Hoon's DIYish Engine Build Thread

[billbadass]

sad day Hoon, I can't begin to think of what you and your family are going through and my prayers and condolences. thank you for sharing your story.

 

[GTI Jake]

Sorry for your loss, and thank you for sharing as it will hopefully urge more of us to take this more seriously.

 

[jimlloyd40]

 

[Hoon]

Thanks for the support guys, truly appreciated. I will get my ass in gear to get this car back together very soon. I have a large order placed for a lot of OEM parts, and the vendor will not ship until it's complete. I haven't had much motivation to touch it with everything going on, and knowing i'm not going to make much progress at all before i need parts.

Tear down was a bit of a scramble, but i do have a recap video from forever ago that i still need to edit and get posted.

Some tear down pics courtesy of Mrs. Dutch to help get things back on track:

 

[jimlloyd40]

Hoon for all you've been through I sincerely wish you the best of luck with the engine. Really looking forward to the results.

 

[TrueGTI]

Motor is looking great. Very sorry for your loss dude.

 

[THEREALVRT]

truly sorry to hear about the passing of your pops. my sincere condolences to you and your family at this difficult time.

 

[billbadass]

yeahhhh budddddyyyy!!! nothing like having a motor torn apart in the garage one of my favorite things because it means big time power going to be taking its place

 

[PowerDemon]

Lookin good! Do you have any photos of the pistons? How do they look?

 

[Hoon]

Lookin good! Do you have any photos of the pistons? How do they look?

They looked near perfect, the machine shop never gave them back to me. I think I have a pic somewhere I'll try to find. A tiny touch of detonation on the tops from when I had fuel starvation at the track somewhere around 35K miles, but that's nothing that has any effect whatsoever.

My issue was that the bore on cylinder 1 was way out of spec and the rings did not have enough tension to continue to seal. Whether that was heat distortion (I've done many pulls to 170+mph), a factory defect, or a combination of the two I'll never know. The bores on 2-4 did show some wear, but less than 1/2 of cyl 1.

I'm actually shocked by how good the motor looked. Still had nice crosshatch on the cyl walls (which is why I was very surprised that I had to go 83mm), rod bearings looked brand new, everything was super clean (Amsoil every 5k), etc. Main bearings showed a tiny bit of wear but nothing even noteworthy.

 

[PowerDemon]

They looked near perfect, the machine shop never gave them back to me. I think I have a pic somewhere I'll try to find. A tiny touch of detonation on the tops from when I had fuel starvation at the track somewhere around 35K miles, but that's nothing that has any effect whatsoever.

My issue was that the bore on cylinder 1 was way out of spec and the rings did not have enough tension to continue to seal. Whether that was heat distortion (I've done many pulls to 170+mph), a factory defect, or a combination of the two I'll never know. The bores on 2-4 did show some wear, but less than 1/2 of cyl 1.

I'm actually shocked by how good the motor looked. Still had nice crosshatch on the cyl walls (which is why I was very surprised that I had to go 83mm), rod bearings looked brand new, everything was super clean (Amsoil every 5k), etc. Main bearings showed a tiny bit of wear but nothing even noteworthy.

I'm confused. Did you have a ring failure in cylinder 1 or was it just accelerated wear on the rings/cylinder wall from the higher operating temps/pressures which caused the low compression and knock?

I agree from the photos at least. The crank looks almost brand new. Glad to hear the other internals held up well at the increased power output.

 

[Hoon]

I'm confused. Did you have a ring failure in cylinder 1 or was it just accelerated wear on the rings/cylinder wall from the higher operating temps/pressures which caused the low compression and knock?

I agree from the photos at least. The crank looks almost brand new. Glad to hear the other internals held up well at the increased power output.

No visible ring failure.

The GTI uses a different piston ring than the R, and I haven't had both in hand to verify, but it likely has lower tension for MPG. If I put enough heat in it to cause it to lose tension, I guess that would be a ring failure, but I never actually broke anything. Initially I thought this was the issue (loss of tension), until I got the measurements on the bore.

I'd have to check notes but I believe cyl 1 had .004" taper (cylinders always wear more at the top, so think of an ice cream cone). To put that in perspective, the piston to wall clearance on the new motor is .002", so the clearance had essentially tripled.

 

[Diggs24]

SO basically cyl1 had distortion? Id say considering it's location that was heat caused.

 

[PowerDemon]

Assuming the failure is the result of excessive heat I wonder if running water meth or something to cool the combustion (beyond E85) would have made a difference. Or if having individual EGT bungs per cylinder would be beneficial to keep cylinder temps better in check. Hoon have you thought of installing an EGT bung anywhere?

 

[Hoon]

SO basically cyl1 had distortion? Id say considering it's location that was heat caused.

I would agree. The crosshatch pattern still looked great so i don't think it was just general wear.

Assuming the failure is the result of excessive heat I wonder if running water meth or something to cool the combustion (beyond E85) would have made a difference. Or if having individual EGT bungs per cylinder would be beneficial to keep cylinder temps better in check. Hoon have you thought of installing an EGT bung anywhere?

I ran 28psi from a hybrid on pump gas for 10K miles. The issues began during that time, but lets be clear, the tune was not a factor. It was not lean, had very reasonable timing, essentially zero knock, and the engine tear down showed no indication otherwise. This was a very reputable tuner, i was not self tuned at that point.

I love hybrids but one of the realities that we have to accept is even the better designed ones are not nearly as efficient as a full frame unit. They just can't be, they're constrained by stock housings. They have more backpressure, higher EGTs, and less of a factor higher IATs. The better ones are manageable, but when you put one in the hands of a moron who does 30 second WOT pulls (see username) it's only going to last so long.

I'm really not a fan of WMI on these cars. It requires a long explanation, but i plan to be E85 only at this point. No more pump gas unless it's a soft tune for a road trip or something.