Hot Rods 3x2 setup on a 671 Blower

Hey Guys..I have a 3x2 setup with small base Rochester carbs, that I want to put on a 671 Detroit blower, I was told by a guy that I would starve the front and rear cylinders of fuel. also I would like to use a progressive linkage. This is only for the street use.
Please let my know what you think.
Thanks

 

Before diving in, I would think through some technical issues:
The vaccum operated power piston will see constant vacuum from being on top of the blower. There are ways to modify a carb to see manifold vacuum. It's called boost referencing. Not sure how to do it on your carb.
Do some research on fuel total requirements. If your tri power set doesn't have idle circuits in the end carbs you might have some tuning issues.
The tri power on a blower has been around for a long time, but usually with different carb choices. Hope you get it all worked out and let us know.

 

^What is said above^. Also, progressive linkage, no. Diving around on one two barrel is not going to feed a 671 equipped engine. Research blower threads and read lots of info.

 

I put over 100k on a progressive linkage dual quad holley setup on a blower....it works fine....you'd be amazed how well it blends. And I doubt it's going to need boost reference, because it won't make much boost without letting in much air, because....

The big problem I see is that three deuces is about half the CFM you need on a 6-71. Maybe if you could squeeze 6 or 8 of them on there, you might have something.

 

Now we're talkin'.....

 

Here's my 6x2 set up that I run a progressive linkage on. The front two driver's side carbs are the primary carbs. It's an 8-71 on a 582 BBC, the carbs are large base Rochester 2g's.

It's runs great on the street and the track. I never had any issues with any cylinders running lean.

 

OK..then what size of Holley carb's should I be looking for, remember street only.
Thanks

 

Are we supposed to guess what engine you plan on putting this setup on?
Size matters!
Engine size that is.

 

500 to 750 depending on the size of the engine.

 

Seriously??? I know it won't be long before Google can read your thoughts and predict the futures, but we aren't there yet.

Tell us about the engine combo. Big difference in carb requirements between bolting that 6-71 to the side of a 300 I6 or on top of a 460 punched and stroked to 600 ci.

 

>>>I have a 3x2 setup with small base Rochester carbs, that I want to put on a 671 Detroit blower>>>

More likely a 350. 8^) Jack E/NJ

 

why try to run 3x2 set with blower?

 

Sorry guys...I feel like a dum ass....its a 350 with a 383 forged crank, rods, & pistons...30 over...Edelbrock 70cc chamber heads,
671 Detroit blower converted and rebuilt for gas.

 

I like the old school look

 

When was three rochester 2bbls on top of a 6-71 ever a look?

Just curious.

 

so, do you have any pictures of "old school" 3x2 / 671 to share here?

 

sorry I don't I just like the look of 3x2 set up.

 

I don’t know anything about blowers, but I like 3x2s also! Sometimes it’s about what you want.....not necessarily what you need!






Bones

 

https://www.jalopyjournal.com/forum...carb-plate-holley-94-intake-manifold.1041500/


Maybe still available? Jack E/NJ

 

Could always go with 3 AFB's like this guy. I talked to him at a show several years ago and he drives it all over the place.

 

Check this add in the Classifieds, from almost 4 years ago, but still active. Except it's Holley carbs, not Rochester:
https://www.jalopyjournal.com/forum...carb-plate-holley-94-intake-manifold.1041500/

 

There's this one in the Induction thread:

 

Here's a place to buy the adapter:
https://www.dashman.net/product.html?id=83

 

Thanks, I have the adapter, just need to find the right carbs with the right CFM.

 

If there is anyone out there running 3x2 carbs on a 671 street blower, would you please tell me what your running for carbs and what kind of CFM you have.....Thanks

 

Just use the ones you already got first. Jack E/NJ

 

For comparison, my 389 inch Pontiac with a 6-71 has two 750 cfm carbs. I started with two 600s, but the dyno proved them too small. To make boost, blowers need to draw free air through the suction side and three small cfm carbs may be too much of a restriction. They may also not be able to supply enough fuel, but only an air/fuel sensor can tell you for sure.

What are the cfm ratings of the carbs?

-Abone.

 

I did a quick HAMB search and it appears Holley 94s are about 185 cfm. If so, three of them might be OK on an unblown small block, but adding a supercharger will be dicey. A huge key to a blown engines lifespan is fuel delivery.

Another option is to hang six of those suckers on there like Thrashers ride. Plenty of cfm and it looks kick ass.

-Abone.

 

My buddies 32 ford glass car we built has a 406 chevie with a tk 500 trans and 4:11 gears has twin 750 holley blower carbs on a 8:71 runs excellent ,it is a street car,good gas mileage.I drove it from san jose to Pleasanton a few times

 

2Gs ranged from about 250 to 450. Jack E/NJ