engine woes, engine rebuild Options

[arkitect]

New to this, first post.

Trying to get some opinions on an engine rebuild. I've got a 70 914 with the engine in pieces....should I try to get the parts - pistons, rings, bearings ect. or try to find a good used motor. Assuming it's a 1.7.

I know, this is a pretty loaded question.

[ConeDodger]

I agree completely with the recommendations for McMark and Raby Aircooled Technology.

If I was looking for a driver, I would build a 2056 with carbs. Nice little power boost over the stock engines of any size. DJet is good with the 2056 as well but cam choice is critical. The next important thing to remember is that the heads are critical. You can spend as little as you want on the rebuild and if you don't pay a lot of attention to the heads you could end up doing it twice which is now a lot of money. On several occasions I have seen heads that have been rebuilt which have cracks in them or loose seats. I am not saying that Len Hoffman is the only place to go and I doubt Len would tell you that either, but Len has a careful process that gives you the best chance of your heads not giving you problems. Now, the problem; Len will not work with old original castings any more. Your rebuilder should bake the bare heads in an oven at 400 degrees F. This is the temperature at which bad things happen in a running Type IV engine. My operating cylinder head temperature in the engine I am using right now is 250 degrees F. and rises to 300 degrees F. when I spank it like a bad Catholic girl or go to a 5th gear cruise on a hot day. At 400 degrees, Len sees valve seats actually just fall out of the casting. Now, imagine this happening in your new engine; disaster! It will mess up the head which will need rewelding and machining to restore its shape before it can be rebuilt again. It will take out the cylinder and if you're lucky just the top of the piston. If it goes through the top of the piston, it probably will destroy everything inside the case and ventilate the case as well.

I am not saying you cannot do a cheap on the fly rebuild. You probably can but know where you are going from the start. Minimum, you need a cam with valve train and valve job, as well as a gasket kit and bearings. I would guess even do it yourself you are looking at $1000.

Don't be afraid to spend some money. There is nothing more expensive than a car you will not drive because it doesn't run right or reliably. Buy a $100 bike and you will hang it from the rafters, buy a $2000 bike and you will put a 1000 miles a year on it.

Talk to McMark, he is close and very trustworthy.