I have some O27 in the attic, but am not an expert. I think it's interchangable, except O27 stuff can run on a tigher curve. True O scale may not handle the curve radius. If I recall, it is made for 31" curves. And, as you said, the height is different, so while it's the same gauge track it may not mate exactly, and may require a bit of effort to connect the 2 together.

Is O27 dead? I don't think so.

 

I also believe the track pin diameters are different between O and O27, besides radius and rail height differences. O27 stuff runs on O fine, but some O gauge may derail on O27 curves and through switches. Electrically there is no differences.

 

There is a way to cheat with O27. I recently converted my layout to older track and it turned out to be O27. But I can still run my large FM on the curves. I did put a straight piece in the middle of the curves to help with overhang on large engines. It does seem to help.

 

So is O27 a dead gauge as o is supposedly the same just higher track ?
Is this the correct thread area for 027 questions??

Anyhow I read that they are interchangeable somewhat
if you put shims under 027 track
same track with and eng run off 3 rails?

D
Thanks
Noobie Jamie

ifferences between 027 and Lionel O gauge track:

027 is a 27” diameter, O gauge is 31”

Pins and rail stock are thicker and taller between the two. The biggest issue is thicker pins as 027 track can be shimmed

027 was a less expensive line of trains, generally, than O gauge

Smaller transformers from the 027 line may not have enough power to run O gauge engines.

O gauge engines weren’t designed to traverse
027 curves, although most can

 

027 was common for starter sets and was less expensive alternative to O gage track.
If you search local ads you can still purchase used 027 sets.

 

So is O27 a dead gauge as o is supposedly the same just higher track ?
Is this the correct thread area for 027 questions??

Anyhow I read that they are interchangeable somewhat
if you put shims under 027 track
same track with and eng run off 3 rails?


Thanks
Noobie Jamie

Welcome to the site. You can mate o/27 to O track, you just need to shim up the o/27. They sell transition pins to mate the 2.
Or you can make your own.
A little info here for you. How to clean.
Track 101

Tubular Track

I did a video on cleaning tubular track. I needed two pieces for a signal project and decided to film it. I used scotch brite until the surface became smooth. Even cleaned up the sides. Enjoy I now use common oil to wipe after cleaning. Alcohol works too.

www.modeltrainforum.com

The difference between the 2,

 

I thought that O27 was no longer being made by anyone, but it was cataloged by Lionel as late as 2017. Trainworld has some in stock. While the smallest O27 curve is 27” diameter, I have some in O42, O72 and I think O54.

 

From Tandem Associates ...

 

O and O27 are the same 'Gauge' as in the distance between the rails.
There are physical differences in the construction of the track however. As others are pointing out, O27 is lower and the curves make a tight 27" diameter circle that some large postwar and many modern engines and cars cannot navigate. O27 was made to be the starter track for Lionel. It's less expensive and made flimsier of thinner metal stock. O27 is not being manufactured anymore. Menards is selling new O track however. If you are a newbie coming into this hobby I strongly recommend O track over O27.
However no matter which track you go with they are both the same guage.

 

I’m still confused how the index says O27 won’t accommodate larger engines like the trainmaster yet mine runs fine on O27. Does the issue on come with a full curve? My curves are split by a straight section.

 

The extra straight between curves can solve the radius issue.

 

So learned something new from Millstone mike posting, that the O27 came from Ives. Had assumed (wrongly) that it was designed to fit in tighter spaces that the larger O31 (if you will) gauge .