Anyone Seen #6-8 Cyl issues on E85?

[DougS550]

I was just wondering. I see a few people who have cratered their #6 or 8 cylinders on their boosted cars. Is this mostly happening on boosted pump 93 cars or is it happening on E85 boosted cars also.
Taking out self induced issues such as improper tune, over heating, excessive boost, knock/tempuature etc.
Thanks

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[ice445]

I doubt it, the safety margin for knock with e85 is insane. Although if you don't test your fuel it's possible to run too aggressive of a tune still.

 

[DougS550]

I doubt it, the safety margin for knock with e85 is insane. Although if you don't test your fuel it's possible to run too aggressive of a tune still.

When I switch later spring, I will put an inline E fuel sensor in so all I have to do is check my phone. So i guess besides replacing spark plugs and periodic checks/maintenance, due to the ethanol, I guess I can live with that. Thanks

 

[illtal]

When I switch later spring, I will put an inline E fuel sensor in so all I have to do is check my phone. So i guess besides replacing spark plugs and periodic checks/maintenance, due to the ethanol, I guess I can live with that. Thanks

The rear cylinders run hotter than others due to them getting less airflow and the fact that the water cools from front to rear. it's just how the design is done. the water from the front is sent to the rear of the head then it comes back to the front. So the rear cylinders are not only get the hottest exhaust water they get the hottest intake valve 'cooling' water as well.

The tune needs to be dialed in then backed off if 93 is going to be used.

 

[HKusp]

@CoryS and I have both had issues with #6 ring land. Mine was on a very hot day, 93 octane tune that was pretty aggressive, and multiple back to back pulls. CoryS broke one on 93 and one on E85 if I recall correctly. Hopefully he'll chime in and set the record straight.

 

[illtal]

AED did a video on this (I posted it somewhere), those cylinder head mods do nothing because there is no fresh water coming into the head with these "cooling mods. They can't do anything but store a portion of hot coolant in it because the heads have the same pressure on both sides.

 

[NGOT8R]

I have the MMR Head Cooling Mod on my car. I installed it while I had the tranny out, otherwise, it would have been impossible to do (properly) with the tranny in.

This may sound silly, but can anyone think of the best way to test the temperatures of cylinders 7 & 8 with a heat gun? If the testing is not too difficult to perform and can be done with a temperature gun, I’d be willing to give it a try on my car pand report back here with results with the results.

 

[illtal]

I have the MMR Head Cooling Mod on my car. I installed it while I had the tranny out, otherwise, it would have been impossible to do (properly) with the tranny in.

This may sound silly, but can anyone think of the best way to test the temperatures of cylinders 7 & 8 with a heat gun? If the testing is not too difficult to perform and can be done with a temperature gun, I’d be willing to give it a try on my car pand report back here with results with the results.

do you have an infrared heat gun? if so you can point it at the head directly between the Exhaust Valve but that proximity to the headers may give false readings. I have one but I only used it for my motorcycle race tires.

You would ideally need the exposed area on the head, above the manifolds. that way you can check them all in the same spot

 

[illtal]

here's the video

 

[NGOT8R]

do you have an infrared heat gun? if so you can point it at the head directly between the Exhaust Valve but that proximity to the headers may give false readings. I have one but I only used it for my motorcycle race tires.

You would ideally need the exposed area on the head, above the manifolds. that way you can check them all in the same spot

I do have an infrared temperature gun. Can you take a pic of your engine and add arrows pointing to the areas that you would like to see readings taken from?

 

[illtal]

I do have an infrared temperature gun. Can you take a pic of your engine and add arrows pointing to the areas that you would like to see readings taken from?

My car is without engine as of now: Let me see what I can get together

 

[ORRadtech]

I don't know how it would correlate to head temps, but if you measured the headers as close to the head at each cylinder as possible wouldn't that give an indication if one is running significantly hotter than the others?

 

[illtal]

My car is without engine as of now: Let me see what I can get together

I don't know how it would correlate to head temps, but if you measured the headers as close to the head at each cylinder as possible wouldn't that give an indication if one is running significantly hotter than the others?

What you're doing is measuring EGT at that moment not the actual temp around the head.
EGT should be significantly hotter than the actual Head temps. I actually do not know what the correlation would be. Would a Hotter cly lead to a higher EGT or lower EGT. One would think more compression would cause a higher EGT but that's not true. It's actually a lower EGT.

In this case we probably should just do that because it would be nearly impossible to do anything else in the engine bay. I just realized looking at some photos it would be nearly impossible to get the actual head temps above the manifold/header area.

It would be better if we had a Infrared Camera and could see the difference in temps.

 

[NGOT8R]

Okay guys, I put my car on the lift, so that I could gain access to all exhaust ports and shoot the infrared beam at them for temperature readings.

I also took readings from the front of the left and right cylinder heads and the MMR Head Cooling Mod standoffs that are pressed into the engine. See diagrams, photos and test results below.

Front of driver’s side head (area directly below #5 cyl.) = 113.5

Driver’s side MMR Head Cooling Mod standoff = 119.1

Front of pass. side head (area directly below #1 cyl.) = 135.8

Pass. side MMR Head Cooling Mod standoff = 177.6

Exhaust port flange area

#5 Cyl. = 231.2
#6 Cyl. = 295.7
#7 Cyl. = 278.7
#8 Cyl. = 239.0

#1 Cyl. = 263.8
#2 Cyl. = 210.9
#3 Cyl. = 246.2
#4 Cyl. = 319.2

Dash gauge readings (immediately prior to temp checks)

Dash gauge readings (Immediately after temp checks)

 

[illtal]

Shit.... I think we are going to need a thermal image scanner. These numbers are all over the place.

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