Quote:
Originally Posted by 930cabman
Why would one cheap out and not replace the original Dilvar with "factory steel" when the engine is stripped down? Percentage wise does $500. make a difference? Did the factory steel studs come along after the breakage issues were discovered or did the factory turbo models use them? Our 911s will be going in for this repair soon but as far as I know our 930 is not affected with the stud breakage issue and all the while the 356 just keeps motoring along without complaint.
thanks all for the positive comments
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Factory conventional STEEL Studs are not know to break - They are made from a high grade steel and the 'Class' of thread fit is an order better than any currently available aftermarket studs that we have seen.
Factory studs gauge to 5g6g which is a 'close fit'.
We have checked several makes of aftermarket stud and they all gauge at 6g which is a 'commercial fit'.
This means that a Porsche stud will 'rock' less when inserted into the case.
A standard steel stud from Porsche in the UK has a price of $8.00 with Sales Tax
I am not sure that the fit is of great importance but at 8 bucks there doesn't seem much reason not to use them.
The 993 Dilavar stud are currently $36.00 each.
If you are building an engine with an Aluminium Case I don't believe Dilavar is needed.
The SC engine used steel studs on the upper row an Dilavar on the lower row which IMHO is a poor design decision and something have never understood.
Questions about the quality of Dilavar studs have been asked for years and I think it is safe to assume that there have been some 'dubious' quality studs in the supply chain for years and they should be avoided.
I have commented in the past that there are Dilavar studs being advertised as being made for a magnetic material and this means that they are NOT Dilavar which will always be non-magnetic.
I would tend to use Dilavar in a magnesium case and a standard steel stud in an Aluminium case as the extra cost just doesn't seem justified.
We do make our own Grade 5 Titanium Studs which we use in magnesium cased engines and these also reduce the expansion forces due to the lower Young's Modulus of Titanium.