Ian Epperson
Samba Member
Joined: January 12, 2005
Posts: 2262
Location: Alameda, CA
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 Posted: Mon Jul 30, 2007 9:59 am Post subject: |
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| npconnor wrote: |
Jeez, that struck hard, where am I going to get another engine?  |
Sorry 'bout that. It's better if you're prepared for it than if it just fails on you.
| npconnor wrote: |
| How do I "set the valves?" I'm all set on oil and belts, going out tomorrow. How much do new engines cost? Could I get a "beefier" engine (1.7? 1.8L?) and still have it fit without it hanging out the back? There's quite a bit of room back there... |
You absolutely could put a "bigger" engine back there (bigger in quotes because the engine will not take up any more space, just the interior combustion chambers would be bigger). However, as others have said, it'll cost more money in the short and long run. I'm STILL putting my 2270 in mine - it's taken almost $8k in non-engine expenses and a significant amount of time.
Here's an older post I did on setting the valves:
| Ian Epperson wrote: |
The Muir manual "How to Keep Your Volkswagen Alive" has a good section describing not one, but two different methods to adjust valves.
I found this page online:
http://www.geocities.com/MotorCity/Downs/9413/howto.html
But the writing isn't clear and I disagree with the amount of work he recommends.
What you're setting is the clearance between the rocker and the back of the valve. In the center of the engine, there's a shaft with a series of lobes on it - the cam shaft. These lobes press against rods (push rods) that extend left and right to the heads. You can see the tubes these run in when you look under any VW engine (push rod tubes). Because the valves have to be pushed from the outside, inward, these rods push against a rocker. When you pop open the valve covers on the left and right side of the engine, these rockers are what you see. Those rockers press against the back of the valve. The valves are disks on the end of a shaft in a T shape. The disks cover holes in the engine and when they're pushed inward (via the shaft) they open the hole. Valve springs hold the valves closed until they're pressed. Each cylinder has an intake valve and an exhaust valve and it's critical that they open and close at the proper time.
When the spark fires, those valves must be closed so that the gasses will push the piston instead of just blowing out of the intake or exhaust. To close the valves, the engine just let's them go and the spring pulls them shut.
One end of the rocker has a threaded stud and a nut on it. The end of that threaded stud is what actually pushes on the valve. It's threaded so that it's adjustable. On a cold engine, there should be .006 of a inch clearance between the end of the stud and the end of the valve, when the valve is relaxed (closed). Nearly any auto parts store will sell you a cheap set of feeler gauges. These are strips of metal of different thickness - one will be .006 inches thick.
So, here's the procedure. With the engine cold, block the wheels and put it in neutral. Use a wrench to turn the engine until it's at TDC (Top Dead Center - there's a big mark on the lower pulley, when that points strait up and lines up with the seam of the engine, that's TDC). When you're at TDC, either #1 cylinder is ready to fire, or #3.
Here's how the cylinders are laid out:
| Code: |
(front of car)
_ == _
[3_| |_1]
[4_| |_2]
==
(back of car)
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See how #1 and #3 are opposite of each other, they're always in the exact opposite of their cycle. Same with #2 and #4 - but those two fire at BDC (Bottom Dead Center, 180 degrees opposite of TDC). Once you get used to it, you can look at the valve rockers and see if they're engaged, but for now an easy way to figure out what should be firing is to pop open the distributor. Figure out which wire goes to #1, then when the little rotor inside the distributor cap points to it AND the engine is at TDC, then #1 should be firing, and the valves should be relaxed.
So, with your trusty new feeler gauge, and a 13mm box wrench and a nice flat screwdriver, slide under your car and look at #1. You'll see two rockers that get pushed from the bottom and press against two springs at the top. You should be able to rock the rocker back and forth just a very little bit. Rock it downward, and try to slide the feeler gauge between it and the end of the spring. If it fits with the .006, try a .008 feeler, and if the .008 feeler fits, it's too wide. If it doesn't fit, try the .004 or even .002 feeler - if neither of those fit, either the valve is WAY too tight, or it's not in the firing position. If you've got to adjust the fit (here's the fun bit) you've got to loosen up the nut, then move the screw bit in or out as needed, then while holding the screw bit, tighten the nut. One way to do this is to tighten the screw until it holds onto the feeler gauge a bit, then tighten the nut (then curse when it's too tight and try again). Another way to do it is to run the screw in until it's just right, then remove the feeler gauge and carefully watch the screw and try to hold it with the screwdriver while you tighten the nut (then curse when it's too tight and try again). You'll need to check, and possibly set, both valves on the cylinder before moving on.
Now, crawl back out from under the car. Relax a bit, have something to drink - you've got three more to do. Rotate the engine COUNTER-clockwise (backwards from how it runs) 180 degrees to BDC. Now, #2 will be in firing position and can be checked. Once done with that, you're done with the side - check the valve cover gasket to ensure it's not leaking, then close up the valve cover and snap the retaining bail into position.
Half done. Now for the left side, rotate the engine counter-clockwise 180 again to get to TDC - now the #3 is ready to fire, and the valves are ready to check. Afterward, another 180 counterclockwise will set #4 ready to check.
There! Done!
After you do this a few times, you'll find that the same valves usually fall out of adjustment in the same way. When an engine overheats, the valve adjustment gets screwy. Often time, #3's exhaust valve needs to move (#3 exhaust is the hottest part of your engine). Older engines don't seem to move as much as newer engines - so if you've a fresh rebuild, you'll find that the valve adjustment may move quite a bit.
If the car is hard to start - cranks and cranks until it finally kicks over - it's usually a sign that it's time to set the valves. |
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npconnor
Samba Member
Joined: February 13, 2007
Posts: 194
Location: Central Texas
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| Posted: Sun Aug 12, 2007 11:54 am Post subject: |
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Here is a little update!
I put my belt on and changed my oil ALL by myself! Felt kind of proud, hopefully soon I'll be as knowledgable as you all! Still need a couple of essential parts... need 2 seat belts and the bolts for all 4 so I can have some saftey equipment on my car. I didn't see holes in the rear for the belts to attach on... I hope I don't have to make the holes...
I got some more lights working and put some nice auxiallry lights on the front. (those lights could blind the sun gods!  )
The only other important thing I can think of is my speedometer is broken, it looks like it's all hooked up but could it be I just need a new cable running from the tire to the "box" (the cable attacjes to the front left tire correct?)
also, if it's not too much trouble, could someone post pictures of the inside of their wiring?(The inside of the box on the left of the dash) I need pictues of each resister box so I can just copy and double check what wiring I have done. I still have a few wires NOT hooked up to anything.
I didn't get the chance to bring my car back, my Mom said: "no." So I asked my Dad if I could rent a trailor and tow it back myself. He said sure but I'd have to pay for it all. Argh, my Dad can be kind of a cheepskate at times.
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'73 Thing
Austin Air-coolers Gang |
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