Technical Custom building a 4-53 Street Blower

Hey Bad,

I found a surplus of 6-53 blower housings. Thought maybe you could make use of them somehow : http://www.surplusman.com/Detail.php?itemid=3691

Mark

 

Well Rat, We've been discussing that one recently. Actually, we almost had a tall deck a little while back to work with. Falcon Bob, saw one for sale at Billet Proof. He should have bought the darn thing. I would have, but couldn't make it there...

I keep hearing that the head ports and bolt holes are the same for a tall deck. If that's the case, it wouldn't be a problem to build one from what we have so far. I just need to know the exact spread for a new plenum for the 6-71 and for the intake runners.

The manifold we have almost works for a Dodge Hemi. I had a chance to test that one out recently. New runners would have to be Fabricated along with a porting change on the plenum. Otherwise, everything else would pretty much remain the same.

This is in part why I have chosen to make the manifold a modular design. We could fab the runners as is providing that the pattern is the same. Then we could do two or three plenums for the right application for each Dosoto engine.


Octamag, thanks for the interesting link.

 

Wow, that came out awesome...now ya need to cook one up to put a 6v71 onto a 331 Chrysler Hemi. Not that I would have anything to gain from an intake like that

 

One project at a time, people. One project at a time...

We have to finish this project before we can move onto the next. I know everyone here is very excited about this. We are too! I want to see where this build will take us before we start thinking about doing this for other hemi's.

I will be resuming work on the blower pretty soon. I still have to make the front cover, the snout, the rear bearing cover, the thermostat housing, and the carburetor plate.

In the future I may post a tech segment on how to accurately measure your heads for the intake runner flanges. This would let you fellow HAMBers help us with future manifold projects that we may have. You could provide us with a set of real world measurements and drawings to go by. Does that sound like an idea?

 

The next piece in this project I will be working on this week is the front cover. Then I need to figure out the carb plate for two Holley 4150's...

 

Well, I'm back posting again... I just wanted to say that I'm currently back working on this blower project after doing some vacationing recently.

The bearing plates now have the mounting holes for the intake manifold adapter plate. The holes are 5/16 dowels and 3/8-16 heli-taps. Once, all the parts get hard coat annodized, I will be installing the inserts.

I'm currently in the process of machining the front cover for the blower.

We are going to try out a pre-made carb plate for 6-71 blower. I'm not sure how it's going to fit. We will most likely have to modify it...If it works at all. If not, at least we tried.

I should have some more photos ready to post by or before next week...

 

Well, we are moving forward with this project quite nicely. As with most prototyping and design work, it simply takes time.

The front cover is almost complete. I guess what's stopping me is the purchased items. I've been busy designing and machining and haven't allowed myself the time to order the parts. However, I need to do this to be able to complete the snout. I need to order the front seal and bearings.

Falcon Bob supposed to be getting a stock 291 water pump so we can get the front of the motor mocked up to determine the actual snout length. That is another thing we must do before wrapping up the snout.

Anyways... Ah... Here's some more pictures.

Project Photos:

 

i'll be interested in how you build the snout, what the bearings look like, the drive shaft.

 

This is a top notch build. From what I can see, the machine work looks to be well done, and the engineering well thought out.

The one thing I keep coming back to is the question, "Why convert this compressor section instead of buying one?"

I'm supercharger ignorant. Is there a reason that you wanted this specific compressor section, or are you just using what you have?

It just seems like a lot of work to build the conversion. If a fellow didn't have the machine tools, the skill, the material, and the time to do the conversion, would it not be more cost effective to buy a 6-71 that is already prepared to go atop an automobile engine?

What I'm asking, is whether there is any advantage to going through the non-trivial amount of trouble to convert this compressor section rather than buying a unit that was ready to go. Money VS Time? Coolness factor? Performance? Something Else? I'm just wondering, and this is a totally serious question, because I know basically nothing about all the different superchargers available. I know how they operate and all that, but the differences between the models and makes, I got nothing.

Obviously, I know that you had to build the intake regardless, 'cause it's for an obscure (or maybe better said as "non-mainstream") engine with no aftermarket support.

 

@Budd:

The construction of the snout will be covered later on. The design will not differ much to most standard designs. The components will consist of the snout body, front seal, the bearings and retainers, the input shaft, c-ring(s), and drive gear coupler. The sizing of the internals and design details are currently being worked out...

@CoolHand:

Your questions about converting the blower are very good and valid ones. Your right. Most people who are not willing or able to do the work would obviously purchase a unit.

We are converting the blower because that is what we have to work with. It is also imparted by the coolness factor, having access to the machinery and tooling, the unvailabilty of the parts for the application, and the knowledge and creativity we have. The conversion is a learning experience not only for us, but also for the general public. I think it's also to see if we can actually do it, and do it successfully at a reasonable cost with the "do-it-yourself" attitude in mind. We like building stuff ourselves. That's part of the fun of hot-rodding.

Up intil recently, the 53 series units have not been available for comercial resale converted for gasoline engines. Although, I have heard that there was supposed to be kits for them at one time. Not sure on that though. However, Lain Murphy now has these blower available for resale converted. There is a link in this thread for the web-site, if your interested.

As I have stated several times before, this kind of project is not for the average person. You must be willing and able to do the work. If you do choose to go this route, you will have something to go by.

 

Thanks for laying it out there, that's kind of what I figured.

Please don't think I was trying to run down your project or anything of the sort. It is obvious that you all have a good handle on the mechanicals and the machine work is top notch.

And I know exactly where you're coming from on the Do-It-Yourself-No-Matter-What factor.

I'm in the midst of building an English Wheel, entirely from scratch, including the hardened 4140 anvil wheels and the elevator mechanism.

I will likely end up spending nearly the same amount on mine as if I'd bought a kit (especially if I count my time worth anything), but this one will function exactly how I want it to, be made from the parts I wanted used, and be built in the shape I wanted it in. Hell, it'll even be painted the color I want it painted too.

I know exactly where you are coming from.

This is a very cool project, and the end is result is going stump the hell out of people when they see it setting atop that DeSoto motor. That ought to be worth something all by itself.

 

@ CoolHand:

I didn't take your questions about our project in a bad way at all...

I've had the blower core for about four years I think. I was looking for a blower to convert for a SBC I was going to build up. The original plan was to use a 6-71 on a 350 built as a 383 stroker or even a 406. Both motors I currently have sitting in my garage.

Falcon Bob located this 6V53 blower core in West Virginia for a 100 bucks. Since the unit needed parts machined for it in order to convert it, I set it aside intil I had time to mess with it.

The whole project started when Falcon Bob found a 1955 291 CID Desoto Hemi. He knew he wanted to use this motor for a custom pickup truck project, which consists of a custom built frame and a 39 Dodge cab and box. Bob wanted to build something that was crazy and over the top, so we both played around with the idea of supercharging the little Hemi as time went on.

There is not much available in parts for either the 6V53 Detroit Diesel Blower (intil recently with Lain Murphy, but only for SBC and Flat-Head Ford applications) or the Desoto Hemi. Since both pieces are sort of rare odd balls in the hot rod seen, we decided that this would be the perfect project to build totally custom. So, your exactly right! It would be really something that nobody has ever seen.



The project is still going quite nicely. I am finished with the carburetor plate for the blower. Can you say dual Holly 4150's?

I am currently working on the crank pulley for the motor. Instead of using a cog style setup, we are going with a nostalgic double v-belt design. So, we are using a SBC 3 groove pulley at the crank. The inner groove will be used for the accessories, and the two outer grooves are for the blower. That is if everything works out right.

What do we have left? The rear cover of the blower, the tensioner pulley and bracket, and the snout/drive assembly. The snout will be finished once we determine it's length.

I should have more photos to post pretty soon!

 

I was going to wait to post when I had the more pictures, but I had some information about the crank dampener that may prove useful to some.

The bolt holes used for the pulley on the dampener is 6 holes on a 2.812 BHC. The interesting thing is that one of the holes is rotated 5 degrees from the rest of the holes. It's still for a 2.812 BHC, but just rotated. I believe this is so you couldn't mount the pulley on the dampener backwards. So it's 0, 60, 120, 180, 240, 295 degrees...

Here is a photo of my handy work converting a 3 groove SBC crank pulley to a Desoto. The other photo is actually a drawing for people who need help with the dimensions of the holes.

 

Okay. I have some questions about this hub or dampener. I was thinking about this thing after I made the last post.

We got this part with the motor. I have no idea if it's the stock piece or not. Besides the odd bolt pattern, it has 5/16-18 holes in it. Are we missing something here? This particular piece doesn't have any timing marks on it either.

We even looked up several dampeners from Hot Heads to see what they had to offer. They have three versions; a stock replacement, a fluid version for blowers, and a SFI approved steel for blowers. The last two have timing marks that we could see. We didn't want to go buy one unless it absolutely warrants it.

Does this piece look like the stock version or is it an old aftermarket piece? Not sure on this because we never built one of these motors before.

There are numbers on the back: N2 127660 1735045

Here's a photo of the darn thing:

 

Thanks for posting! Great work.

 

Yes BBM, that is stock for the 276/291. I have several just like it. Steven.

 

@ Power58:

I'm assuming that the bolt hole dimensions were of some help to you. I kind of figured that someone would get use out of that.

@ Bullrack:

Thanks for the info about the dampener. I figured that it was probably a stock piece, but I just wanted to double check.



I should be finishing up the rear cover and the drive gear coupler for the blower this week...

The rear cover functions as a rear bearing retainer and dust cover. The cover will be gasketed to ensure it seals against the rear bearing plate and it has the same bolt pattern as the front cover. Other than that, it's mostly for looks.

Here are some more photos of our progress:

 

All I can say is "DAM that looks good" one more time. Can't wait until you get it on a running engine.

 

I'm glad your enjoying the photos...

And Yes! More photos:

 

I'm currently working on the drive gear coupler.

I wanted to cover the basic parts of the snout design. The snout I'm building for my blower shouldn't be much different to most designs currently used.

Parts:

1 - 6061-T6 Aluminum Snout Body
1 - 25 mm dual lip w/ spring seal (62 mm dia. X 7 mm thickness)
2 - 20 mm 5200 light series sealed duplex bearing (20 X 47 X 13/16)
2 - 4150 moly steel bearing retainers (6 bolt design)
1 - C-ring clip
1 - 4150 moly steel input shaft (drive diameters 25mm to 20mm to .750 spline)

I'm basically going to build it similar to a machine spindle. Some of the details on the dimensions are pending...

The bearings are double sealed and are rated for about 4700 lbf dynamic load, 2700 lbf static load, and 9000 rpms with grease. This should be adequate for our purposes. You could also substitute a 5300 medium series bearing. It's a little bit heavier, but the difference is not that much to worry about. We probably wont run this blower much over 8000 rpms (if that) anyways. If it does go up to or over 9000 rpms, it wont be for very long. We have to remember that we are pushing a 2200 lbs vehicle around with this motor.

Both front and rear bearings will press into a held bore and are kept in place with the steel retainers. Both bearing bores will be concentric within .001 of and inch. The thru hole will be clearanced for the 20 mm shaft section (probably .875 dia. or so).

The front seal will press into a 67mm X 7mm bore. The shaft diameter here is at 25mm. There will be a shoulder between the two diameters that rides against the front bearing inner race. The c-ring will retain the shaft at the rear bearing inner race.

Except for the physical dimensions, it is not much different than what would be used on a 6-71 blower snout.

I'm waiting to do the snout intil we know the exact length. I guessing that the snout should be about 5 or 6 inches in total length.

Here is a photo of a 6-71 input shaft and coupler:

 

All the machine work for the new billet rotors have been completed. Yes, each set of rotors and shafts are lighter than the stock pieces. They are 2.25 lbs lighter per set for a total of 4.5 lbs total.

However, the shafts still need to be ground, splined, and pin hole drilled and reamed. That will be taken care of after anodizing due to the small amount of surface building that takes place. This is usually .0002 to .0008 during the normal anodizing process. We desire a metal to metal press fit to no more than .0002 press.

Each rotor has four 5/16 lock pins which are pressed thru the rotors and shafts. There will be two pins drove from one side and two pins drove in from the opposite side in a blind flat bottom hole, which is fully reamed to press diameter. This should help keep things really secure and minimize unbalanced weight. This means that each pin will be driven into the holes down to a 1.300 inch depth and not all the way thru the rotor. The pins will fully engage the rotor pin hole to depth on the other side of the rotor shaft more than .125 inch. Then the pin will be locked in with a flat head screw with a little bit of thread locking compound. The rest of the balancing issues will be addressed later during the dynamic balancing of the assembled parts.

Hopefully you can understand what I've just said.

The pins haven't been taken to length yet. Just in case your wondering...

Here's some photos of the work:

 

Boy you are going to have some real satisfaction when you mash down the go pedal on this one!!! Spectacular stuff. Are you going to pin the rotors to the drive gears? Sorry if you have previsouly explained that I have not gone back and studied. Thx.

 

So, will you sell a guy endplates? that back cover looks NICE!

 

Why not drill and ream the pin holes thru, then countersink both sides, and use two keeper screws.

That would not only positively retain the pins, but solve your balance issues (or very nearly so).

Any particular reason why you're wanting to go with a single keeper? Is it just to keep the weight down?

EDIT: I may have asked this before, but how were those rotors made? Extrusion? Cut from bar stock? Something else?

If you machined them from bar stock, how did you cut the hollows in the ends of the lobes? Or for that matter, the center shaft hole? Long bores like that are always a bitch to bore accurately, so I'm always interested in seeing how different guys go about doing it.

 

@ Tudor:

The rotor shafts will be indexed and splined to match the drive gears. On The driven side (left facing front), there will be a .25 thick ground steel washer that seats down inside the gear that has a thru hole for a 3/8-24 bolt for the end of the shaft, which holds the gear in place (near stock configuration). On the drive side, the coupler bolts to the front of the drive gear with four 1/4-28 bolts and one 3/8-24 center bolt which is also piloted. So, to answer your question... The gears are indexed, splined, and bolted into place on the shafts.

Although the coupler is not complete, here's a pic. I hope it helps.


@ Tman:

I could possibly do that. Is this for your 4-53?

You would have to have your stock rotor shafts reground to 20 mm to accept bearings (5200 light series duplex front and standard deep grove radial for rear). Then you would need a front cover, bearing plates, rear cover, bearing retainers, thrust washers, and possibly shaft wear rings.

I haven't even included a snout either. That depends on what your doing or if you plan on adapting and existing. I know a 192/250 powercharger snout goes for around $770.00 from The Blower Shop online. That's not including pulleys and tensioner I think.

 

I would be good with just the plate

 

@ Coolhand:

We played around with the idea of using double screws. There are several reasons why we chose this single screw design.

We wanted to be able to use "off-the-shelf" parts as much as possible especially when it comes to fasteners in this build. We are using 5/16 X 1.5 case hardened pull dowels cut to 1.300 length with 10-32 flat head alloy screws. If we used two screws, we would have to make custom pins with threaded holes on each end, which would also require grinding the diameters. Would that out of the realm of possiblilties? Absolutely not.

However, the head size of the screw is about .377 diameter X .130 long at 82 degrees included angle. The dowel is .313 diameter. The wall thickness between the shaft bore and the valley of the rotor is 1/4 inch. If we reamed the hole all the way thru, that would only provide about .120 inch on each side for the pin to engage the hole in the rotor. This is not to mention that you would lose at least 2/3rds of the chamfer for the flat head screw.

Are method allows for full pin to bore engagement at least on one side in the rotor and .125 seated on the other side, while still giving us the full chamfer for the screw head. The chamfers double as a locator and as a strong clamping point due to more surface area.

We also did the opposited pinning for two reasons. First, to minimize stress in the design. Two, to equalize weight distribution.

Yeah, we could have just reamed the holes thru and just pressed the pins in, but I wanted a bit of insurance that they were not going anywhere...

As for the rotors, they are CNC machined from billet solids using the original rotors for measurements. Measurements were taken on a CMM.

The bores were indicated centerline. Center drilled, drilled, bored (Criterion head and 5 inch long boring bar) leaving only about .005 in hole, and Wickmen Reamed to size. Wickmen reamers are nice because they cut really straight and leave an excellent surface finish especially in aluminum.

The bore is only held to about 5 inches in depth of the material. The remaining 3 inches or so is actually clearanced to about .010 over the bore size in order for the shaft to slip all the way thru. Bores are inline within .001 concentricity.

Does this answer your questions?


@ Tman:

Just the bearing plates? Or rear cover?

 

CoolHand, if you need more information about how to machine and bore deep pockets and holes, leave me a PM. I would be happy to help.

 

Sorry, I have bearing plates. Just rear cover.

 

We've been watching and following what 345 Desoto has done with his 291 Desoto blower motor. I must say it's has been very informative for us as far as what choices there are for motor internals. Well, at least the cam and lifter options we could go with.

Falcon Bob has been in contact with Donny Johansen for the last couple of weeks. It looks as though Donny will be grinding a hydrualic roller cam for our motor.

I don't know all the details as of yet, but it looks like we will be running the cam along with the same LA style lifters 345 Desoto used, and a set of custom length hardened push rods. Of course, this means doing the same clearance grinding to the lifter access holes that 345 did on his 291 motor. Well, unless someone tells us differently.

I guess from talking with Falcon Bob, the cam specs are pretty fat. Donney will be grinding us something that's really crazy. Bob seems to think we need to go with a set of custom Ross forged slugs fitted to the new cam specs. I guess there may be a valve clearance issue he's worrying about.

We also decided to upgrade the old stock crank hub to a fluid dampener setup. Might as well after doing all of this work so far... I also suggested going with a different crank pulley. I think the one we are using may be too big for our purposes. I only plan to overdrive this blower to only about 10% anyways.

Once we get all the cam and valvetrain issues worked out, I will be posting a complete detailed list of components and proceedures.