Mechanical Tensioners/Stomski

[Bb5280]

Hello All

Tore down motor w/ Carrera tensioners, thinking about leaving those out and using the mechanical tensioners from Stomski racing - they worked very well on timing application etc. The website says they can be used - and would like to.

Question is - the timing chain covers have the hole for the tensioner oil line input. I think i can bypass the lines, but does anyone know of a plug I could use to fill that opening or if I decide to use the mechanical tensioners, do I need to get new timing chain covers?

Thanks

[rwest]

I’m not super knowledgeable, but I believe that solids should only be used on race cars that live life at very predictable temps and rpms.

Just going off memory, but I believe they will be either real noisy on the street or too tight most of the time on the street.

[Bb5280]

Thanks - it is for a racing application but wondering if worth all the trouble if I have to find new chain covers and alter the lines.

[Flat6pac]

You can buy the covers cheap but use what you own because they work and you own them.
Bruce

[Bb5280]

Thanks Bruce - question is - are there plugs I can buy to plug the hole in the cover that the Carrera tensions oil line comes in to?

[jrbennett]

I don't know how big the hole is, but if you measure it I'm sure you could find a freeze plug that is the right size.
I assume most people that remove the Carrera tensioners just use early covers without a hole and earlier oil lines.

freezeplugfactory.com

[Bb5280]

Thanks everyone.

[otto_kretschmer]

Originally Posted by Bb5280

Hello All

Tore down motor w/ Carrera tensioners, thinking about leaving those out and using the mechanical tensioners from Stomski racing - they worked very well on timing application etc. The website says they can be used - and would like to.

Question is - the timing chain covers have the hole for the tensioner oil line input. I think i can bypass the lines, but does anyone know of a plug I could use to fill that opening or if I decide to use the mechanical tensioners, do I need to get new timing chain covers?

Thanks

More than a decade ago I almost lost the motor on my 76 2.7. One of the dowel pins on the right cam casting that locates the chain tensioner elongated the hole it was pressed in. I ordered a used casting from one of the recyclers in the Burbank area. They sent me the covers with the holes for the carrera tensioners. I filled the hole with a metal filled epoxy. The type that comes in a roll and you slice a chunk off and mix it with your fingers, preferably wearing latex gloves. I cleaned the hole with sand paper and acetone.

The epoxy is still there and doesn't leak. I replaced the stock tensioners with mechanical tensioners like the Stomski. I would check them every other oil change. I plan on going back to the original tensioner with a safety collar and I'll probably buy a new cover without the hole.

[Trackrash]

If you are going to get rid of the Carrera tensioners, sell them as a kit. Have you priced them?

Not sure why you would though....

[Bb5280]

Thanks Otto -

[Steam Driver]

Having used mechanical tensioners on my 914-6 eons ago (before the Carrera tensioners were around) I don’t think they’re a good idea for a street engine, even though I used them successfully for around 15K miles.

They were noisy on start-up, particularly in cold Wx, so low rev driving was in order. As soon as the rattle went away it was fine. No cam timing issues, but when the engine was rebuilt the intermediate shaft sprockets were excessively worn.

FYI I made my own solids out of the old tensioners by using a set screw in the bleeder screw boss. I seem to remember this required minor machine work to make this happen but my geezer brain doesn’t remember what exactly. I also had a gage block to put between the plunger and idler to provide initial clearance. Compress and lock plunger, insert gage block, release plunger, tighten set screw. I don’t remember the thickness of the gage but it was fairly thick, like 2mm, maybe more.

I think this “solution” was provided by Chuck Stoddard as something they were doing back in that era.

[KTL]

The mechanical tensioners are often used by racers because they're bulletproof in terms of avoiding a hydraulic chain tensioner failure. But you definitely lose the cushioning/damping effect provided by the hydraulic units.

JB Racing has a simple set of instructions they provide for these