Belt tensioner

Phil Spicer · December 08, 2014, 06:48:26 PM

Needed to put a little tension on the alternator belt. Remembered some talk about a tensioner so thought I would build one. $2.95 at the hardware. Got a 4" turnbuckle & welded a short length of 1/4" round on each end.
Cut off the eyelets, bend 2 short lengths of round and weld them on the ends. Worked like a charm, saved some boat bucks & didn't have to check all the auto parts stores.

Bobg · December 18, 2014, 07:11:31 PM

great idea, will also work for my motorboat. Love these ideas that come up on this forum. thanks

KWKloeber · December 19, 2014, 02:29:34 AM

Mannnn I wish I had a welder. Or better yet that I hadn't moved so far from my buddy/master stainless fabricator

For those who don't partake, there's also a couple alternatives... a tension jack
http://www.mscdirect.com/product/details/35438209?item=35438209&fromRR=Y

and a reversed bar clamp
http://c34.org/bbs/index.php/topic,5408.msg33516.html#msg33516

kk

Ron Hill · December 19, 2014, 09:12:02 AM

Phil : Too bad you didn't ask as I've got one that's not being used - ever again!!

It can't be used on a M25XPB or M35BC engine (easily)

Phil Spicer · December 19, 2014, 11:54:30 AM

Ron, send it to Erie with the boat...it will be needed some day.
KK , Bar clamp, good solution. Never thought of it. I never thought about MSC. Have one down the road. At school we use MSC all the time, but $21 vs $3. I'll go to school & weld. More fun & less boat bucks.

Merry Christmas to all at our site. Take care of each other.

Ken Juul · December 20, 2014, 09:01:48 AM

I like collecting tools. But I don't understand the need for this for our boats. Open the engine access door in the head, Pull on the alternator with your right hand, tighten the bolts with your left. Job done.

Ron Hill · December 21, 2014, 02:26:31 PM

Ken : The whole idea behind the belt tensioning tool is that you can set it up and test the tension before you tighten the nuts! I've done like you say and that works, but it could lead to over or under tension.

Just easier to use the tool and more precise to also be able to look down and then maybe move the alternator aft or fwd a bit to get the best alignment (beside tension).

A thought

KWKloeber · December 21, 2014, 05:15:48 PM

Quote from: Ron Hill on December 21, 2014, 02:26:31 PM
Ken : The whole idea behind the belt tensioning tool is that you can set it up and test the tension before you tighten the nuts! I've done like you say and that works, but it could lead to over or under tension.

Just easier to use the tool and more precise to also be able to look down and then maybe move the alternator aft or fwd a bit to get the best alignment (beside tension).

A thought

So Ron, you're saying in conjunction with whichever method to set the pulley distance, owners need a Krick-It?
http://c34.org/bbs/index.php/topic,5078.msg57780.html#msg57780

KK

Stu Jackson · December 21, 2014, 10:29:20 PM

As noted in the "101 Topic" belt tensioner thread, the later engines don't need one, because their alternator bracket assembly is vastly different than the M25 series engines.

Ron Hill · December 22, 2014, 02:08:35 PM

Ken : I'm not saying that you also need a "Krick-it".

The belt tool allows you to set the tension once installed - hands off. Then you can look down and probably move (pushing against the pulley) the alternator aft with one hand while you tighten the bolts with the other - for belt alignment.

As Stu points out the raw water pump is on the port side of the engine (in the way of the belt) on the M35BC and M25XPB engines. Also the alternator weight (hinged on the bottom) can easily be pushed with the heal of the hand to the correct tension position on those engines.

A thought

KWKloeber · December 22, 2014, 02:12:41 PM

Quote from: Ron Hill on December 22, 2014, 02:08:35 PM
Ken : I'm not saying that you also need a "Krick-it".

The tool allows you to set the tension one installed - hands off. Then you can look down and probably move (pushing against the pulley) the alternator aft with one hand while you tighten the bolts with the other.

As Stu points out the raw water pump is on the port side of the engine (in the way of the belt) on the M35BC and M25XPB. Also the alternator weight (hinged on the bottom) can easily be pushed with the heal of the hand to the correct tension position.

A thought

So, I'm confused .... <<The whole idea behind the belt tensioning tool is that you can set it up and test the tension before you tighten the nuts!>>

How do you set the proper tension ---- with a jack, or with a tug, or using gravity, or a sky hook, without knowing what the tension actually is?? (ie, a krick-it or another gauge?)

Ken

Stu Jackson · December 22, 2014, 02:37:15 PM

Quote from: KWKloeber on December 22, 2014, 02:12:41 PM

How do you set the proper tension ---- with a jack, or with a tug, or using gravity, or a sky hook, without knowing what the tension actually is?? (ie, a krick-it or another gauge?)

Yup, "the olde sky hook" method has always worked for us.

1/2 inch deflection on the long length of the belt, and able to turn it 90 degrees by hand.

KWKloeber · December 22, 2014, 02:42:35 PM

Quote from: Stu Jackson on December 22, 2014, 02:37:15 PM
Quote from: KWKloeber on December 22, 2014, 02:12:41 PM

How do you set the proper tension ---- with a jack, or with a tug, or using gravity, or a sky hook, without knowing what the tension actually is?? (ie, a krick-it or another gauge?)

Yup, "the olde sky hook" method has always worked for us.

1/2 inch deflection on the long length of the belt, and able to turn it 90 degrees by hand.

It might be very enlightening to see how that compares to a gauge! plus/minus 50% would be my guess.

kk

Ron Hill · December 23, 2014, 12:36:24 PM

Ken : The Olde Farmers Almanac came out with the twist of 90 degrees or the 1/2" deflection.

Readers have been doing this for the last 100 years without any consequence.

A thought

stevewitt1 · December 29, 2014, 04:55:12 PM

Wow,
It's amazing at how such a simple device generates so much good conversations and ideas.

Phil: I made one almost identical to yours two boats ago and it's still in my boat tool bag. Just one of those hides I collect from another way to skin a cat. I see this thread with a bunch of right ideas and no real wrong ones. But then, I'm pretty simple minded.

Well; belated Merry CHRISTmas and a Very Happy New Year to all of the great people on here.

I'll be driving my munchkin down to FL next week so she can run her marathon at Disney but she promised we could come home in time for the Strictly Sail show in Chicago.
If any of you are there, please say Hi! I'll be the one walking around with his mouth hanging open drooling while looking at all the neat stuff I can't afford!

Steve

visit us at www.ocontoyachtclub.com & www.warbirdsix.com