R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Nitro On-Road

Reply
 
Thread Tools Search this Thread
Old 08-10-2003, 10:03 PM   #1
Tech Fanatic
 
Join Date: Aug 2001
Location: Nashville, TN
Posts: 852
Trader Rating: 49 (100%+)
Default any engine tuners out there?

I am looking for some reputable engine tuners that will take my problem engines and be able to do the following:

1) diagnos problem(s) I am having with an engine
2) Fix if possible
3) Learn the particular engine characteristics (what makes this particular engine tick)
4) Prepare engine to mount into car and take off.


The reason I am asking is I have several engines and a couple of them have quirks. Quirks are potential air leaks, running lean on bottom end once hot, inconsistent idling, shimming not correct.

If anyone knows of a person or business that can do this type of work, please let me know.

thanks.

[email protected]
rodneybarrett is offline   Reply With Quote
Old 08-11-2003, 03:11 AM   #2
Tech Elite
 
Corse-R's Avatar
 
Join Date: Aug 2001
Location: Madrid (Spain)
Posts: 2,121
Default

Rodney:

Why try to pay to someone for fixing your engines?, at least you can try to get some good advice here before shredding many bucks into this. Answer to this questions and see if we can help you in this matter.

- What brand/model are? (Please, tell me that aren't Picco XP12...).
- Going lean on bottom end is a common quirk. What kind of plug are you using, car and fuel?. Sometimes we center into a part of the problem (going low-end lean when hot, but this is at the same time that the tank is almost empty? if yes, try to make your fuel pressure line longer, could be a problem of excessive fuel pressure or an air leak in your engine.
- How many litres of fuel have passed thru those engines? When a engine ticks, usually is a problem of the side skirt of the piston (worn) or a problem with the main bearing (worn).
- With your unstable idle, have you tried to solve changing the o-rings of the carburetor? Ever I carry a bag for rebuilding the o-rings of the carburetors. You will amaze how much problems can solve a bag of o-rings.
__________________
Cheers,
Corse-R
---
[quote=MugenDrew;2684554]BATTERIES are for FLASH LIGHTS, gasoline is for cleanin parts, alcohol is for me to drink and well NITRO...everybody know thats for racing.[/quote] :D:D:D
Corse-R is offline   Reply With Quote
Old 08-11-2003, 12:22 PM   #3
Tech Fanatic
 
Join Date: Aug 2001
Location: Nashville, TN
Posts: 852
Trader Rating: 49 (100%+)
Default

Corse-R:

I have two engines with problems. And I'll be the first to admit I haven't master tuning engines yet so that was the reason for the question. I take a lot of advice from people and I think sometime the advice contradicts itself and I don't know which is right.

I have ideas about the engine problems but having validation and understanding how they were fixed would help a long way in my continued education of 2 -stroke engines. And sometime it might not be something I can fix. And that's good to know too. It is like paying to get mentored.


But I give it a shot here:
Both are different issues so I list them seperately.


1) Sirio .12

Plug 7 - cold
Fuel Maxy 30%

Symptoms:

The stock carb has issues. Novarossi carb works ok. So I know the problem is in the carb. What happens is when you try and start it gets started fine but very very rich on the bottom end. However, once you clean the carb out, the bottom end gets very lean with a very high RPM at idle. Also, the temp goes out of control. If you let it sit at idle, the thing will load up and stall again. And the same thing happens once you start it again. This is with a fuel to half tank of gas too so I don't think it is pressure related. I have already had the carb back to trinity once but all they did was replace an o-ring and send it back. It is the 3-needle one. It still does the exact same thing.


2) Mugen MT12

Plug - typically cold - 5 or 7
Fuel 30% Maxy
head clearance .3 mm


This engine works well except goes lean about 2 minutes into a run. So lean that it almost flames out coming out of a corner. I believe it is an air leak somewhere but not sure how to diagnose it.


BTW, is there any place you can recommend to get all the different types of o-rings in bulk for these engines. I would be looking for o-ring for the following types:

Pixy .12
XP12
MT12
Sirio



thanks.


Also, I am still interested in hear from someone who knows a company to perform this type of work.
rodneybarrett is offline   Reply With Quote
Old 08-11-2003, 12:46 PM   #4
Tech Elite
 
stefan's Avatar
 
Join Date: Aug 2001
Location: Bavaria, Germany
Posts: 3,273
Send a message via AIM to stefan
Default

Rodney,

here is my 2 cents:

First of all, get rid of the cold plugs. .12 engines need hotter plugs, MC59 or MC8 work great ---> BIG Difference

Second, if you suspect an airleak, why don't you just take the engine in question apart and seal it (I use air seal, but silicone works fine)

Judging by the symptoms you are describing (leaning out after a few) I'd say that your engines are generally to rich on top and too lean on the bottom.

Try to richen the bottom end up 1/2 turn and then lean top end out until the sucker runs right.

Also, have you checked you tank and your fuel lines for being air tight?

Are you coming to Fernando's in two weeks?
stefan is offline   Reply With Quote
Old 08-11-2003, 01:10 PM   #5
Tech Apprentice
 
Join Date: Mar 2003
Location: Bulgaria
Posts: 91
Default

Can you guys tell me what glow plug do I need for a RB .12 5 port engine? I'm not sure what the stock one is but for info I run 16% fuel and the outside temp is around 30-35C. Also can a leaky front bearing cause the engine to run hot. Any answer appreciated.
Speed De is offline   Reply With Quote
Old 08-11-2003, 01:14 PM   #6
Tech Fanatic
 
Join Date: Jun 2003
Location: NoVA
Posts: 856
Send a message via ICQ to mtx3racer Send a message via AIM to mtx3racer
Default

OS and MCCoy med-cold plugs work very vell. As far as the front bearing, i am not sure.
mtx3racer is offline   Reply With Quote
Old 08-11-2003, 01:34 PM   #7
Tech Apprentice
 
Join Date: Mar 2003
Location: Bulgaria
Posts: 91
Default

Well my choice here is between RB and Novamega plugs but thanx for the info.
Speed De is offline   Reply With Quote
Old 08-11-2003, 01:41 PM   #8
TAW
Tech Addict
 
Join Date: Jun 2003
Location: Franklin, TN
Posts: 518
Trader Rating: 18 (100%+)
Send a message via AIM to TAW
Default

Stefan, this is Troy. I used to run hot plugs in my Nova based motors and on the suggetion of some of the guys down there I now use nova cold plugs...go figure might try the hot ones again just to see even though I am not having the problems that Rodney is. I am going to try and make it down for the big race but he is still unsure.

later

Quote:
Originally posted by stefan
Rodney,

here is my 2 cents:

First of all, get rid of the cold plugs. .12 engines need hotter plugs, MC59 or MC8 work great ---> BIG Difference

Second, if you suspect an airleak, why don't you just take the engine in question apart and seal it (I use air seal, but silicone works fine)

Judging by the symptoms you are describing (leaning out after a few) I'd say that your engines are generally to rich on top and too lean on the bottom.

Try to richen the bottom end up 1/2 turn and then lean top end out until the sucker runs right.

Also, have you checked you tank and your fuel lines for being air tight?

Are you coming to Fernando's in two weeks?
TAW is offline   Reply With Quote
Old 08-11-2003, 06:48 PM   #9
Tech Elite
 
Corse-R's Avatar
 
Join Date: Aug 2001
Location: Madrid (Spain)
Posts: 2,121
Default

Quote:
Originally posted by rodneybarrett
2) Mugen MT12

Plug - typically cold - 5 or 7
Fuel 30% Maxy
head clearance .3 mm


This engine works well except goes lean about 2 minutes into a run. So lean that it almost flames out coming out of a corner. I believe it is an air leak somewhere but not sure how to diagnose it.
Ok. Regarding Sirio. Change the carb and put definitely a Novarossi carb on this engine. Sirio Plastic/Metal carbs are JUNK (no matter what kind of improvements are made on those damn carbs, still leak). Sent many, many many many mails to Sirio stating this. And the problem in the carbs is heat cycle related, metal expands and stretches the plastic, then metal when cool, shrinks, but plastic is stretched and don't shrinks.

Sirio is a very good engine and extremely reliable, ever you change the carb for a Nova/RB/Novamega one.

Regarding MT12.

First: With a 30% Nitro stick with a Novarossi 6 or 7, is what this engine needs. But your main problem comes with the lack of enough combustion chamber, you need to raise at least 0.2mm adding two 0.1mm (cooper) shims to the combustion chamber.

Make this change and you will see how the engine performs much better without overheating. Is very possible that you overheated the P/S and then this is shot. But worth a try to add 0.2mm to the combustion chamber and see the improvements.
__________________
Cheers,
Corse-R
---
[quote=MugenDrew;2684554]BATTERIES are for FLASH LIGHTS, gasoline is for cleanin parts, alcohol is for me to drink and well NITRO...everybody know thats for racing.[/quote] :D:D:D
Corse-R is offline   Reply With Quote
Old 08-11-2003, 08:44 PM   #10
Tech Elite
 
vones's Avatar
 
Join Date: Mar 2003
Posts: 2,022
Trader Rating: 1 (100%+)
Default

Since we are on the subject of engines...can any tell me if the Rody Roem RB .12 conrod and piston is the same with the Novarossi S5...cos mine got busted last weekend and I culdn't get an replacement on time for a big race nxt week....
vones is offline   Reply With Quote
Old 08-11-2003, 09:31 PM   #11
Tech Fanatic
 
Join Date: Aug 2001
Location: Nashville, TN
Posts: 852
Trader Rating: 49 (100%+)
Default

Corse-R.

That's what I was afraid of on the sirio. Maybe I just didn't want to concede so quickly. Why would sirio make a running change to the carb (eliminated the middle needle) if they weren't having problems with them. But try to convince Trinity of that. It isn't going to happen. I might try one more time.


On the MT12:

I believe that the piston/sleeve is ok. I have taken the P/S out and the piston still sticks about 1mm or more before the top the of the sleeve.

I will try adding another .1mm shim to see if that helps. adding the first .1mm shim actually help control the temp some.


Stefan:

I am going try and come down but right now it is still up in the air.
BTW, I do have a Mugen now.
rodneybarrett is offline   Reply With Quote
Old 08-12-2003, 03:41 AM   #12
Tech Elite
 
Corse-R's Avatar
 
Join Date: Aug 2001
Location: Madrid (Spain)
Posts: 2,121
Default

Quote:
Originally posted by rodneybarrett
Corse-R.

That's what I was afraid of on the sirio. Maybe I just didn't want to concede so quickly. Why would sirio make a running change to the carb (eliminated the middle needle) if they weren't having problems with them. But try to convince Trinity of that. It isn't going to happen. I might try one more time.


On the MT12:

I believe that the piston/sleeve is ok. I have taken the P/S out and the piston still sticks about 1mm or more before the top the of the sleeve.

I will try adding another .1mm shim to see if that helps. adding the first .1mm shim actually help control the temp some.
Deal directly with the manufacturers, send it a mail and explain all this. In all case try to involve them on you carb issue. But I tell you. A Sirio with the Nova carb is like the day and the night, you will not wrong with it.

Put directly a pair of 0.1mm additional shims, is what you need. With 0.3mm you had a chamber for 16 - 20% Nitro %. You need two more for the 30%.
__________________
Cheers,
Corse-R
---
[quote=MugenDrew;2684554]BATTERIES are for FLASH LIGHTS, gasoline is for cleanin parts, alcohol is for me to drink and well NITRO...everybody know thats for racing.[/quote] :D:D:D
Corse-R is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Motor Rebuilders/Tuners hrnts69 Electric On-Road 4 12-24-2007 09:21 AM
Engine tuners in US? loopedout Onroad Nitro Engine Zone 37 04-11-2007 01:40 PM
Will there be motor tuners at Birds? Ginsu Electric On-Road 4 11-17-2005 06:50 AM
.21 engine tuners click, dublin Nitro On-Road 4 12-10-2003 04:46 PM
Serious gas engine question. pro engine tuners look here Ron Nitro On-Road 28 11-13-2001 04:27 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 06:20 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net