odd noise from Supercharger

[AlleyCat]

Odd one really but when i was doing some motorway miles the other day, at around 70mph there seems to be a noise from where the supercharger is. it sounds like some bones rattling in a box.

any ideas? or is this normal? its my first supercharger experience.

[willisdavidge]

If this is a eaton unit used on an A series application its probably shot bearings, they tend not to last as they where not designed to ingest fuel, the last conversion we did covered 15000 miles before the blower began to rattle.

[AlleyCat]

hmm yes it is, and it barely done 1000 miles! so this may sound silly, but is that a supercharger rebuild job? or just complete new one?

[Mini_Lund]

willisdavidge said:

If this is a eaton unit used on an A series application its probably shot bearings, they tend not to last as they where not designed to ingest fuel, the last conversion we did covered 15000 miles before the blower began to rattle.

What measures can be done (if any) to prevent this as I was contemplating the Eaton45 blower unit for my 1293.

[AlleyCat]

sounds like what ive got. mines a 1293

thing is the rattling only starts at high speed. its generally fine otherwise.

[Mini_Lund]

AlleyCat said:

sounds like what ive got. mines a 1293

thing is the rattling only starts at high speed. its generally fine otherwise.

Are the gains worth it for the £1000+ bill?

[AlleyCat]

mine is also chargecooled, but in answer to your question its worth the £1000 just to be able to say you have a supercharged A series let alone the gains theres pice of it in this thread of PH http://www.pistonheads.com/gassing/topic.asp?h=0&a...

[willisdavidge]

The one we had was so noisey we changed it just in case! they are sealed and cant be rebuilt as BM say replace at 100k but having looked into it, it seems to be a common problem of noise even on the Bm Cooper s so I thinks it do with the sealed for life bearings, most other blowers have an oil feed and vmax are working on a mod like this for mini applications, they also do a oil change kit for them so that may help.

We found no visible play in the rotors but the coating was peeling off indicating the rotors distaste for fuel! the old one is still sitting on the shelf waiting for me to have a closer look.

[Mini_Lund]

willisdavidge said:

The one we had was so noisey we changed it just in case! they are sealed and cant be rebuilt as BM say replace at 100k but having looked into it, it seems to be a common problem of noise even on the Bm Cooper s so I thinks it do with the sealed for life bearings, most other blowers have an oil feed and vmax are working on a mod like this for mini applications, they also do a oil change kit for them so that may help.

We found no visible play in the rotors but the coating was peeling off indicating the rotors distaste for fuel! the old one is still sitting on the shelf waiting for me to have a closer look.

So for forced induction are a set of mirage manifolds and a T2 turbo, more viable/reliable?

[Cooperman]

Take a look a the Shorrock supercharger. They seem to work well with the A-series, even though they are a bit old-tech. I worked on one for a 1275 Sprite and it sure went well. If you Google 'Shorrock' there are a load of data sheets on the web.

[willisdavidge]

turbo and supercharging have always been for and against on an A series, the eaton blower and std metro turbo unit (T3?) are a bit too big for A series road application as you only tend to get full boost at max rpm not making for good road manners smaller hybrid turbos work better along with superchargers like the U.S. one minispeed used to sell that was a compact unit with proper oil feed and the carb bolted directly to it worked superbly with no carb icing!

The beauty of the eaton conversion is ease of fit and price and it does work,
but of course the trade off is bearing wear/carb icing (can be scarey sometimes) and odd fuelling issues when the the su carb on the long intake is used.

I do prefer traditional tuning on my trackday engine but I have planned to try an eaton with 45 strapped to the side of it for some time, I might change my mind when Ive tried it!