B&M 250 tensioner/idler spacer length?
 

AM I THE ONLY ONE IN "OSO LAND" THAT RUNS OR HAS A B&M 250 BLOWER LAYING AROUND????
Can someone....anyone, that has a B&M 250 blower and is running a serpentine belt system PLEASE measure one of the 4 spacers that the tensioner/idler bracket mounts to.
Even with the spacers in place and the blower on the boat this shouldn't be difficult at all.
I aked if anyone might be able to help me out with this a few days back and as easy as it is to do.....I'm really surprised that there weren't any responses to my post.
So, if a fellow boating enthusiast could take a few minutes to help another enthusiast out I would sure appreciate it because I could really use some help here. Thanks, Mark

Ttt

Mark, I have an EFI setup on my 502s. My 502s are not serpentine though. I can go out and take alook at it on Saturday and see what if any spacers I have. I can take a few pics for you if you want as well.

rgrgoog, any help at this point would be so appreciated! Just curious, are you running a cog belt or serpentine belt system on your 250 blower? If you are running a serpentine belt on your blower, if you could take a tape measure (it might actually be easier using a straight ruler if you have one) and measure 1 of the 4 spacers that sits between blowers tensioner/idler and intake manifold I couldn't thank you enough!

I'm seriously almost to the point to where I'm going to start emailing people that have Bbc B&M blowers for sale and ask if they can take this spacer measurement for me because I just haven't had much luck so far and I'm really needing someone to help me out with this one.

Thank you so much for the reply, Mark

I have the serpentine system. I will go out on Saturday and measure it for you with some pics so you can see where the measurements originated and ended.

I have attached 2 pics of my system I had taken previously.

Jim

VERY nice looking set up! What kind of intakes are those. The head unit is definitely a 250 serious blower. I've never seen a 250 with that style of manifold or a front snout that long. Did you buy your boat set up like that or put the blower, etc... on yourself? Thanks again for any help you might be able to send my way! It's very appreciated!

Mark those are the B&M 250 Blower EFI setups. I bought the boat with the setup on it a while back. Right now I am only running them at about 4lbs. I am thinking about going to a slightly smaller pulley this year. The Blowers are also going in for their 2-3 year/50-75 hour refresh. I am also pulling my motors this year. I wlll be going with new exhaust and probably top ends refreshed at a min depending on the results from the leakdown and compression tests.

Jim

The spacers seem to be 4 1/8"

Jim
What pulley sizes & compression are you running to get 4lbs?

I will have to measure them Sat and see because my main drive pulley is smaller than the listed size in the charts for them.

I have 250 blower with carbs, 540 cid, 4 lbs boost @ 5000 Lower 16 rib pulley is 6.5" upper is 3.75" @ 5000 rpm blower is 8,650 rpm . It is tough to know with the wide sweep guage if it is 4 lbs or 4.5 lbs etc.... this year I'm going to use and industrial guage better suited to read low numbers