Counterbalanced Crank
 

Is there a way to determine if a car's engine has a counterbalanced crankshaft without dropping the oil pan? My thought is if the engine is run at a certain speed an "excessive" vibration will show up. Is there another way?

Re: Counterbalanced Crank
 

Remove the crankcase breather pipe on the driver's side of the engine and look inside.

Re: Counterbalanced Crank
 

Thanks Bob. I am exploring a way that, if I did not own the car, I could determine if the engine was rebuilt with a counterbalanced crankshaft.

Re: Counterbalanced Crank
 

There are fairly inexpensive boroscopes (inspection cameras) available. Would threading one down the oil fill render the crankcase visible?

JayJay

Re: Counterbalanced Crank
 

I have a 'scope similar to that one. I have never tried it but I don't think it is flexible enough to navigate thru the baffle in the filler tube.

Counterbalanced Crank
 

I have that scope, I can try it out tonight. I know you can use it to inspect the crankcase with the timing cover off, but I haven't checked the filler tube.

Update: Nope

Re: Counterbalanced Crank
 

Simple. Get a guy in your club to drive your car that has had his car without a counterweighted crank, and then got his engine rebuilt with one. A drive down the road at 50MPH, then take your foot off the gas, and reapply. The vibrations in the steering wheel, and the rear view mirror, plus his experience will tell you in about 2 minutes.

Re: Counterbalanced Crank
 

slightly off subject.
I bought a set of counterweights about 20 years ago. I'd like to know if i can just bolt them on to the crank and go with that??
There are no instructions with this item.
Tks, Jerbo

Re: Counterbalanced Crank
 

That's NOT a good plan. Actually applying weights to an A/B crank is a somewhat complicated process. Some weights bolt on, some weld on and some are pressed on. BEFORE applying weights the crank should be magnafluxed. The crank should then be straightened and checked for proper journal sizes. Then, except for the press-on weight type, the crank can be ground if need be. In any case it should be balanced afterward.

Press on weight application is quite involved and has been covered in other posts in the past.

Re: Counterbalanced Crank
 

Pete is right. He's not being rude when he tells you this. Sometimes we try to save people from pain later, and some folks take it wrong.

One other thing. When the journals are machined they should not join the bosses at 90 degrees. There should be a shoulder there (a curve up - I forget the technical name) otherwise the crank is succeptable to snap down the road (did you catch that funny LOL). I have experienced this, and it is no fun. Just because you hire a big name shop, and pay a big price is no guarantee the work will be done right.

Re: Counterbalanced Crank
 

Might want to magnaflux the crank after installation of weights too. I wound up with 2 cracks after a press on installation by a reputable machinist. Things can go sideways anytime.

Re: Counterbalanced Crank
 

Fillet is the word.

Re: Counterbalanced Crank
 

To seek answer to your Q....First thing to evaluate...is it an A or B engine. If B, the answer should be apparent. If A engine, and you are serious about knowing... take off pan. Only about 20 quarter inch fasteners to remove.

BTW....
The oil fill tube is removable.
I would remove that tube to view crankcase area... short of removing pan.

Re: Counterbalanced Crank
 

Is there a reliable non-destructive way to remove it? I wanted to remove and repaint it when I was repainting my engine block, but couldn't figure out how to do it without risking damage.

Re: Counterbalanced Crank
 

I have found that the oil breather pipes are extremely difficult to remove from Model B engines, but no so on Model A engines.

Re: Counterbalanced Crank
 

A good question.
I made a tool/device. The idea was to make it grab the pipe using full circumference. Upward pressure using hammer strokes /tapping on bottom... while twisting ‘tool’ handle... back and forth.

Wasn’t easy, but not in hurry took plenty of time. Tube came out... paint was scratched.
This was a B engine tube.

Alex,
I took my tube out because it was filled with crud and HAD to be cleaned. If it was not , I would have spray painted it in place.