EME35 vs DA35

[tbrum]

If I were to get a DA, I would just order it through Jeff at Thunderbolt.

But I bought my DA35 as a combo pack with my 83" EF MXS. At the time, EF was the only place that had them in stock!! Even DA was out. They said they'd have more in 6 weeks, LOL

[Buck Tracker]

Rodger that guys thanks! Kinda what I was thinking, either Jeff or GH

[lorne@pro-rc.ca]

Hey Trev, just curious to what your timing is. These little engines seem to come at 34 deg. I like to go to 26 to 28 if using a tune pipe. I have seen a few great engines (DA MVVS) develop conrod bearing noises on tune pipes especially. I like to retard my timing so the engine does not ignite on the up-stroke.
What is your opinion on this?

[Banshee]

Hey Trev, just curious to what your timing is. These little engines seem to come at 34 deg. I like to go to 26 to 28 if using a tune pipe. I have seen a few great engines (DA MVVS) develop conrod bearing noises on tune pipes especially. I like to retard my timing so the engine does not ignite on the up-stroke.
What is your opinion on this?

You have my interest now. Why would tune pipes cause Conrod bearing concerns? Does the heat or scavenging associated with tuned pipes cause concern.

[Machzx]

The theory is right the pipes would introduce the fuel charge sooner
That's why rotary valve engines or case reeds are better as they control the incoming charge better
Hmmmm
Never thought of that

[-Snuts-]

Hey Trev, just curious to what your timing is. These little engines seem to come at 34 deg. I like to go to 26 to 28 if using a tune pipe. I have seen a few great engines (DA MVVS) develop conrod bearing noises on tune pipes especially. I like to retard my timing so the engine does not ignite on the up-stroke.
What is your opinion on this?

You have my interest now. Why would tune pipes cause Conrod bearing concerns? Does the heat or scavenging associated with tuned pipes cause concern.

The theory is right the pipes would introduce the fuel charge sooner
That's why rotary valve engines or case reeds are better as they control the incoming charge better
Hmmmm
Never thought of that

I too am watching for the reply, and actions taken. Of most interest, why retard 6-8*?
-Snuts-

[Machzx]

Ok hang on if pipes pull charge in earlier it won't change cuz the fuel is always there when piston comes up
Plug fires it at same time either way

[lorne@pro-rc.ca]

I know mvvs ignitions have 2 settings on the ignition. The setting for pipes retards the ignition 2 or 3 degree. The theory is Pre-detonation is harder on the con-rod bearings.
I believe some of the problems with the first eme engines and conrod bearings was caused by the timing set to more than 40 deg advance on early engines.
Jeame from eme said he never changed the bearings in the eme 120 since first production. If the timing was wrong on these they kicked like a mule when starting so most got the timing changed. Only ever had bearing problems in one eme 120 that I know of but had a handful of eme 60. Some of these still had the timing set to 40 deg.
I could be totally wrong about this but it is just my observations.

[tbrum]

Ya Lorne. I haven't touched the timing on this and it is set at 28deg. Same with my GP engines on tuned pipes.. 28deg.

But any of the ZDZ's I have seen run at stock 28deg on tuned pipes with knock and ping (predetonation) and I have always had to tweak the timing back to 24deg... smoother, no predetonation and no loss in power.

Perhaps even though I can't hear any predetonation on the EME35, perhaps there is and it's hammering the bearing.

Thanks

[Buck Tracker]

See Trevor using pipes can wreck your motor! LOL hehe