How long should I expect a 1584CC engine to last?
If you maintain it properly, including valve adjustments and oil changes, and don't push it too hard, it could last you indefinitely.
Mostly right. If the valve gap is too large the valve will not bounce on the seat, in fact valve bounce has nothing to do with clearance at all. It's controlled by a combination of cam ramp angle and valve spring seat pressure. You can't control the ramp angle unless you do a custom grind, but you can set spring pressure. Exactly what spring pressure is a question for your head and/or cam guy. The real problem with too large a valve clearance is that you will hammer the crap out of the pushrod tips, lifter cup and rocker cups, most likely leading to a pushrod failure.
The actual dwell time of the valve on the seat is also determined by the cam grind, how long the lifter is riding on the base circle of the cam. As the engine warms up, the valve clearance will decrease to around .002" or so in a stock setup. This is due to the expansion coefficiant of the various parts in play. To tight and you risk holding the valve open as the engine warms up, this can lead to a burnt valve, and seat damage. Too much clearance and you're back to hammering your parts to death. --Ryan
Typically speaking, how often have you guys had to actually adjust valves? I know you are supposed to check every oil change or every 5000, but are you making changes every time? WHat is considered normal?
It depends. Stuff wears so the clearance should open up over time, how much time is relative. What you want to watch out for is a valve that gets a little tighter each time you check/adjust. If one is showing up a few thous tight 2 times in a row then you should really consider popping the heads and getting them freshened up. Usually guys are pulling the heads for a valve job before problems show up and they just replace their valves then. --Ryan
I have 93K on this engine I installed in July 1995. Dailly driver, 22-mile round trip, grocery-getter, errander-getter. I adjust valves at 3K, and change the oil (20/50 Valvoline Racing) before 3K regularly, electroic ignition, 009, header, stock exit, aftermarket washable-air cleaner. She runs good on premium fuel, 21-28mpg, (just got the new HOT VW mag to read-up on increasing fuel economy).
Oh, I do drive her like I stole it ... Patrick.
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