I have been reading that lately alot of people have been using stock honda valves with aftermarket valvesprings and retainers. Are oem valves better then or equal to the quality of aftermarket ones?

 

from what i've read,(on h-t, can't remeber the thread though) the stock valves are less likely to break. the aftermarket valves break causing more damage to cylinder walls, etc. the stock ones are more likely to just bend. i plan on using the stock valves when i install new cams/springs/retainers.

 

it kind of depends on what valve company you're talking about.
i have seen race motors with planty of broken stock valves...and bent.
as i understand it valves don't just bend themselves though, or break, usually there is another underlying cause.
i have always run type r valves and have had 0 problems in any situation.

 

In my experience bent valves, stock or otherwise, are generally a result of piston to valve contact. I usually determined that it was caused by either timing belts skipping a few teeth, over-reving, or valve float. In either case user error was usually to blame, either the timing belt was not properly tensioned upon re-instalation, someone went from 5th to 2nd or higher lift/duration cams were installed w/o stiffer valve springs. Just what I've noticed when me or my friends fucked up valves.

James

 

exactly what i'm saying....the majority i see are over revs, i have seen some incorrectly mic'd motors which have bent valves upon start up. but they don't just bend themselves.....when a piston slams into it at 9000rpm, aftermarket or not, you are not going to have a happy valve.

 

thats what i meant, if piston to valve contact occurs the stock one are LESS likely to break. Meaning a not so costly rebuild if it does occur. But i have no first hand knowledge of this (whether aftermarket break more often). However if i gain a little peace of mind using stock valves i'm all for it.

 

i see, the last over rev i saw with stock valves looked pretty bad. The entire head was trash as well as 3 of the 4 pistons. all kinds of valve parts in all the cylinders. A lot of it depends on the engine speed your at and how quickly you stop running the car, also the severety of initial contact. like i said, either way, you may be screwed but a more maleable metal may bend instead of breaking...which may help.....may.

 

I couldn't say whether OEM are less likely to break/bend than say Ferrea upon impact with the piston. But, as was previously stated, at 8000+ rpm contact between pistons and valves is not going to yield anything positive, stock or otherwise.

James