Pelican Parts Forums

Pelican Parts Forums (http://forums.pelicanparts.com/)
-   911 Engine Rebuilding Forum (http://forums.pelicanparts.com/911-engine-rebuilding-forum/)
-   -   Where to get camshaft rocker arms reconditioned? (http://forums.pelicanparts.com/911-engine-rebuilding-forum/660811-where-get-camshaft-rocker-arms-reconditioned.html)

polizei 02-25-2012 09:25 AM

Where to get camshaft rocker arms reconditioned?
 
Guys,

I live in the Philadelphia area, and I'm looking for a reputable shop that can inspect and recondition my camshaft rocker arms. Any suggestions? I don't mind shipping them out!

What should I expect in terms of cost?

Thanks! ;)

AlfonsoR 02-25-2012 12:59 PM

There's a few people on this forum that might do it

1. Steve Weiner - Rennsport Systems Engine Services | Rennsport Systems | Porsche Performance Systems and Support

2. Camgrinder (Dougherty cams) Dougherty Racing Cams

3. cgarr on this forum, but I don't know his business name or details

911pcars 02-25-2012 01:05 PM

Several folks can regrind the rocker tips. Fewer can reharden and regrind once the hardened surface is gone. Ask and let us know please. Webcam used to advertise that service, but I think new rockers were cheaper.

Sherwood

304065 02-25-2012 01:10 PM

Send them to Verden Tool, they just did a few for me. They do a nice job.

121 East Blackwell Street Dover, NJ 07801
(973) 366-7510

polizei 02-25-2012 04:21 PM

Thanks for all the input guys. What's a reasonable price tag for reconditioning?

Steve@Rennsport 02-25-2012 04:48 PM

Quote:

Originally Posted by 911pcars (Post 6582293)
Several folks can regrind the rocker tips. Fewer can reharden and regrind once the hardened surface is gone. Ask and let us know please. Webcam used to advertise that service, but I think new rockers were cheaper.

Sherwood

Hi Sherwood,

The rocker pads are not hardened from the factory; these cast iron parts are simply ground with a radius matching the cam lobes. In certain cases when using hard-welded cams, we hard-chrome the rocker pads to prevent failure.

FWIW,......New, OEM rocker QC has really slipped and we've noted that most of the new ones from the dealer are not ground correctly, leaving one side higher than the other. This results in most of the valve spring pressure being applied to one side of the pad and cam lobe, resulting in higher rates of failure.

Each and every new or used rocker arm now gets checked here to ensure the pads are straight and parallel with the rocker shaft centerline and cam lobes. Naturally, these are also rebushed as needed.

JMHO, but new ones aren't cheaper, especially when factoring the effort required to make sure they meet QC. :) :)

hcoles 02-26-2012 05:52 AM

Quote:

Originally Posted by Steve@Rennsport (Post 6582706)
Hi Sherwood,

The rocker pads are not hardened from the factory; these cast iron parts are simply ground with a radius matching the cam lobes. In certain cases when using hard-welded cams, we hard-chrome the rocker pads to prevent failure.

FWIW,......New, OEM rocker QC has really slipped and we've noted that most of the new ones from the dealer are not ground correctly, leaving one side higher than the other. This results in most of the valve spring pressure being applied to one side of the pad and cam lobe, resulting in higher rates of failure.

Each and every new or used rocker arm now gets checked here to ensure the pads are straight and parallel with the rocker shaft centerline and cam lobes. Naturally, these are also rebushed as needed.

JMHO, but new ones aren't cheaper, especially when factoring the effort required to make sure they meet QC. :) :)


Steve, I wish I knew this a couple years ago, I would of had you QC and h. chrome my rockers when they were out and I saw pad surface failures. No wear on my camgrinder 964 cam. Do you recommend the "new" cgarr bushing type?

911pcars 02-26-2012 08:53 AM

Quote:

Originally Posted by Steve@Rennsport (Post 6582706)
Hi Sherwood,

The rocker pads are not hardened from the factory; these cast iron parts are simply ground with a radius matching the cam lobes. In certain cases when using hard-welded cams, we hard-chrome the rocker pads to prevent failure.

FWIW,......New, OEM rocker QC has really slipped and we've noted that most of the new ones from the dealer are not ground correctly, leaving one side higher than the other. This results in most of the valve spring pressure being applied to one side of the pad and cam lobe, resulting in higher rates of failure.

Each and every new or used rocker arm now gets checked here to ensure the pads are straight and parallel with the rocker shaft centerline and cam lobes. Naturally, these are also rebushed as needed.

JMHO, but new ones aren't cheaper, especially when factoring the effort required to make sure they meet QC. :) :)

Steve,
Good to know. Thanks for the correction. Perhaps I was taking too many cues from WebCam as it relates to their hard weld regrinds.

While we're on the subject:
How much material can be removed before valve/rocker geometry and/or safety is compromised?
Can the valve stem be shortened to restore the correct geometry?

Sherwood

Steve@Rennsport 02-26-2012 09:20 AM

Henry,

I don't know what Craig uses for bushings, we use a material that's proven to be very durable for us. :)



Sherwood,

Webcam's hardweld material is VERY durable, however its a lot harder than the OEM rocker pad so hard-chroming these pads is mandatory for these things to live.

Not very much, about .002-.003. The valve stems really cannot be shortened enough to correct geometry; we only adjust valve lengths on hydraulic-lifter engines to keep the lifter inside its range after machining the seats.

hcoles 02-27-2012 07:30 AM

Quote:

Originally Posted by Steve@Rennsport (Post 6583723)
Henry,

I don't know what Craig uses for bushings, we use a material that's proven to be very durable for us. :)



Sherwood,

Webcam's hardweld material is VERY durable, however its a lot harder than the OEM rocker pad so hard-chroming these pads is mandatory for these things to live.

Not very much, about .002-.003. The valve stems really cannot be shortened enough to correct geometry; we only adjust valve lengths on hydraulic-lifter engines to keep the lifter inside its range after machining the seats.

Steve, Craig was/is developing the use of Garlock bushings for rockers. Exactly where the effort stands I don't remember.

lindy 911 02-27-2012 08:53 AM

John @ Costa-mesa machine

KTL 02-28-2012 05:51 AM

Web Cam still does rocker servicing. Its on their page with the SOHC 12V 911 cam listing.

Craig uses Permaglide bushings in his rebushing.

http://forums.pelicanparts.com/911-engine-rebuilding-forum/374004-rocker-arm-bushing-source.html

Seems to work pretty darn well. He's working on testing an additional type of bushing that chris_seven has sent him from the UK.

burgermeister 03-02-2012 02:08 PM

I rebushed my rocker arms (as well as the idler arms & sprockets) with the Garlock / Permaglide bushings, and I haven't had any issues in 9000 miles.

hcoles 03-02-2012 03:11 PM

Quote:

Originally Posted by burgermeister (Post 6596541)
I rebushed my rocker arms (as well as the idler arms & sprockets) with the Garlock / Permaglide bushings, and I haven't had any issues in 9000 miles.

Good to know even the high speed application (sprocket) is working well with no early failures. I like the idea of the Permaglide, and will do that the next time I'm in there which could be never. Curious, did you just hone the rocker arm bushings after install to a slip fit, measured gap or do they become close enough after pressing in? Did you notice any decrease in valve train noise?

mradovan 03-03-2012 10:15 AM

Jay's Precision Machine in Santa Clara Ca, (408-980-0743) specializes in redoing 911 rockers. Jerry Woods enterprises recommends and uses Jay. It is approx $300 to $350 to a full set. He replaces the bushings with a factory equivalent material and reams to size. Then the faces are resurface to be exactly correct with respect to the bushing centers. I have seen the finished product and they look great. He will be doing mine for my 911SC in the next few weeks. If you decided to use him tell him Matt from Santa Cruz recommended him. Jay is a mechanical engineer by education (I am a practicing ME). He does things the right way.

Matt

burgermeister 03-03-2012 01:12 PM

hcoles, the fit was perfect on every bushing, tested on a new rocker shaft.

Valve train noise didn't change, but I also used my old somewhat worn rocker shafts (rotated 180 degrees) in all but 1 location.

One word of caution is that the rocker face wears to fit the cam. Once the bushings are off by 8 thousands, and you press new bushings in, the rocker will need to re-wear to match the cam, causing lots of valve adjustments. If you have the cash, I'd get the arms refaced.

The idler sprocket and arm require a bit of trickery to get the garlock bushings to work. See:
http://forums.pelicanparts.com/911-engine-rebuilding-forum/582903-idler-arm-bushing-replacement.html

Neil '67 911S 03-11-2012 05:09 AM

Quote:

Originally Posted by mradovan (Post 6598179)
Jay's Precision Machine in Santa Clara Ca, (408-980-0743) specializes in redoing 911 rockers. Jerry Woods enterprises recommends and uses Jay. It is approx $300 to $350 to a full set. He replaces the bushings with a factory equivalent material and reams to size. Then the faces are resurface to be exactly correct with respect to the bushing centers. I have seen the finished product and they look great. He will be doing mine for my 911SC in the next few weeks. If you decided to use him tell him Matt from Santa Cruz recommended him. Jay is a mechanical engineer by education (I am a practicing ME). He does things the right way.

Matt

Jay is a very capable machinist but be forewarned. Unless you are among his insiders, it could very well be many months before he returns your parts. It took him some 8 months to do two pairs of 912/356 heads, reface two sets of 356/912 rockers and reface a flywheel for me. Calling him once a week or every other week for a progress report results in nothing more than a big phone bill. And, he will only answer the phone around 5 PM PST. That said, however, he knows what he is doing. He was Harry Pellow "The Maestro's" machinist.

Henry Schmidt 03-29-2012 04:41 AM

Supertec is now taking rocker rebuilds to a new level...........
The process is as follows.
Remove old bushing and adjuster
Black Oxide rocker
Clean threads with a forming tap.
Replace bushing with high quality friction reducing DU bushing.
Surface contact pad.
Dry film Moly coat pad
Cryo treat entire assembly

We can rebuild yours or exchange from stock on hand, quick turnaround (same day) if exchanged.

We can also micro polish rockers shafts..

http://forums.pelicanparts.com/uploa...1333035981.jpg
__________________

TT Oversteer 03-29-2012 07:42 PM

What is the cost for your rocker rebuild exchange service Henry?

Henry Schmidt 03-30-2012 06:28 AM

Quote:

Originally Posted by TT Oversteer (Post 6655957)
What is the cost for your rocker rebuild exchange service Henry?

We developed this process for in-house rebuilds and it's a new deal for us. My thinking is that they should cost about $30/ea when done as a set.


I'm negotiating to buy a Cryo business so that will help control costs and speed up turn-around.


All times are GMT -8. The time now is 08:18 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website


DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.