Hello everyone! I've been working on my 8ba flathead for the past year or so and have finally set up everything in a way that works well, so in my head that meant I need a blower to mess it all up again. I just purchased a 471 blower with new rotors and new gears; it also has front and back plates and its been converted for gas use... Got a decent deal. So, the search for parts commences. I want to set it up as old school as possible. I plan to make between 4-6 PSI boost. I wasn't necessarily trying to spend a fortune. I have a good block but haven't spent that much time on internals. I found a MUNRO intake manifold online for around $700 and some snout options but still not sure about how this should all be set up. I heard some people prune their case (for looks I ***ume?). Honestly if it all fits, I don't care much about that. I also figured it would be smart to know my rpm's when setting this up, so I purchased a tachometer to hopefully make things easier for myself. I plan on running my dual holey 94's on top of the blower (hopefully that's enough) and would like to use v-belts. I expect I'll need 2 belts for the blower and another for accessories. I don't have a lot of space but would love to keep my mechanical fan somehow. If anyone's already set this up, I'd appreciate some advice/tips... I've never messed with blowers before, so this will be a fun experiment. here’s my flathead and this one here is one i found online with a 471 blower. Looks awesome
@Bandit Billy ! ? "Fan" Pic shown it's look's To be 1:1 pulleys . Whats your static compression? If static is 7:1 with 1:1 ratio is around close to 13 psi boost (4:71) = compression ratio total will be close to 13:1 ,, I do not think 2 94's enough CFM , a 94 are like 160 -180 cfms You would need about 25 percent under driven top pulley to make roughly 6 psi boost, On 7:1 static compression with 6psi will = 10:1ish under boost 2 94 should be enough I think with thought you could squeeze a mech fan in there with 2 v belts. Or even 1 inch belt ... It would be a custom made bearing stand pulley with fan. Or turn around the blower face it backwards run a drive shaft down the side to drive the blower belt off V belts Or a 1 inch ,,,I think outside the box, I think the new blowers on the Camaro are done this way blowers are backwards with the dry shaft
My brother's car I am building for him. I pruned the case because of the water manifolds, and he wanted the 2" belt. Custom alternator brackets. No room for mechanical fan.
The roadster with the blower is Carly Moodys I’m pretty sure. She posts a lot online but I bet this video would have clues.
Yup! I'm basing my build from hers a bit but not going pink on the block haha. and I may not prune it if it all fits. I wondered if I could do 1 v belt on the blower since im gonna be underdriven quite a bit but dont want to slip obviousy
Are you asking if I am a fan or what did I do for a fan? I am a fan of blown flatheads but alas I used an electric fan to cool mine. Not that anyone can see it buried in there so I don't worry about it. Mine is pruned (less is more?), it is a tight fit with a non-pruned (bushy?) 471 but it can be done I suppose. I do suggest spending a bit of time porting, relieving and dialing in the QR. And do spend some money on mains. You can just catch a glimpse of the fan here. It is buried in a br*** and German silver shroud where it has been doing its job nicely for several years.
pictures of a 3-71 with pruned case, and mechanical fan, for your enjoyment. 2 V belts isn't much for a 4-71.
@Ed95 Angle /deg of V , size of belt , & how much contact surface of Belt V to pulley V, you can look up spec's for this, Best to use Industrial/Commercial spec's information. @Bandit Billy you where one of that I thought of for B-FH's , probably had more knowledge of maybe how to run /set up mech fan on a Blower . My self I am sure I can fabricate & machine parts to accomplish. I have a roadster it has a FH now , I do not know if I am going to change direction keep the FH add one of the blower's , 4 bang , Jap straight 6 , 406 427 sb, & parts for close to 500 cid sb , BB's , 455 Buick , I have many other brands & combo's
With my Edelbrock heads compression should be more around 8:1, but maybe a bit less. I have STD bore and stock 8ba cam
By Looking @ previous pics I came up with another thought , You could make in a way & use the Blower belt Idler to attach a fan to, Also & depends witch way/ Direction you run / route belts would determine which style fan to run so it pulls air, & you could run correct length belts to center in the middle of the radiator
I am running a mostly stock bottom end, 3-71, flipped upside down, and pruned. Makes 200 hp and has ran low 8s in the 1/8 mile drags, 12s in the quarter.
Whats the formula? How do you determine pulley ratio and how do you know if the dual 94s is enough or not?
Just a few examples chart's & math.. The calculated numbers BELOW Does Not apply For your FlatHead just examples of other ways to calculate , Blower Cid Pulley ratios Blower speed Etc..
What the purpose to Pruned? Cleaner look Was done when a intake was not made for the outer mounts's ? Seem weaker with bolt's moved in ward As in not a wider anchoring point's. Leverage to twist. In post # 11 The idler not best to have on Left side for Clock Wise rotation . Post # 26 thats unique way to drive the blower off the F-H water pump to a certain extent. @JimSibley was the end plats reversed so air trapped in between case and lobe Or Air straight threw center & out the center ?
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