Okay... I'm pretty sure now cyl 4 did have detonation.. I got the head off.. And there is a hole in the piston edge and ring - a whole chunk is missing. The smoke I guess must have been oil burning as it got pumped through the piston, out the hot turbo and exhaust manifold (piston, intake and exhaust ports are covered in oil).

Here a pic of the piston.



Cylinder walls look okay - just some caked on residue where the piston was damaged, although won't know for sure until it's all cleaned up. However, I am probably just going to get a built block and be done with it.

Thanks for all the help guys! I'll post more pics later if anyone is interested.

Thanks!

S.

 

That looks more like /burned through then broken off, at least from your photo.

Get your fuel system checked as well.

How did your HG look?

 

Agreed, it does.. HG seems to be okay:



That's a pic of the block with the HG still on. I took the HG off and quickly inspected it - nothing obviously wrong with it..

Also not sure why cyl 1 and 2 had lower compression (approx 100psi each) since HG looks fine. Could be rings or poor sealing valves I guess, but I somewhat expected a HG issue between 1 and 2.

Thanks!

S.

 

Oh now I see it's cyl 1. Notorious for running leaner than others.

I bet it leaned out / got way hot for some reason and started melting stuff.

Do you have a wideband and/or logging and where looking/doing both/either at the track when it happened?

 

The burnt hole is cylinder 4, not 1. #1 is on the timing belt side.


Def looks like a fueling issue. All other cylinders look good, with normal carbon deposit on the piston. In contrast to the clean and burnt #4. Get your injectors flow checked, maybe even just replace them as a precaution. If you have a ported head or intake manifold, the porting for #4 cylinder may not be matched too well with the others, and you may want/need to replace them.

 

Oops you are correct, I had it turned around in my head, I blame Monday morning without coffee yet.

Rom, what is your power mod list? E85 correct?

 

Hey Razor,

Here's the list:

- E85 fuel
- RC 1200cc injectors
- Kelford 272 cams
- SuperTech 98lb springs/retainers
- ETS top & bottom hard pipes
- ETS intercooler
- Tactrix 3-port boost solenoid
- Walbro 400lph pump
- RRE 3" exhaust
- RRE Test pipe
- RRE 3" downpipe
- Shep-built 600HP transmission
- Synapse Synchronic DV

I think that's everything!

Thanks!

S.

 

Thanks for the list. Do you have a wideband installed? How do you have the Wally400 setup?

 

Also, maybe that cylinder was having fueling problems from earlier.. I had one spark plug blow its top (melted) and I just assumed that it was a faulty plug.. and as mentioned earlier the second plug had the same issue (when I pulled the plug it had a melted ground too), in addition to the melted piston..

Maybe that RC injector was failing running that cylinder lean... Is RC known for failing (maybe because of E85)?

Thanks!

S.

 

RC does not recommend using their injectors with E85..

 

Deleting this post (glitched and only posted half a post - see next post!)

 

Yes, I have a wideband, but it doesn't log - and I can't recall what it said when I had the issue.. However, I do remember me thinking that it didn't seem to be going rich enough (typically it goes to 10:1 and less, but I was seeing it hover more around 13:1, although it would still hit 10:1.. I didn't think too much in to it at the time since I wasn't seeing knock and it fluctuates in real time all the time so it's difficult to get a bearing on "normal"). I will be doing a lot more logging from now on!

The 400 is a single pumper just replaced the OEM. Stock fuel lines, rail and regulator.

Thanks!

S.

 

I used RC 1kcc injectors for five plus years on E85 with zero issues. I even pulled them out towards the end and sent them out to get cleaned and they still flowed great even before cleaning.

I also had tons of my customers use RC's on E85 for years with zero issues.

Walbro also states that their 255lph pumps aren't for E85 but they last forever on E85.

 

The car was at 10.X AFR on E85 at WOT? That's way too rich for E85.

13.X is too lean on E85 at WOT. That will burn things quick.

Also, the Evo 7/8/9 fuel pump assembly, the big white plastic thing, there is an integrated filter molded into the assembly that can clog from E85 usage. I went through two of them over five years.

Once that starts clogging from e85 (it actually breaks down as it's cardboard style), the car will start leaning out as it gets starved. It leans out enough that it can melt things.

Usually you can tell visually if you look at the assembly, the filter side will be much darker.

Where are you located in California Rom?

 

Something not right was happening. AFR's with E85 should be pretty steady around 11.5-12 if the car is tuned properly.

I also used some RC 1k's for over a year with E85. That doesn't mean it's recommended. When I called and asked about it, they said their injectors are not designed for the hydroscopic nature of alcohol fuels.