Anybody Actually Goin' Fast With a Holley 3 BBL?

[markjohnson]

We're fine. I'm feeling a little less "punchy" tonight. I like that word. Anyway, it's been many years since I messed with those 3BBL's. Just about 20 years ago, in fact, but a lot of it is still clear to me. I never had a chance to take that L-88 to the track while the 3 BBL was on it, but I did run it with the 850 and ran 11.70's with a 3.70 rear gear and I was actually pretty happy with it for the time. I have found another 3 BBL here in St. Louis that actually is already equipped with one the Motion Gear Drive Injector kits and it kinda peaked my interest in fooling around with one again. I'll add this too.......when I dis-assembled my 950 with that optional rear Secondary Metering Block, I noticed that the rear Secondary Boosters are a little closer together than they are in a standard 4 BBL and that the fuel passages in that metering block may not be lining up with the passages in the main carb body. Never noticed this when I first worked on it but I wish I would have. They say the Secondary Diaphrams are not manufactured anymore so treat any of them gently. Holley does make one that can be made to work (#135-6) but it requires some tricky surgery. As far as adjustable air bleeds, I have them on my 950 HP but have been advised by some people much smarter than me to leave them alone and I have heeded their advice. On an interesting note.......there used to be a Drag Radial class that required use of a single 4150 Holley (no Dominators) and we had talked of taking TWO used-up swap meet 3 BBL's and building a 'ringer' carb by using the large oval butterfly throttle plate on the Secondary AND Primary sides. That would have been interesting!

[Smokey]

What was or is the difference in your 850...and the newer versons of the 850HP? I'm blind on carb knowledge but let my dyno room friend help me with mine. I gained 29hp on my 396 with a new hp series over the stock 4346. But we are comparing apples to oranges again. And just think I used to use a 660 center squirter on it before I found the 4346.

[PxTx]

I beleive the centet squirters are specific for dual quad applications, so the idle circuit would not work well for 8 cylinders.

Interesting comment about the metering block on the 950. As for ajustable air bleeds, they are great for fine tuning, especially when A/F ratio is fat on lean in a particular area, but great otherwise. If you think of the fuel traveling up a soada straw and an air bleed as a crack in the side of the straw, fine tuning the fuel signal is a little easier to comprehend.

If goals for a 3 barrel are to be a low 11 second carb, I trust you can get it there. It would be nice to have some sort of baseline, but we can always start with the the mechanical kit and squirter mod and see where you are at.

Interestingly enough, Mark Hasset Jr brought a wide band 02 setup to tune the Phase III car with at this year's SCR. I really think it's a nice way to tune A/F whether we're talking EFI or carbs. Unfortunately, they broke a pushrod and did not get far on the tune.

Now I beleive Mark's Phase III L88 has run 11's, how deep into the 11's and with which carb I don't know. Maybe he'll see this and post.

[Salvatore]

In my days I was always told that a smaller carb that runs 85-90% efficient is better than a bigger carb that runs 60% efficient. I always had good luck with the 750 double pumper in the 70's on my LT-1 nova. That carb seemed to run better out of the box than the 780 I started with that had small modifications. I also was under the impression (from the guys who ran it) that the 3 barrel Holley was a bust. At least in the early days it was. Racers would put it on their LS 6 chevelles and slow it up in both et and mph. But like I said this was the 70's.

[Kim_Howie]

Talk about going to get toasted. I love my Carter carbs. They don't leak, there very responsive and idle better than any Holley I have owned.

[StealthBird]

The Motion gear drive kit was developed because back then, there was a definite attitude in enthusiast magazines that vacuum secondaries were for station wagons, not for performance. We know more nowadays of course. Vacuum secondary carbs produce just as much power as a mechanical secondary carb, they're just harder to dial in because they don't have a secondary metering block, just the plate. Drilling holes was time consuming, and swapping in a metering block was easy. Besides, you drill some holes in that vac secondary plate too large, you're sort of screwed. That's why most shops opted to replace the plate with a block, and then go to the gear drive. More of a shot off the line, in race trim, with slicks, but there's a lot to be said for vac secondaries on a street car. Once the butterflies are opened up, there should be no difference. The problem is tuning that secondary....

Just for the record, the larger Holley 3-barrel is a 1030 cfm unit, not a 1050. The only difference between the Holley 950 3-barrel (3916) and the 1030 cfm (4604) is that the 1030 uses dump tubes for the secondaries, no boosters, similar to the way the Q-jet works. The primary circuits are exactly the same as an 850.

I've been using a 1030 on the street for several years now, and have swapped back and forth with a 950HP. The 950HP is more responsive, understandable as it has smaller venturi. Wide open throttle, seat of the pants, can't tell a difference.

I know that's not scientific, just wanted to throw away a couple pennies today, so that was my .02 cents.

[Plowman]

On the 1968 Dana of Brian H,has a Holley 3bbl,he is doing!

[PxTx]

I saw that, looked like they had the Eelco secondary squirter kit but with the vacuum secondaries left in place. Probably the best setup going!

[12secHonda]

[ QUOTE ]
Interestingly enough, Mark Hasset Jr brought a wide band 02 setup to tune the Phase III car with at this year's SCR. I really think it's a nice way to tune A/F whether we're talking EFI or carbs. Unfortunately, they broke a pushrod and did not get far on the tune.

Now I beleive Mark's Phase III L88 has run 11's, how deep into the 11's and with which carb I don't know. Maybe he'll see this and post.

[/ QUOTE ]

Yeah, I ripped the AEM wideband out of my Civic just before we headed to St. Louis this year. Was really looking forward to playing with jetting. But, the pushrod kinda ruined that plan lol. I'm no carb expert, so I wont attempt to go into discussing 3 barrel pro's and con's. But for what its worth - we did go 11.90's on one. That was with a 1.9 ish 60 foot and without really playing with the carb on a dyno or even using a wideband at the time...

[PxTx]

Posted for a point of ref.

There are certainly tricks specific to make a 3 barrel run, and bolting on a newer- more tunable carb can be attractive. It's my intention to squease all I can out of the 3 going on Monica's L88.

Motion cars had a garantee of 11,50's right, so I suspect the ol' 3 had to deliver the goods.