MainePorsche

Ken,
Thanks for getting back on the question.

Alan

Did anyone install this configuration yet? Its been 4 years...? I think its actually a pretty good idea and intend to give it a try. I checked it out off the car briefly - seems to work OK. It's going in over the next week with a new WP, Belt and first time PKT fitting. Had a devil of a job finding Mica/Mylar washers for this.

Its been sat on the shelf waiting for the next TB/WP job - Water leak last week kicked this all off - but TB was due anyway.

Alan

davek9

Alan I have not, about a month ago in communication w/ Ken said he was testing something, I'd suggested an insulated "cap" on top of the piston and a wire running to it, similar to the Stock setup.

Alan the shafts of the bolts must be isolated too as well if doing it by the tensioner body, right?

I just picked up one of PKen's new "silver" backing plates to replace a Black one (no issues, but while I'm in there) and have a T belt redo going on for my current 86.5 SC Twin Screw project.
So very interested in also giving something a try

Dave

Alan

Yes - and that part is pretty easy - just thin wall heat-shrink tube - to center it. Then Mica/Mylar washers below the tensioner body and under the bolt heads. For one of the bolts you need to add a ring terminal on top of the tensioner body to make electrical contact.

I do think Ken is right that this tests the most critical failures of the tensioner - both failing to tension due to hydraulic cylinder pressure loss/binding and also over-extension - running out of tensioning range.

The actual tension of the belt will be different than the stock static case so the stock tension check probably doesn't make so much sense. I have come to terms that this about the best possible simple solution.

I envisaged a sacrificial thin wire belt "cage" that could detect excessive belt flap and also migration off the cam pulleys. I also considered optical track checking. However these would require quite a lot of fabrication and trial and error work that I just don't have time for.

Will report back on results - will maintain the plain ground point as a backup plan

Alan

davek9

Sounds good, need to look for the isolating washers, just want to make sure this puppy doesn't move once secured
Yes keep it simple always work best for this kind of thing too.

Thanks for revisiting this,
Dave

Alan

I'll post some pictures when it is done.

Alan

PorKen

I'm interested in seeing your results, Alan! I was going to test this after working on the PKT-S but after so many R&R's of the belt covers I was in no mood for another.

The limit sensing should work fine (hopefully it is never needed). What I'm mainly interested in testing is if there would be false alarms (due to temperature changes, harmonic frequency, etc.).

davek9

I'm worried about the tensioner working its way loose from the washers being used?
Was looking at it last night maybe a "sheet" of insulating plastic for between the tensioner and the mount?
Or just good gasket material?

Thoughts?

Thanks,

Dave

Alan

I think the washers will be fine - and anyway the bolts will have loctite - they won't be moving anywhere. Mylar & Mica are both used for high power heat-sink mounting for their good thermal & compression characteristics

Alan

davek9

OK, should torque down good then, thanks!

Dave

Alan

Tensioner is in and isolated after mounting - so far so good.

The PKT-S Air Pump Bracket works perfectly with my Vacuum Pump.

Alan

BC

Which vacuum pump? Having "Something" there in CA would help with visual smog.

Alan

GZ 102 Vacuum Pump

Of course you could always just leave an air-pump there (vanes removed?) - a vacuum pump implies something attached to the output so gets complex and expensive by the time you are done.

Alan

This is a GZ VP102:

BC

Thanks for the link. Modern cats really don't need an air pump. I am always working towards the test pass, not specifically the letter of the law.

Alan

The stock cats don't really need an air-pump either - not when warmed up. My car passes emissions very easily without (about 3 times now) - but we don't have a visual equipment test in AZ - just the sniffer. I actually don't think the air pump had been pumping anything much for quite a while before I took it out... My vac pump system is closed - after 2 AOS passes it goes back into the CAI so nothing else is vented anywhere - clean system.

Anyway we digress - back to the PKT topic. It should all be buttoned up tomorrow - then I can run it and see if I get any false warnings. I still have the option to ground the sensor wire - though getting to it will be a major challenge from the top - so hope it works out well. Don't want to have to take the belly pan off again.

Alan