David Vizard bench flows a BBD 2bbl

-
Rat Bastid said:
I don’t know but it would be fun to test. Of course, you’d need to do the port work after installing the bigger valves.
Click to expand...
It would be interesting to see the difference but I doubt they will do that in this build. Can't say that I blame them it would add alot of extra steps to an already pretty big job.
 
If the engine built to displace about 500cfm is gonna basically do it no matter what carb you run, carbs only flow a specific cfm on a flow bench, on different engines they flow different amounts at wide open. It's just the two barrel and intake is way more restrictive which will kill say 50 hp which will bring down the cfm the engine will displace somewhat but still be way over the carbs 250 cfm. And the holley 500 cfm two barrel is rated like a two barrel so really be closer to the 318 one.
 
Dartswinger70 said:
If the stock LA head were to be used they would need positive deck height pistons. Last I checked they cost 1000 dollars or so.
Click to expand...
Wow $1000, what pistons would those be?
My 318 has a positive deck height, pistons were around $400US (kb 167). The domed 399 is about $50 more.
 
273 said:
If the engine built to displace about 500cfm is gonna basically do it no matter what carb you run, carbs only flow a specific cfm on a flow bench, on different engines they flow different amounts at wide open. It's just the two barrel and intake is way more restrictive which will kill say 50 hp which will bring down the cfm the engine will displace somewhat but still be way over the carbs 250 cfm. And the holley 500 cfm two barrel is rated like a two barrel so really be closer to the 318 one.
Click to expand...
Can you clarify the part about the 500cfm 2bbl rating and the bbd carb?
 
92b said:
Can you clarify the part about the 500cfm 2bbl rating and the bbd carb?
Click to expand...
Two barrels and four barrels are rated at different vacuums, 3 "hg and 1.5 "hg so two barrels are rated higher than if they were measured with the 4 bbl 1.5 "hg, higher the vacuum the more air will pass through. DV flowed the bbd at the 1.5 "hg.

A carb really don't have a static flow amount "cfm" it depends on how much vacuum is being applied/produced.
 
Last edited:
Ted265 said:
Wow $1000, what pistons would those be?
My 318 has a positive deck height, pistons were around $400US (kb 167). The domed 399 is about $50 more.
Click to expand...
Have you priced pistons lately?
 
Furious65 said:
Mmm, I think that was their assumption and they mislead themselves.

UTG, DV, and Andy are pretty much using stock parts yet they are modified and will be extensively so on some of them. Most anyone that thought you could "tune/tweak/recurve/jet/ to get the 300" out of a 318 with a BBD carb and 100% untouched OEM cam, or any piece for that matter, knew it wasn't possible and were looking forward to UTG's failure so they could point and laugh. Honestly, this build wouldn't get near the scrutiny it has so far if UTG wasn't involved. People need to take their bias out of it and just pay attention and learn from what DV is putting out there and let the chips fall where they may.
Click to expand...
Really all Tony did was donate the junk I suppose
 
Last edited:
I would be FAR more interested if these "gurus" would take your typical set of parts from a decent buildup and show real world ways to make more power. MOST guys building up an engine for their hotrod, doing it themselves and with a reasonable budget, will be able to achieve a nice 400-475 hp with bolt on parts. I'd like to see them take that setup, and show us "normal dudes" what changes to make so we take that 400-475 hp engine and make it a 475-550 hp engine. That would be interesting to me.
 
So their goal is 1 hp per cubic inch?

Food for thought:

1969 Dart stock eliminator Q/SA 318 2 bbl with minimum weight of 3094 with driver ran 12.93. This equates to 287 hp. Would love to know what the hp is on a dyno.
 
There's a big difference between a generic "Recipe for 450 HP" and "Lets make 1 HP per cube with stock parts"

Any monkey can bolt parts together but building efficiencies across the board with a airflow limited engine takes smarts and hard work.
 
Also the carb they stated only flowed 256 cfm which means they have to make 1.24 HP per cfm. There are things that can be done to the carb to increase airflow like thinned throttle shafts and plates and contouring the booster to name a few. Its not out of the question, not easy but will require a well thought out approach.
 
I think a lot of people play with the thought of "what if". These guys are just putting wheels of motion under the "what if". That is a great thing!
 
Ted265 said:
Fair enough, I think for the majority of builds the hypers would do just fine.


Not for about 6 months or so. just checked summit - the hypers are $488 a set now.
Still not that bad
Click to expand...
That is a good price for those. The .30 overs are even less @ $458
 
Hysteric said:
Also the carb they stated only flowed 256 cfm which means they have to make 1.24 HP per cfm. There are things that can be done to the carb to increase airflow like thinned throttle shafts and plates and contouring the booster to name a few. Its not out of the question, not easy but will require a well thought out approach.
Click to expand...
The engine isn't gonna only see 256 cfm, it would only see that if it was pulling 1.5"hg at full throttle but it will be pulling vacuum way higher than that, air is compressible, it's just gonna use more pumping power to do so.
 
273 said:
The engine isn't gonna only see 256 cfm, it would only see that if it was pulling 1.5"hg at full throttle but it will be pulling vacuum way higher than that, air is compressible, it's just gonna use more pumping power to do so.
Click to expand...
And the mice are up to full speed.....
 
92b said:
It would be interesting to see the difference but I doubt they will do that in this build. Can't say that I blame them it would add alot of extra steps to an already pretty big job.
Click to expand...
I'm sure there are tons of 1.88" intake valves littering the floor yanked out of perfectly working J heads in favor of 2.02"s at Tony's, easy bet those will be going in at a minimum. WITH port work.
 
273 said:
The engine isn't gonna only see 256 cfm, it would only see that if it was pulling 1.5"hg at full throttle but it will be pulling vacuum way higher than that, air is compressible, it's just gonna use more pumping power to do so.
Click to expand...
Sorry you're right they did test it @ 1.5"hg. Maybe they did that because everyone thinks in terms of 4 barrel cfm. Maybe I was a little too hasty in my calculation of hp from cfm. Need more coffee......

Agreed Air is indeed compressible and above 150 ft/sec the venturi coefficient of discharge is substantially constant.
 
Last edited:
Killer6 said:
I'm sure there are tons of 1.88" intake valves littering the floor yanked out of perfectly working J heads in favor of 2.02"s at Tony's, easy bet those will be going in at a minimum. WITH port work.
Click to expand...
I might not have said that clearly. What I meant was if they put in bigger valves we probably won't see the stock valve vs big valve test to see the HP difference. To me that would be interesting.
 


I recommend re visiting this, this is what Tony's knowledge and skillset is capable of. This fail is may be acceptable if it is done by a teenager in a high School auto shop IMO.
 
Last edited:
Mean416 said:
I would be FAR more interested if these "gurus" would take your typical set of parts from a decent buildup and show real world ways to make more power. MOST guys building up an engine for their hotrod, doing it themselves and with a reasonable budget, will be able to achieve a nice 400-475 hp with bolt on parts. I'd like to see them take that setup, and show us "normal dudes" what changes to make so we take that 400-475 hp engine and make it a 475-550 hp engine. That would be interesting to me.
Click to expand...

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^Totally agree--100%
Things I don't understand about this endevour.

1. Why limit yourself to a tiny 2bl? Just use a good 4bl and test with the stupid 2bl at the end and marvel at how it lost 70-90hp.
2. Why state from the outset "all stock parts"? That was just dumb/naive and probably just hyperbole to get us on the hook--which we are

The above quote is the camp I'm in. As stated it really isn't all that hard to get 400+hp with some nice realistic parts and normal machine work. These gurus should be in a position to show us how to get a gnarly hi-revving 500+hp with their skill set divulging REAL techniques whether "secret" or just hyper-attention to detail. As it stands this 300hp goal is asinine and fruitless. J.Rob
 
"Nicks garage" shows what these engines can do for real. No Uncle Tony fantasy imagination nonsense. There are channels worth watching the thing is deciding if you want fiction or non fiction content. Nicks will show you LA 318 making 230-250- hp and he will show 340-360 making dern near 400 hp . It really is all about what you want to watch on YT. Uncle tony is for couch potatoes, Nicks is for guys actually building engines Just my $.02 IMO there obviously is a lack of information being put out there that I consider to be common knowledge, for example IMO if one were going to do a 318 build these days go with the 5.2 magnum just for the heads and roller cam setup that should be a no brainer. UTG touts that 70s 318 and people the misinformed will run out and get one he should be saying "get a magnum they are still in the junkyards" . 70 LA engines are just old low HP smog engines the 70s 360 was close to being just as bad as the 70s 318. The 360 had dished pistons low compression etc. But the 360 had the bigger valevs and ports even on a 318 you neeed good flow this is why I would choose the magnum if I was starting out on a budget.
 
Last edited:
Dartswinger70 said:
"Nicks garage" shows what these engines can do for real. No Uncle Tony fantasy imagination nonsense. There are channels worth watching the thing is deciding if you want fiction or non fiction content. Nicks will show you LA 318 making 230-250- hp and he will show 340-360 making dern near 400 hp . It really is all about what you want to watch on YT. Uncle tony is for couch potatoes, Nicks is for guys actually building engines Just my $.02
Click to expand...

You're 95% correct. The problem is almost everything Nick builds makes about 400hp--He can show you how to build a 400hp 340 and he can also show you how to build a 400hp 440. Until the supercharged 440 episode I honestly started thinking Nicks dyno was broken and "stuck" at 400hp--LOL Nope . I guess he is in his wheelhouse building smallblocks and bigblocks that seem to make around 400hp. Yes there are a few exceptions of course. J.Rob
 
Mean416 said:
I would be FAR more interested if these "gurus" would take your typical set of parts from a decent buildup and show real world ways to make more power. MOST guys building up an engine for their hotrod, doing it themselves and with a reasonable budget, will be able to achieve a nice 400-475 hp with bolt on parts. I'd like to see them take that setup, and show us "normal dudes" what changes to make so we take that 400-475 hp engine and make it a 475-550 hp engine. That would be interesting to me.
Click to expand...
DV has and wrote books about it.
 
You must log in or register to reply here.
-

Back
Top