What size is this OS engine

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truggy83

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I picked up this OS engine for $25 from a local guy. He said it came out of an HPI. It says O.S. Max on one side. It says CV-R under the exhaust manifold. The muffler says HPI. It has good compression. I was just wondering how good of an engine this would be and if it would be fast as say a traxxas 2.5 R or 3.3?
Zi6_7122.jpg
 
id say a 15 looks like a small block mount.looks like a os 15 max i got
 
I wouldn't bet my life on it but I'm am pretty sure its a .18 cv-r the .15 are cv the only other way to check would be piston size.;)
 
ok how would this engine compare to a traxxas 2.5 R or 3.3? I don't want to put anything in my rigs that will make it slower.
 
If its the .18 which I'm pretty sure it is it should perform as good if not better. os is a very good engine better than anything traxxas makes.:D

---------- Post added at 10:35 AM ---------- Previous post was at 10:32 AM ----------

.18= 3.0 cc but cranks high rpms
 
when I bought it, he told me he thought it was either a .15 or a .18 and that it was out of an HPI, I believe it was a car of some type. I have no way to start this thing to see how it runs. It has a sealed backplate on it and I don't have a starter box. I might put this in my pede :)
 
when I bought it, he told me he thought it was either a .15 or a .18 and that it was out of an HPI, I believe it was a car of some type. I have no way to start this thing to see how it runs. It has a sealed backplate on it and I don't have a starter box. I might put this in my pede :)

You can buy pull start for that engine.:whhooo:
 
You can buy pull start for that engine.:whhooo:

I don't know which pull start will work for this. I went to OS website and the only engines I see that may be similar are .18 cv-rx. I don't see any that just say cv-r.
 
I don't know which pull start will work for this. I went to OS website and the only engines I see that may be similar are .18 cv-rx. I don't see any that just say cv-r.

I am not sure if there is a difference why don't you give os tech line a call they can probaly give you the answer you need.I think you can order direct from them.

---------- Post added at 1:23 PM ---------- Previous post was at 1:18 PM ----------

Just did a little checking the x means pull start.Hope this helps you.:D

---------- Post added at 1:26 PM ---------- Previous post was at 1:23 PM ----------

Check a break down of the engine see exactly what you need make sure the internal parts are the same crank ect.
 
I am not sure if there is a difference why don't you give os tech line a call they can probaly give you the answer you need.I think you can order direct from them.

---------- Post added at 1:23 PM ---------- Previous post was at 1:18 PM ----------

Just did a little checking the x means pull start.Hope this helps you.:D

---------- Post added at 1:26 PM ---------- Previous post was at 1:23 PM ----------

Check a break down of the engine see exactly what you need make sure the internal parts are the same crank ect.

Thanks. I will check that out.
 
Any chance you can take some better photo's of it? One from top down and one from the side that isn't blurry would help.

Based on the photo you have, I'd say it's a 15. The crankcase of the 15 and 18 are subtly different. But, I'm having a hard time finding any OS that has the edges of the cooling fins milled down to be shiny like that. The old 15-CV had a really weird looking head that was unmistakable and the 15-CV-R(X) had a black head (I had 2 of them). The 18 CV-R(X) did not have any of the ano on the fins ground off (had one of those too).

If it's a 15, it will be more stable to tune than a 2.5/2.5R, but it won't put out the RPM's or power. If it's a 18, it will have a bit more torque than a 2.5/2.5R, but won't have as much RPM. That said, it would be better suited in a t-maxx than the 2.5 is.

This was my OS18CV-R(X):
2005-0305-NMTThrottleLinkage.JPG


This was my 15CV-R(X):
2005-0107-XXX-NT-BodyOff-topBrakeLinkage.jpg
 
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looking from your pictures the 15 does kinda look like it from the top looking down. The exhaust coupler piece even looks the same. The head has the same bolt pattern. Here is some more pictures. Hopefully they will be a little more clear. Did HPI put O.S. .15's in some of their cars? I remember the guy that sold me this telling me it was out of an HPI and I even have a black muffler that says HPI on it that came with it.

Zi6_7131.jpg

Zi6_7130.jpg

Zi6_7129.jpg

Zi6_7128.jpg


---------- Post added at 4:16 PM ---------- Previous post was at 4:01 PM ----------

Here is a video if it helps any. I don't know why my camera is not acting right.



---------- Post added at 4:21 PM ---------- Previous post was at 4:16 PM ----------

after closer inspection I see some bits or blue paint on the exhaust mainfold. Think maybe they painted the head blue? I might just pull the head off to check. If I measure the piston how can I tell what it is?
 
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dang only a .12. I don't know what I will use that for. Well thanks for helping me figure it out.
 
Sorry.

Would probably cost you more than it's worth to get a pull-starter on it. Requires a new crankshaft, backplate, pull-starter assembly, starter shaft and OWB.
 
Well I have it sitting next to some of my r/c tires sorta as a decoration. Guess It will keep serving that purpose.
 
i two am in the same boat. i have an o.s motor that was in a savage that was given to me,with a black hpi muffler. But the head on this one has some designs on the top ring of the head.
 
Any chance you can take some better photo's of it? One from top down and one from the side that isn't blurry would help.

Based on the photo you have, I'd say it's a 15. The crankcase of the 15 and 18 are subtly different. But, I'm having a hard time finding any OS that has the edges of the cooling fins milled down to be shiny like that. The old 15-CV had a really weird looking head that was unmistakable and the 15-CV-R(X) had a black head (I had 2 of them). The 18 CV-R(X) did not have any of the ano on the fins ground off (had one of those too).

If it's a 15, it will be more stable to tune than a 2.5/2.5R, but it won't put out the RPM's or power. If it's a 18, it will have a bit more torque than a 2.5/2.5R, but won't have as much RPM. That said, it would be better suited in a t-maxx than the 2.5 is.

This was my OS18CV-R(X):
2005-0305-NMTThrottleLinkage.JPG


This was my 15CV-R(X):
2005-0107-XXX-NT-BodyOff-topBrakeLinkage.jpg
I have one and it is an 18 n also the crank case if you look on O.S website the crankcase they use for the 18 it is the 15’s crankcase so They’re identical no subtle changes like what you’re trying to say they’re identical look on their website if you don’t believe me I run nothing but OS and they also have more power than a 3.3 or the 2.5 or even the 2.5r witch the 2.5r is the best out of the three 3.3 have bad over heating n broken internal problems with them
 
I have one and it is an 18 n also the crank case if you look on O.S website the crankcase they use for the 18 it is the 15’s crankcase so They’re identical no subtle changes like what you’re trying to say they’re identical look on their website if you don’t believe me I run nothing but OS and they also have more power than a 3.3 or the 2.5 or even the 2.5r witch the 2.5r is the best out of the three 3.3 have bad over heating n broken internal problems with them
Kind of wish I still had the 18 just for reference, or better photo's of it. I still have an old 15 laying around I think.

Looking online at images for the 15 cv-r(x) crank case (part# 21501030) and the 18 cv-r(x) crank case (part# 21811000), they do differ. Where the sleeve seats, there's a raised lip on the 18 that isn't on the 15. Then again, could just be amain and hobby town both used the wrong stock photo's. The part numbers differing would also suggest they aren't the same. The crank case for the 15 is listed as the same crank case for the 12, so those appear to be the same.

2022-1111-os15cvrx-crankcase-pn_21501030.jpg

2022-1111-os18cvrx-crankcase-pn_21811000.jpg


Considering the post is 11 years old and both engines have been long since discontinued... it's likely irrelevant anyway.
 
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