The V8 Owners Forum -

Hey, looking for opinions/answers on whether it is acceptable to run accessories (alternator, dry sump pump etc) from the main blower belt, i.e. instead of using an idler.

I'm not madly keen as the belts do stretch whilst running (drag of the blower) but if everyone says it is fine then I could consider it!

Tom, what blower belt are we talking about ??
A Gilmer drive Roots blower, well forget about that.

Not sure if you'r talking about a full ally Rover or Chevy block or an cast iron boat anchor also here.

But a Gilmer drive needs some slack otherwise it will pull the sealing out.

On my ally Rover block the belt needs cold more slack than average described as an alloy block expands more when heated up. Average is 1" but that wont work on an ally engine. Figured that out after replacing a couple of snout seals. 1 5/8 " is what works best in my occasion which is about ½" with a fully heated engine.

Its like you say, as I run a fixed idler and no tensioner.

It will be a wide 1/2" pitch toothed belt on a roots, and is going on an ancient lump. Space may be a bit of an issue which is why I am wondering, I almost need an auxiliary drive that then drives 2-3 other things!

Don't use a 1/2" pitch belt. 1/2" came out with the ark although I still sell a lot of them.

Technology has moved on and the HTD form with its deeper toothform and bigger tension members means that you can run the same width belt and get a greater safety factor. Moving on from standard HTD types you can go for higher rated GT3 or CXP belts and then there's still the Polychain or Synchrochain belt types left.

Gilmer drive ( toothed belt ) is used on many custom occasions without a blower.
It might work out using a tensioner ( heavy spring loaded idler ). As long as you have some slack for the blower on a heated up engine, it might do the trick.

Knowing you are handyman enough to fabricate something.
Tom MacGyver

Ehhhh don't use MacGyver tape.. for this...

I used 8mm round tooth belt on the Mazda and it was fine, very friendly, to be honest I want to use the 3" wide square toothed belt for the loud wine that comes with it!! This is not a serious car and will not be stressed in any way.

JP I will be fabricating a lot for this project! My only worry with trying to run 3 items from one big belt is getting enough wrap to prevent tooth slip/jump, I think I am going to have to find/make a front pulley which will give me a small toothed belt for aux and a main one for the blower. Hopefully I can find a big block one that will be suitable from the States. That way I will get a harmonic damper as well all built in...

You might consider a Meziere electric water pump for your application. It saves you one thing to drive and makes things a lot easier to drive ( Crank - blower - Alternator ).

These Meziere looks slim fit and are available for a lot of US boat anchors.

I considered an electric water pump but they are costly and not sure if they are man enough for the job- unless I spend serious money on one! I also need to drive a dry sump pump, but looking through my spare parts tonight I have just found that RV8 front pulleys are the exact same diameter so I may be able to use one with 2 sets of belts!

Hi Tom
have you seen the set up on the front of my engine? it is like this
http://www.ebay.co.uk/itm/Moroso-63849- ... 4acacf6cc2
but mine has one multi V belt pulley and 2 toothed belt pulleys. It bolts on the front of the damper to be honest I think a chap of your abilities could replicate it pretty easily and just buy the pulleys and fit them.
pulleys are like this
http://www.ebay.co.uk/itm/3-700-CV-Prod ... 1e86f25b97
and this
http://www.ebay.co.uk/itm/CV-Products-H ... 257c9053b4
best regards
Mike

Hi Mike, I think I will try and get away with one like this http://i.ebayimg.com/t/Rover-V8-4-0-4-6 ... QTT9RtRBY/$(KGrHqNHJBkFBTVr%2BHbpBRtRB(pDgw~~60_35.JPG

And bolt a toothed pulley to the front, although I can worry about it later! I've still got to figure out how to fix the front pulley on, as the Nash has a huge nut on the end of the crank, rather than an internal thread, it only leaves 24mm of shank for the pulley to locate on, so I may make a threaded spacer (like a round nut) to extend it, then drill the crank and use a bolt like most modern engines. Plenty to think about!