Burroughs or Krikit cambelt meter

[Mike6]

I Understand that the Burroughs meter is obsolete and that an alternative to check cambelt tension is the Krikit meter but where can you buy this in the UK. Everywhere I have looked is US based.

[sailorbob]

I've got a couple of new Krikit 1's (part no. 91107) lying around (bought as spares) and can let them go. £10 for one delivered if you're interested.

[Mike6]

Is this ok for measuring cambelt tension. In which case I will have one. Thanks

[andydclements]

Personally I'd not trust the Krikit. A local Excel owner used one and despite it reading spot-on for the target figure, the bearing was whining very loudly, a quick set it by hand go and it was silent, then when compared to mine which was set with a different gauge both his and mine read low on the Krikit but equal.

I use a Facom one, DM16

[sailorbob]

Yes, it's used for measuring the cam belt tension. See this http://www.espritfactfile.com/timingbelt2.html for useful info about the cam belt from Tim Engel.

[andydclements]

But don't the manufacturer themselves even advise it's just designed for V belts?

[ramjet]

Correct Mr Clements.

[Mike6]

I think it is a case of twisting the belt as described elsewhere and using the meter. I think a lot of people simply rely on the quarter twist in either direction rule but I wanted to verify with a meter as well. I have seen elsewhere on the forum that the Krikit does the job

[ramjet]

So does twisting the belt but it doesn't make it right. As Andy said, the manufacturer of the Krikit themselves do not recommend the Krikit for cambelts.

Guys on here have successfully used TuneIt! and a mic on their laptop to tension their belt. Someone on here confirmed this method using a Burroughs and it was spot on.

http://www.gates.com/brochure.cfm?brochure=2264&location_id=2742

[Vulcan Grey]

Acoustic method is the most accurate!

I've used the Lotus Clavis gauge, a Laptop, and an Android phone to do the acoustic method, and compared the acoustic methods to the Krikit, and the Krikit varies quite a bit.

You can download a free app for smart phones that will find the primary resonant frequency for you. There are also free programs for a laptop with a cheap wired microphone.

You measure on a cold engine with the crank at 30 BTDC, and you pluck the belt between the intake cam and the oil pump.

See this

https://docs.google.com/open?id=0B2nifoCpaFSfOGJkMjQxMDUtNzk1YS00YjEyLTgyZTAtYmI5NjE4MjgxMmRm&authkey=CO_S1NoE

and this

https://docs.google.com/open?id=0B2nifoCpaFSfNTAyY2JiZWYtMDMxYS00NjM5LTlhOTEtNDg5ZTY2MWMwYTMx

[Wilf]

The facom one I had not come across before, instructions look like belts are set to a common tension regardless of application, based on the belt thickness. I will need to look into this as price wise it looks reasonable.

[semi42]

try ebay....search "laser 3899"

[GavinT]

Without sounding stupid...can anyone tell me why the engine should be set at 30 degrees before TDC?, also would the the same sound pitch be used for both the HTD and HSN belts?

[andydclements]

The timing angle is one of four points where the same situation is in place per cam rotation (as cams are opening valves so giving resistance to being rotated the tension in the belt increases in one place and slackens the other side of the pulley), and 30 is one where you can measure it easily hence the choice.

[Vulcan Grey]

Note, the acoustic method is not to be used on the square toothed belts.

The acoustic frequency depends on the shape/size, material, and the tension. So it may be slightly different for other belts like the gates blue, but I am not sure how different...

[Tony K]

I have a Burroughs gauge and a couple of Krikits, and the Burroughs is not consistent at all. The two Krikits, one older and one newer, are fairly consistent but by no means perfect. I rely on the Krikits. Some "good habits" when using it:

1) Measure the tension on the old belt a few times before removing the belt. Rotate the engine twice and measure it a few more times. Repeat a few more times. You won't get the exact same reading every time, but you should be hitting it at least 80% of the time.

2) Pay close attention to where you place the Krikit on the belt. It has a ridge on the side that is supposed to be off the edge of the belt, but when you do it that way, the gauge is not in the middle (of the width) of the belt. So I take measurements both ways - mostly with the gauge on the edge of the belt, plus some with the gauge at the middle of the belt. You will get a higher reading with the gauge at the middle of the belt, because the edge of the gauge is holding it off of the belt a little more.

3) When you press on the Krikit, make sure you are not pressing in a manner as to tip it toward the long end (with the indicator). Shift your pressure toward the short end so you don't inadvertently "tilt" the Krikit into giving a lower reading.

4) Use two (or more) Krikit gauges.

5) Do the 90-degree test anyway. When you are satisfied with the Krikit reading and the twist test is spot on, you know it's good.

[Mike6]

Thanks for advice about using the kriit. Mine arrived today from Derek (thanks).

However engine is in bits so cannot test tension of existing belt. Currently struggling with getting a consistent reading with shimming the valves. Every time I adjust a shim thickness readings seem a fraction out so thinking that as long as they are all at the higher end of the tolerence all should be ok.

[DanR]

The clearance "grows" so aim for the tighter settings. Otherwise your tappetty sounds will become more pronounced sooner rather than later.

I'm assuming there's no worn pits and they are perfectly flat on both sides.

[lotus4s]

Danny, what do you mean by "the clearance grows"?

Generally, the valve clearances close up over time/use from repeated pounding into the seats so you would typically shim for the high side of the spec.

Edited November 26, 2011 by lotus4s

[DanR]

I found the shims tend to develop depressions from the stem tips faster than the seats receding. Modern seats seem to last very well.

I usually set them around the middle of the tolerance values.

Edited November 26, 2011 by DanR

[lotus4s]

Hmmmmm, after rebuilding several 910 engines and checking valve clearances on several others, that has not been my experience.

[DanR]

Interesting. Maybe what I'm seeing is a result of the oils and the gradual reduction or elimination of ZDDP.

[lotus4s]

_{Maybe it's because you're in Australia, don't most things work backwards down there....}

Edited November 27, 2011 by lotus4s

[andydclements]

On heads which are iron but without hardened seats I'd expect regression of the seats to cause gaps to close, but with hardened seats I'd expect the eventual wear between the top of the stem and the face of the shim to open the gaps up, and that's what I've found by way of dimples in the shims.

Just my experience.

[GavinT]

Andy, would the Facom one, DM16 be suitable for an HSN square tooth belt?