Thread: Which blower is this?

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Greetings from snowy Finland,

I'd like to know what type/size of blower is the one on that picture?

I think it is a 4/71 roots blower, am I right?

Thanks for answers.

Thanks for your fast reply.

If you have links or other information about these pumps and/or converting a "pump" to a "blower", i would be interested.

Thats definately a little 4-71 and it looks to have just been pulled off a diesel. Ive seen 6-71 blowers that have been run without the gasoline conversion and they seem to work just fine.

What do you think when you look at that picture?

I was thinking of welding that back together, do you think it would work? When you think about it, those parts arent really under extreme stress, it should be ok if i have it welded.. or not?

I was thinking of that also, but i would like to know if it is possible to fix that or not?
I can do all machining and welding work myself, but i'd just like to know can i fix that or will i have to buy a new one or both. I guess i could try, but i'm just asking if someone would know is it worth a try or not.
if not, where could i buy those parts?

Looks like a 4-71 GMC blower off of a Detroit Diesel.
These were used to clear out the 2 stroke engines of exhaust gas. They are quite plentiful as cores, but the rotors usually go the wrong rotation to use on a 4 cycle engine. Most of them need serious rebuilding to work at all on a hot rod.
Jeff

Originally posted by Capri26i
Greetings from snowy Finland,

I'd like to know what type/size of blower is the one on that picture?

I think it is a 4/71 roots blower, am I right?

Thanks for answers.

This one has lots of markings that I can't understand, most likely Russian language, and for example, all bearings were Russian (stamped USSR).

The core and all other parts are like new, but that rotor has that "minor" damage on it. I think i'll try welding it if i can't get a good rotor anywhere.

You could probably get a set of good used rotors off Ebay. Without converting it to gas or putting in new bearings it will probably run a little "loose", not much boost.

My engine has Electronic engine management system, and the fuel injectors are in the intake manifold after the blower, so only air goes through the blower. Or should i go with something like this http://cgi.ebay.com/ebaymotors/ws/eB...category=33553

What does this "gas conversion" include then???

All bearings and seals are like new, this blower has most likely broken soon after it was installed, and then replaced, so all other parts are very good. So all i need is to fix/change that rotor and make up those belt gears and tensioner??