns and wait for things to settle.
4. If I missed something let me know. I don’t claim to be a guru or such, and the way I did it is not the only way. Just trying to offer some recent practical “how to” that turned out pretty doggone good. This note is the compilation of many bits & pieces of info I pulled from many sources & it is “fresh” Some of the Weber data I found out there is 20 years old and a few fine point have changed.
5. If you need any clarification on what I wrote & actually meant, or spotted something I goofed up, send me a note at seagle06@knology.net. I’d be glad to learn any points from you. I also rebuilt all my calipers-that’s a story too!
6. HELP-Any 356/912 folks down my way…the good ole boys want me to put a Chevy V8 into the Targa- anybody with a 912 in eastern GA or thereabouts? Thanks.
7. Good luck & happy 912 motoring. God bless. Cheers, George