Chris,
Quoting myself: "The article discussed the over torquing of the bolts causing localized material yielding around the bolt head and the nuts which is a good reason not to exceed the specified torque " The material they were talking about was the head and the lower end girdle. If you plan to exceed the specified torque, which I think was 34 ft-lbs, then I would trust that you are using some larger diameter and thick washer on both ends to eliminate this problem? I know that I am picking at the nits but there is no reason to go down the creek that is full of failed K series motors.
Dodge fun to watch you guys go through this "reloading"!!!
Rex
Glad you are enjoying it. Read on.
Rex,
In the RE article, where he talks about the bolts causing fatigue failure of the block, it can’t very well be an underhead crushing problem since the bolts don’t bear on the block, only the head and ladder. And when he talks about “bearing crush” I believe he is referring to distortion of the block/ladder due to overtorque overloading, and consequent distortion of the main bearing housings and/or alignment, not the underhead area of the bolts.
Some clarifications, if I may,
A) A point raised by Rex and clarified by IO, the lower bearing area of the OEM "sandwich bolt", now with a proposed change to an ARP stud, is what the OEM refers to as an "oiling ladder". This part serves 2 functions. Its' oil passageways deliver the oil supply to the bottom end, and its' threaded portions secure the "sandwich fastener". It has "plenty" of bearing area to prevent "crush", as long as the material spec itself is adequate. This is the point of "upgrading" to the "newer" type ladder, supposedly made from stronger material. Nothing prevents the fabrication and use of a steel ladder, should the need arise.
2) Anytime fastener torque is "altered" from its' former specification, nearby housing bores will "most likely" be affected. This type of "distortion" (just a clamp load change actually) is easily determined by precision measurement of the components in a "mock-up" and "torqued-up" format. We plan to do this. Correcting any main bearing housing bore distortion will be accomplished by "align honing" the mains, usually a "piece of cake" operation. Because the K has an aluminum main cap "girdle", surfacing that item is more complicated than grinding individual steel/iron or aluminum main caps. But, of course, this can be accomplished.
A further note is that the main bearing bore needs to be established early on in the build cycle, because other dimensions such as block "deck height", con rod length, piston compression height, etc, are tied to this dimension.
d) At the upper end of the ARP stud assembly will be a large area "bearing washer" as supplied with most ARP stud kits. This should solve any "crush" issues with the seating area on the head. Any cylinder head material crush issues that arise in the "mock-up" process, could be addressed with a solution heat treatment of the head. Call me "optomisty", because I doubt that this would happen and heat treatment be required. Even @ 50 ft/lbs, the applied clamp load is low compared to other alloy block engines, and we are increasing material spec and bearing area where we can. And additionally, although ARP "recommends" 50 ft/lbs as the applied torque, we can choose to utilize a lesser amount, should the block itself prove to be made of "cheese". I have it on good authority that Sargento is ready and willing to supply a firmer cheddar.
z) A greater concern for me was the regression of the cylinder head material at the point of the compression seal when using an MLS type gasket. Readers of the build diary may recall that the Rover OEM fix is to install an .030"/.040" stainless steel "sandwich plate" between the head surface and the upgraded MLS gasket. I believe that this issue is reduced, or perhaps even solved, by the decision to use a solid copper head gasket with a wire o-ring and receiver groove. Instead of the load being applied to a 2/2.5 mm wide compression seal area, the clamp load will be spread across the full width of the cylinder barrel combined with as wide an area of the head surface as practical. This has to be an improvement. And additionally, we can not afford to give up ANY un-necessary amounts of compression volume, such as with thick MLS gaskets and/or sandwich plates. That would just be stupid . . . . .
X) Bore center to center spacing is presumed to be 88 mm, since that is the port spacing layout. Of course we are going to double check this critical dimension.
Y) In this application, what I mean by siamesed is that the barrels WILL need to have a "clearance flat" machined into the water jacket/head face areas for the purpose of fitment of a larger OD barrel than the existing bore centerline spacing allows, to allow water flow between cylinders, and to allow simple single cylinder manufacture of barrels, as opposed to a "block of four". The purpose of the larger barrel OD is to gain bearing area at the "foot" of the barrel where it bears against the cylinder block. This is, in my opinion, a crucial weakness of this engine when modified for higher output.And, finally, my labeling of the Simon Erland articles as "technical" was somewhat "tongue in cheek". I'm sure Mr. Erland is a gentleman and he is obviously a fine writer. He is also clearly enamored with the Rover K engine series, and his lack of redress to what are some, "short-comings" of the design, leads me to speculate that he may not have ever dealt with the frustration of trying to modify an engine designed for one purpose, into something else entirely. But of course, I could be wrong about that, and if so, I apologize in advance to Mr. Erland.
HAPPY HOLIDAYS TO ALL!!!! And ta ta, for a bit . . . . . .
Eggnogsuckingboy