250/256 Holley/Weiand Superchargers.

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pdq67
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250/256 Holley/Weiand Superchargers.

Post by pdq67 » Sun Oct 29, 2017 5:08 pm

How big an engine will these support?

I ask because I feel that the little 144/177 superchargers are a bit small on any decently sized engines..

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Re: 250/256 Holley/Weiand Superchargers.

Post by bigjoe1 » Sun Oct 29, 2017 7:56 pm

I do know that on a 350 SB Chevy, they make 100 more HP than without it





JOE SHERMAN RACING

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Re: 250/256 Holley/Weiand Superchargers.

Post by vortecpro » Sun Oct 29, 2017 8:42 pm

Back in the 80s we used to take that 144 and put it on a 300 inch motor with as much compression as I could get. I used a Ron's injector on Alky, a lot of power at the time.
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Re: 250/256 Holley/Weiand Superchargers.

Post by mark_follweiler » Sun Oct 29, 2017 9:01 pm

put a 144 on a 81 Camaro. turned it into a BEAST! for a 81 Camaro...... :wink:

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Re: 250/256 Holley/Weiand Superchargers.

Post by F-BIRD'88 » Mon Oct 30, 2017 12:29 pm

Better to look at it from a how much horsepower will it support perspective.

A 142-144 blower tends to top out about 480-490hp on gas.
Starts creating more heat than real boost if you spin it too hard without intercooling.
Or methanol.

A 177 tends to top out abut 650hp on gas. you have to spin it fairy hard to get this.
As you spin a roots blower faster more heat is created.
Both these tend to work real good up to about 2.3 2.4 :1 drive ratio on gas.
Methanol or water injection which cools the charge allows you to push them harder
and make more reliable power with that.

I would imagine the 250-256 will top out about 800 +/- on gas.
( again makes more on methanol)

The lil Eaton 's Magnuson blower make more power than the size would suggest
as the are more efficient. In that they move more air and heat that air less by their design.

The lil Eaton Magnuson MP122 hh ( high Helix) has shown 600 dyno hp on a hot 406 SBC
( And a mountain of torque) when spin agressively.

It is relative to what you bolt the blower on to. Bolting a 144 on a 305 SBC is going to have more of a power gain effect on it than say on a 383. at a said drive ratio

If you build the engine to pump a lot of air too, then the boost is lower and power is higher relative to the drive ratio used on the blower.

You want to put a BIG carb or 2 carbs on any all these so they can be all they can be and make power without pump HP loss. Again think in terms of how much HP you want to create. Be generous here.

If you bolt a roots blower on a restrictive low perf engine (small heads small cam small exhaust) you will create a lot of gauge boost and only modest power relative to a good deep breathing engine.
At a said drive speed.

The blower drive pulleys that are supplied in the kits are relatively mild.
You can "step on it harder" than that by increasing the drive ratio up to the point where
charge heating becomes excessive. At that point intercooling is required ( methanol,,,,Water )
Roots blowers love intercooling.


How much power are you looking to create?

There is no sbc intake manifold for the 256 Blower and it is out of production.
It was used on BBC marine motors (525SC) Dyers Blowers does service and rebuild these
and the others too.

Ont the street for reliable supercharged power you have to balance engine compression ratio, blower drive speed ignition timing @WOT and gasoline octane.
Detonation must be avoided on pump gas. Higher octane allows more agressive drive speed and boost and power.

Roots superchargers are air movers not compressors.

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Re: 250/256 Holley/Weiand Superchargers.

Post by F-BIRD'88 » Mon Oct 30, 2017 12:36 pm

On your typical low cr 350 SBC high perf street the 142-144 blower makes about 450 460hp
and a great amount of TORQUE at moderate boost and blower drive speed on pump gas.

2.00 to 2.10 drive ratio If when you try to push it harder for more power beyond this
the blower starts to create a good bit of heat and the 6 rib belt tends to slip.

More drive speed requires the 10 rib drive and higher octane fuel. 100+
They tend to top out about 480-490hp on gasoline in non-intercooled form.
if you want 600hp from a SBC use the 177 blower.
If you want more than 600hp from a SBC use a 6-71 or a 8-71 blower.

If you want a "small blower" and want between 500 and 600 HP from a hot street/strip SBC
the Eaton/Magnuson MP122hh is what you want.

So....how much horsepower is enough?

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Re: 250/256 Holley/Weiand Superchargers.

Post by F-BIRD'88 » Tue Oct 31, 2017 9:57 am

Other choices that are great replacements alternatives to a 250-256 blower is the TBS (The Blower Shop)
190 CID billet roots blower. it is available in a SBC kit. It should make a bit more power than a 177 Weiand as it is a bit bigger at 190 CID. This Billet case roots blower has a 4-71 style top flange for a blower carb adapter allow using various carbs setups. Single 4150, Dual AFB's or single 4500 or even EFI.
It also has a rugged drive system using either 10 rib or 16 rib belt and pulleys.
It is a good looking blower that appears well made. Its a bit smaller than a 6-71.

Last is the new Edelbrock Enforcer Classic dual carb or EFI blower.
It is a 140cid (2300cc) based on a Eatons 2300 supercharger. Same efficient Eaton supercharger design as the Eaton/Magnuson MP122hh. Can use 2 AFB carbs or 2 EFI throttle bodies. Can be intercooled.

700++ Horsepower capable. A much better idler/drive belt tension system.

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Re: 250/256 Holley/Weiand Superchargers.

Post by vortecpro » Tue Oct 31, 2017 10:12 am

My/Gary 144 ran 138 MPH @ 3350 in a car that was a piece of junk in Phoenix in 110 degree heat. I get 687 observed HP. I did make a custom tensioner.
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Re: 250/256 Holley/Weiand Superchargers.

Post by F-BIRD'88 » Tue Oct 31, 2017 10:25 am

vortecpro wrote:
Tue Oct 31, 2017 10:12 am
My/Gary 144 ran 138 MPH @ 3350 in a car that was a piece of junk in Phoenix in 110 degree heat. I get 687 observed HP. I did make a custom tensioner.

Thats on Methanol,,, right? Do you remember the drive ratio? Did you use your own or custom drive pulleys?

Like a larger diameter 7.80" crank pulley... (10 rib)
Were you using it on the B&M Holley intake manifold (which is a bit compromised to get a low height) or on a better SBC blower intake manifold?

Some people go for a cogged belt/pulley system for racing (requires a blow off valve on the manifold like a 6-71.


Impressive perf. These lil blowers love Methanol fuel or Water/meth injection and race gas when you drive the hell out of them.

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Re: 250/256 Holley/Weiand Superchargers.

Post by vortecpro » Tue Oct 31, 2017 10:01 pm

F-BIRD'88 wrote:
Tue Oct 31, 2017 10:25 am
vortecpro wrote:
Tue Oct 31, 2017 10:12 am
My/Gary 144 ran 138 MPH @ 3350 in a car that was a piece of junk in Phoenix in 110 degree heat. I get 687 observed HP. I did make a custom tensioner.

Thats on Methanol,,, right? Do you remember the drive ratio? Did you use your own or custom drive pulleys?

Like a larger diameter 7.80" crank pulley... (10 rib)
Were you using it on the B&M Holley intake manifold (which is a bit compromised to get a low height) or on a better SBC blower intake manifold?

Some people go for a cogged belt/pulley system for racing (requires a blow off valve on the manifold like a 6-71.


Impressive perf. These lil blowers love Methanol fuel or Water/meth injection and race gas when you drive the hell out of them.
It was injected alky with compression, 6 rib which was constantly a problem. We put walls on the pulleys to keep the belt on with a custom tensioner. Would have been faster in a good car, but power was like an on and off switch with that injector, very low buck power, the problem.........joe was going 138 MPH in his NA small block station wagon at the same time :shock: theres some reality for you...................yes the 80s
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Re: 250/256 Holley/Weiand Superchargers.

Post by F-BIRD'88 » Wed Nov 01, 2017 4:04 am

Good stuff.... "joe" is that Joe Sherman you're talking about? He's too much eh! He has probably forgotten more about what it takes to go fast than we all will ever know.. 8)

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Re: 250/256 Holley/Weiand Superchargers.

Post by F-BIRD'88 » Fri Nov 03, 2017 12:49 pm

pdq67 wrote:
Sun Oct 29, 2017 5:08 pm
How big an engine will these support?

I ask because I feel that the little 144/177 superchargers are a bit small on any decently sized engines..

pdq67

PDQ67 are you thinking about supercharging your 325 cid sbc?

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