The pros and cons of twin plugging a 930 are certainly debatable and many of them are discussed in the following old thread . . .

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/396372-advantages-twin-plug.html

When the engine is heavily loaded CHT is going to be one of the largest contributors to detonation which is why I think the known disadvantages of losing several square inches of head cooling surface area isn't worth a small tweak in ignition timing the twin plugging might give you.

+1SmileWavy

progress!
 

looks like a front end rebuild is due

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/610090-1987-930-front-end-rebuild.html#post6038111http://forums.pelicanparts.com/uploa...1306111856.jpg

CHT + Boost = Ceramic Coating

Stay Tuned,

PFM

Measuring Valve Spring Heights
 

My plan is to get the heads built up this week, so I have a couple of questions. Are all 930 valves springs set to 34.5mm and what do you use to measure them with while shimming?

Also, do I really need a $50 tool to measure the height?

Pelican Parts - Product Information: PEL-TOL-P228

Thanks,
RC

EDIT: I'll be running SC cams so that may affect the height wanted too and I read somewhere a builder recommended 33.5mm heights for 930s...

sanded shroud
 

ready for painthttp://forums.pelicanparts.com/uploa...1306284499.jpg

rockers
 

Rocker refurbed by: Dougherty Racing Cams

Thanks John, they look better then new!
RChttp://forums.pelicanparts.com/uploa...1306374246.jpg
http://forums.pelicanparts.com/uploa...1306374273.jpg

What Valve Spring Height???
 

I have a set of Super Cup cams, which I think are John's grind cuz they are stamped DRC.

I need to know valve spring stack height for new valve springs, so if anybody knows pls helpSmileWavyhttp://forums.pelicanparts.com/uploa...1306415368.jpg

The rockers look great Rick.

As far as the recommended spring heights and related info, if its not on the cam card I would suggest contacting John for the details since you are the owner of his product now after all.

I did ask him to chime in when he gets time cuz I don't have the cam card. However, I found what looks like the lift/timing on his website:

SC on Turbo int/exh

Duration at 1mm = 236/224
Duration at 0.050" = 228/218
Lift = 0.450"/0.395"
lobe seperatrion angle = 113
lift@overlap setting 1.4-1.7mm

he's good i lost the cam timing card from my ssc cams and last time i had the engine apart i called him and he knew right away what i had and what to time the cams at.

Cam Timing is set at 2.0mm. Valve spring open height 1.5 mm from coil bind. IF you plan on shifting over 7000 rpm, consider an aftermarket valve spring.

http://www.drcamshafts.com/profiles/supercup.htm

Thanks John, I'll set them at 35.5mm +/- a frog hair and the warranty on these 2005 cams doesn't start till they are installed, right?:D

good progess today
 

http://forums.pelicanparts.com/uploa...1306710225.jpg

http://forums.pelicanparts.com/uploa...1306710245.jpg

http://forums.pelicanparts.com/uploa...1306710268.jpg

today's progress continued
 

http://forums.pelicanparts.com/uploa...1306710386.jpg


http://forums.pelicanparts.com/uploa...1306710409.jpg

Next heads
 

http://forums.pelicanparts.com/uploa...1306710511.jpg

http://forums.pelicanparts.com/uploa...1306710522.jpg


http://forums.pelicanparts.com/uploa...1306710534.jpg

I get nervous when I see a nose bearing without the o-ring and the bearing case dowel installed.

Good eye and what you can't see is the missing dowel pin on order too:)

Nice edit and you missed a couple other things too. Let me know if you see them?
RC;)

Heads getting assembled
 

2 down and 4 to go:D
http://forums.pelicanparts.com/uploa...1307016496.jpg