Things to consider when mounting a 250 E engine

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chris
Posts: 82
Joined: Sat Mar 02, 2013 7:52 am

Things to consider when mounting a 250 E engine

Post by chris » Mon Oct 21, 2019 2:21 pm

Hi All,

I am in the process of mounting my freshly rebuild 250 GTE engine. I have done several demanding engines in the
past but each engine has its specialities. I thought it might be helpful to collect things to consider when doing a 250 engine. Especially helpful for me at the moment ;-)

Things like:
- two of the locating dowels for the head must be hollow as they act as oil galleries
- tension of springs in rebuild kits for water pumps might be wrong/ if in doubt try to use old spring
- timing marks are just for assembly of engine, exact timing must be checked differently using exact opening of inlet/ exhaust of number 6/12 piston according to TDC
- use 0.5mm stainless sheets to hold o-rings in place when mounting chain case to be able to mount headcovers later
- check mechanical pump action and make sure that there is no play in actuating lever
- ????

I am sure you all have your things which should be considered. This sight might be a means to preserve it for others.

Any hint, idea, experience welcomed. Thanks a lot.

Christopher

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tyang
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Location: New York
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Re: Things to consider when mounting a 250 E engine

Post by tyang » Mon Oct 21, 2019 4:02 pm

Hi Chris,

The timing marks at PM 1/6 that line up the cams to marks on the front of the bearing stands were made when the engine was first timed in. You are correct, they're good reference points for assembling an engine, but immediately change when the timing chain stretches, or any surface is machined.

Here's one:
There are two small o-rings that slide down on the rearmost (towards flywheel) main bearing studs. You can see them in the parts book. forget these o-rings, or don't use rtv, you'll get leaks on the outside of the engine.

Tom
'63 330 America #5053

chris
Posts: 82
Joined: Sat Mar 02, 2013 7:52 am

Re: Things to consider when mounting a 250 E engine

Post by chris » Tue Oct 22, 2019 1:50 am

Hi Tom,

Thanks. Right, they can be also seen in the 330 parts diagram in the exploded view.

Another one I was told is to use thread seal at the base thread of the head studs.

A good tip I read in your blog is also to check the crankshaft for free turn after mounting of each rod and piston before mounting the crankshaft end seal (simmering in my case after conversion).

To get the oil pan to seal properly Ferrari used a special paint and I have read about different ways to try to seal it. I had mine vacuum pressure sealed bya company in Germany. This way every tiny crevice is sealed.

I am sure others have additional useful tips.

Thanks
Christopher

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