Belt wear in aluminium alloy parts - adj cam gear

Anthony

Following on from the discussion regarding Al. Alloy B230 crank / underdrive pulleys
https://ozvolvo.org/discussion/comment/44766#Comment_44766

I wish to show the wear characteristics in an alloy adjustable cam gear on my B230 T engine after a few years use. The gear was replaced immediately.
Note the wear on all belt contact faces (Haven't practiced BBCode on a Mac) so here is a link:
http://people.physics.anu.edu.au/~amh110/special_pics.htm

Anthony

AshDVS

Anthony, do you know what type of aluminium was used (was it 6061 or 7075?) and was the gear coated in any way?

Here's your pic -

Definitely a throw away.

Anthony

Brand was MVP (Portland, USA). Spec only said - hard anodised. - so once you wear thru the anodised surface, wear will increase dramatically.

I note modern IPD sales info just says aluminium with no grade mentioned. It should at least say aluminium alloy!

I haven't seen comparable examples of wear characteristics if Al. Alloy in grade 6061-T6 or 7075 (close to old descriptor Duralumin) was used, compared to whatever was used in the MVP offering from years ago,
Hopefully 6061-T6 would wear a whole lot better than the pic I supplied.

The bottom line is the machinist or company that makes belt-contact products - needs to select the highest grade Al. Alloy he can obtain in his country. And the final price of the product will reflect the higher price paid for the best materials.

Anthony

AshDVS

Very true. It's probably been in service longer than they may have planned or intended anyway.

We offer Nuke Performance Products. The Nuke gear is made from 6082 (common in europe, but quite close to 6061) with a very durable coating.

The old (ie. truly adjustable) IPD gear was very good as well. I believe it was made from 6061.
The new one, really, isn't adjustable at all - it's notched so it can be removed and refitted in a different place iwth preset timing settings. Fitment is adjustable (or can be varied), the gear is not.
As you mention though, no real detail of material is provided.

It's a case of you get what you pay for though. Offerings are growing in a budget-conscious focus, and shrinking in products focused on quality.

What did you replace your MVP gear with in the end?

Major Ledfoot

Anthony;44888 wroteThe bottom line is the machinist or company that makes belt-contact products - needs to select the highest grade Al. Alloy he can obtain in his country. And the final price of the product will reflect the higher price paid for the best materials.

Thanks for posting this, something certainly to be mindful of.

A belt /pulley problem is always an annoyance, but cam gear problems with 16V engines can end up being nothing short of catastrophic.

Vee_Que

I will need to inspect my old style ipd cam gear. I also don't run mine exposed. Jay has the new style one and runs it exposed. I think that needs to be checked more.

Philia_Bear

While the tentacle wagon was still b230 powered I was running an mvp unit
Got over 100,000km on it when I pulled the motor
Still looked new and did not have any wear issues
Was never left exposed (always had a belt cover)