Do not try this at home!

A few weeks ago we were invited to a birthday party to be held in a remote inn.

What do you do when you don't know the way? Of course you follow somebody that does!

Even if he has a brand new BMW and I have a 55 year old 2 ton buick with a newly restored engine? Of course!!

Well, found out Tallulah won't go 100mph over a longer distance but only 95mph the hard way.

Amazingly she could easily start the next day although she could not run idle, and beside the damage to the piston NOTHING else was!!

Those straight eights sure were made to last

Wow! What is the root cause for something like that? Just excessive RPM? Or is there something else that causes the piston to burn up like that?\

Sure hope this is repairable.

JD

Not really sure of the cause.

This is cylinder no. 8 closest to the firewall and my local expert/friend thought it probably was because of extensive heat. But it could also be a faulty piston, as the engine was totally rebuilt for less than 2500 miles ago, or something else.

A new piston with rings and gaskets are ordered and should arrive late next week and I'm not expecting any other problems than cleaning up the mess I've made in the garage

If anybody has suggestions to something specific I should check BEFORE assembly, please shout it out!

You might want to pull one of the other pistons and compare weight before installing the new one. also check the spark plug heat range reference for your engine.

Jeez!!!!!!

Yeah I stick to 50 on the highway in this thing....think Im DEFINITELY goona keep it that way. Very sobering reminder of what can happen when the envelope is pushed.

The engine is finally rebuilt with a working manifold and carburator and runs better than ever

Only damage was the single piston.

A few probable reasons turned up along the way:

The hole for the stove-pipe was unpluged and the intake valve for cylinder 8 was totally off. Both gave a to lean mixture, which would account for the damage.

But even though everything should be great, I don't think I'll be racing Tallulah for the time beeing

Yep lean mix will melt pistons in no time, my hubby has verified that a few times while he was racing in the early nineties

A good thing can be to install a lambda sensor -- and have it wired so that it will make the idiots light come on if the car goes lean... a normal sensor will do but a wide band one is even better since the switch on a normal one is way to lean for old car. Note: It will most likely not detect once cylinder going lean but it can save you from having eight melted pistons pistons .. all according to my hubby -- hehe I don't have a clue but I showed the pic to him...

Cheers Dyna

I can discuss orbital mechanics and ephimeris adaptation, but I got lost at 'lambda'...

Maybe my idiot light is on...?

Cheers,

JMC

Standard oxygen sensor. Narrow band senses about 14:1-15:1 (pretty lean) and switches around .45V for 14.7:1. Wide band senses about 10:1-20:1 and switches around 1V for 14.7:1. The trick would be wiring it in, unless you wanted to buy a whole system.

One source for this kind of project is:

http://web.archive.org/web/20021208015829/www.diy-wb.com/info.htm

Cheers Dyna

PS: hehe no John you don't have your idiot light on just different words for the same thing

rlb:

Now, that makes sense, especially following a quick trip to Wikipedia, where they graciously point out that Lambda = Air Fuel Ratio (AFR). Thanks for the brief explaination. Old pilot here. Large print and bright colors are helpful. Back in the day, the guy with the stick assessed proximity to 14.7 AFR by ear and a keen eye on CHT.

Cheers,

JMC