Blake

This is an advance look at an engine rebuilding parts selection guide I am working on to help people identify the pieces of the engine commonly replaced. Later I will post some of the text, a parts numbering system that is easy to understand and a price list. Once the real guide is done, I will post it as a PDF.

Here are the first couple illustrations to show how the parts are categorized.

Blake

Of the items in Figure 2 above, we typically re-use Oil Control Rings if still in spec and recommend the deletion of the Oil Pan Gasket (silicone leaks less). Don't confuse the Oil Control Rings (metal) with the Oil Control O-rings, which are *always* replaced. Never use aftermarket oil control O-rings...in our experience they are very prone to failure, whereas the expensive flourinated rubber OEM O-rings are proven to last consistently. Aftermerket metallic apex seals also tend to be short-lived and low quality, in our experience. The only really smart substitution are our Heavy Duty water seals, which take more heat and are typically re-usable even after tens of thousands of miles (great if you ever need to go back in to freshen up the motor). We tested the HD Water Seals for 7 years in many engines on the street and track before selling them to the public.

Blake

Bearings can often be re-used if not worn out, but in a quality rebuild you always replace them to re-set the clock to zero. A worn bearing will show a lot of copper, usually on the side opposite the spark plugs. Front main bearings tend to die faster than the rear because they are the last thing in the system lubricated. Detonation can kill main bearings, due to the side-loading force. Always replace both at the same time. We usually call good, used bearings without a lot of miles on them "Seasoned". Seasoned bearings are fine to re-use and dramatically reduce the break-in time of a rebuilt motor. Seasoned bearings are the only ones you should use in a race car.

Blake

By the way, "Durable" does not mean indestructible or infinite wear. It just means you don't *plan* to replace them unless they are damaged or otherwise out of spec. Careful inspection and measurement is still essential.

Blake

We do not recommend replacement of the tension bolt washers unless they are really ugly. In all our years, we have never seen one leak. Some rebuild kits include them for some reason, but it is wasteful spending in our opinion. Save that money and put it to better use.

Blake

More FYIs:

In all cases, replace the earlier stock corner seal spring with the FD corner seal spring. The FD corner seal spring is a much improved part.

FD rotor bearings are technically a different part but substituting the earlier part is fine, in our experience.

GSL-SE, 4-port 13B NA and 12A RX-7 apex seals only use one, long spring. However, it is possible to machine the seals to accept an additional short spring for better sealing.

Blake

To keep this thread uncluttered, I have decided to lock and sticky it and delete the two 3rd party posts that were made. If you have engine building or parts selection questions, please post it in the Engine Building Thoughts thread. If I think the question relavant, I will add the info to this thread.