Important info for u HO6.9 builders out there....

[Dieselcrawler]

just got talking to my machinist that does all my engine work for personal and work. me and him got talking about the 6.9 and things to do to them and looked up some info......

Valve springs.... are the same part number from the 6.9 all the way up to the 7.3 powerstroke.

Lifters.... same thing. no difference.

he did say do not go any higher than 140lbs of pressure on the valvesprings. the lifters will collapse around there.

just some good info.

 

[The Warden]

FWIW the lifters are also the same on the IDI's as on the 6.2l, 6.5l, and even the 5.7l abortion

I can't remember if it's been mentioned before, but did he say how much pressure the current valve springs are rated at?

VERY interesting that the PSD uses the same springs and lifters...

 

[Dieselcrawler]

if i remeber him correctly, he did say stock pressure is around 60-75.

 

[The Warden]

Ah okay...while 140's apparently the limit without causing imminent lifter failure, I wonder what the max pressure you can go to without affecting the overall lifespan of the various parts (lifters, pushrods, cam lobes, etc) would be?

 

[Dieselcrawler]

i did ask what he would do, (build lots of race motors) he had said finding a spring that was around 100-110 lbs. he said pushrods will be fine at that pressure.

 

[bike-maker]

Different valve springs have different spring rates; for example double springs would have a higher rate. This means that two different springs with the same 140 pounds of seat pressure could be different at open pressure (with the valve open). In my experience, open pressure is the number that really counts.
Another thing to consider; having higher valve spring pressures does nothing but rob horsepower unless you NEED the extra pressure to keep the valve train from floating. As far as I know, this isn't an issue with IDI valve train unless you try to put an exhaust brake on one.

 

[Dieselcrawler]

they guys runnin the higher gov spring were talking about a stronger spring.

 

[Worstenemy453]

So if all of them use the same valve springs whats the point in changing them unless you go to aftermarket ?

What aftermarket options are available.

 

[FordGuy100]

PSD guys run Comp (I think?) 910 springs.

 

[Worstenemy453]

PSD guys run Comp (I think?) 910 springs.

http://www.jegs.com/i/Comp Cams/249/910-16/10002/-1?CT=999