Differences between old and updated oil bolts.
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From: SoCal
Differences between old and updated oil bolts.
Many have seen the pics that cdelena showed comparing the old and updated oil bolts. The new 4 hole design has holes each a shade over 1mm diameter and the old has 2 holes each a shade less than 2mm diameter. Total oil outlet area is slightly larger for the old bolt.
The new bolt spring is noticeably 'weaker' than the old with range of travel being less.
Given these observations, I think the active spray time would be greater with the new bolt; it will open with lower rpm &/or lower oil pressure, since the latter two are related. Given a situation where the oil pressure is low but the engine is still working hard (hot day, hot, thinned oil, heavy engine load at 'lower' rpm), the old bolt might not flow very well to cool the 'over heating' pistons.
Thoughts?
The new bolt spring is noticeably 'weaker' than the old with range of travel being less.
Given these observations, I think the active spray time would be greater with the new bolt; it will open with lower rpm &/or lower oil pressure, since the latter two are related. Given a situation where the oil pressure is low but the engine is still working hard (hot day, hot, thinned oil, heavy engine load at 'lower' rpm), the old bolt might not flow very well to cool the 'over heating' pistons.
Thoughts?
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From: On a fencepost
If the same amount of oil, is going out of 4 holes of less total area than the original 2 holes, then won't that mean a longer jet, as well as 4 jets instead of 2. Just washed the car, so that's a bit of garden-hose physics! 
Anyway, if that's the case, wouldn't that mean the oil from the bolts cools and lubricates the pistons more of the time.
-Brian.
Anyway, if that's the case, wouldn't that mean the oil from the bolts cools and lubricates the pistons more of the time.
-Brian.
Joined: Mar 2001
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A slight diversion but similar train of thought:
https://www.s2ki.com/forums/showthread.php?...&threadid=84722
https://www.s2ki.com/forums/showthread.php?...&threadid=84722
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From: SoCal
Originally posted by bmarshall
If the same amount of oil, is going out of 4 holes of less total area than the original 2 holes, then won't that mean a longer jet, as well as 4 jets instead of 2. Just washed the car, so that's a bit of garden-hose physics!
Anyway, if that's the case, wouldn't that mean the oil from the bolts cools and lubricates the pistons more of the time.
-Brian.
If the same amount of oil, is going out of 4 holes of less total area than the original 2 holes, then won't that mean a longer jet, as well as 4 jets instead of 2. Just washed the car, so that's a bit of garden-hose physics!
Anyway, if that's the case, wouldn't that mean the oil from the bolts cools and lubricates the pistons more of the time.
-Brian.
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From: South of the pier, Huntington Beach, CA
Am I correct in thinking these bolts don't spray directly but rather act as a throttle in the oil passage on the way to the sprayer. And if you throttle that "garden hose" before the nozzle the resultant spray will be less forceful? 
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From: SoCal
[QUOTE]Originally posted by gernby
[B]
If "a shade less than 2mm diameter" is about 1.9 mm, and "a shade over 1mm diameter" is about 1.1 mm, then the old bolts would have about 5.7 mm^2 and the new bolts would have about 3.8 mm^2.
[B]
If "a shade less than 2mm diameter" is about 1.9 mm, and "a shade over 1mm diameter" is about 1.1 mm, then the old bolts would have about 5.7 mm^2 and the new bolts would have about 3.8 mm^2.
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From: WA
[QUOTE]Originally posted by gernby
[B]
If "a shade less than 2mm diameter" is about 1.9 mm, and "a shade over 1mm diameter" is about 1.1 mm, then the old bolts would have about 5.7 mm^2 and the new bolts would have about 3.8 mm^2.
[B]
If "a shade less than 2mm diameter" is about 1.9 mm, and "a shade over 1mm diameter" is about 1.1 mm, then the old bolts would have about 5.7 mm^2 and the new bolts would have about 3.8 mm^2.
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From: Ocean City
It is possible for 4 smaller holes to flow more than two larger holes. Flow area is only a part of fluid dynamics . . . final pressure may or may not be governed by the jets themselves.
Definitely it is better to have a wider window of cooling though, and remember its the cooling of the pistons/cylinder liners that's important. Rather than the oil itself.
Definitely it is better to have a wider window of cooling though, and remember its the cooling of the pistons/cylinder liners that's important. Rather than the oil itself.
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From: Laguna
Originally posted by bmarshall
If the same amount of oil, is going out of 4 holes of less total area than the original 2 holes, then won't that mean a longer jet, as well as 4 jets instead of 2. Just washed the car, so that's a bit of garden-hose physics!
Anyway, if that's the case, wouldn't that mean the oil from the bolts cools and lubricates the pistons more of the time.
-Brian.
If the same amount of oil, is going out of 4 holes of less total area than the original 2 holes, then won't that mean a longer jet, as well as 4 jets instead of 2. Just washed the car, so that's a bit of garden-hose physics!
Anyway, if that's the case, wouldn't that mean the oil from the bolts cools and lubricates the pistons more of the time.
-Brian.