1LikesJL Racing .12
04-12-2008 | 05:52 PM
#1366
Tech Regular
Joined: May 2003
Posts: 445
dear all,
i'm in need of advice. I've got myself an ofna jl3 engine. I've done the break-in without issues.. comfortable running temperature.. good smoke trail, nice sound while accelerating, etc. After the break-in I was happy with the performance although I knew the motor could be pushed further. So far I was using 20% nitro.
After I changed to 16% I've started seeing some issues. To get the same performance and get the car to shift at same spot on the track, I had to lean a bit the hsn. Now the temperature runs higher...260F with less performance then I've had with 20%. any leaner and the engines gets too hot. Also when gradually accelerating the car off the ground, it starts fine but at a point in time, the revs start dropping rather than increasing, but there's still alot of smoke coming out...
I've read somewhere that this engine is shimed already for 30% nitro. Should I remove a shim and see if it helps?
I may blame the pipe as well. I'm running a copy of an efra 2017 pipe.
I ordered a picco 2607 now but it's still a month away to get it. Would the tuned pipe make the difference I'm looking for?
thanks.. sorry for the long post.
g
i'm in need of advice. I've got myself an ofna jl3 engine. I've done the break-in without issues.. comfortable running temperature.. good smoke trail, nice sound while accelerating, etc. After the break-in I was happy with the performance although I knew the motor could be pushed further. So far I was using 20% nitro.
After I changed to 16% I've started seeing some issues. To get the same performance and get the car to shift at same spot on the track, I had to lean a bit the hsn. Now the temperature runs higher...260F with less performance then I've had with 20%. any leaner and the engines gets too hot. Also when gradually accelerating the car off the ground, it starts fine but at a point in time, the revs start dropping rather than increasing, but there's still alot of smoke coming out...
I've read somewhere that this engine is shimed already for 30% nitro. Should I remove a shim and see if it helps?
I may blame the pipe as well. I'm running a copy of an efra 2017 pipe.
I ordered a picco 2607 now but it's still a month away to get it. Would the tuned pipe make the difference I'm looking for?
thanks.. sorry for the long post.
g
In your case, I would remove one of the copper shims and richen the HSN out from the leaner settings you tried above. Then I would retune the motor. If you have to much head clearance with low percentage nitro............the fuel mixture is not being compressed enough for optimal burn. The motor will produce lots of smoke, create lots of heat as a result of over leaning... ...........and not make alot of power. Don't blame the pipe......maybe it's not the optimal pipe........but if the motor ran good with the 20% ...it will do fine with the 16% ....if it's shimmed properly. I would have removed a shim with even the 20%.
04-12-2008 | 05:59 PM
#1367
Gortan,
RayJ is right, you will need to remove shims if running lower percentage nitro, other than 30%, I would suggest a total of .30mm shim, right now out of the box the engine had a total of .60mm shim=(3 x 20mm shims) you will need to remove 2 x .20mm shims and add 1 x .10mm shim = total of .30mm.
RayJ is right, you will need to remove shims if running lower percentage nitro, other than 30%, I would suggest a total of .30mm shim, right now out of the box the engine had a total of .60mm shim=(3 x 20mm shims) you will need to remove 2 x .20mm shims and add 1 x .10mm shim = total of .30mm.
04-12-2008 | 11:48 PM
#1369
Tech Adept
iTrader: (1)
Joined: Dec 2006
Posts: 131
where would it be possible to get parts for jl3 online, such shims, conrod etc?
preferably based in europe...
do shims have to specific for a motor or would it be possible to use shims from other manufacturers?
thanks...
preferably based in europe...
do shims have to specific for a motor or would it be possible to use shims from other manufacturers?
thanks...
04-12-2008 | 11:56 PM
#1370
04-14-2008 | 05:54 PM
#1372
Tech Addict
Joined: May 2007
Posts: 590
for 16%nitro, 0.3mm will be enuff.
04-15-2008 | 01:05 AM
#1373
Tech Adept
Joined: Mar 2003
Posts: 226
From: Tallinn, Estonia
Don't just look at the shims and assume it's your head clearance, it's not in most cases. Take off the button, turn the piston into uppermost position (make sure the liner does not lift) and measure the distance between piston and upper edge of the liner. This will be your measurement A.
Then remove all shims from the head button and measure the height of the button part that goes into the liner. This is your measurement B.
Now do A-B, this equals your head clearance with no shims. Can be both positive and negative (although I've only seen positive, but I haven't seen too many of them
). If the result is, lets say 0.3 mm, this means you should only use a 0.1mm shim to get a 0.4mm head clearance. Around 0.4-0.45 is what I've often seen suggested for 0.12 engines and 16% fuel.
In real life things can be a bit more complicated, if the piston has a dome or cavity, the button is not cut straight, but at an angle, different volume of the button cavity etc... they all affect compression. So it's not 0.4mm set in stone, but depends on the engine, application and environment.
Then remove all shims from the head button and measure the height of the button part that goes into the liner. This is your measurement B.
Now do A-B, this equals your head clearance with no shims. Can be both positive and negative (although I've only seen positive, but I haven't seen too many of them
). If the result is, lets say 0.3 mm, this means you should only use a 0.1mm shim to get a 0.4mm head clearance. Around 0.4-0.45 is what I've often seen suggested for 0.12 engines and 16% fuel.In real life things can be a bit more complicated, if the piston has a dome or cavity, the button is not cut straight, but at an angle, different volume of the button cavity etc... they all affect compression. So it's not 0.4mm set in stone, but depends on the engine, application and environment.
04-15-2008 | 02:11 AM
#1374
Tech Addict
Joined: May 2007
Posts: 590
Don't just look at the shims and assume it's your head clearance, it's not in most cases. Take off the button, turn the piston into uppermost position (make sure the liner does not lift) and measure the distance between piston and upper edge of the liner. This will be your measurement A.
Then remove all shims from the head button and measure the height of the button part that goes into the liner. This is your measurement B.
Now do A-B, this equals your head clearance with no shims. Can be both positive and negative (although I've only seen positive, but I haven't seen too many of them). If the result is, lets say 0.3 mm, this means you should only use a 0.1mm shim to get a 0.4mm head clearance. Around 0.4-0.45 is what I've often seen suggested for 0.12 engines and 16% fuel.
In real life things can be a bit more complicated, if the piston has a dome or cavity, the button is not cut straight, but at an angle, different volume of the button cavity etc... they all affect compression. So it's not 0.4mm set in stone, but depends on the engine, application and environment.
Then remove all shims from the head button and measure the height of the button part that goes into the liner. This is your measurement B.
Now do A-B, this equals your head clearance with no shims. Can be both positive and negative (although I've only seen positive, but I haven't seen too many of them
). If the result is, lets say 0.3 mm, this means you should only use a 0.1mm shim to get a 0.4mm head clearance. Around 0.4-0.45 is what I've often seen suggested for 0.12 engines and 16% fuel.In real life things can be a bit more complicated, if the piston has a dome or cavity, the button is not cut straight, but at an angle, different volume of the button cavity etc... they all affect compression. So it's not 0.4mm set in stone, but depends on the engine, application and environment.
you could also use the 'solder test' to check actual head clearance.
04-18-2008 | 05:11 PM
#1378
Tech Apprentice
Joined: Apr 2007
Posts: 67
I was just wondering if anyone has purchased this engine from Tower Hobbies and if they got the evo3 or if it is one of the older ones. On their website it doesnt say which version, it just says jlr red dot and has a picture of what looks to be the older one. Since newer versions have been out for awhile, I didnt know if it was possible for them to still have the older ones.
04-18-2008 | 05:22 PM
#1379
Tech Adept
iTrader: (-1)
Joined: Jan 2007
Posts: 124
From: Switzerland, Europe
I was just wondering if anyone has purchased this engine from Tower Hobbies and if they got the evo3 or if it is one of the older ones. On their website it doesnt say which version, it just says jlr red dot and has a picture of what looks to be the older one. Since newer versions have been out for awhile, I didnt know if it was possible for them to still have the older ones.
04-18-2008 | 05:30 PM
#1380
I ran a Stock EVO3 at the Kyosho US Open champs and it ran great. Awesome bottom and mid torque. I geared for the straight and I had plenty. It lacked the power of my Murnan Reddot but it is a very very strong engine. With the IDM 2617 it flat out hauls azz.
Guys I'm telling you there's not a better bang for the buck out there.
Guys I'm telling you there's not a better bang for the buck out there.