Head Temp?

[IBinSaneDiego]

OK, I broke in a new motor, had it running good today, was tuning it and watching my temp, and was not exceeding 240. Measured at the top, with a Atomik temp guage. And after tuning, and a run in the dirt, I was running back in the parking lot, running track length spurts... and constantly montoring the temp.... and the connecting rod broke? Ya think maybe I should be measuring the case below the cooling head? I' running a Mach 427.
There was always a good trail of smoke when excelerating.

Also, is there a problem with running back to back tanks of fuel.

 

[jon2]

Wait a minute, Isn't the second engine that broke on you? same engine as well?

 

[IBinSaneDiego]

this was built with all new parts except crankshft. 2nd... let's see... I've stopped counting how many engines I've gone thru. I suppose If I blow two more, I'll sell everthing.

 

[Plaidfish]

Dude you have to be doing something wrong...this is just nuts.....do you have a local shop that can help you?
are you getting any smoke all the way up to top RPMs?
How long are you pinging WOT spurts?
and is it blowing while it's revving or on take offs?
are you mounting the engine?
can you spin your clutchbell freely?

 

[olds97_lss]

Your supposed to measure down inside the head by the glowplug. The hottest point is supposed to be towards the side where the exhaust port comes out. At least according to what I've read...

What are the temps outside? What fuel brand/nitro %/oil % are you running?

 

[IBinSaneDiego]

This last time it blew while in a wide circle about 1/2 throttle.
I also had new clutch, bearings spun freely.

How long are you pinging WOT spurts?

A few 5 sec runs, and then 2 sec spurts followed by lower rpm and checking the temp after what would seem a hard run. Temp never exceeded 257, at which time I ran it very easy to cool down.

What are the temps outside? What fuel brand/nitro %/oil % are you running?

Temp... about 65 mostly cloudy.
Fuel? Odonnel 20%

With a larger cooling head than the previous LST motor head, wouldn't it keep the top portion of the motor cooler than the bottom half? Possibly making it harder to read the top of the glow plug temp? becase of the height?

I was very careful in breaking it in, taking it easy, running about 4 tanks before making tuning changes.... and not on the same day.

I have another motor ready to go for tomorrow? I think I'll go by the lowr half reading, and run it extremely rich... forget about speed.

 

[olds97_lss]

Well... running too rich on a new engine can snap a con-rod by hydro-locking it. Getting too high RPM's (no load on engine) can snap a con-rod.

I had a friend blow 2 OS 21 RG's in a row with less than a half gallon through either. He was on the same gallon of fuel by the time he got to his third engine... He ended up going with a different engine totally though the last time.

From what we can figure, he was running too rich too long. He didn't lean it out enough soon enough and it over-stressed the internals.

 

[nitromad]

I use an onboard micro digital temp gauge. I've always been told to measure the temp on the fin below where the cooling head starts, about level with the glowplug. Did you mean you measure the temp at the top of the cooling head? if thats what you meant remember you're measuring engine temperature, not cooling head temperature. At an engine temp of 230 deg, i can comfortably touch the cooling head with my bare hand for 1-3 seconds. I can't imagine how hot your engine is internally if the top of your cooling head is at 250 degrees. But I'm not sure if thats what you meant in your original post. Anyway follow these guys' advice. They know a lot and will help you out.

 

[IBinSaneDiego]

Well I broke in a new motor today. Monitoring the temp from the head to the
area near the exhaust port. Idled thru 2 tanks, letting it cool down completely before the next tank. Then ran another 4-5 tanks (letting it cool down each time). Constantly monitoring temps... seems to be working just fine. Took it really easy with very short burst, then idled thru the turns.

Maybe it was running 2-3 tanks yesterday without stopping even though the temps were ok? After taking it apart, I guess the heat caused the ring in the bottom of the connecting rod to come out, causing the bottom of the connecting rod to break around the part connected to the crankshaft.

 

[olds97_lss]

Thats what happened to the to OS engines I was referring to up above. The end of the rod just snapped off.

What engine did you end up going with this time?

 

[aj200415]

Ok, my freind has a t-maxx and we race every weekend at a track, and he got a new head for it. It is huge compared to the stock one! Well, I'm the pit man, and i take the temps. I take the temp by setting the temp meter on top of the head as close as i can to the plug and reading it. Since it has a new head, should i be doing anything different when i read the temp?

 

[IBinSaneDiego]

Thats what happened to the to OS engines I was referring to up above. The end of the rod just snapped off.

What engine did you end up going with this time?

In the last paragrah of my last msg... regarding the rod and crankshaft. The rod cracked half way up the bottom ring connecting it to the crankshaft. I keep buying rebuild parts for the same motor since I have all the other pieces for it.

 

[olds97_lss]

Maybe it's time to try a new brand... sell the parts on ebay and forget about it.

How long do you drive around to totally kill a reciever pack by the time you get there?!?!?