missfires and E85 = bad news
#1
missfires and E85 = bad news
I guess I am the only one having major issues with E85. I have toasted two engines now from having missfires on E85. I first bent a stock evo 8 rod. I then built a eagle rod engine for car that suffered the same fate. Neither engine has any sign of detonation. very conservative tunes with EGT not exceeding 750. A/F in the low to mid 11s.
My take on what is happening. If you have a misfire with e85 the exhaust stroke will be pushing an ignitable mixture. at TDC on exhaust stroke there is that darn wasted spark. This ignites the mixture. Since ethanol burns slow and long the burning mixture continues till the new A/F charge enters. The piston traveling up the bore toward firing stroke is met with already expanding fire. With the crank pushing rod up and fire pushing piston down and the rod being at an unfavorable position you have the perfect senario to bend a rod.
I have very quiet exhaust on car and very perceptive tuning ears. So I caught both engines before a rod was thrown out side of block. I believe others who have blown motors on E85 may be having misfires as well. But just arent aware of this prignition condition that results. No rod is sacred. Rods arent designed to be strong in the position that causes this bending force.
I am bailing on the E85 dream for now. I am building a new block for car and I am going to return to 93/alky injection. I found an unbelievable alky injection pump. Will make a new thread on that.
My take on what is happening. If you have a misfire with e85 the exhaust stroke will be pushing an ignitable mixture. at TDC on exhaust stroke there is that darn wasted spark. This ignites the mixture. Since ethanol burns slow and long the burning mixture continues till the new A/F charge enters. The piston traveling up the bore toward firing stroke is met with already expanding fire. With the crank pushing rod up and fire pushing piston down and the rod being at an unfavorable position you have the perfect senario to bend a rod.
I have very quiet exhaust on car and very perceptive tuning ears. So I caught both engines before a rod was thrown out side of block. I believe others who have blown motors on E85 may be having misfires as well. But just arent aware of this prignition condition that results. No rod is sacred. Rods arent designed to be strong in the position that causes this bending force.
I am bailing on the E85 dream for now. I am building a new block for car and I am going to return to 93/alky injection. I found an unbelievable alky injection pump. Will make a new thread on that.
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I think I am getting misfires at idle, or it could just be due to my afr's bouncing with my FIC 1450's.
-Will
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E85 won't knock, you'll just push parts. If the headgasket is strong enough (as it is on evo's) you'll start to push rods. I pushed a car wayyyy past MBT but luckily it was a 1g DSM (stock motor) so the stock headbolts lifted and it started pissing coolant.
OP, whats your timing curve look at and at what boost/power level?
Again, I'll reiterate. May as well ground the knock sensor on E85, it doesn't work in my experience. The reason why is the car actually won't detonate before MBT like pump gas or most race gases. So you push it past MBT, start doing too much negative work, bam something wants out.
OP, whats your timing curve look at and at what boost/power level?
Again, I'll reiterate. May as well ground the knock sensor on E85, it doesn't work in my experience. The reason why is the car actually won't detonate before MBT like pump gas or most race gases. So you push it past MBT, start doing too much negative work, bam something wants out.
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You are running E85 a bit rich, it will misfire from that.
I've been running E85 for two years straight in my personal Evo 8, stock motor, no issues, over 20,000 miles on straight E85, 365 days a year. 412 whp / 400 wtq on our Mustang dyno.
I've tuned over 40 Evos so far on E85 with no engine issues from E85. A handful of them are driven on circuits as well, which is bloody hell on the car..
I'm not an engine builder but those photos almost look like the motor could have been running past MBT. What kind of timing where you running?
- bryan
I've been running E85 for two years straight in my personal Evo 8, stock motor, no issues, over 20,000 miles on straight E85, 365 days a year. 412 whp / 400 wtq on our Mustang dyno.
I've tuned over 40 Evos so far on E85 with no engine issues from E85. A handful of them are driven on circuits as well, which is bloody hell on the car..
I'm not an engine builder but those photos almost look like the motor could have been running past MBT. What kind of timing where you running?
- bryan