Webra .61 c/l mod?
06-23-2009, 11:43 PM
#1
Thread Starter
Webra .61 c/l mod?
I recently acquired an older Webra .61 with a 5/16 venturi, plenty of healthy compression, of course the story is too good, I ran the engine on my test stand tonight and got one good run I ran it quite rich and it produced a health 2/4 break when lifting the nose of the stand up. After shutting down I discovered all that wonderful compression had gone away, and to top it all off the glow plug stripped out of the head.
So off to the workshop I go alan keys in hand I proceed to strip the engine apart, what I found was a chunk missing from the top of the piston near the cylinder, a piece missing from the ring, a very small amount of aluminum filings not enough to make up for the missing pieces, I'm hoping the pieces went missing over time.
Now here is the weird part on the intake side of the cylinder and the piston are two holes, they look like they where put in by hand, I will try and post a picture.
Can any one tell me if these are stock or not. And does anyone have a spare piston with ring and head laying around?
So off to the workshop I go alan keys in hand I proceed to strip the engine apart, what I found was a chunk missing from the top of the piston near the cylinder, a piece missing from the ring, a very small amount of aluminum filings not enough to make up for the missing pieces, I'm hoping the pieces went missing over time.
Now here is the weird part on the intake side of the cylinder and the piston are two holes, they look like they where put in by hand, I will try and post a picture.
Can any one tell me if these are stock or not. And does anyone have a spare piston with ring and head laying around?
06-24-2009, 07:28 AM
#2
RE: Webra .61 c/l mod?
These holes are stock. The intention of these holes is to allow the incoming fuel/air charge to flow through the piston and keep it cool. OS used this design in their "Max" series.
How's the weather in Sioux Lookout, I'll bet it is hot and dry.
Jim
How's the weather in Sioux Lookout, I'll bet it is hot and dry.
Jim
06-24-2009, 10:50 AM
#3
RE: Webra .61 c/l mod?
Quite a few of the earlier baffled piston engines had those extra holes. It helped with transferring the usually dead area under the piston, helped cool the piston and gave better lubrication to the top rod bush. The photo shows my Enya 60-IIIB piston/liner.
06-25-2009, 11:25 PM
#7
Thread Starter
RE: Webra .61 c/l mod?
Hi Jim, typical summer in Sioux when the sun shines it's windy, when the wind dies its raining. unless of course it's during the week when we all have to work the weather is perfect.
