4-71 GMC blower ??? Want to put it on my Flattie

Bored & Stroked...I have a few 4-71's, neither has a cross bar, top or bottom.

 

R Pope you have a few then fess up one...........LOL

 

I am in no hurry but I want one for my Vick . that is not going to be touch for a while.

 

If you want a setup 4-71 blower I have them ready to bolt on and run with the clearances you need for a hot rod for $450 plus shipping. This includes a gl*** beaded case and endplates, tear down and inspection set clearances, machine off the flange at the side and re ***emble with new seals. The rotors are triple pinned in front and the rear bearing plate cutdown. The real challenge will be making a snout to drive it all and clear and align with the flathead parts. call me at 316-393-1105 or send me an e-mail to gary_r@cox.net and we can get this thing going. I can do the machine work on your manifold if you need. I've been doing blowers for about 40 years and can send you some pictures of some 4s.

 

I have 2 questions:

When was the V53 blower born?

When was the -71 blower born?

Here is a pic of the V53 my Dad is setting up on a Lincoln V-12...

 

FWIW... Mitchell from New Zealand makes a 4-71 manifold for $299. Sometimes they pop up on Ebay, but I contacted him once about one and I think I still have his info if you want to go that route. Lemme know...

 

Interesting - I stand corrected TWICE in two days Do you know if they came from the factory that way - or has the center bar been removed? (Which is a common practice). Are they GM cases - or aftermarket? I'm just trying to gather as much info as possible. I have four 4-71's -- all have the center bars.

 

Here is a link to another vendor that has a purpose built 4-71 manifold:

http://www.uncommonengineering.com/catalog.html

Here is a link to H&H flatheads -- they have been into blown flatheads for quite some time. They bought out Barvey Navarro before he p***ed and have also repopped the famous SCOT blower:

http://www.flatheads-forever.com/home/

Best of luck in your adventure!

 

Here are some pictures of 4-71 that was rebuilt..........this is what the rotors should look like......................still waiting for the machine work to put it on the Navarro manifold.
If you want someone to rebuild the blower for gas, Lain in Colorado is the guy, he is the one making the "New Scott" blowers for H&H, and is a member of this site.........although I haven't seen him post lately.
If you do build your own manifold.............don't forget the "pop-off-valve(s)" like on the Navarro manifold...........could end up saving the motor if you ever backfire!

Oh, if you are going to shoot for 7/8lbs boost you will need to use a main girdle support, better than stock rods along with forged pistons to keep the motor alive for any length of time.

 

I totally forgot to send a picture of main web support I will be using with this blower motor.
Of course it will require making a heavily modified oil pan but because I plan on using an external oil pump driven off the crank I would have to modify it anyway.

 

Yup, 4-53.....I have an NOS one. I posted the cfm chart in a blower thread the other day. I plan on running mine on my flatty, Joe Abbin mentions them in his Fathead Blower book.

I SAID 4-53

 

Wow!! That's a seriously reinforced center main!!!
How much HP do you think you'll get from that flattie?

Flatman

 

Flatman,

It does support the center main, but also ties the outer block rails together limiting flex in the outer block........................would like to have a little over 400HP with 9/12 lbs of boost.
I will do some experimenting on the street motor which will be running 6/8 lbs of boost and I won't be using the main/center web...........................we will see????????????

 

We make all the snouts , pulleys, idlers, tensioners ,drives , manifolds etc fot the 471 and the SCoT blowers for the Flatheads, so if your in need of parts and pieces or info give us a call and check out the web site at flatheads-forever.com
Thanks Max Sr.

 

Once again 4-53

And not a 4Vanything

 

TMAN my blower is the same thing you have? If so what are you doing for end plates and snout. I understand that I have to fab up a manifold as well as a carb plate. But I am curious to were to get the parts I will need if this case is still good.

 

Yes, I have an NOS one exactly like yours (minus the gouges) A blower guy in another thread mentioned the 4-71 gaskets and end plates will bolt on, I need to find one to try. Otherwise, I was going to machine my own setup. For the flatty intake, I will mill tthe top off an intake and add a plate. Local engine genious did one with some added features and it came out nice

 

Here is a search I ran

look at the thres ***led "453s" Mine is the right one pictured in Pauls reply

http://www.jalopyjournal.com/forum/search.php?searchid=3367575

 

Mine does.

 

Yeah Crustnut has a tech about taking an old aluminum intake and chopping it down. I am really interested in youtr progress. Oh yeah thanks again for reminding me about the GOUGES.............LOL........ I still think it is worth the $50 bucks . I will use it to make a manifold and carb plate.

 

As for the mounting on my style blower it seems stronger than the other style.

 

I'm happy to say that John was nice enough to sell me his "extras" and that Navarro/4-71 combo is waiting patiently for a new home on top of a flathead.

 

Agreed, the thru-bolts are nice, I like the fact there is no ugly flange like a 4-71 would have.

 

When were they first made?

No one knows? That's hard to believe...

 

Dunno Kris, but mine came in 80s vintage packaging. In fact I think there is a date code on mine.

 

Making a manifold adapter:

http://victorylibrary.com/mopar/blower-GMC.htm