Valve lifter mixed up

[Ron0z]

With my cylinder head removed I upended it and all the lifters fell out. Oops! What to do? Search the web and see what others do.

People have asked this question in many forums all over the web. They asked for advice but in everything I read I didn’t come across a reasonable answer. I worked out my own solution. Here it is for anyone who may be interested.

Mine was a 4 cyl 16 valve head with double overhead cams. A 1993 Corolla. One way of fixing this would have been to insert a lifter, bolt up the cam and measure the valve clearance. Then if that lifter was wrong, remove it and repeat the process with the next lifter. I think the maximum possible combinations works out to be 16 x 15 x 14 x 13 x 12 x 11 x 10 x 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 which is a very large number. My solution was to take some measurements as carefully as I could then use a spreadsheet to help me decide which lifter goes where. Easy-peasy, but time consuming.

I was hoping to see some discolouration on the lifters that might have indicated the difference between exhaust and inlet valves. I didn’t see any colour difference.

I completed the following work in a spare room of my house using an old table as a bench and a comfortable chair to sit on. I could have done with a micrometer which would have made measuring the shim thicknesses easy and accurate. I had a good quality digital caliper and using that was fiddly and error prone, but it worked for me. A micrometer would have been better.

Step 1. I had the lifters stored separately from the head. With an A4 sheet of paper I sketched circles on the paper in the same orientation as to where the lifters would be located on the head. To ensure there was no mistake I wrote the locations of each on the A4 sheet. Decide on a numbering system (eg. A to P; i1a to e4b). Whatever works for you. I didn’t want to remove the shims should it give me problems. Use a micrometer to measure each shim size. Bear in mind that the valve stem will contact the centre of the shim. So, measure it in the centre as carefully as possible, and note the measurement in a notebook against the relevant location.

Step 2. Insert the lifters into the relevant positions and bolt down the cam shafts. Keep everything oiled as you go. Ensure there are gaps between cams and lifters. If not, relocate some lifters. You need to ensure there are valve clearances on every one.

Step 3. Measure the valve clearances and record the them in the notebook. Spend time getting the measurements as accurate as possible.

Step 4*. Create a spreadsheet with your data. The spreadsheet will use a couple of cells to hold measurements and a third cell for a calculated value. So, for each of those groups of three cells, there will be 16 of them in one direction representing valve positions. Then in the other direction representing the 16 lifters. The idea is to display the valve clearance that will result by locating a particular lifter in a particular location.

Step 5. You know the valve clearance specs for inlet and exhaust. There will be a max and min spec. Visually look at the spreadsheet at the calculated field and decide whether the gap is within the range of an inlet or an exhaust valve clearance. Compromises may need to be made. Colour the ones that are most suitable. There may be multiple options that fit the specs. There may not. When all 16 have been allocated a single value you’ll know which lifter should be allocated to which valve. (Don’t assign the same lifter to more than one valve. An easy mistake.) The attachment shows a snippet of the spreadsheet I used. To provide an idea of how to proceed.

Step 6. You now know where each lifter should go. Transpose your choice by drawing arrows on the A4 sheet to indicate where the lifers are going to be moved from and to. Do that carefully. Double check the arrows against your spreadsheet. Have cuppa, then check the arrows from and to once more. Then move each lifter into the new valve locations. I removed the lifers and placed them on the paper in the correct locations, then following the arrows relocated them into the head. Job done.

 

* You’ve measured the lifter shim thickness (Shim size). You’ve measured the valve clearance (Actual gap). The sum of those two is the distance between the top of the valve stem and the underside of the cam (Dist (valve to cam)). The correct shim size will be the Dist minus the valve clearance spec and if you measured everything accurately this will be easy.

In the spreadsheet, for each of the groups of three cells, one cell shows the Dist between valve and lobe. Another cell shows the shim size. The third cell subtracts one from the other, and that will be the valve clearance, had that particular shim been used in that position.

My spreadsheet showed some combinations to be perfect, others less so. Some were badly off. Use colours to narrow your decision making process.

When I did this I found that a few clearance figures were badly out of spec. If I had a situation when I was down to the last couple and one clearance was within spec and another badly out of spec, I preferred to choose two that resulted in having them both only mildly wrong and with a similar clearance than having one good and one bad.

I never bothered to check the clearances once the head was on the block and camshafts bolted down. I didn’t want to go through the process again. When I started the engine it sounded good even though some of the calculated clearances were worse that I would have liked.

 

 

[Tony Prodigy]

Hi Ron and a huge thankyou for taking the time to share your experience. I admire your dedication and patience. I'm known here for my OCDness, as you Sir seem to suffer the same affliction as I do. That is something only an OCD guy would undertake and be of the mind to make a spreadsheet too 😃 

I'm no good with excel. Tried and failed miserably many times because I hardly use it and any gains I make, I quickly forget when I need to use it again at a later date.

Anyway buddy, I'm glad it all worked out for you in the end.