Sts D30m

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Defiantspaz

Defiantspaz

Active Member
Messages
105
I bought an RB modded STS D30M from STSMicroengines.com this spring. The heat cycle breakin was going great until the backplate came loose during the bliping part of the break in, some blue loctite and all was well again.

I was having some serious issues with the needles of the STS carb moving and leaning out the tune. The needle issue was so bad that it made a full 2 gallon break in almost impossible. I tried green slime, teflon tape and even teflon paste to try and hold the needles from moving but nothing worked. I bullied the STS through the first gallon and a half but constantly have to mess with the needles started to get really boring.

I had a spare HPI K4.6HO from my Hellfire and decided to swap the 9mm STS's carb for the 9mm HPI carb. WOW, problem solved. I have now finished the break in and the engine is just insane. Before the carb switch the tune would be good for a few minutes and during that time the engine was extremely powerfull. Then it would just start to run silly hot because the needles would move. With the HPI carb the tune stays constant.

I have a 3 speed transmission and I am running 15/47 gearing and with the RB STS the truck pulls the front wheels at will. My local track has short straights so alot of top end gearing isn't needed, as it is now I don't top out with this gearing. I am considering moving to a 16/47 so i can keep the wheels on the ground easier. The look on peoples faces when I pull a wheely for the entire front straight is priceless.

I haven't noticed any sacrifice in power from the switch in carbs. When the STS was in tune the performance was the same as with the HPI carb. If anyone of you guys are having a similiar issue with moving STS needles try out either an Axial 9mm or HPI K4.6HO 9mm carb, you won't be disapointed.

Picture012.jpg


When my Savage had the K4.6 powering it with the same exact setup it needed help to pull the front wheels because of how low it is. The difference in power is unbelievable.
 
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Hey DS. Your back!!! How it going. That great info you just posted, and thanks for doing so. STS RB DM30...... ITs good to be king!... Isn't it DS?....lol. If I just didn't get a n OS 30 vg, I'd be too jelious to speak. Nice choice in the super mill class, bro. And before we even get started on the subject, I already know your DM 30 will spank the OS 30, without question. Its good to hear form ya again, my friend.
 
ive been looking into getting a sts D30M but i didnt know how thay preform and what the difference between the sts D30M engine and the sts D30M modded engine
 
benny said:
ive been looking into getting a sts D30M but i didnt know how thay preform and what the difference between the sts D30M engine and the sts D30M modded engine
Click to expand...
The RB Modded version is a Rick Brake touched version. It recieves additional porting and polishing with bearring upgrades, ect. If you got the budget, you won't be disappointed. At least in the proformance end of it. From what DS is saying here is all about some quality issues he's having with the DM 30's carb.
 
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Thanks Doob, it's good to be back again. The 30 VG is a great all around mill, I wouldn't be jealous.

The main issue is that STS uses a poorly sized needle o-ring and it doesn't make enough friction inside the carb to hold the needles still. Combine this with a super course needle thread and it doesn't take long for the engine to lean out.

I am going to take some vids of the truck with the HPI carb installed so you guys can see how well it works.
 
Sounds great, DS. I'll Be a watch'in!!... I haven't started the brake in yet on the OS. You got any reccommendations on my approach Now that your rep level IMO?
 
The OS 30VG has a funny piston sleave combo, not ABC. I would still do a heat cycle breakin. What I did with my STS,

6 cycles to 200 deg F in less than 2 minutes:
Get a heat gun, a hair dryer sucks, and heat the head to get the glow plug area to 100 deg F with the piston at BDC then start the mill and let it idle. Use the heat gun to raise the temp on the head to 200 deg F at the glow plug and then shut down the mill, try to do each cycle to 200 deg F in under 2 minutes. Put the piston at BDC and let the mill cool to ambient temp before starting another cycle.

6 cycles to 200 deg F in 3 minutes:
Same as above but try to take a while longer to reach the 200 deg F mark.

After the 12 cycles then I went to the now debated blipping part of the break in. First off when you blip the throttle you are just cracking it not going WOT. I think when people think of blipping they automatically think they need to floor the trigger and then let off. This is not the case. I would just get the truck to move forward using no more that 1/4 throttle and then let off. I continued to do this in half tank intervals returning the piston to BDC and letting the mill cool to ambient after each half tank, I suggest the last half of the tank so you can control the temps better just don't let the mill run out of fuel. I continued this blipping for 10 half tank fulls.

Next I went to half throttle bursts of 2 seconds. I would ramp the truck up to speed in 2 seconds reaching half throttle at the end of the run. stop the truck and repeat. Do not let the mill get above 210 deg F, if it does richen it up and continue. I did this for 8 tank fulls.

I then moved on to 3/4 throttle bursts of 3 seconds. Same as above just takes more time and you use more throttle. Do not let the mill get above 220 deg F, if it does richen it up and continue. I did this for 8 tank fulls.

Time for some fun now! FULL THROTTLE bursts of 4 seconds. Do not let the mill get above 230 deg F, if it does richen it up and continue. I did this for 8 tank fulls.

Basically you want to expose the mill to varying levels of RPM, heat and load. As it starts to loosen up you will need to keep your self under control. Don't jump the gun and start reving it out until you finish the entire break in.

After all of the above was done I tuned the mill to hit 250 deg and drove the truck on pavement anyway I wanted. I would do full throttle runs, quick accellerations and wheelies if the tune would allow. Just remember to keep the mill fat and happy.

After 2 gallons were run through my RB STS I then tuned it for max power. This break in is what I have done for all of my mills and it make the mill very responsive and powerfull. It take a long time but it is well worth it. My Savage X F4.1 would stay with my friends idle broken it K4.6 SS.

Just remember that the time spent now means the better the mill will perform and the longer it will make you smile.
 
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I thank you very much, DS. The forum should do the same, IMO. This information was very generous on your part. I certainly apprecieate it, my friend.
 
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Sts .30

Bought one need some advice. Which glow plug do most of you guys use with this engine, and I want to try a new clutch or should I just stick with the 3 shoe.
 
I am running the HPI aluminium clutch shoes with the gold springs, here comes the HEAT.

I have a modded STS D30M and Rick recomended the McCoy MC-59 glow plug.
 
Yes I did. I also used 30% nitro because you can run a richer better lubricating fuel setting and still get the engine to idle.
 
Well I am not so lucky, I preffer 30% fuels. 30% seems to be more forgiving during breakin tuning than the lower %'s are.

If I could get Odonnell or Byron's I would run either of them. I personally run Trinity monster power race blend and love it. I have been told by many people, professional modders and novice racers alike, that the Trinity fuel is only good for cleaning air filters BUT I have never had an issue running it.

The track near my house has race league that I just can't get enough time off of work to attend all the time. When I do show up most people there run Bluethunder or Traxxas Top Fuel, funny these are the same people who say the Trinity is crap :dunno:

What ever fuel you are most comfortable tuning with should be the one you chose.
 
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