Well, I Am Going To Add Triple Webers To My 3.0L M20…

[digger]

Thank you for the details Digger. I have reached out to Rama, and they do not have anything to do with carbs any longer. I am about to pull the trigger on some 45's Webers. My options are between a 5 progression hole vs 3. The cost is about $1000 more for the 5-hole. The seller/tuner (based in England) says the 3-hole setup would be fine since I have a SOHC. I can understand how a 5-hole would work more smoothly, but it would require more tuning etc. I dont mind spending more, but only if it makes sense. Any advice between the two?

Does anyone know is Andrew (SkiFree) is still around? He seems to have all the answers I may need, but he hasnt been active on any of his accounts in 5-years. I recall him being a regular on this form in the past.

Sorry, i cant provide any informed comments about progression holes

try contacting Adams Autosport https://www.instagram.com/adamsautosport/?hl=en if you haven't already. Someone else might have other contacts

[TobyB]

You'll be able to make either 40's or 45s work, and the difference will be mostly in mixture control.
It might not even be all that hard to get either to work in similar circumstances.

However, this has been my experience:
I bought a 2L race car that had 40s with 32mm chokes per the rules of the class.
It ran fine, made 150 solid horsepowers, and pulled to a 7000 redline, falling off starting about 6700.
Long runner Canon manifolds.

The rules changed. Now 45s were ok, and chokes were unrestricted.

I went to a 34mm choke, and then a 36mm choke, and the redline went to 7500 with absolutely no falloff.
Idle SHOULD have gone to shit with 36, but the car metered well from 2000, and pulled strongly
(as in, solid a/f ratios) from there. Horsepowers were never measured, but lap times said they went up significantly.
Doing the straight maths, probably to 180.

I then got me some Spanish 45's, and lap times went to hell. After some EGT gauges, it turned out that one
jet well of one Weber was machined too deep, and there was no real fix for it.
Then I got me another Weber, and stuck 36mm chokes in, and after some more tuning, got back to my
40 lap times. Went to 38 mm chokes. Didn't go noticeably faster, and tuning wasn't any more difficult.
The jet combinations made more SENSE than they did on the 40s (larger mains, smaller air correctors)
but the lap times stayed roughly the same. This was on the same type Canon manifold, but opened
up for 45s. All the other variables factored in, the 45's weren't good for more than tenths of a second
on the straights. Which in a race car is all well and good, but on a street car, silly.

So here's my limited opinion: with a smaller cylinder M20, I'd stick with 40s on the street. Then the throttle
plate will open further at just-off-idle, and the progressions will have a chance to work. If you start
on a 34mm choke, tuning will be easy, and your carburetted top end will probably be over 7000, based on what
I experienced with the 2l engine. You WILL be giving up just a titch- but unless you're planning on
tuning at Bonneville and running tracks with long straights, you're REALLY not going to notice all that much.
What you get in return is better mixture control at idle.
Is it a big deal?
Prolly not. So if 45's make you happier, do that.

As to progression drillings, I've always been frustrated by the Weber method. If I was to spend real time
on street development, that's where I'd start filling and drilling....

For spark, it's not going to matter. I used a 6MSDal for the limiter with a rusty Accel coil
and never had any blowout problems.
If you already have the 'squirts, I'd use it for its tunability. There's both power and driveability in a good,
load- sensing spark timing system.

I found DBilas' opinions to be... opinions. And their products to be... heavy. They certainly go fast, though.

t
opinions are like Miatas...