I don't know shit about these things,so I'm asking,I got a 5-71 or something?can't really tell,but it's short=rotors 10in.long,shorter? then a 6-71/ 8-71 I think?,just got it from a freind who has no idea ether(old stock truck nasty but free and it rolls free too,and will clean & polish up) I wish to make this work on my Ford 292 y-block,so I'll be making lots of custom parts for both no $$$bucks any way and nothing to buy anyway most likely. Yes I'm really good at fabing shit,but this is one type I have not worked with,had a McC/Pac type on a Study years back and it was fun tell the spool & balls tore up. Has anyone made there own nose drive and back plate etc,tip? I planning on flat mill/cutting top of a intake manifold off and making a plate bolt to it,to bolt superC too,and make a plate for 2 small 4bbls on top,that part seems fairly EZ,but nose drive and backplate will have much to do with were she sets front to back on manifold. This going on my "A" roadster and I plan on driving with 3 Vbelts for older look,not cog belt. I did a Google and got no info from that. Thanks 4 any help or ideas,other then don't do it! The Bat Miami Fla
PM Cheaters Pete here on the HAMB...or do a search on his posts and youll see how he did it using V belts !! Rat
Thanks,I found Pete's Teck,http://www.jalopyjournal.com/forum/showthread.php?t=123899 nice but missing much of what I need; 1#.What is this blower with 10in long rotors????5-71 ot what? 2#.What is good pulley sizes for only 3 or 4 psi @ 3000 or so? 3#.Has anyone made a nose drive and or a backplate that can make the case shorter by,I think driving with only the front gears?like 4-71 if I'm getting any ideas from Pete's photos. 4#.Is there a TECH on rebuilding there superchargers,with photos or drawings anywere? I do plan on using 3 belt crank pulley that I have made by some leth work and bolting a steel 3 belt to were the 1 belt was. Has any one ever used the 12V Alt w3V pulley as a belt ten? Thanks
use the HAMB search, it found this thread when searching for gmc blower rotor length http://www.jalopyjournal.com/forum/showthread.php?t=11759
A good book out there is "A Do-It Yourself Guide to Street Supercharging"by Pat Ganahl.I think I bought mine at Summit.Has some good info especially if you are not familiar with them.
Thanks much,I'll go looking for that book,. This thing must be a 4-71 by yu'll's info,super,that a big help. Gess I'll need to see if that books got any info on making stuff myself or not? I'm looking at photos showing a backcover(to much to buy)but looks like it saves some room from the stand point,in my case the dist is in the back of the y-block and it needs room,so I can't mount supercharger any more back then what clears the dist. Thanks
You can make the back cover yourself. I made mine out of a thin sheet of aluminum. All you will need, if the blower is in good shape, is a front snout(proper length), one v-belt pulley, and the proper bearings in the back. I run up to 12-15 lbs of boost on one v-belt and have not had any problems.
Your upper pulley depend of your lower pulley, when you got your lower pulleydone, you can calculate your upper pulley for amount of boost you want. send a pics then we can tell you what blower you got! then what size of pulley you need for 4 PSI..
FYI the detroit diesels ID is the cylinder number and cubes. There was never a 5 cylinder I know of. They started with a 2-71, usually a power unit, then 3,4,6 (238 hp) 6V, 8V (318)and a 12V, althoughI haven't seen the V12 yet, be a really long blower case. Of course there is the 53 and 92 series, the 92's are generally 8V's and 6V's where the 53's generally top out at 6V.
You can make the rear plate.When I did my first one it had come straight of a diesel.What I did was machined around the rear bearings and shrunk a ring around it to strengthen.Being a smaller blower with lower boost you probably can get away without it.Good Luck.
Sorry about the 5 thing,I just did not know there are no 5's,it was a wild guess. I'll plan on making the back plate,and a nose drive as well,I'll find out a way to post some pic soon I hope,this blower is a 4-71 by all the info,thanks to you guys I now have. Crankpulley is first step,I'll get her in the leth today,this stock y-block one is 6.5in a 1-belt and it's got a small chip on outer lip anyway,but rubber harm-B is nice still ,so I'm cutting old 1-V back to mount a steel 3 belt 6in.die,should give nice line up with water & alt + 2 outer belts for super drive 2 for drive on super should look good even if one would work OK. thanks
GM 4-71 is what this thing I got is,I started trying to mock-up on to motor ,looks like the size is fine,but all the photos I look at of 6-71/8-71 on the net show gear end(the 2 grears between rotos) at front and round opening were nose drive is on left side of car,this thing I have with gear end in front has round hole for nose drive on the right?????not left,do I take it apart and flip insides???if that can even be done? (Ya I know read the book I don't have yet/or will have for a few weeks,it may say or not) I see a seal & bearing kit on egay ,but can't find that listed anywere else? Looks to me so far,like my hardist job will be making a nose drive.
For what its worth, a 12v-71 engine uses (2) "6-71" sized cases mounted end-to-end. There was never a 10-71, although a blower larger than a 8-71 is often called that. another example of the aftermarket bastardizing terms that were originally meaningful and relevant. cheers! good luck with that project! Pete
Don't forget the 16Vs, two 8V71s together. The 6-110s had a very large centrifical unit. Kind of like a Paxton on steroids.
can a vee belt pulley be installed Behind the flat belt drive pully of a 4-71 GM supercharger. post here and send to [email protected]
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