Frodge

How long should I expect a 1584CC engine to last?

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Wayne

If you maintain it properly, including valve adjustments and oil changes, and don't push it too hard, it could last you indefinitely.

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MY72BUG
Hi Frodge:  If I might be allowed to add my two cents worth; here goes:
     Like Wayne says - valve adjustments are critical to the life of a VW engine.  Why? Well with solid lifters a very specific gap MUST be left between the end of the valve and the rocker arm.  The gaps must be set cold following the directions in your Haynes or similar book, using persistence and care.  Any amateur mechanic can do it and face it, he will spend more time to get it right than any shop mechanic.  The gap must be tight enough to allow the valve to dwell on the valve seat sealing the compression but also transferring the heat to the valve seat.  If it is too tight the dwell period is too short, the heat does not transfer and the valve starts to burn out.  Too loose and the valves " bounce " on the valve seat.  Of critical importance to you is that you record the gaps as you find them when you set out to do the adjustments.  So in your handy log book you record #1 intake ___, #1 exhaust, etc.  You do all of your settings and the next time you go to do this job ask yourself if the gaps have grown or shrunk over the period of time in question.  If they have shrunk, alarm bells should be going off !  If that gap is closing on its own, the valve is stretching and this is a prelude to a valve head coming off and dropping down into your combustion chamber.  This will provide one very unfortunate answer about the longevity of your 1600 CC !!  Jump on the problem when the problem is noticed = cheap rebuild.  Ignore the valve gap adjustments ( and oil changes ) and you may watch your 1600 do an expensive super-nova.  Routine maintenance is the key. One more point to ponder.  Any modifications to your VW engine ( changing oil cooling systems, boosting horsepower  through carburetion changes, hot camshafts etc. )  come at a price paid in engine longevity.  VW engines were designed to run understressed.  Unlike other 4 cylinder engines of their day, they do their highway speeds at a lower RPM and they can do it all day.  Toy with the work of  German engineers and you play with fire.   Keep it stock, keep it simple, treat it right and it will last.  Dan (MY72BUG) in Goderich


I'd rather have a partial bottle in front of me than a partial frontal lobotomy.
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Ryan

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

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Frodge

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?

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Ryan

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

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Friedle

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.

'72 Super. Paint-7/20/09, 400+k miles, New engine case "41" Brazil, rebuilt German heads, new Bosch electrics, new Solex German carb. new German silencer. Built by Steve Tims Performance/Enterprises, Riverside CA. '73 OEM airfilter, (Fram elemement), chrome stock wheels, daily driver, 25.46-27.50mpg, driven 20+years.
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