liamb2387 Posted June 1, 2014 Share Posted June 1, 2014 So today was meant to be the first proper out with the car with me and my brother in law. Buying the car was a joint venture. He's yet to see it. Got it all packed up in the car with every thing i might need only to get there and find the the glow plug has blown (no spares yet) Took it out yesterday for a test run and tuned it the best I could. Although iv learnt loads in the last couple of weeks, I'm still very much a beginner. At one point there was steam coming from the engine. Is this me tuning it badly that's caused it to blow? How can I prevent it happening so quickly again? To be fair, its a second hand car. The glow plug could of been an old one. Wish model shops near me were open on a Sunday!! Sent from my Nexus 5 using Tapatalk Quote Link to comment Share on other sites More sharing options...
jizwizard Posted June 1, 2014 Share Posted June 1, 2014 running too hot and lean mate richen it up Quote Link to comment Share on other sites More sharing options...
liamb2387 Posted June 1, 2014 Author Share Posted June 1, 2014 Still trying to get the right balance. So the HSN was to lean? And if I make it richer that should make the engine cooler? Sent from my Nexus 5 using Tapatalk Quote Link to comment Share on other sites More sharing options...
Huktonfonics Posted June 1, 2014 Share Posted June 1, 2014 (edited) Was the car brand new ? Or pre-owned ? If its new keep it rich and follow the break in procedure. Glow plugs blow during break in or for any other number of reasons. But yes, if you richen it up it will cool it down. Where was the smoke coming from ? If it was coming from around the engine block it could be oil or spilled fuel burning off. If it was comming from inside the engine, for sure, richen it up. If anything check the manufacturer website for factory needle settings and start over. Edited June 1, 2014 by Huktonfonics Quote Link to comment Share on other sites More sharing options...
behappy2755 Posted June 1, 2014 Share Posted June 1, 2014 Just to make sure you tuned it right- 1. HSN, tune it so you get good speed on straights, but make sure there is still a little bit of smoke coming out. As you drive more and more, you will feel if it is too rich or too lean. (If your GP keeps blowing this means it might be too lean, check for a nice trail of smoke.) 2. LSN, there are three tests for this: the pinch test (almost useless), the stand/go test, and the accel test. To do the stand/go test warm your car up and let it idle for 30 seconds, then pull on your trigger- if the engine quits by revving up, it is too lean. On the other hand, if it quits by bogging, it is too rich. The accel test is an extra bit to the stand/go test, so after you get the engine to take off ok, do it again, and look at the accel. If it is slow, it is slightly too rich, if it starts to cut out, it is too lean. 3 idle, re-tune this every once in a while, keep in mind your throttle trim. Quote Link to comment Share on other sites More sharing options...
liamb2387 Posted June 2, 2014 Author Share Posted June 2, 2014 Cheers for the in depth answers. I'm going to try this out today. After I get some new plugs. The reason I didn't realise I was running too lean is because I still had a trail of smoke, but I think thats down to the fuel I'm using (optifuel 20%) I was slightly unsure how to check the lsn, but iv got something to go with now with behappys post. Let's hope I don't blow the new plugs. Also, the cars a 2nd hand one Sent from my Nexus 5 using Tapatalk Quote Link to comment Share on other sites More sharing options...
liamb2387 Posted June 2, 2014 Author Share Posted June 2, 2014 Since getting the new glow plugs, iv been trying to start the engine. Been messing about with it for about 3 hours. Every time I manage to start the car it flies off with out me pulling the trigger. If I brake, the engine stalls immediately. If I adjust the throttle trim to close it a bit, it won't start at all. I'm running out of patients. I gone back to factory settings. The new glow plugs are the only ones the shop had in stock, quikfire warms Sent from my Nexus 5 using Tapatalk Quote Link to comment Share on other sites More sharing options...
Anthoop Posted June 2, 2014 Share Posted June 2, 2014 Yes. As you have found some fuels can be smokey and the engine can be too lean....and also some fuels can give off little/no smoke but still be on the rich side. Try to listen to the sound of the engine (albeit hard if you do not know what you are listening for). Whilst it obviously makes sense to only turn the needle (say HSN) a small amount at a time to fine tune it, it can also be beneficial to make larger turns to distinguish the sound of lean/rich and to build a knowledge of where the point of correct will be. So if we start the engine (with rich settings) and get it warmed up for a minute or two then do one full throttle/high rpm run we know it is rich, then lean the HSN 1/4 of a turn and another flat out run...Repeat the process until you have gone too far and each time listen to the different sound. (Notes- Of course do not persist with full throttle if the engine is struggling, no need to do runs a mile long, you may need to be gentle opening the throttle to get to high rpm if LSN is very rich). Now you should know both what lean/rich can sound like and know that the correct mixture will be within X turns of the needle. Always warm the engine before trying to tune, keep an eye on the fuel level, always richen up a bit from the optimum performance. In response to your above post (that came whilst typing)- If the plug is not correct then you will struggle. The idle screw should always control the minimum idle speed so when applying brakes the throttle should not close to a point of stalling the engine. If the LSN is lean then the engine will rev high. Set everything rich with a throttle gap of 1mm. Start-warm-set HSN first and then LSN....when adjusting LSN you may have to adjust the idle speed. Stick with it...it should all come together in the end. 1 Quote Link to comment Share on other sites More sharing options...
behappy2755 Posted June 2, 2014 Share Posted June 2, 2014 Idle adjustment includes the throttle trim and idle screw mainly, but can the LSN can also play a big role. To solve your idle problem- 1. Remove the air filter, so you can see the idle gap 2. Tune your throttle servo using your transmitter, just make sure that the idle gap is the smallest it goes (you dont want it to get smaller when you apply the brakes! 3. Assuming that your other needles are tuned correctly, adjust the idle screw so that the engine runs ok at idle. (Make sure you put your AF back on at this point!!) 4. Re adjust the throttle trim so that it it is in the middle, and doesn't change the idle gap. Quote Link to comment Share on other sites More sharing options...
liamb2387 Posted June 2, 2014 Author Share Posted June 2, 2014 But why would all this suddenly need adjusting when all iv done is change glow plugs? Sent from my Nexus 5 using TapatalkSo annoyed today. Felt like giving it up already Sent from my Nexus 5 using Tapatalk Quote Link to comment Share on other sites More sharing options...
behappy2755 Posted June 2, 2014 Share Posted June 2, 2014 The GP's might have different burning temps. Quote Link to comment Share on other sites More sharing options...
liamb2387 Posted June 2, 2014 Author Share Posted June 2, 2014 And could that throw out the settings? Sent from my Nexus 5 using Tapatalk Quote Link to comment Share on other sites More sharing options...
Nitroholic Posted June 2, 2014 Share Posted June 2, 2014 The heat range of a plug is VERY important. In simple terms, they control the ignition timing. Your engine is basically a 2 stroke layout, so the port timing is fixed. The inlet/exhaust always open at the same point on the stroke of the piston or rotation of the crank. What the plug varies is how quickly the mixture gets ignited. A hotter plug will ignite the mix sooner than a cooler one. If the coil in the glowplug is too hot, you can get pre-ignition, where the mix is burning before the piston gets past top dead centre. Bad news. Too cool, and the piston is past TDC and you lose power. Your fuel mixture will also affect how well the mixture burns....so if you are way too rich, a hot plug may get it started....but once things get up to temperature...it will not be happy. Using hte correct grade plug for your engine is actually a very important thing. A lot of people opt for a 'middle of the road' plug, which will give reasonable performance in most conditions... but racers will take a range of plugs and vary it for optimal performance. Now...as far as setup goes.... I always start with the idle gap. Set to 1mm, and adjust the linkage so it has a bit of slack at fully closed and no trim on the transmitter. The stop screw should ensure it does not close when you brake. No point in going further without that correct. Next thing...I can't see if you mentioned the car you have...but that is important. Mainly so we know what engine you are running. Big block and small block engines run best with different plugs and fuel. If you have LSN and HSN at factory settings, you should have a stable idle....if all is well. Otherwise you potentially have an air leak somewhere. The factory setting for hSN is very rich....so once you have a stable idle...you would then look to tune that to the best setting. Listen to the motor ( it should never sound 'frantic' or sound stuttery on the over-run ) . Then you can tweak the LSN if it needs it. The idle may creep up as you lean off the HSN, or you may have poor pickup. Keep the adjustments small and run between changes long enough to clean through any surplus fuel. Very important if you are leaning off an engine.... you don;t want to find out that it was only running rich due to a build up fuel in the crankcases.... 1 Quote Link to comment Share on other sites More sharing options...
liamb2387 Posted June 2, 2014 Author Share Posted June 2, 2014 Hold on. The glow plug that was recommended by the rc shop says suitable for 18 to 21 engines. Mines a 28!! Could that be my problem? Sent from my Nexus 5 using Tapatalk Quote Link to comment Share on other sites More sharing options...
gavin28 Posted June 2, 2014 Share Posted June 2, 2014 depends, what plug is it and what engine? Quote Link to comment Share on other sites More sharing options...
liamb2387 Posted June 3, 2014 Author Share Posted June 3, 2014 Qwikfire warms are the plugs. Engine is macstar28 Sent from my Nexus 5 using Tapatalk Quote Link to comment Share on other sites More sharing options...
liamb2387 Posted June 3, 2014 Author Share Posted June 3, 2014 Another forum member, mickturnip has kindly offered to help and have a go at fixing it himself so hopefully that will do the trick. Sent from my Nexus 5 using Tapatalk Quote Link to comment Share on other sites More sharing options...
Anthoop Posted June 3, 2014 Share Posted June 3, 2014 How glow plugs are labelled can be misleading at times and I have not used the QuikFire plugs but as the one you have seems to be the hottest (?) then that is not going to help at all. Ideally you want a colder plug of standard length for the MacStar .28....the manual recommends RB 6 and McCoy MC-9...I have used McCoy in the .28 and yes it will work fine if you can get them easily. There are a load of other plugs that will be fine that I have used...NovaRossi C6S...OS 8 + (note this is a short plug but will work fine and is common)...Fireball Super Cool (this is the cheapest of any of the plugs mentioned and available here- http://www.racing-cars.com/pp/Product_Category/Nitro/U2848.html ) Mick should get you up and running in no time. Quote Link to comment Share on other sites More sharing options...
liamb2387 Posted June 4, 2014 Author Share Posted June 4, 2014 Yeah, Mick was really helpful. But!! Looks like the engine is wrecked! No wonder iv been struggling. Sent from my Nexus 5 using Tapatalk Quote Link to comment Share on other sites More sharing options...
Anthoop Posted June 4, 2014 Share Posted June 4, 2014 Bah...time for another engine then. Quote Link to comment Share on other sites More sharing options...
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