Fitting the heads

[xabia911]

Hi,

I have a question for you experienced builders:

I am rebuilding my 3.2. All the articles I have read say fit all the cylinders first and then fit the heads.

Is there any reason for not fitting the cylinders and then heads and cam tower to on side first and then doing the other side?

Thank you

[r lane]

Probably not, but the accepted scheme is to pull everything up together. The less the possibility of the package becoming biased to one side or the other as you are working with a bunch of pieces that need to float together in harmony. Do not start torqueing the heads down until the cam towers are located in place as well.

[Flat6pac]

If you try assembling the engine piece by piece you will spend time doing things over.
Put the individual head on x 3 you have 18 8mm bolts you have to hit to load the cam tower
Sub assemblies are the way the auto industries do it, including Porsche.
Bruce

[xabia911]

Originally Posted by Flat6pac

If you try assembling the engine piece by piece you will spend time doing things over.
Put the individual head on x 3 you have 18 8mm bolts you have to hit to load the cam tower
Sub assemblies are the way the auto industries do it, including Porsche.
Bruce

Thank you. Have not seen that method

[boyt911sc]

Both methods work. Whatever is your preferred method sub assembly or piece by piece method is a choice. No where in the rebuilding books by Wayne Dempsey nor Bruce Anderson mentioned the preferred method.

I fully agree in removing the cam tower/cylinder heads assembly as a unit specially if you are under time constrain like in a race event to get the engine back on the car for the next run. We are talking about engine assembly after an engine rebuild.

In my case, I find it too strenuous and heavy to lift the cam tower/cylinder heads/cam shaft/ etc. by my self without using some sort of a lifting device. For me, it is more practical to do it piece by piece. The decision which method to use is all yours to decide. The so called professional or expert engine rebuilders often come up with techniques or procedure that novice or non-expert like us would find more challenging. A good example is dropping the 911 motor leaving the transmission in place. For bragging right yes.

Tony

[xabia911]

Thank you for your reply,

Basically I need to know wether I have to fit the cylinders to BOTH sides first before adding the heads etc

OR

can I complete one side with cylinders/heads/cam towers and THEN do the other side

[boyt911sc]

Originally Posted by xabia911

Thank you for your reply,

Basically I need to know wether I have to fit the cylinders to BOTH sides first before adding the heads etc

OR

can I complete one side with cylinders/heads/cam towers and THEN do the other side

Xabia,

Use cylinder hold down nuts to keep the cylinders from sliding out. Rotate the engine 90° and install the cylinder heads one at a time. Do not torque the cylinder head nuts until you are ready and done with alignment inspection. This would be a good time to test the exhaust studs alignment with your header or HE.

And do not forget the engine cooling tins and oil return tubes before the installing the cam tower/s. Make a note or reminder to yourself because I have committed this blunder a couple of times and you won’t be happy. Place a sticker or tag on the cam towers with a note “engine tin & oil return tubes”.

Take your time and don’t rush the assembly. You will be OK.

Tony

[xabia911]

Sorry but I do not seem to be getting the answer to the question.:

Is it absolutely necessary to install ALL the cylinders before proceeding with heads/towers?

OR

Can I just complete one side (Cylinders/heads/cam towers) and then flip the motor and complete the other side?

[r lane]

As I stated, I think that is acceptable, I have never done that. I prefer to get everything set, and then torque side to side. Your 6 heads are on the engine, not torqued. Both cam towers have sealant applied. Drop on one tower with a few nuts, go to the other side and repeat. I snug up all of the cam tower nuts as well as the cylinder heads and little by little bring everything up to torque from side to side. I do make sure the cam tower is fully seated before I start torqueing the heads. Oil tubes and baffles precede all of this.

[xabia911]

Thank you

[jpnovak]

Keeping the engine symmetrical helps with the balance of the engine on the stand. I do not like getting it lopsided with weight. This makes it very difficult to rotate as needed to add parts or shift from side to side.

No you do not have to install all PCs at once. As Bruce said, keeping the single task (all wrist pins, all rings, all cylinders keeps your mindset on a particular task, keeps a specific tool set on the bench and generally is more efficient.

[xabia911]

Thanks, The more input the better

[Walt Fricke]

There would have to be some special reason to install parts on one side, and then to on to other parts without going to the other side first. You must have thought of a reason - what is it?

As you have seen, none of those responding think what you were wondering about is a good idea as a practical matter.

This may be sort of like the mantra of never put a nut (or nuts) on finger tight and don't tighten it (them) before going on to something else. Because in the fullness of time something will distract you, and you will forget to go back and tighten.