1988 Festiva LX 'Red' (diesel conversion)

[Frank Lee]

I'd be inclined to fix the Festiva engine if the long block is good. They're economical enough.

[Christ]

Ok, here are some relevant measurements -

First for the Festiva, next for the Mystery crankshaft -

Festiva:
Crank end - 3.265''
Center bearing bore (pilot OD) - 1.375''
Pilot bearing width - ~0.350''

Mystery Crank:
Crank end - 3.345''
Bushing OD - 0.822''
Flywheel center hub width - 0.525''
Centering hub OD - 1.695

And here's a pic of the new crank pattern approximately laid out on the Festiva flywheel:

[Christ]

The trouble I have with drilling the pattern that way is the remaining shoulder width... looks to be less than 5mm, and M10 bolts are required for the new crank...

AFAIK, min shoulder should be at least bolt dia/2 or greater.

Can anyone else weigh in on that?

[Jasen]

How about welding plugs in the old holes, then drill and tap your new holes. Cut the plug's the exact same length, turn/have turned and balance checked.

[mikeyjd]

Watching with interest to see how this comes together

[Christ]

Originally Posted by Jasen

How about welding plugs in the old holes, then drill and tap your new holes. Cut the plug's the exact same length, turn/have turned and balance checked.

I thought about that, but money will quickly become an issue. I can probably find some .504 press fit plugs cheap enough and press them in myself, but then having it ground and rebalanced for the plugs in addition to having the center milled out and the rear face widened will up the cost considerably.

I have an engineer friend I'm going to talk to about drilling 5 of the 6 holes centered between the existing pattern. The offset hole on the new crank is 12* off from standard 6-hole and will likely intercept one of the existing holes, and it may be well enough to place the bolt within the existing hole. If he says it's OK, I'll take his word for it. Not really all that difficult to pull an engine and replace a flywheel if it doesn't work out.

Also, as a last resort, I'll talk to ACT or some other flywheel company and see if I can get them to mill a Festiva flywheel with the Mystery engine's pattern in the center... shouldn't cost me more than a 'custom' light weight flywheel, since they already make components for both engines. It'll just be a matter of changing the jigs and tooling halfway through the work order.

[Christ]

Originally Posted by Frank Lee

I'd be inclined to fix the Festiva engine if the long block is good. They're economical enough.

38-40MPG isn't 'economical enough'. There was nothing wrong w/ the engine, I thought the carb was junk and buyin a new one was simply out of the question. Later, I found out that there was a sensor unhooked that would have caused every problem it had, so I felt like a dolt for that... but meh, this is an exercise in fun for me.

Even if I gotta spend a couple hundred bucks to convert it to diesel, it'll pay for itself in fuel costs [which are zero, btw] in no time flat, no matter what MPG it gets.

The only reason I even set an MPG goal for it is for others who also want to complete a similar swap. If I can reach the goal, it'd be a good swap for others to try.

Oh, btw, the new engine has ~58HP, so obviously it'll go 45. LOL.

[cRiPpLe_rOoStEr]

So, would you still eventually consider a Diesel conversion at an uncertain future?

[Christ]

Originally Posted by cRiPpLe_rOoStEr

So, would you still eventually consider a Diesel conversion at an uncertain future?

No, the new engine is a diesel. It's still a 'mystery' engine, even though I know exactly what it is. I'm not gonna unveil it until it's halfway in and someone manages to identify it from the pictures I post lol.

I'm trying to come up with a reasonable change purse to have the flywheel machined to fit the new crank, so I can keep using the stock clutch and simplify the swap a bit.

Barring that, I can make a 1/2'' flywheel spacer puck to adapt the patterns myself... I'd rather keep away from things of that sort though, because space is already at a premium under the hood and this particular 4 cylinder engine is about as long as the Festiva's OE motor was.

[Frank Lee]

I think I know what the engine is... muahahaha!