Ken, Looks like ARP do not offer socket head screws, only 6 or 12 pt bolts. I know someone who used ARP 12pt bolts for the flywheel, they onlybfitted because he had a belt driven alternator, so plenty

ARP manufacture high quality bolts. They are available from several reliable sources: Jegs or Summit racing. Ken Sent from Rogers Yahoo Mail for iPad

I doubt it will have a detrimental effect. , Laurie

Indeed so Ron. Buyer beware!

This is how I see it. If the bolt (assuming from any reputable maker) torques up to the specified tension without failing (irrespective of manufacturer/grade), then it won't fail if the joint stays

Pete: My understanding of the rational of purchasing AN fasteners in addition to an almost infinite incremental selection of grip lengths, is that the credibility of the fastener can be traced.

It is worth noting that the strengths indicated by bolt grades are minimums, and that there are a lot of very dodgy manufacturers who will mark bolts as whatever they want to sell, regardless of

Yes, to all that. My experience with propellor bolt breakage: I had 8.8 MPa ‘high tensile bolts’, and perhaps they were, but they were also very brittle. After around 150 hours 4 broke in

The 'grades' referred to are the ultimate strengths and yield percentage for the fastener, whether it be metric or Imperial. A 12.9 grade bolt had an ultimate strength of 1200 MPa and will yield at

Mick/All: Someone with more familiarity than me can chime in; but, grade "8" is an SAE fastener grade rating and 12.9 is a metric fastener grade rating. Since JABIRU manufactured the engine using SAE

Ron, More the reason to get 12.9 rated screws Mick

Disadvantage of looking at old items is that that they can be out of date and you lose the advantage of new comments/information. I made a lever mechanism that compressed each spring from free length

Jay, Your link leads to #10-32 screws ? They are very small and not flywheel type

(question) Hi. All (6) my pistons show, pretty much identically : wear in the gudgeon pin mating surfaces on the piston. On two sides opposite each other per end. perfect symmetry everywhere. It

Most socket head cap screws are rated at grade 8 for what that is worth. Ron M

Mick: If you search the archives, you will discover that I mentioned sometime ago that the double spring is/was not necessarily equated to more spring pressure. I feel that double springs have

Went back and checked a past order that I made. I had to buy a box of 100 (genuine Unbrako), but the price was not bad from this outfit. https://www.mscdirect.com/product/details/67802488 Jay

Re. Being pulled off the forum: I run a couple of groups on groups.io. Every now and then, I get a notification that a member has been 'evicted' because they have marked a message from the forum as

Several years ago I was asked to remove the broken studs in the 2200 crankshaft, the prop departed on climb out. Aircraft fortunatly was high enough to turn round and land back on runway. What

Laurie, I guess it will take a longer than 30 hrs to have detrimental effect ? Got to assume that lots of solid lifter Jabs have had double springs installed. Still strange that my tests showed