Finding the Hz value for Cambelt tension

Finding the Hz value for Cambelt tension

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Discussion

cavebloke

Original Poster:

646 posts

234 months

Sunday 15th January 2023
quotequote all
I have a Peugeot 306 Rallye with the XU10J4RS engine (middle schematic) and I want to accurately set the tension using an OEM-ish method.



Peugeot say you should use the Gates STT-1 sonic cambelt tension tester but I don’t have access to one and annoyingly they don’t give the Hz value you’re aiming for.
I’ve seen people using simple smart phone apps to get cambelt tension on Ducatis and want to do the same to check mine.
I’ll do the usually tighten till you can twist it 45 degrees at the longest span but I want to do it this way too as it’s more scientific.
Can anyone help me find the correct Hz value for my cambelt?
Any help much appreciated!
Cheers.

finlo

3,840 posts

210 months

Sunday 15th January 2023
quotequote all
cavebloke said:
I have a Peugeot 306 Rallye with the XU10J4RS engine (middle schematic) and I want to accurately set the tension using an OEM-ish method.



Peugeot say you should use the Gates STT-1 sonic cambelt tension tester but I don’t have access to one and annoyingly they don’t give the Hz value you’re aiming for.
I’ve seen people using simple smart phone apps to get cambelt tension on Ducatis and want to do the same to check mine.
I’ll do the usually tighten till you can twist it 45 degrees at the longest span but I want to do it this way too as it’s more scientific.
Can anyone help me find the correct Hz value for my cambelt?
Any help much appreciated!
Cheers.
When I were a lad it was always a 90° twist on the longest run!

Mikey G

4,784 posts

247 months

Sunday 15th January 2023
quotequote all
Unless you have a very good frequency measuring unit forget using apps etc. I do belt tensioning on industrial machinery on my day job using the frequency method and it works very well. I have also built a number of Peugeot engines and changed cambelts on others including XU5/9/10's 8v and 16v using the twist method. No issues. I wouldnt complicate it and also wouldnt rely on the frequency method unless you have the right tools.

Krikkit

27,000 posts

188 months

Sunday 15th January 2023
quotequote all
Another who's used the twist method on Peugeot engines with no ill effects over many years and thousands of miles.

catso

14,854 posts

274 months

Monday 16th January 2023
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I've used the Gates app on my phone when tensioning my Ducati cambelts but I prefer to use the 'old-school' methods first and then confirm with the app.

That said, it seems pretty accurate to me as long as you have a calm, peaceful environment to use it in but I'd still double-check with the twist/go-nogo/tension meter where possible.

cavebloke

Original Poster:

646 posts

234 months

Monday 16th January 2023
quotequote all
catso said:
I've used the Gates app on my phone when tensioning my Ducati cambelts but I prefer to use the 'old-school' methods first and then confirm with the app.

That said, it seems pretty accurate to me as long as you have a calm, peaceful environment to use it in but I'd still double-check with the twist/go-nogo/tension meter where possible.
This is what I’d like to do. Set tension by the twist method and then just validate it using the Hz value.
Sadly I can’t find the Hz value to aim for, so it doesn’t look like it will be possible.

Unweder

19,111 posts

228 months

Thursday 19th January 2023
quotequote all
Mikey G said:
Unless you have a very good frequency measuring unit forget using apps etc. I do belt tensioning on industrial machinery on my day job using the frequency method and it works very well. I have also built a number of Peugeot engines and changed cambelts on others including XU5/9/10's 8v and 16v using the twist method. No issues. I wouldnt complicate it and also wouldnt rely on the frequency method unless you have the right tools.
This ^ over 35 yrs on the tools never lost a belt ever after completion of this task

Evoluzione

10,345 posts

250 months

Saturday 28th January 2023
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The 90 twist method is the stupidest thing I ever saw. I can take any correctly tensioned belt and twist it to any angle I like, it depends how much pressure I put on it.

Mikey G

4,784 posts

247 months

Sunday 29th January 2023
quotequote all
Evoluzione said:
The 90 twist method is the stupidest thing I ever saw. I can take any correctly tensioned belt and twist it to any angle I like, it depends how much pressure I put on it.
Which is why a lot of manufacturers went the way of using spring loaded tensioners, easy to setup and repeatable, no need to fuss about with a Hz meter. The negatives though is many people forget about the spring tensioner and inadvertantly doing other maintenace like replacing a crank damper pulley turn the engine backwards causing the belt to slacken on its tensioned edge making a jumped tooth a possibility.
But on older engines the twist method is a good guage, and I expect most people to be applying a medium pressure and not taking a ham fisted approach.

When i'm back in work I may investigate the accuracy of a phone app against a Hz meter but may be a while depending on what maintenance schedules fall on me.