2.7 rebuild?

[Robert Adams]

I am inheriting an extra 2.7 engine including the injection parts with the purchase of a 77S with about 84K miles. The extra engine has supposedly had the valves redone and is sitting all apart in boxes; I do not know the history or the miles on this engine. The one in the car is OK, although it hasn’t run in a while and will no doubt need some attention. Either way I have two engines and one car.
My question, any suggestions on what could be done with the second engine before putting all back together again to either make it more reliable ( beyond the studs replacement) and/or increase the power out put (2.9?)?

[Biff]

Buy Wayne's book on engine overhauling, all your questions will be answered! Good Luck

[Grady Clay]

Robert,

Most on the Forum recommend that it is a better bargain to buy a good used 3.0 or 3.2 and start there. It will cost less to do the required mods to a 3.0 than to a 2.7. The result will be a more powerful and durable engine. About the only downside is the 3.0 is slightly heavier.

The first thing is to read Wayne’s engine rebuild book cover-to-cover.

Considering you already have a spare 2.7 it would be worth doing some low cost investigating before making any decision. You are going to need to know if the crank and rods are good. Most local crank grinders can measure them for you – just inspect, no repair. Having the crank Magnafluxed is a good second step.

You need to determine the condition of the case. This is not easily done but you can pay a high-end precision machine shop to inspect some of the surfaces. If the case has some disaster, this will tell.

The pistons and cylinders need to be inspected to determine if they are Nikasil or Alusil. They need to be measured for wear.

I would have a shop disassemble the heads, keeping everything associated with its installed location. Someone who is used to looking at good valve jobs can tell the condition. The valve stems and guides should be measured. Don’t reassemble the heads; just devise a way to keep everything organized.

Have a Pelican/PCA party and get some knowledgeable eyes to inspect all the other parts after you have them clean and organized. You can compare to Wayne’s steps and verify everything is there.

As you have gone through the above process take lots of good digital images and keep them organized. I would try and keep your costs under $200.


Now you are ready to make a decision.

Using the lists in Wayne’s book (and Bruce Anderson’s) figure out what you want and what it will cost. There is a lot of good info on this Forum.

Call around and see what a good used 3.0 or 3.2 will cost.

If you decide to not rebuild the 2.7, you now have clean and organized set of parts in known condition with documentation. You can either keep the set as spares for your 2.7 or build a 2.7 (or 2.8) some day. If you decide to sell the parts, they will command far more being in documented condition. Cardboard boxes of dirty and unknown 2.7 parts aren’t worth much. Is this engine original to the 911? If so, I recommend you keep it.

Best,
Grady