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Discussion Starter · #1 ·
Okay I have checked the dwell/points, they are ok. Then the vacuum, I have problems what vacuum I have, is lost when RPM is increased. The timing mark on the flywheel is close. Engine is running rich, plugs are pretty black. When driving the car it has no power.

Thinking the last check is going to be the valve timing. Both books that I have are kind of vague on this. I searched our site and have not really came up with much. Any help would be great. Because I can see what I will be doing after work for the next few days. If it is the valve timing what gaskets should I start looking for?

Thanks

Parker
 

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Finding the leak

Have you tried spraying carb cleaner around the outside of the carb while its running? Listen to the idle, if it changes, you have a vacuum leak at that point you sprayed. You can do this with the lines as well. When you have a leak at the carb, the carb has to be set much richer in its mixture to compensate for the air its sucking in. Not good.
 

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The Good Oil on Cam Timing ...

ParkerVH28 said:
Thinking the last check is going to be the valve timing. Both books that I have are kind of vague on this. I searched our site and have not really came up with much. Any help would be great. Because I can see what I will be doing after work for the next few days. If it is the valve timing what gaskets should I start looking for? Thanks Parker
Just need to remove the rocker cover - so a rocker cover gasket is all that is needed; unless the timing needs to be redone. Then a gasket for the triangular cover on the front of the head will be needed too.

When the rocker cover is off position the motor with the ball in the flywheel so that #4 cylinder is at TDC on the firing stroke ( both rockers loose indicating no valve lift on either intake or exhaust). Now look at the chain drive sprocket on the front end of the cam. The dowel that locates the sprocket should be at 12 o'clock and the three retaining bolts postioned as shown in the attached pic. - or very close! That is it.
HTH
 

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ParkerVH28 said:
...I have problems what vacuum I have, is lost when RPM is increased. ...plugs are pretty black. When driving the car it has no power.
Thinking the last check is going to be the valve timing.
First, vacuum. By definition, manifold vacuum drops off as the throttle is opened, since manifold vacuum is created by the pressure drop created by the carb butterfly. Think of the engine as a pump, which is "sucking" air past the carb. At an idle, the carb butterfly is a restriction, which creates a pressure drop, so the manifold is at a lower pressure than the surrounding atmosphere (which is a vacuum). As the throttle is opened, the restriction is less, so less vacuum. So that isn't a concern.

Valve timing is almost certainly NOT your problem. The CIH uses a timing chain, which CAN slip a tooth, but I think that is almost an urban legend (unlike rubber cam belts, which are much more prone to stretching and jumping a cog).

A vacuum leak is possible, but you say the plugs are black, which indicates a rich mixture. A vacuum leak creates a lean mixture (everything else equal), and has little effect on power at higher rpm (the amount of air at 4000 rpm is very large with respect to even a sizable vacuum leak). Vacuum leaks cause a poor idle, and poor off-throttle response (when initially reving from an idle).

My vote is either a badly out-of adjustment carb (flooding or too high a float level, wrong jets, or a typical Solex!) , or (drum roll please) a worn cam or out-of adjustment lifters. I hope it is the lifters.

Both require the same initial procedure. Remove the valve cover. Crank the engine over with the ignition wire removed (or ground the high tension lead from the coil, but don't let the engine start or you will get sprayed by oil). With the engine cranking, see if all the valves are being depressed the same amount (about 0.390", or about half an inch). Pay particular attention to the rear valves, as the rear cam lobes are the most prone to wear. If they look OK, heck, even check the valve timing while you are there. Then read the FSM (if you don't have one, get one; no excuses!) for the procedure on lifter adjustment. If you have hydraulic valve lifters (post '70), the procedure is easy. Just rotate the engine to put that cylinder at TDC (Top Dead Center) in the firing position (both valves closed; if you rotate the engine by hand, you can watch the intake valve close, and as the piston comes to TDC, you are set). Then loosen the lifter nut until the lifter is "loose", then tighten until the wiggle goes away. Tighten one more turn. Do the other lifter, rotate the engine to the next TDC (order: 1-3-4-2) and you are done. The solid lifters are adjusted differently, and you need to read the FSM for that. Well, it is similar, but you use a feeler gauge (engine hot) and set the gap between the lifter and valve at spec (0.012" exhaust and intake). The FSM has some bizarre procedure where the engine is running while you set valve lash, but you can start with the engine hot and shut off.

If it is the cam (which is common, and my vote), you need to remove the head, so you need a head gasket set, a new (or good used) cam, and new lifters. More often than not, this is the time to look at other engine work. How IS the engine? Have you checked the compression? Done a wet and dry test? Does it burn oil? Does the chain rattle (new chain and possibly tensioner and guides)? Is the oil pressure good? OK, you get the drift.

Good luck and HTH.
 

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Discussion Starter · #5 ·
Keith, thank you. I was out of town and not able to work on the car over the weekend. So it sounds like I have my work cut out for me over the next few days. I want to get this car up and running correctly over the next five weeks, before it goes into the shop for the repaint and to get the seats redone. Sounds like I should start with the carb. The PO checked the compression last year in July dry and had compression in the range of 120 to 125 on all four cylinders. I will have to borrow a gauge to redo the work. But another instructor at the school has one, so not too big of an issue. Okay I am going to cave in and ask some novice questions. HTH? FSM? CIH? And NOS? Thank you Keith, gtjim and kjhuffman.

Parker
 

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Parker, the initials are for abbreviations to speed up the process of communications on line in real time for the most part. Here's what they mean:
HTH - Hope This Helps
FSM - Field Service Manual
CIH - Cam In Head (vice over head or in block cam location)
NOS - New Old Stock (New parts that are in the box, sometimes, that have been sitting for years somewhere).

HTH.
 

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Discussion Starter · #8 ·
Okay, thank you both. The only one I had pegged was FSM. Another great day, still learning, still above ground.

Parker
 

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Not Only but Also .....

HTH = Hope That Helps
FSM = Factory Service Manual
 

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Black spark plugs kind of gives it away, it is running way too rich, I agree it would be hard to have the cam jump time but it may have been timed wrong from way back as the timing is kind of a tricky procedure in an Opel.
I suspect your carb is AFU, may need some adjustment, overhaul, or a whack with a BFH. Should the carb be NFG as well as AFU there are lots of posts about how to remedy that, the fuel injection projects are fascinating, too.
Now, I do hope everybody understands the additional abbreviations I just threw in... :D
 

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Discussion Starter · #11 ·
Jeff, for some reason I knew those. Must have been all those years driving concrete and log trucks. ROTFLOL. But I do have to say I am totally impressed with the vast amount of information I have been able to retrieve from all you. I do appreciate the groups great sense of humor. Back to the Opel. I have another instructor at the school who is adamant that I check for a plug exhaust system. Sounds easy, will keep you all posted.

Parker
 

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jeff denton said:
Black spark plugs kind of gives it away, it is running way too rich, I agree it would be hard to have the cam jump time but it may have been timed wrong from way back as the timing is kind of a tricky procedure in an Opel.
I suspect your carb is AFU, may need some adjustment, overhaul, or a whack with a BFH. Should the carb be NFG as well as AFU there are lots of posts about how to remedy that, the fuel injection projects are fascinating, too.
Now, I do hope everybody understands the additional abbreviations I just threw in... :D
for those who were wondering

AFU: always functions uselessly
BFH: big friendly hammer
NFG: nolonger functions good
:D :D
 

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My personal favorite FM.....fu..n.. er a form of magic used to fix what everybody thinks is not worth attempting or looks impossible and comes out as a whole new idea.
 

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Awesome work, baz. You know how to direct a "family show"!
The plugged exhaust is a serious idea, that always seems to be the last thing checked, it threw us off a couple weeks ago when dealing with a boat performance issue...
So, you've driven a mixer, Parker? I've been around a bunch of that... Truck driving takes on a whole different perspective in that respect!
Your GT performance clues don't point toward cam wear, but do look at your lifters when you get the cover off. God knows what cam you are running and how it was timed, a head-off valve job/cam & lifter swap may be in order, at that time a study of the cylinder walls/ridge may indicate you need to build a nice fresh 2.0 out of a tired 1.9. Look at Rally Bob's 2.0 buildups and agree that is the way to go! :cool: Were I restoring a street GT on a budget (instead of competing with rules demanding "stock") my car would have the simple .080 overbore with Venolia pistons.
 

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Discussion Starter · #16 ·
The Winner is (drum roll please)

Well, Kwilford, Alberta and Jeff Denton, Kalispell had it figured out. The lobes on the cam for #1 and #3 are flat. Redid the compression and can’t get a reading above 105 PSI. So I will start dropping the engine and transmission tonight. Any thoughts on giving it a little boost? I don’t want to get too carried away. Maybe one of the cams from the Opel Source? Best place to buy parts, NAPA, Checker, CarQuest, Advanced Auto, Etc.?

Thank you all

Parker
 

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I hate being right. Hey, what part did Jeff get right??? :D

You are about to dip into the black swimming hole of engine rebuilding. My advice? Wear a body condom :eek:

When you buy a cam, you need (must have) new lifters. But the advice goes on from there.

First, check a few things:

1) did you do a "wet" compression test? Test normally (throttle wide open) and then repeat after squirting a teaspoon or so of engine oil into the plug hole just before you check that cylinder. If it increases more than 10 to 20 psi, the rings (and possibly cylinders) are worn. If not, the valves are leaking. Or both.

2) When you pull the head, make sure the valves are in decent shape. Any sign of burning or uneven seating means you are least lapping, possibly grinding, the valves. You might need a new valve or four. Guides are often worn, and although the FSM says you need valves with oversize stems, new bronze guides can be installed and reamed to fit the stock 9 mm Opel valves. Or you can take this opportunity to install bigger valves (lots to read on this topic). You might also consider getting hardened seat inserts installed on the exhaust valves. But before you spend a nickle, get the head magnufluxed. Cracks are common in the #2 and #3 exhaust valve seat area. Remedy is a new (to you) head.

3) If the cylinders aren't too badly worn (ring ridge, taper, out of round, scored; get a machinist to check for you), then a light hone (to "break the glaze) and new rings might suffice. The old pistons can be re-used, but only if you don't need to over-bore your cylinders. If you need new pistons, try to get flat-tops for the compression increase. Again, MUCH more to read on this subject.

4) Plastigage your main and rod bearings. If uncertain, get your crank checked by your machinist. If the crank is OK, then new bearings will do. Otherwise, a crank grind and under-size bearings are in your future.

That is some of the highlights. HTH and good luck.
 

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I must have been right about worn lifters at least...
Parker, may I suggest you get the OGTS catalog, look at their website, and do business there. Dennis and Gil are extremely dedicated to the preservation and maintenance of Opels, for that alone they deserve total respect and major success. They sure have been good to me.
Now go to any parts store and mention the name Opel. Ten bucks says the man will say "huh?". A twenty says he can't spell it, they type it on the computer with the only vowel in it wrong. :rolleyes:
Try it, tell me if I am right!
 

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jeff denton said:
I must have been right about worn lifters at least...
Parker, may I suggest you get the OGTS catalog, look at their website, and do business there. Dennis and Gil are extremely dedicated to the preservation and maintenance of Opels, for that alone they deserve total respect and major success. They sure have been good to me.
Now go to any parts store and mention the name Opel. Ten bucks says the man will say "huh?". A twenty says he can't spell it, they type it on the computer with the only vowel in it wrong. :rolleyes:
Try it, tell me if I am right!
Last time I checked, Opel, car, and Opal, gem, both have two vowels and two consonants . . . :rolleyes:
 
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