School me on valve springs. And studs

[littleredstroker]

From.what I understand anything over 40 psi you need them... My stockers seen 35 so I'm betting a 38r would hit more...

May be why my stockers now making a funny " hooting" noise @ 800-1200rpm...

sent while trying not to JJ My rods!!!!!!

 

[backwoodsboy]

Speaking of studs, if I upgrade to 38R with 160cc injectors would I need them?

Might as well if you're under the valve covers anyways. Better to have them and not need them than to blow a well seasoned gasket, and end up pulling the heads. Just my 2cents.

I'll be doing studs and springs amongst other things when I get my tax money back from Uncle Sam. If no-one beats me to it I'll do a write-up on the springs.

 

[dentexpowerstroke]

What are the behives from comp? I put in 910s because I thought it was either those or the competition springs a few sponsors offer.

 

[Lang]

Thanks backwoods, dentex did you shim them? I've seen quite a few who haven't and are just fine

 

[CSIPSD]

Speaking of studs, if I upgrade to 38R with 160cc injectors would I need them?

No. I would not waste money on studs or springs for a set of 160's...

From.what I understand anything over 40 psi you need them... My stockers seen 35 so I'm betting a 38r would hit more...

May be why my stockers now making a funny " hooting" noise @ 800-1200rpm...

sent while trying not to JJ My rods!!!!!!

Has nothing to do with boost pressure. It has to do with cylinder pressure. Chitty tune with 25# boost but 3000 psi cylinder pressure means even studs wont hold...

Good tuning and 45# boost with 2400 psi cylinder pressure means factory bolts hold just fine.

Might as well if you're under the valve covers anyways. Better to have them and not need them than to blow a well seasoned gasket, and end up pulling the heads. Just my 2cents.

I'll be doing studs and springs amongst other things when I get my tax money back from Uncle Sam. If no-one beats me to it I'll do a write-up on the springs.

Its your money, but a waste for anything below a 238 hybrid.

 

[IDP]

What he said, as long as the heads haven't been off in while the gaskets kinda glue the heads to the block and help hold it on. Anything less than a hybrid, studs aren't really needed. Seen lots of trucks with hybrids be fine for many years. Springs have to be shimmed if they aren't they won't have the correct seat pressure and mess up the pressure through the entire spring travel. Could end up being weaker than a stock valve spring.

 

[littleredstroker]

What he said, as long as the heads haven't been off in while the gaskets kinda glue the heads to the block and help hold it on. Anything less than a hybrid, studs aren't really needed. Seen lots of trucks with hybrids be fine for many years. Springs have to be shimmed if they aren't they won't have the correct seat pressure and mess up the pressure through the entire spring travel. Could end up being weaker than a stock valve spring.

Soooo I thought you wanted all the valves the same height? In doing this wouldn't the seat pressure not be equal?

sent while trying not to JJ My rods!!!!!!

 

[littleredstroker]

Ans how exactly do you measure cylinder pressure ?

sent while trying not to JJ My rods!!!!!!

 

[PSDEng]

Ans how exactly do you measure cylinder pressure ?

sent while trying not to JJ My rods!!!!!!

Voodoo math.....unless you have the very pricey equipment to measure cylinder pressure...which some sponsors on here do (cough cough Swamp's). Maybe there's some way to infer cylinder pressure from a backpressure reading but that I just don't know.

Right about now is when Jason should be chiming in embarassing me in front of everyone in the thread telling me I'm 100% wrong LOL :morons:

 

[4.0l sahara]

Maybe I'll do a write up later but I'm lazy. This is how you measure installed height.

 

[bruce]

Idk i still think a rod will let go before a stock head bolt will. If it was me id get a junk yard forged rod engine and throw your parts on that but thats me

 

[Lang]

http://powerstrokearmy.com/forums/showthread.php?t=5813

 

[littleredstroker]

So that leaves each valve with a different seat pressure.... Correct

sent while trying not to JJ My rods!!!!!!

 

[907DAVE]

Ans how exactly do you measure cylinder pressure ?

sent while trying not to JJ My rods!!!!!!

Something like this with a nice and fast labscope.

 

[littleredstroker]

Something like this with a nice and fast labscope.

Assuming that goes into the glow plug hole ?

Someone please explain why spring height is more important than having equal seat pressure all the way around
sent while trying not to JJ My rods!!!!!!

 

[907DAVE]

Yup.

Equal spring height should mean equal seat pressures.

 

[littleredstroker]

How.... All the valves can't set at the exact same height after 200k Miles, some have to be worn more than the others no? If a valve sets farther in the head than another valve , even if by only .010 and you set all the valve heights to 1.750 ( for example ) wouldn't that mean its not shimmed as much as the next valve, or shimmed too much depending on how much wear is on the seats? Or am I totally missing the bus on this one

If one is shimmed more to reach the 1.750 it would have less seat pressure than the other ......right ?
sent while trying not to JJ My rods!!!!!!

 

[907DAVE]

Yeah, don't think your following. If you the valve sets deeper into the head, it protrudes out the other side further - this is what you are shimming for.

Just because one valve may be shimmed more than another does not mean the installed height will somehow be different. As long as all the spring are "compressed" to the same height they will all have the same (very similar) set pressures.

 

[littleredstroker]

Yeah, don't think your following. If you the valve sets deeper into the head, it protrudes out the other side further - this is what you are shimming for.

Just because one valve may be shimmed more than another does not mean the installed height will somehow be different. As long as all the spring are "compressed" to the same height they will all have the same (very similar) set pressures.

I guess I was thinking you measure from the head, not the shims .. your saying you measure from the top of the shims, Right?

sent while trying not to JJ My rods!!!!!!

 

[907DAVE]

Either way. As long as the heights match your golden.