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Rocker Arm Redux
It's been about ten years since I last rebuilt a 911 engine, and I'm about to do it again on a type 930/2 with 9.5:1 and aggressive cam. The rocker arm pads on this engine are by far the worst I've ever seen. It looks almost like there were air pockets in the casting. So I'm declaring them NFG.
What developments have happened in the 911 rocker arm world in the past ten years? I know Pauter makes some that look pretty nice but are rather expensive. I see some Porsche replacement versions, but they look quite different than I'm used to (993 version?). Bottom line is I need new replacement rockers for a high performance 3 liter. And an "Oh by the way", I'm debating PMO 46's or ITB EFI. I tried a Megasquirt ITB years ago and got fed up playing with it and resorted to Webers. If there's an ITB/EFI near plug'n play system at somewhere around $4K, I'm interested.
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Current: 914/6 GT Conversion, Cayman Old: Many PCars + Formula Racecars Last edited by roblav; 05-19-2019 at 07:04 AM.. |
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05-19-2019, 06:58 AM
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Puny Bird
Join Date: Nov 2002
Location: Port Hope (near Toronto) On, Canada
Posts: 4,566
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On EFI nothing is plug and play, I like sdsefi (dot com) because it's about the easiest to program and doesn't require expensive dyno time.
Hot cams and weak vacuum play havoc with the MAP sensor and you often have to tune in TPS only, what MS calls "alphaN". I run TPS only with my 2.6 liter type 4 in my '67 bug with no issues at all. $4K is a pretty small budget if you count the PMO TB's. there's some threads on DYI motorcycle ITB's, then the $4K is do-able. I used 46mm GSXR TB's on my bug.
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'74 Porsche 914, 3.0/6 '72 Porsche 914, 1.7, wife's summer DD '67 Bug, 2600cc T4,'67 Bus, 2.0 T1 Not putting miles on your car is like not having sex with your girlfriend, so she'll be more desirable to her next boyfriend. Last edited by Mark Henry; 05-19-2019 at 08:14 AM.. |
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05-19-2019, 08:10 AM
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Thanks Mark... yes, it's a 914/6 conversion project.
I built ITBs in 2013 for a 3.2 Carrera using 1999-2000 GSX-R 750 throttle bodies. It wasn't that difficult. I'll check out sdsefi and leave this option open for now. Still need rocker arms! Thanks, RL
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Current: 914/6 GT Conversion, Cayman Old: Many PCars + Formula Racecars |
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05-19-2019, 02:14 PM
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Quote:
Of course I read that on the internet. And now I repeated it..... but I had some rockers resurfaced that had some pitting/craters and they came back looking like new.
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Heavy Metal! Part Deux - The Carbon Copy Project Heavy Metal https://tinyurl.com/57zwayzw (SOLD) 85 Coupe - The Rot Rod! AX beater Quality Carbon Fiber Parts for Classic 911s: instagram.com/jonny_rotten_911 |
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05-21-2019, 04:08 PM
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Registered
Join Date: Jul 2000
Location: So. Calif.
Posts: 19,910
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Surface hardness depth on the valve end is finite on rocker arms. When excessively worn or resurfaced X times, more of the softer base material is revealed. In addition, the lift ratio changes slightly as the rocker geometry drifts due to resurfacing operations. Not sure who checks the hardness. Check with whomever claims they can resurface used rockers.
Also depends on the camshaft material. Welded cams tend to have harder lobes compared to machined and treated cast iron. However, I'm not privy to the latest in camshaft metallurgy. Best to check with the cam and rocker people. WebCam used to recommend using new rockers or their rocker arm rebuilding/treating services. |
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05-24-2019, 02:59 PM
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Registered
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Thanks much! They're needed for new Webcams.
How much are those Pauter rocker arms? Price is not listed on website.
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Current: 914/6 GT Conversion, Cayman Old: Many PCars + Formula Racecars |
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05-25-2019, 05:50 AM
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