Broken intake spring

[Diesel Doug]

Howdy!

Wife was driving the truck when the engine started to miss and vibrate. Also alot of black smoke on start of acceleration then graying out after leveling out. Did a compression test and no.6 cyl. was dead after several tries one time got 125 psi. ( bum deal have to take off passenger side ex. manifold and turbo to check compression )
Found that intake valve spring was broken. easy fix just alot of time to put engine back together.
I realize that thinks do break under normal use. If the tach is right WOT is 4200 rpm and I do push this from time to time. Could this have lent to this breakage.
Can stronger springs be used.
Why cann't a diesel turn the higher rpm as gaser?

Doug

[tom.mcinerney]

I'm not aware any reason why reving 4200 would stress spring. I think you just got unlucky.
Member 'Clevite Kid' {AKA 'Dr Lee', ProEngineer} has commented on the issue of Diesel Revs, can possibly "search" in this, the 'Ask Dr Lee', and the 6.2L forum.
I recall the good Doc characterised diesel engines as inherently low revving due to the fact that combustion begins only following the injection of liquid fuel into the cylinder . The fuel must vaporize before igniting...slows process.

[Peter J. Bierman]

Another thing on the RPM's is the mass of the moving parts.
Diesels are far more "heavy duty" then the gas engines, so the parts like crank, rods and pistons weigh a lot more.
To go high RPM they need to be even stronger and heavier then they allready are.
All that mass has to be stopped and started on the end of every stroke.
Try to imagine the G forces that act inside your engine :eek:
The bigger the engine, the lower max RPM.
30.000 HP marine engine does only 100 RPM!
Pistons weigh tons on those engines.

Peter