How does a torque to yield Bolt work?
Stretch bolts for cylinder heads Stretch bolts, or torque to yield bolts, when properly torqued, loose some of their diameter to the stretch, but are elastic, and if variations in the gasket material or other things occur they keep their clamping force by varying their diameter slightly, but frequently, like breathing.
What’s the correct torque sequence for head bolts?
As stated earlier, start at ten and go down for all three sequences. Start at 35 then 55 then 72. Loosen all bolts and repeat process again for the final time. Doing it twice will ensure they are properly torqued. First time the bolts may stretch some, reason for doing it twice. Second time should set them in good.
How to torque up stretch cylinder head bolts?
However if you are still using an old 14 bolt block then you can re-use the 4 bolts that are fitted to the lower row. However these are only to be torqued to 20NM with lock tight applied. This is simply so they have no effect but fill the holes. This is to be done after torqing the main 10 bolts up as detailed below.
Where are the torque settings on a MG?
Bolt/fixing Nm ft.lb Engine Engine Engine Camshaft cover bolts 9 7 Camshaft gear bolt 8mm bolt 10mm bolt 33 65 24 48 Crankshaft pulley bolt 205 151
How to set torque on big end bolts?
Fit the stretch gauge over the bolt and zero gauge. Tighten the bolt to desired stretch. Loosen second bolt. Fit the stretch gauge over the bolt and zero gauge. Repeat proceedures 6-11. Big end ARP stretch settings/torque settings.
What do I need to tighten head bolts on Subaru 2.5L?
You will need both inch and foot pound torque wrenches as well as a torque angle gauge. Clean the cylinder heads and the block mating surfaces thoroughly with lacquer thinner or acetone.
Why are stretch bolts torque to yield bolts?
Since the common introduction of torque to yield bolts, confusion has arisen, especially in regard to their reuse and as to when and if they can be re-torqued. Principally this is due to two sets of technologies existing side by side and often in the same engine.
Is there a way to check the torque of a bolt?
Bolt torque can be checked with a tool such as a torque wrench, but without a value as a guideline, a torque wrench offers no advantage. To arrive at the correct torque value, several other values must be found first. Two principles influence the correct clamping pressure for each bolt, known as clamp load.