9eleben swivel feet rockers ..., give me your opinion ... Options

[SirAndy]

soooooo, please give me your opinion on 911 swivel feet adjusters on a warmed over TIV ...


i get A LOT of noise in the drivetrain, but all the vales are adjusted right (and double/triple/quadrupple checked)
looks like there's some play between the pushrods and the swivels.

so, what's one to do? go back to 1.7L rockers ???
(IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif) Andy

[Aaron Cox]

QUOTE (SirAndy @ Mar 31 2005, 11:15 PM)

soooooo, please give me your opinion on 911 swivel feet adjusters on a warmed over TIV ... i get A LOT of noise in the drivetrain, but all the vales are adjusted right (and double/triple/quadrupple checked) looks like there's some play between the pushrods and the swivels. so, what's one to do? go back to 1.7L rockers ??? (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)  Andy

im doing the same thing....

911 swivel feet on 1.7 8mm rocker arms. deck the faces .060 and use custom length pushrods.

Benefits:
from what i hear....
quieter
easier to adjsut valves
less valve tip wear.....


other than that its just another 120 bucks..... (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

EDIT: oh... they are still loud....

are the shafts galled????
custom pushrods???
geometry set up????

[SirAndy]

QUOTE (Aaron Cox @ Mar 31 2005, 10:18 PM)

and use custom length pushrods

i assume that's my problem (not having custom length pushrods) ....

i didn't build that engine, you know.
(IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif) Andy

[Aaron Cox]

QUOTE (SirAndy @ Mar 31 2005, 11:21 PM)

QUOTE (Aaron Cox @ Mar 31 2005, 10:18 PM) and use custom length pushrods i assume that's my problem (not having custom length pushrods) .... i didn't build that engine, you know. (IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif) Andy

interested in parting ways with your setup????

if you go back to stock...


i betyour geometry is fucked.... and have the rockers been decked 0.060?

[SirAndy]

QUOTE (Aaron Cox @ Mar 31 2005, 10:23 PM)

and have the rockers been decked 0.060?

that's like asking me if the head bolts were torqued down correctly ...
i didn't build the engine and i have *NO* idea if anything was done at all and/or done right if done.

at this point i'm thinking of going back to stock just to be sure i know what's in there actually works.

are there any *REAL* benefits for the 911 swivels? besides "easier to adjust valves" ...
(IMG:http://www.914world.com/bbs2/html/emoticons/idea.gif) Andy

[Aaron Cox]

supposed to be quieter.....

let me know if you would like to part ways with that setup.....
ill double check and deck them myself.... and buy cro mo pushrods....

BTW- i also hear the whole assembly needs to be shimmed....

[SirAndy]

QUOTE (Aaron Cox @ Mar 31 2005, 10:31 PM)

supposed to be quieter.....

that's it ?????? are you serious ????

why would one spend a shitload of $$$$$ on custom parts just to make the engine "quieter" ???? (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)

especially if it's going into a track/race car ???

i'm confuzzled ...
(IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif) Andy

[Aaron Cox]

QUOTE (SirAndy @ Mar 31 2005, 11:36 PM)

QUOTE (Aaron Cox @ Mar 31 2005, 10:31 PM) supposed to be quieter..... that's it ?????? are you serious ???? why would one spend a shitload of $$$$$ on custom parts just to make the engine "quieter" ???? (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif) especially if it's going into a track/race car ??? i'm confuzzled ... (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif) Andy

see above:

QUOTE

Benefits: from what i hear.... quieter easier to adjsut valves less valve tip wear.....

[SirAndy]

QUOTE (Aaron Cox @ Mar 31 2005, 10:38 PM)

QUOTE Benefits: from what i hear.... quieter easier to adjsut valves less valve tip wear.....

ok, let me try this one more time:
that's it ?????? are you serious ????

there has to be more. i can't believe anyone would spend money on custom made cro mo pushrods because it makes the engine "quieter" or makes valve adjustment "easier" (whatever both statements exactly mean anyways) ...
the "valve tip wear" might be a factor, but is it really *that* bad with a stock setup ??? i can't imagine that, or all stock engines would be at the shop all the time ...

someone please fill me in with some hard facts here, otherwise, i'll have a setup for sale very soon ...
(IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif) Andy

[MecGen]

Hi Andy
Heres a scoop from the bin there done that, and would do it again
My heads had custom machined SS valves, big vigin stock valves that get machined to a spec. The rockers pads where slitely decked to equal all the base hieghts, and all custom guides installed. I had looked at a 911 rocker set up, but way too expensive, so I did some measuring and a Buss motor T1V, has the same srocker set up as my 2.0l but uses the smaller 8mm compared to the 9mm 911, (I might be wrong on the sizes, its early in the morning and I am going from memory).
Check a VW swivle rocker price now we are talking.
Something to stress here wich is not related to your motor because it has already been built, rocker geometry is directly related to your cyl heights. Push rods need to be adjusted for length, I don't see an option here, after compression is set the head bolted on, the rocker deck and lifter are unajustable, leaves the push rod. My pushrods where sized, one at a time, to have @ half lift the rocker @ level, strait 90deg at valve stem. swivle foot strait line with valve. This will cure a lot of guide wear/smoke issues down the road. Back in the day I used a Jewel lathe to trim down the pushrods, never needed longer rod, but now I am sure the push rods can be found with adjustment screws, although this is expensive.
I have had a quiet, reliable, min maintenance/adjustment needed, setup for ten years now, on a mild hopped motor, no failure in the valve train watsoever, not a lot of 914s can say that.
Would do the buss thing again if I was going to keep my 2.0l.
I'm late for work!
Regards and thanx for letting me use your site Andy
Joe


(IMG:http://www.914world.com/bbs2/html/emoticons/beerchug.gif)

[ChrisFoley]

Without custom length pushrods you will get rapid valve guide wear.
That means noise in addition to oil consumption, and more.
Even with stock adjusters you need custom pushrods after any mods.
Like Joe said, you want the rocker adjusters to be in line with the valve stem at half lift.
I would recommend against using the cheapo swivel adjusters but I have no direct experience with them.

[SLITS]

Ok, let's go for the theory......

The stock rocker slides across the valve stem tip as it pushes down on the tip 'cause it's traversing an arc. The contact tip of the rocker (adjustment screw) has to be slightly arced to swing this arc. If it were absolutely flat, it would dig into the vavle stem tip and give minimal contact surface. This, in effect, side loads the valve stem and creates accelerated wear in the valve guide.

A roller rocker would be nice, 'cause it "rolls" across the tip with considerably less friction.

A swivel tip would have somewhat the same effect as a roller, as the foot is in a constant relationship to the valve tip and the adjuster itself "swivels" with the angularity of the arc. Hence, less movement across the tip of the valve..less wear...less side loading.

Rocker geometry is a whole 'nuther thing. Extra lift can be had by running an odd geometry. It's all a geometrical thing as to obtaining the maximum vertical travel for the arc swung by the rocker.

If your pushrod is to long, you lose vertical movement as the rocker is positioned on the backside of the arc. If it it to short, the same thing occurs.

For maximum lift from the arc swung, the rocker is positioned at <90 degrees from the plane of the valve tip. As the arc is swung, the rocker ends up at a position of >90 degrees.

To obtain this, the pushrod and pedalstal are modified, because of the head height (c/l of the rocker shaft) from the c/l of the camshaft.

Wasn't this fun?