Here is the criteria I used for testing my twelve new springs from Porsche and the the results.



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Here are some photos showing the horizontal and vertical cracks in the valve spring seat for exhaust #6. The seat is very difficult to remove from the spring. I am replacing the retainer, spring, and seat. Could this be part of my problems with cylinder #6?



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It's also upside down, the tight coil goes into the seat.

Thanks for the input on the coil being upside down.

Laurani

My black and silver spring height checking tools are too large in diameter to use on my 1976 911s 2.7 liter head. The P10C will fit but I cannot see the slot with the line showing the correct measurement.

I have determined that there were some shims installed when the engine was built by others. I cannot get the shims off the head with a magnet.

Any ideas on how I can measure the spring height would be appreciated.

Lauran

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Never heard of doing that on an assembled engine, just on each separate head. Good luck.

I’m with John, it’s time to take it apart.

NO, NO NO. There is no need to take the engine apart. Read my post a page back on how to measure the Retainer height.

If you have that tools old to hold a dial indicator for measuring the cam position/valve lift at TDC, use that with the dial to measure the Retainer height. Get yourself a measured spacer, example 1.00' 25.40mm and use that. assemble all the parts except the spring. Fit the spacer and measure the difference between the spacer and Retainer. Add the two together and that's your Retainer height. If you get as an example, 37.50mm and the spec suggest 35.50, add 2.00mm shims. If the shims come in 0.25mm then you would add 8 shims. Simple and you could have save3d yourself all those tools you bought.

Suggestion and advice, the spring installed height will not get you the same seat pressures. If you want those, you will need to measure each spring at its installed height. At "home" that will be difficult.

Lauran,

I agree with Neil. You could install the valve springs with the correct spring height/s without tearing the motor. But you will need P7E and P7I with the correct valve spring height gauge. Pull the motor out and do the work with the motor sitting on an engine stand. You are NOT experienced enough to do the installation in situ. It is more difficult and challenging to install the valve springs with the motor in the car.

Tony

If you are prepared to do this in the car, PM me and I will help you. I think I have a tool that was an actual Porsche tool for changing the springs in the engine. I have not seen it in years but I do think I have one.

The locks will be the issue when reinstalling the springs. Patience and perseverance will conquer. Grease too.

I have a p7E and P7I spring compressor tools. What is the correct valve spring height tool? Do I need a special stand for a digital dial indicator such as a Porsche P207 tool ? I have several digital dial indicators.

Neil,

Please email me at "lauranlhoward@live.com" .
Yes I am prepared to do this in the car with your help.

Lauran

Sent you a long email. Any questions you are welcome to call me. I have sent you my cel number.

Here is some information on the camshafts in my engine.http://forums.pelicanparts.com/uploa...1692634227.jpg

The engine is in a 914/6.

With that cam, you should check your P/V clearance as well. The Intake will have less.

What is P/V clearance?

As additional information, the records for the car show that the engine was rebuilt 36 years ago and that 24,000 miles have been driven since the engine was rebuilt.

I have not removed all of my engine's valve springs. I am working on one cylinder at a time starting with cylinder #6.

Lauren,

I thought you were installing cam as well. Forget what I said about checking if that cam has run this long.

I made you up a spacer, exactly 1.00" 25.40mm long. It sits inside the spring base and the Top Retainer fit on the top.

Just so you understand, we do not use those fancy tools when we do retainer heights. We use a 1.0'' spacer.

Here is what to do. To remove the springs, have the piston at or near TDC on each cylinder. Be careful with the depression of the spring as you are pushing the valve into the piston a little. Remove the locks, Retainer and spring. Fit the spacer, retainer and locks. Pull up on the retainer to seat the locks in the retainer. Now turn the engine 90° CW so the piston will be approx 1/2 way down the hole. This way you can push the valve down until the retainer touches the spacer.

Now fit that Porsche indictor holder and position the indictor so it sits on the retainer. Zero the dial. Now pull up om the retainer carefully and slowly counting the revolutions the needle does and where it stops when the valve is on its seat. This will be the Retainer height with the spacer height added in. example, if you read 0.400" on the dial or whatever its in if metric, add the 1.00" and the retainer height will be 1.400".

I did check and that Porsche tool will work. Just make sure your indictor has enough travel when the valve is down and the retainer against the spacer.

I do not know the installed spring height from memory. This is shown in the spec books. Subtract that from what you measured and that will be what you add in shims. If the shims are 0.020" thick and the difference what you measured and what the spec book states , divide that number by 0.020" and that will be the number of shims to add. It will probably be either side of what is required in shims. Go with the higher number safe. You may get 4,5 shims, so add 5. If it reads 4.2 shims add 4.http://forums.pelicanparts.com/uploa...1692834526.JPG
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