Ferrari 412 - Newly Rebuilt Cylinder Heads / No Compression Cylinder #1

Yes, this is possible. I am aware of which pistons are up when I am installing the cams and just make sure I don't let one hit. You do need to be careful when assembling these things.

 

At TDC on compression, yes. At TDC at the end of the exhaust stroke & the start of the intake stroke, both are open, overlap. So at some point when putting the cams in, one cylinder will be at TDC overlap. Care must be taken not to let the valves hit then.

 

At TDC, there will always be a cylinder at TDC with the valves at overlap and another cylinder at TDC compression. I haven't had a 412 open lately. I had one arrive yesterday that will be open in the future and I can be more specific. So to answer, yes, there are valves open and close to the piston at TDC.

 

When installing any cylinder head I usually move the crank about 10 degrees left or right of TDC l..just to bring the pistons down slightly. That way any chance of piston to valve contact is greatly reduced. Once the cams are installed bring everything back up to TDC and time away..

 

Good idea.

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No..head then cams. I have a personal theory about it..but it's just too long to type .lol

 

It's much easier to shim the tapets while the heads are out. On the other hand in order to inster the head together with the cam, you do have to cut the large o-rings that seal the timing chest. Once these rings are cut you need to use some sealant, which I don't like.

The manual states that you have to cut these rings, so the official procedure is assuming "camshafts already on the head".

 

How could it be normal to have zero compression?

 

As said to you in our private discussion, my valve seats were replaced and machinated so that the valve do not protrude. It made me feel better but I had to use very thin valve shims that are made by the manufacturer but not stockpiled everywhere.

The valve seats are so beefy (~4mm thick, 7mm deep) that you can grind them quite a lot without any second thougt.

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Until you run out of valve shims thickness, so you have to be thinking about it as you set up the valves. I don't set up valves that need non standard shims. I find it tends to make things more difficult later.
You heads look nice. It should be running great soon it looks like.

 

The shims I used were regular Ferrari shims, unfortunately these are thinner than what was used in the Fiats of that era, and hence I had to pay for the prancing horse premium. Before using the superformances valves I could use such cheap shims. This being said I wish I had replaced that sodium filled valve on the first rebuild! My engine was an absolute mess after this valve failure.

Car is back in business. Quite recent actually as I did 400km with it. Had to drop the right head twice, the left one was even more troublesome and had to be removed 4 times! On the plus side, I can now drop a head in 13hours...