Project of the Month built by deeferdog
Home Model Engine Machinist > Showing Them > A Work In Progress > Rockerblock I.C.--Something a little different-

Reply
 
Thread Tools
Old 07-01-2017, 04:49 AM   #211
corky
 
Join Date: May 2017
Posts: 9
Liked 1 Times on 1 Posts
Likes Given: 7

Default

Converted my standby generator to propane a couple of years ago, the propane
regulator required a vacuum line to the back of the diaphragm to control the flow of propane, the propane was introduced into the top of the carb. above the butterfly.
The regulator had the same button on the rear of the diaphragm, to Prime at start.
I am running a 25 hp twin on 8 psi propane


corky is offline  
 
Reply With Quote
Old 07-01-2017, 02:41 PM   #212
Brian Rupnow
Project of the Month Winner!!!
 
Join Date: May 2008
Location: Barrie, Ontario Canada
Posts: 9,610
Liked 3683 Times on 3010 Posts
Likes Given: 36

Default

So here we are, ready for round two of the propane game. This set up is as per the video I watched, with a separate venturi tube extending out in front of the carburetor air intake. The small metal pipe which the clear flexible tube is attached to, protrudes approximately half way into the "venturi tube. This will create a restriction in the inrushing air so it will create a low pressure area where the end of the tube is. The carburetor has not been changed in any way. The liquid fuel line which runs up to the bottom of the carburetor has been plugged with a piece of 1/8" steel dowel inserted into the original fuel feed line. The new brass "venturi tube" is a very light press fit over the carburetor air horn with a bit of green Loctite to help it stay in place. The original carburetor throttle should work to control engine speed, same as it always did. I will give the Loctite a few hours to set up, then try the engine again to see what happens.


__________________
Brian Rupnow
Brian Rupnow is offline  
 
Reply With Quote
Old 07-01-2017, 08:46 PM   #213
grapegro
 
Join Date: Jun 2013
Posts: 80
Liked 4 Times on 4 Posts
Likes Given: 1

Default

Hello Brian,
Due to computer problems I am unable to send attachments, but I feel you have the basis of a working unit. In principle, similar to a vehicle gas conversion. Will be very interested to see how you fare with this unit. Norm
grapegro is offline  
 
Reply With Quote
Old 07-02-2017, 12:25 PM   #214
Brian Rupnow
Project of the Month Winner!!!
 
Join Date: May 2008
Location: Barrie, Ontario Canada
Posts: 9,610
Liked 3683 Times on 3010 Posts
Likes Given: 36

Default

Sadly, I must report that I had no luck at all with Propane. I have tried all of my bag of tricks, and the engine simply won't fire and run on Propane. This is not a really big deal, and like many other things, you don't know until you have tried. I do have a spare gas tank setting around, and by making a simple bracket I can add it to the existing Rockerblock assembly. With the coming of summer, I don't want to spend a lot of time in my machine shop, so I will end this thread now and say a big Thank You to all the people who have followed my build.---Brian
__________________
Brian Rupnow
Brian Rupnow is offline  
3
People Like This 
Reply With Quote
Old 07-02-2017, 11:42 PM   #215
Crisptrans
 
Join Date: May 2016
Location: Pottsville, Pa
Posts: 9
Likes Given: 1

Default

Brian, don't think of your demand valve so much as a regulator for pressure of your gas, think in terms of scuba diving. The air from your tank only flows when you draw on it. It's known as a demand regulator also. It will only flow gas when it's asked. Propane forklift is the same way. More people have problems with too rich a mixture of propane than they do with too lean. It takes a surprisingly little amount to make an engine run. If I recall correctly the explosive concentration of propane is somewhere in the neighborhood of 2-10 %. Any more or any less= no joy. With enough patience and persistence I'm certain your motor will run on propane, not throwing in the towel is key. Your ability to create these little gems is amazing. Keep at it and if I can be of assistance don't hesitate to message me, I'm not the sharpest knife in the drawer but I do have a little experience that I will gladly share.
To
Crisptrans is offline  
 
Reply With Quote
Old 07-06-2017, 12:18 AM   #216
Brian Rupnow
Project of the Month Winner!!!
 
Join Date: May 2008
Location: Barrie, Ontario Canada
Posts: 9,610
Liked 3683 Times on 3010 Posts
Likes Given: 36

Default

After my failed attempt to even have the engine fire on Propane fuel, I was beginning to wonder if perhaps the ignition timing or valve timing had "slipped" from the original settings where it ran so well on naptha gas. I had a spare gas tank setting around, so I installed it on the engine, and without readjusting anything the engine fired right up and ran well. I decided to have a 40 minute "endurance run", and about half way thru the run I picked up my camera and shot a short video. That explains the nasty oil on everything.---I had given all of the bearing surfaces a good squirt of lubricating oil and filled the water reservoir before starting the run. The water stays in the reservoir with no problem, but the oil quickly turns black and splashes all over the place.---Brian
__________________
Brian Rupnow
Brian Rupnow is offline  
2
People Like This 
Reply With Quote
Old 07-06-2017, 12:35 PM   #217
ShopShoe
Senior Member
 
ShopShoe's Avatar
 
Join Date: Oct 2010
Location: Central Iowa, Central U.S.A.
Posts: 669
Liked 96 Times on 87 Posts

Default

Brian,

Thank you for posting the latest video. I would say the great sound and hit-and-miss kind of makes up for the oil splashes.

Anyway, I know you build your engines to work, not look good on the shelf (which they do, anyway).

--ShopShoe


ShopShoe is offline  
 
Reply With Quote
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



Newest Threads






- Top - Member List