I have found some interesting information and would like to hear other peoples input based off of these facts.


It's been said the LE5 valve springs need to be upgraded to handle boost over 15 psi.

Some facts:

-L61/LE5/LSJ/LNF all use the same valve springs.
-LE5 intake has 0.00954811024 more inches of valve lift then the LNF
-LNF exhaust has 0.0102721654 more inches of valve lift then the LE5
-LNF can push 24 psi on the valve springs with no valve float

Does the LE5 really need upgraded springs to run more boost or is this just a myth? The facts don't seem to add up

 

good question, i'm betting its just a myth.

 

either way.. whether a myth or not it seems like its a good thing to change em so ucan rev the sucker higher. how do u know if u have float btw? ive seen 17 psi on my 2.4 accidentally lol, but i dont know wut the symptoms of valve float are.

 

Misfiring or backfiring. Car may stumble or lose some acceleration. Sometimes noises can be heard from the engine, which is usually bad.

 

valve float almost alwasy = valve tap which almost always = damage

 

Not necessarily. It may finally seat before piston reaches top of the cylinder. It may bounce off of valve seats, which could be bad.

 

Interesting

 

They don't "need" to be replaced, its just recommended that you do so.

 

People have said the valves float at boost over 15 psi.

 

U also need to consider compression ratio at 15 psi with 10.6-1 comp

 

Curious on the answer to this as it will determine what pulley I'll be running this spring.

 

its really not that hard, you have to retime the car afterwards, but other then that you can get the special overhead valve compressor tool from ebay (kent moore...ill get number later from mine) for like 40$ and just use an air compressor to keep the valves up.
i did all of mine (not including retiming) in about 4 hours (including all take down and reassembly with tool put away lol)....
better to be safe then sorry...and then you can rev out higher too

 

Don't worry about those details. A lot of people push a lot more then 15 psi through these motors. Do some research.

Not much help but ok.

 

how is that not much help? its saying that why NOT do them lol
its not too hard AND you dont risk bending all your valves and ripping your head apart...ive done that too and it sucks *****...would have gladly done this over the bending of valves

 

the CR is part of the important details.. most of the people that are pushing more then 15 psi are running valve springs or lowered compression there have been a hand full of companies who've documented valve float at around 16-17 psi on the LE5..

 

lol. This has nothing to do with compression ratio. Did I ask for help with that area, no.

People have documented proof? It would seem the LNF should be experiencing valve float not to far behind the LE5.

 

hahn, zzp, RPI, and ddm have all documented some float starting around 17 psi on a 2.4

 

I guess the question becomes how come the LNF does NOT have valve float?

 

Lnf's cr is diffrent and there lift is also diffrent

 

CR has nothing to do with valve float. Are people stupid????

I also quoted the difference in lift being almost nil.

 

yes over 7200 rpms though

 

Ding ding ding.

 

jeeze insulting everyone else on their lack of knowledge yet you havent come up with a theory on it yourself. Guess your an idiot as well?

 

I don't know where people are getting the idea compression ratio effects valve float. I never even mentioned compression ratio in my original facts because I knew it had no effect on the question I'm asking. I'm asking about what the motor can withstand or anything of the such. I've come up with a theory that says valve float won't be an issue, but I wanted to hear some expert opinions.

So under 7000 RPM, valve springs should be able to handle a bit more. Let's say 18-20?

 

i havent really gotten an that answer, but ZZP said they stopped seeing gains at 7200 at 15psi then they went to 7500 rpm at the same boost level

i dont run that many rpms so im not too concerend with it