I recently pulled my motor apart after it went south a while back... I found that the rings seized on the #4 piston due to what looks like detonation. The piston was chipped pretty bad at the top toward the side (they are the je dished turbo pistons). The #3 was almost as bad but not nearly like #4. #'s 2 and 1 were good. The weird thing is when looking at them it looks like it ran progressively lean towards #4... #1 was great, 2 was good but not as good, 3 was bad, and 4 is trashed. The head also needs to be rehoned because it looks like the piston came up high enough to slap the head and bend some valves. Whats done is done but my question is what is causing the motor to run more lean as you go down the cylinders. I thought injectors but it ran lean in order from 1 to 4 which I can't see happening with injectors that perfectly. I am still having them sent off to be balanced and cleaned by rc to be sure. They are 550cc Siemen Deka injectors The rods are fine and so were the bearings.

Here is my setup to better understand the problem I hope:

B18C1
9.1 JE Dished Pistons
Crower Rods
Block Guard that looks like it was installed unevenly. Pulling it out and sleeving it.
550cc injectors
AEM fuel rail
Walbro fuel pump
Skunk2 intake manifold
Drag turbo kit.
Hondata stage 3
MSD 6A

Our only other thoughts were that the skunk2 mani was the problem but I really dont buy that. If the air rushed into the mani it would lean out the #4 not the #1

And the thought was that the actual fuel lines might need to be bigger, not just running a high volume fuel pump and rail.

 

ttt

 

Hmmmm, the only thing that comes to my mind at the moment as a possibility is an unreliable fuel pump?

bad gas?

How much boost didja run at the time?

 

18lbs... But its not like it ran lean on all 4 cylinders. I ran lean in order like it was pulling fuel a little at a time starting with 1 and all the way up to 4

 

its funny i run into this post.

i had to replace my headgasket yesterday and while inspecting my pistons i notice my #1 was perfcet then going down my pistons start showing signs of detonation. the surface of my pistons seem slightly melted and it gets worse going down the line.

i figure this motor wont last long so its about time to rebuild

i was trying to think how it could do this

 

Hmm, good questions in this thread.
Its pretty much impossible for it to be fuel related since the whole rail is pressurized throughout........unless of course there are bad injectors. Injector sync could be off, but doubtfull unless you have a standalone and someone has been playing with parameters they shouldnt have been.........I dont believe hondata has control over individual cylinders.

My only guess would be how the air runs through the intake on its way to the comustion chamber. Colder denser air would cause a lean condition. Maybe as the air moves past the throttle plate, through the plenum and finally down the runners it is getting hot and expanding........since the tb is on the #4 side then it may make sense. #4 would obviously get the coldest most dense air and each cylinder there after is getting different air temps cause of the IM being heatsoaked.
This is just my opinion, but I think Im on to something. An EGT on each runner would definetly tell us something here. Unfortunately it is too expensive for most guys to do something like that.

 

i was thinkin airflow through the IM too, its the only other explaination.............maybe

 

A friend of mine suggested redoing the actual fuel lines and installing a return type system... What Hondas apparently have is called a dead head setup for the fuel rail system... My AEM fuel rail doesn't have a return hose on it. Apparently some of the cars that come with turbos from the factory have a fuel setup that works to where the entire fuel rail is pressurised and then the fuel is delivered through the injectors insuring that all the injectors deliver the same amount of fuel, and then any extra is regulated through the regulator at the other end and sent back to the tank. Not sure if a setup like this would benefit me.

 

6 -AN lines to and from the tank with a good aeromotive FPR would help out immensly imho. 18lbs isn't exactly a little bit of boost. Look at any factory turbo car like the evo and you'll see that they incorporate a return style fuel system. Why? Because it results in more even fuel delivery. In an NA setup a dead head setup is fine because honestly, you're usually not using injectors any bigger than 24lbs. With a dead head setup, near stock fuel pressure and uber large injectors, the fuel delivery isn't going to be consistent to all 4 injectors. In honda speak, the #1 injector is going to see higher fuel pressures than 3, 2, and 1. Larger lines feeding the rail along with a good return style setup is a better system for 300+ hp turbo setup? But I drive a neon so what do I know?

 

Nevermind I just recieved an education on hondas and how they have a return system on them... Its gotta be the pressure at the fuel rail then. Thats all thats left.

 

Actually stock fuel system is good, no need for upgrading to ss lines. Jason Hunt went 10's if not 9's I think on the stock fuel lines in his street crx last year.

 

When you say that the blockguard was installed unevenly, what did you notice? Was it real tight around cyl #1 and got progressively looser towards cyl#4? I decided not to use a blockguard in my engine (posted it instead), but while I was researching them, I noticed that the "fit" issue was a common one. Many of them were tight on one side and loose on the other.

I wonder if cylinder distortion was an issue.

Sonny

 

well it was more like certain spots of the block guard seemed to be lower in the block like it sunk or something. But not low enough to see without running your finger along the guard and feeling the drop off... I am a little worried that it might have warped the cylinders over time, but I will see when the machine shop pulls it out.

 

My simple idea is its just a lack of fuel poor tune. We know that Cylinders 1 and 2 run cooler then 3 and 4. So the detonation will set in on the hotter cylinders first. Yeah I know 3 is supposed to be the hottest but 4 it is furtherest away from the water pump perhaps your cooling system needs to be looked at.