B&M 250 Supercharger: Rotor Restripping and Reassembly (78 Firebird Ep.28)

The rotors from our supercharger appear to be in good shape, but the seals could do with a refresh. I had never done that particular job before, so we'll have to try to figure it out as we go! After that, the supercharger is finally ready to be put back together and we will work through it step by step, problem by problem.
Part Numbers (for this particular unit):
Snout/Input Bearing: 6304-2NSE9C3
Snout/Coupler Seal: 471787
Front Rotor Bearing: 6204-2NSE9C3
Rear Rotor Bearing: BHA1612Z
Rear Rotor Bearing Race: IR-121612
Rotor Shaft Seal: 471224
Case End Gaskets: TBS-9231
Teflon Stripping: TBS-4902B
Sight Glass: TBS-1179
Timeline of filming: March 17th, 2020 - May 13th, 2020
Song List (Order of First Appearance):
0:01 Freedom - Dan Lebowitz
6:38 Casey Don't You Fret - Dan Lebowitz
15:14 Lazy Afternoon Sun - Dan Lebowitz
22:10 Surrender - Dan Lebowitz
(All music provided by KZbin's Audio Library royalty free.)
Thanks for watching, and joining us on this adventure! Please let us know what you think! Consider supporting us via Patreon as well! / fuzzydiceprojects
Follow our Instagram for more pictures and teasers: / fuzzydiceprojects
Check out our second channel for a variety of other content: / @fuzzydicepastimes

[@FuzzyDiceProjects]

This is a pretty big video that started out as three, but I felt like this part of the story needed to be condensed and told all at once. Still, it's not the end quite yet. The next video is (mostly) the last supercharger rebuild episode, then an episode of piecing together the last few bits to install it onto the engine. After that we'll be getting back to the engine itself and trying to speed through the rest of what we went through to make all of our parts work together. Yes, this supercharger has been quite a debacle (partly of my own making) and yes, we all want it to be over with to move onto something else. Nearly ready, thanks for hanging in there!

[@TheRubiks007]

I've been watching since the s10 conversion to the v8. I love what you're doing. I know sometimes it's hard to get vids out but really hope you get sponsored so you could do this more. Keep it coming!

[@punishernation436]

Will you ever put a supercharger on the blazer?

[@sergiobisonte]

blows my mind why you didnt used grease, oil or wd40 on those teflon strips...

[@crimthegrim]

Love it fam keep pushing through!

[@tphvictims5101]

Frank Zappa, Fuzzy dice and bongo’s in the back my Ship of love is ready to attack.

[@gekailin]

"I'd like to point out once again that I. Don't. Know. What. I'm. Doing." Hahaha the Fuzzy Dice disclaimer

[@captaingreatvalue3176]

Yup lol

[@michaelw6277]

Just like the rest of us… making it up as we go along.

[@Cambpro]

Yep! He's humble af

[@writtenaudio]

I don’t think I’ll ever stop watching your rebuilds, coming from a mechanic of a decade you never cease too impress me with your dedication and openness through the struggles of these rebuilds/builds. I truly believe few people can do what you do, especially with how little you have to do it.

[@coltonkruse2313]

Man the pain and heart ache of this project. Good on you for sticking with it. And thanks for filming it. This channel feels like one of the most realistic as far as working on things yourself in your garage. Most of my projects feel similar to this. Where things arent well documented on the internet, information is hard to find and you are "winging" it at best. Thanks for the videos.

[@2koolchris291]

I’m glad you’re posting again. I just love how you make your videos so calming and informative. Even when you don’t know what you are doing

[@constructdestruct360]

When I was a kid, we would use hairspray to install the grips on our handlebars. They slid on easily and dried tight. The kid in me would probably do the same for the Teflon strips.

[@robbiemckinnon7901]

When I needed my supercharger rebuilt, I brought it to my local Watrous Diesel repair shop. They do blowers all the time for big Detroit diesels like 8V92's and so on. A cake walk for them.

[@saleendriver]

Dear God what an adventure. Can't wait to see how it turns out.

[@ExcuseMyFr3nch]

A video.....yes..... happy Saturday yall

[@rexmedina4561]

I swear to god if I made it that far I would have just looked the other way and sipped on my beer and said FI, let’s run it and see what happens. Now, I know it’ll lead to leaks and probably failure, but they aren’t the most efficient superchargers around, even for the technology at the time, but I’d run it just to say, okay, we’ll do it again, but enjoy what we got right now. You know what David Freiburger, don’t get it right, just get it running. But I give HUGE props to you because out of everything they’ve done, compared to you, they ain’t stripped one apart and rebuilt a roots. Idk if they scared or lazy. It’s definitely a good a scratch on my adhd brain to see such commitment.🤘🏽🤘🏽🤘🏽

[@TheBrokenLife]

Hummm... _Fuzzy's Blower Shop_ actually sounds like a legit hot rod shop name. You may have to run with this now that you've started it!🤣

[@sethh8892]

When using Scotchpads, bristle pads, sandpaper, etc... make sure that you only use that pad on a specific type of metal. You can actually impregnate different Metals into other surfaces which can cause them to rust. I figured this out with wire brushes and stainless steel. If you use your wire brush on rusty metal to remove rust and then use that same wire brush on stainless steel it will impregnate and cause the stainless steel to rust. This is also quite true for aluminum, the steel leftover will start to rust and will cause oxidation across aluminum. So be careful with that, or just constantly use new ones 😂

[@punikin7203]

Lubricate the teflon strip while inserting so it doesn't stretch and maybe sand them down a bit before assembly

[@ronskopitz2360]

Was thinking the same thing. Hard to keep them flat/even with sanding, but if not too aggressive that might be what it needs to then “self clearance”. It will be interesting to see how he does with access to a lathe…

[@opieshomeshop]

You don't freaking sand the Teflon strips. There is a tool for cutting them to tolerance. Sanding those will leave very fine abrasive embedded in the Teflon that will ruin the blower. Oh wise one!

[@gb1613]

@@ronskopitz2360 putting the teflon face down while mounted in the rotor and pressing it against a flat surface should keep it fairly uniform while sanding, but these videos were recorded a couple of years ago already so I'm sure he's figured it out by now.

[@davelowets]

NO! You NEVER sand on the strips! They are SUPPOSED to be in there that tight. Depending on the pulley ratios, those rotors can be turning more RPMs than the engine does. The LAST thing a guy needs is for the strip to work it's way out, end up down the intake port, and hang an intake valve. The piston doesn't say hello kindly to the valve when they meet...

[@Aiika__]

I think i would have given up at 20 times over given the amount of issues this thing has given you love seeing someone tough it out and learn new things constantly love the vids man

[@LLCooLM595]

Wow, rebuilding a supercharger seems like a huge PITA 😂 Can't wait to see how it turned out!

[@Cambpro]

Right?! Makes me want to grab one and rebuild it just to have on standby

[@davelowets]

It's not that bad once you do it a few times. An NHRA Top Fuel or Funny Car team go through the supercharger in between rounds at the track, in less than 45 minutes.

[@asandberg6]

I realize your probably already filmed and edited the next episode, but I would try silicone spray while sliding the Teflon seals in place.

[@oikkuoek]

It's the edge of the carburetor opening/intake opening that is killing the seals, rather than too thick of a seal/rotor. The edge has a casting burr, that needs to be trimmed off. You can hear it clunking onto the rotors when spinning them. If only the rotors are trimmed, that causes blow by making the super charger less efficient and still the burr keeps destroying the seals.

[@FuzzyDiceProjects]

I considered that as well, but it actually might have the opposite problem! The openings are pretty smooth on the 250 case, definitely no burrs, while on my newer Weiand 144 they are very sharp. That would probably help with breaking the seals in versus just having the friction against the case walls to do it.

[@oikkuoek]

@@FuzzyDiceProjects Problem with chiseling the seals against a sharp case edge is, it creates fairly big chunks of seal material to go through the engine. Also if the edge grabs the seal, it can, and most likely will, pull the seal out if it's seat, then chewing it up and sending it through the engine. When the opening edges have smooth bevels, that helps the seal to ride and wear easily with a lot less failure. for the install, hot soapy water. For the gear lube, 2T oil. doesn't lock the engine if it leaks.

[@giancarlopbranco]

That's awesome, Mr.! I wish that in my next life I can be determined and persistent as you are! Congrats for your technic and thank's for share knowledge!! 👏👏👏👏

[@StormHawksHD]

Loving the content. Keep up the good work.

[@mcnamarasgarage]

Persistence! Great explanation and sorry to see the Teflon break

[@captaingreatvalue3176]

This is a very unique set a videos can’t wait to see how good it works thank you for posting great content

[@manonmars2009]

This is what I admire in people. You keep at and keep at it until the job is done right.

[@DarkBlood666]

going through your content, especially the firebird blower setups reminds me of the younger me. Ive used all those blowers on my second gen, gone through the whole learning process as you have. Really cool to watch someone giving all the details of these projects. keep up the good work and content.

[@brianp6965]

I bought a used Blower Shop 250 a few years ago to upgrade the Weiand 177 on my boat. The snout seal is leaking a bit and the teflon is definitely worn but I figured I can take it apart and fix it... 🤣 After watching this, I think I'll just spend some time constructing a strong shipping container for delivery back to TBS for a full rebuild by them! I admire your persistence, and this is great content but now I know, this is outside of my skillset.

[@captaingreatvalue3176]

Your so close to finishing thanks for not giving up

[@chadmccolm6544]

Great job and awesome video. Can’t wait for the next episode on this. It will be cool when you mount the blower to the engine and can hear it run. I find that when I take anything apart I learn the in and out of how to do it better each time I fix anything. Keep up the great video’s.

[@Cambpro]

This video was a long wait and I was so glad to see this pop up! Can't wait to see how it turns out, but I guess I hafta!

[@quinnemery1228]

I’ve been eagerly waiting for this one!

[@jesusonic91]

What an history! I would definitiely cried at the end...

[@bleachdealer]

Always a good day when you upload a video!

[@MyLonewolf25]

LUBE! It’s important Use WD-40 to lube them when putting them in. Also don’t sand them down as you’ll imbed grit in the seals. I’d also heavily recommend cleaning the case again heavily with atf and a lot of scrubbing as I’m not sure all that black stuff was just from the seals running in

[@thomasfry3604]

@fuzzydice

[@jw11432]

Sanding the back side should be fine, right?

[@MyLonewolf25]

@@jw11432 you’d never get it level or consistent

[@Mawyman2316]

check the dates he flashes up. You are trying to fix a 2 year old problem.

[@davelowets]

@@Mawyman2316 He'll be doing it again someday, as those strips don't last that long in a street application... 🤷🏻🤦🏻

[@davebaker9128]

For shaving the teflon seals to size them to the case, I think an Exacto miniature plane will do the trick, i got one of these at a craft and hobby store, the blade is extremely sharp and depth adjustable so as to remove the tiniest amount of material per stroke

[@ronskopitz2360]

Great stuff, as always. Thank you!!

[@dreamerx23]

christmas came early! thanks for the video fuzzy! merry christmas and happy holidays to you and your family!

[@friguy4444]

Wow. Your videos are excellent in every way IMHO. Thank you for the hard work in making them. Sucks big time to have the Teflon strip Gak out on you right at the point of "AHH NO WAY ARE YOU KIDDING NOOOOO!! GRRR!!!" That's a very long technical term those that have never studied or worked on cars will not be familiar with but those of us who have know it well. All the best in the struggle !!

[@1leggeddog]

Damn I'd be furious right now if I saw that Teflon crack

[@Peter.A-A]

OMG. How I enjoy your videos. Waiting for next episode, is even worse, than waiting for new episodes of GOT.❤

[@evanford8237]

Yeah! I love watching your videos!!!!

[@rafflesssadiss8182]

Yes a new Video. Have a nice weekends all.

[@mechguy83]

Hey life's a journey an I wold not call them mistakes, remember that experience is earned. Your doing great! Looking forward to the next video.

[@TheThomasites]

It would seem the teflon didn't retract during the night. Maybe a little WD-40 as lube and heating the rotors after for the night to allow them to settle. This would allow the rotors to expand slightly and the teflon stress to balance out. But, at least you know the thickni of what the teflon should approx be (a small wood plane may help in reducing it).

[@Richard.Sanchez]

I'm glad I get to learn from your mistakes.

[@GarageItYourself]

DIYing such parts is always a risky business. I'm assuming you figured out the reason for the tightness and it's now spinning freely but I know from experience how disheartening it can be when you spend so much time and effort to come across problems like this. It changes something fun into something stressful. On the plus side it does make good YT content and I always enjoy watching your videos. Don't stress too much about the frequency of your videos if it's not your main income. Life gets in the way and I for one haven't had a chance to make a video in over a year now. If somethings no longer fun then always a good thing to take as long a break as required before getting back into it 😊

[@frankthetankricard]

I would have sprayed the surface with isopropyl alcohol before inserting those teflon seals. It provides good lubrication for a couple seconds so it might just help. Try it if you ever need to do something similar.

[@Sneddz1]

I needed this :)

[@davidball.]

I was about to go to bed but nevermind. New content means everything can wait.

[@robinrai4973]

godspeed man

[@xXYannuschXx]

"Theres a fine line between "not enough" and "too much" and I dont know where it is" - I can relate to that.

[@cheetahlip]

Dude, this series is like the MCU, I’ve been watching it for years 😂

[@95TurboSol]

It's fun to watch restorations like this, but man I would never do it myself, buying a new one is worth every penny after all this!

[@fisshuman]

Dabeyudi forty gang💪

[@revolutionday1]

Wondering why some type of lubricant (like silicone spray etc.) wasn't used to install those strips....

[@wibblewobble5809]

OOOOOOOOOOOOOOOOOOOOOOOOOOO FUZZY DICE!!!! this makes up for my games severs being down :D

[@dadgarage7966]

There's specific bearing retaining compound. It's green. Loctite 609 or 680.

[@Rose.Of.Hizaki]

Couldnt you do a ChrisFix and use a little _'soapy wourder'_ to help the teflon strips slide into the channel a little easier?

[@davelowets]

Take a Dremel or something similar, and narrow the end of the strip into a point, about an inch long. Then it doesn't bind, and is very easy to get started in the channel, because it isn't pinched. Obviously, just make sure you pull enough through so that you can cut the narrowed point off the end. 👌

[@graemeblair9801]

Silicone or Teflon spray those bad boys in place!

[@seymoarsalvage]

I'm so glad I went with turbo lol.

[@808smycarbreaks_9]

Guess it was a good thing I was up this early

[@silverbell800]

Thankfully for your ad revenue and viewer retention, this whole build is like a train wreck in the sense that it's something horrific I can't look away from.

[@edc6333]

I have found that by using a little carb cleaner will make rubber or plastic slide over metal parts easier such as fuel fittings, you could possibly try that on the rotators next time, and the cleaner evaporates quickly and doesn't leave a residue.

[@mikep60]

Hence the reason for the polished interior.

[@Snap-on_tools]

this is like to watch bob ross build a Supercharger i could watch this all day

[@sterlingjohnson5147]

Woo Hoo!

[@davebaker9128]

I run a 47 tooth 2 inch wide 8 millimeter GMC blower pulley on my 1964 Harley-Davidson panhead, I had the pulley hard anodized before installing, I did this because the original Phase3 front pulley was badly worn after 40 years, the clutch basket pulley was anodized originally and shows negligible wear even after all these years, the blower pulley doesn't have a belt guide edge so alignment is a trick, but the blower pulley has been working fine for over ten years and isn't showing any wear yet, I believe due to anodizing it,

[@Hengstmilch]

use silicon oil for the Teflon Gaskets. i use it often for reinstalling gaskets.

[@jeffr0]

Man, I would have to go to church after all the wordy dirds I’d use!!!

[@alexstromberg7696]

I'd swap out those bearings for SKFs

[@lonerider5982]

I know I'm 2 years late, but for the next time if you check the torque toy have to do it directly on the center of the item (rotor in this case), the aluminium bits you made changed your leveraqe (and torque reading value)

[@ardennielsen3761]

the yield strength of those Teflon strips is between 7 pounds and 330 pounds, being 15 inches long even at 7 pounds pulling to install creates an elasticity tension of 100 pounds 1/3 of maximum ratting for the teflon. worm up the routers to 80% the teflons upper ratting and lightly push the worm strips in that were also heated to increase flexibility.

[@jeremygourde9880]

A lot of guys make a scraper for the Teflon strips. It sets on either side of the strip and has a groove cut to the proper amount of height the Teflon strip is supposed to be and it’s scraped down to the proper height

[@sdmoparmaninsd6713]

should strongly consider using a temporary assembly lube for the PTFE install

[@swatson0061]

I feel your pain on doing things over and over. If something isnt just right, ill beat mtself up over it until I redo it.

[@evsnova74]

I'm sure this is done already but I wonder if you could use a woodworking block plane on them

[@ImTheJoker4u]

Sucks you have to open it up again, but nobody ever said learning on the fly is easy😉

[@davebaker9128]

Also, I have discovered that pure beeswax is about the best anti seize I have used in threaded holes in alloy castings

[@davelowets]

Yes, wax works very well

[@manitoublack]

Love the series. would love to know where you're at, at the end of 2022. since these trials and tribulations seem to be from +2 years ago.

[@sdmoparmaninsd6713]

There is a sleeve retaining loctite compound u should be using on those press fits rather than the thread locker which does just about nothing.... the sleeve retainer is green

[@prancstaman]

Maybe a little heat on the Teflon strips will help.

[@ThatGuyFromNantucket06]

Time for a cuppa and some questionable mechanics. Cheers broksi.

[@mrchew1982]

So, you have at least two different clearances to worry about, rotor-to-case and rotor-to-rotor. It seems like your rotor to rotor clearance might be a little too tight, even after shaving it down (in the next episode😁). I think you're probably ok, but if you want to look into it further you can coat the inside of the case and the rotors (except for the strips) in a light coat of machinists blue (spray on?), then reassemble and spin it. The blue will get rubbed off your tight spots. I watched a racecar rebuilder do this to a roots supercharger somewhere on KZbin, I'll have to look for it... he went so far as to remove material from the case and rotors.

[@mrchew1982]

kzbin.info/www/bejne/Z3Opamd7a65poNU

[@davelowets]

Not for an amateur to try and do himself.

[@philmariop]

Fuzzy, why are you using theadlocker on the bearing shells or inner bores? Loctite 638 would be better for retention. Do you suspect the press fit for various parts is not adequate on its own?

[@traildad604]

Could you use a sort of hand planer to shave down the teflon strips?

[@roscocsa]

I really want a fuzzy and vgg collab. maybe with legit street too.

[@ldenorio]

I was always taught that too much grease would not allow the heat generated by the bearings to disperse properly

[@davelowets]

You heard wrong

[@ldenorio]

@@davelowets this is from timken pdf for proper lubrication - The housing should only be half full of grease. Too much grease causes churning and higher temperatures.

[@davelowets]

@@ldenorio You don't pack a wheel bearing half full of grease and then install it. That would be a QUICK road to failure. You pack it FULL, and then also make sure that the space in the housing is full, and THEN you put the cap on. If there is NOT grease in the empty space, the bearing WILL very quickly sling all of it's grease off from centrifugal force, and then run dry. With a LIQUID lube, such as a gear oil, you would only fill the space partially, but NOT with a grease.

[@matthewklein9225]

Could try silicon spray to lube the teflon

[@mickeyt107]

What ended up being the cost difference between a new blower and your rebuild?

[@N-Lee]

They don't make the 250 anymore. Brand new they run about $3000.00

[@matthewhall9530]

Maybe lubing it with some 2stroke oil would have helped it move? I’ve seen some top file teams use 2 stroke oil as the drive line just in case something breaks and the motor eats it. It’ll burn way easier than gear oil would be.

[@buddybubble3264]

First of all, I really appreciate the time and work you're putting into these parts, although it's yet to be seen if it will all work out. Your skills and ideas are also very good. But when I see how much time and money is invested in it and in the end it's not clear whether it all works and also the fact that a compressor eats up a lot of power and then doesn't get that much more power out of it (compared to a turbocharger, which can be elicited more power through wastegate, intercooler and everything) wouldn't it be more expedient to install a turbo?

[@fastdamo]

kzbin.info/www/bejne/Z3Opamd7a65poNU For future reference this video shows installing the rotor seals in a top fuel supercharger, including using lube to get them in and a tool to un-shrink them after. Just thought this might help.

[@woopdeedoodaa]

Fantastic link, I've seen a few of his other videos but not that one. Great tips in that. It was interesting to see how much the seals shrank back to their original size. I think he used a toothed tool to bite into them to pull it back but that migh be beacuse the strips were so much taller and he was alway going to cut them down to size anyway. I wonder if just a block with some sandpaper glued to it and then pressing that down before hammering it along would be able to key into the seals enough in a home shop situation like this

[@brianbanks3044]

well, THAT was a bummer with the strip.....figures, it happens right as the last bolt is installed....there has to be a special installation or film you can put on the part to help seat them better...I can't see assembly workers fighting with hundreds of blowers a day just so they can ship them

[@keithgaming7027]

Why are you using loctite on the part you're have a new one made?

[@publicroyalty760]

The frustration I felt when the Teflon snapped was a lot, I can only imagine how he felt 😅

[@GoWstingray]

Love your vids, that gauge for turning wont be accurate as you have gave yourself some mechanical advantage with turning plate.

[@CarsandCats]

Why didn't you use blower lube on the teflon strips? It comes in a can made by PJ1.

[@opieshomeshop]

Sandblasted the inside of the blower shell? You might as well toss it in the dumpster. And the Teflon strips have to be trimmed to size before installing.

[@jackmagnium6115]

thats a rotary blower isnt it? i researched these and found out they were the first versions of the roots supercharger(the male/female rotor and screw blower)

[@sirphilo]

Perhaps it needs a little boat ride...

[@StoneMcKnuckle]

Missed opportunity to dub your turning tool "the Turninator".

[@xeakpress2718]

Yaknow I don't even like supeer charges or alot of classics but I like rebuild

[@trillrifaxegrindor4411]

you don't like spelling properly either but its all relative

[@jeorgelowpez2069]

Seems like sandblasting the interior of the case may have been too coarse