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I was wondering if I could get a good step by step on adjusting the valve lash with hydraulic lifters. I read through two different repair manuals, and one doesn't go into it, and the other only steps you through the solid lifter adjustment.
 

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Old Opeler
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Adjustment by the Book

Adjustment of Hydraulic Lifters for Opel CIH Engines

1) Run the engine till it reaches its normal operating temperature
2) Remove rocker cover and fit a splash guard over the timing chain sprocket.
3)Restart engine and run at idle speed.
4)Slacken a rocker nut till the rocker arm starts rattling
5) Tighten the nut slowly until the rocker arm just stops rattling
6) Tighten another quarter of a turn and wait 10 seconds for idle to stabilize
7) Tighten another quarter of a turn and wait 10 seconds
8) repeat twice more so that the nut has been advanced by a quarter turn FOUR times. ie: one whole turn
9)It is important that this procedure is followed exactly because this method slowly preloads the plunger in the hydraulic lifter slowly and allows the lifter to adjust itself to the changing preload
10) The adjustment must be carried out on each rocker arm in turn.
11) Finally stop engine and remove temporary splash shield and refit rocker cover.

With thanks to Haynes Owners Workshop Manual Opel B Serries
 

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OPEL-LESS!!!
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instead of splashguard, you can also cut up a junk valve cover, therefore you dont have oil to run down the side of the head like i sometimes do.
 

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Detritus Maximus
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But what about the "correct" way to adjust lash? I've heard at least two other ways from well known Opel people and they both differ from the book (Haynes/Clymer/Chilton all get their info from the FSM).
 

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Old Opeler
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Share the Knowledge!

I just quoted from the book to give the "official" version!

With new lifters just back off till they rattle, wind down till they stop clicking and then down 1/2 to 3/4 of a turn - slowly.

The whole operation of hydraulic lifters is to remove any clearance in the system and keep it that way for as long as possible without further adjustment.

The old Chevy trick of only winding back down 1/4 of a turn can be used too as long as they are regularly adjusted - which defeats the purpose a wee bit.

I guess the Buick/Rover system of adjustment could be used too.
Just do them cold, with the motor stopped and preload the lifters by .040" (er...... 1mm) and hope for the best:p

If there are other quick and dirty ways to do this messy operation let us all know. Sending it off to a mechanic is NOT an option!
 

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How about for solid lifters......can i get the engine hot and adjust them with the engine off or do I HAVE to adjust them with the engine running?
 

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Well, THIS discussion hasn't been heard for about six months. I guess it was about due...

The procedure referred to in most "aftermarket" manuals (with the messy splash shield and adjusting them while the engine is running) is simply an excerpt from the factory manual from when Opel CIH engines had SOLID lifters. This is NOT required for hydraulic lifters. This was discussed ad nauseum on the board about a year go. RallyBob and I agreed, all the rest are wrong-minded. But don't take my word for it, read the REAL Factory Service Manual.

The procedure is simple. And I quote (with a few explanations):

Carry out hydraulic valve lifter adjustment with the engine off. It makes no difference whether the engine is cold or has operating temperature. Set piston of the respective cylinder to U.D.C (for Upper Dead Center, in the FSM, sometimes called TDC for Top Dead Centre, but ensure that the piston is at the "firing position" and both valves are closed). It is advisable to adjust lifters in the firing order (1-3-4-2). Back off adjusting nut at the rocker arm until a clearance exists. Then tighten adjusting nut until any clearances between valve, rocker arm and lifter are eliminated. Tighten adjusting nut one (1) revolution further. The valve clearance is now adjusted and no readjustment is required.

There, THAT should clear it up. But I still expect a few arguments. Whatever...
 

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I've had both solid and hydraulic lifter motors and have adjusted them both ways, running and not, cold and hot. The only difference is that adjusting them while running makes a mess and usually takes longer. For hydraulics just follow the book. Solids are better to do warmed up, but that is just my opinion. Me personally I don't like working in hot oil or making an unneccessary mess of my car.
 

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Old Opeler
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On the Bench

One of the huge advantages of the CIH head is that the entire valve train can be assembled on the bench with the valve lash all set before it goes on the engine.

The rocker stud has a 1.00mm pitch so one turn moves the lifter down about .040 (more or less due to the rocker ratio) and GM hydraulic lifters are designed to run with .020 to .060 preload. So one turn is right on the money.

Solids can likewise be set to the required clearance on the bench.

The cam needs to be positioned so the notches are in the right place to get at the head bolts though and the motor needs to be in the right place so that the valves don't hit the pistons. They will if either the cam or crank are rotated independently (without the cam chain on).
 

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Opelholic
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I also adjust them as per GTJIMs original post but I wised up and cut a slot in a sheetmetal valve cover to minimize the mess.
 

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PrOpeller
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I found this useful tidbit in the Haynes workshop manual for the Opel Manta 1970-1974...
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Page 43, Section 47
Adjustment of rocker/valve clearances
________________________________

1. Engines fitted with conventional tappet barrels (all European cars {sic}) should have a rocker to valve stem gap of 0.012 inches. Engines fitted with hydraulic valve lifters (all cars sold in the USA {sic}) have zero 'gap' between the rocker and valve stem.

2. If the engine is in the course of re-assembly, and the cylinder head has just be {sic} refitted, tighten the nuts on the rocker pivot studs so that as the engine is turned, the rocker transmits progressively more movement to the valve. Do not tighten to the point where the rocker ceases to become slack at some point during the rotation of the engine.

3. With a cold engine, and with the conventional tappets {i.e. solid lifters} tighten the pivot nut down until a 0.012 feeler gauge can just move between the rocker and the top of the valve stem. (photo)

4. It is important that the gap is set when the tappet of the valve being adjusted is on the heel of the cam - that is on the opposite side to the peak on the lobe. This is achieved by carrying out the adjustments in the following order:

Valves numbering front to rear
Valves Fully Open - - - - Check and adjust
No. 8 - - - - - - - - - - - - - - - - - No. 1
No. 6 - - - - - - - - - - - - - - - - - No. 3
No. 4 - - - - - - - - - - - - - - - - - No. 5
No. 7 - - - - - - - - - - - - - - - - - No. 2
No. 1 - - - - - - - - - - - - - - - - - No. 8
No. 3 - - - - - - - - - - - - - - - - - No. 6
No. 5 - - - - - - - - - - - - - - - - - No. 4
No. 2 - - - - - - - - - - - - - - - - - No. 7

5. The importance of correct rocker/valve adjustment cannot be overstressed. If the gap is too large, the valves will not open fully and the engine 'breathing' will be constricted. If the gap is too small, the valves and pistons may damage each other, and the engine 'breathing' will deteriorate because during the engine cycle both inlet and exhaust valves will open for longer periods that {sic} intended. Both effects will reduce engine economy and power.

6. On engines fitted in cars sold in the USA, and which use hydraulic valve lifters instead of the conventional tappets, proceed as follows:

7. In the same adjustment order as listed in paragraph 4, screw the pivot nuts down until the rocker-valve stem gap diminishes to zero.

8. Undo the nut until a clearance exists and is detectable and then screw back down one full turn. The adjustment is now complete.

9. On the USA engines it makes no difference whether the engine is hot or cold during adjustment.

10. Once the valve/rocker gaps have been adjusted the rocker cover may be refitted. Ensure that the mating surfaces of the cover and the cylinder head are perfectly clean and clear off any fragments of old gaskets.

11. Smear a new gasket with a little grease and then position on the cylinder head. Lower the cover into place and secure the sixe {sic} bolts.
 

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Opeler
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Hydraulic Lifter Adjustment

The procedure is simple. And I quote (with a few explanations):

Carry out hydraulic valve lifter adjustment with the engine off. It makes no difference whether the engine is cold or has operating temperature. Set piston of the respective cylinder to U.D.C (for Upper Dead Center, in the FSM, sometimes called TDC for Top Dead Centre, but ensure that the piston is at the "firing position" and both valves are closed). It is advisable to adjust lifters in the firing order (1-3-4-2). Back off adjusting nut at the rocker arm until a clearance exists. Then tighten adjusting nut until any clearances between valve, rocker arm and lifter are eliminated. Tighten adjusting nut one (1) revolution further. The valve clearance is now adjusted and no readjustment is required.

There, THAT should clear it up. But I still expect a few arguments. Whatever...[/QUOTE]


kwilford: two months ago, I spent enough time on this subject to read every thread on this forum and even made calls to well known Opel GT experts in this country regarding this topic. There are so many different opinions on this topic, it can really make one apprehensive to do the job.

I have a 1973 FSM for my 73 GT and I agree with you. This seems to be the proper method for the hydraulic lifters. However, I'm not sure of the best way to make sure you have the pistons at TDC. I've read and been told of a number of different ways. What do you recommend?

Thanks, Richard
 

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PrOpeller
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I rotate the engine slowly by hand using a 19mm socket on the crank bolt and a long-handled ratcheting breaker bar. You can see when a lifter reaches the top of its travel. You want to turn it a little farther before it starts to go down again. You can use a dial indicator at the lifter or spring to exactly measure this point at half its travel. When the number 8 valve (at firewall) is at this point, you check and adjust the number 1 (first valve from front). When number 6 is fully open, check number 3. Continue by following the rest of the sequence until all are set.
 

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Setting the Pistons at TDC to Adjust the Valve Lifters

I just received a PM from a member asking how I line up the pistons to adjust valve lash. Here's how I do it:

I just usually use the timing mark to start. When the #1 piston is at +/- TDC, the flywheel ball should be right at the pointer (or on CIH's that I have scribed a mark on the crank pulley, its aligned with the timing mark on the chain case). I make sure that the #1 cylinder is at the top of the power stroke by watching the rocker arms as I rotate the crank. If it as the top of the exhaust stroke, the exhaust valve will just be closing and the intake valve will just be opening. At the top of the power stroke, both valves are closed for the upstroke and the down-stroke.

Then I just rotate the crank 180 degrees with a breaker bar, which would put #3 at TDC. Another 180 degrees (which will align the timing marks again) and #4 is at TDC. The last 180 degrees, and #2 is at TDC.

Frankly, it shouldn't be TOO critical if the piston is EXACTLY at TDC. The key thing is that the lifter is on the low portion of the cam lobe, & not on any part of the ramp or lobe top.
 

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solid lifter adjustment

I have read every thread on valve adjustment and I still dont know if I need to adjust them while the engine is running or off, hot or cold. I have solid lifters and .416" lift 270 duration solid lifter cam shaft. I would like to adjust them cold (I guess it has come down to preference) so I guess I would like to know the correct feeler guage size for adjusting them at TDC. also, how crucial is it that it's on the declining side of the cam lobe for TDC? is eyeballing it close enough?
 

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Old Opeler
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It boils down to what does the cam grinder/manufacturer recomend.
If you don't have that info try it warm with the motor off - less messy
If all else fails try the messy method!
 

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Im sure some one else has this cam shaft. so before I go through adjusting it while running I'd like to see if any one knows the clearance....possibly rallybob?
 

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Old Opeler
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It is crucial to know who ground the cam and what exact profile it is before being able to find out setting clearances. Where did your cam come from? Did it come with any specification card?
 

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Jim's right, knowing what the cam grinder recommends for clearance is important. The opening and closing ramps can vary from brand to brand, and may require different lash adjustments. Some of the racing cams I've had ground have .022" intake and .024" exhaust clearance.

That being said, the lash for your particular cam is probably something on the order of .012" intake and .014" exhaust. It sounds like a cam that C & R used to sell years ago, it was called the CR-149.

Bob
 

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It is a C&R camshaft and I was looking through the catalogues that the PO kept and it says part number "CR-733s" on the reciept. but theres a difference between 2 catalogues, in one of them it says part number 733 is the street sport cam is 268º duration and .425" lift, the other one says part number 733 is .416" lift and 270 duration. would that difference matter at all?
 
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