427 engine (part 2) - RHS block - Page 73

**Rich Z** · 01-27-2011, 05:51 PM

Quote:

Originally Posted by shakedown067

AH yeah. Well, I'll shut up.

I guess my boost knowledge was exceeded before reading this thread.

Yeah, no worries. My "knowledge" is being tested all of the time...

**Rich Z** · 01-28-2011, 12:37 AM

I wish I could say that I thought that day was imminent.... There have been SO many times I thought it was getting close, only to be smacked alongside the head, that I'm just not getting my hopes up any longer.

RevXtreme 1 · 01-28-2011, 09:02 AM

The blow off valve is what relieves or "bolws-off" pressure when the throttle blade is shut to avoid the pressure damaging it is intake components.

Thw wastegates regulate the exhaust gasses that spin the turbos. The wastegate does two things, one is the most obvious in controlling the amount of boost by bleeding off exhaust gasses as the pressure meets a pre-set level, but it is doing so not by relieving boost, but by bypassing the exhaust that spins the turbo.

**Rich Z** · 01-28-2011, 06:44 PM

Quote:

Originally Posted by RevXtreme 1

The blow off valve is what relieves or "bolws-off" pressure when the throttle blade is shut to avoid the pressure damaging it is intake components.

Thw wastegates regulate the exhaust gasses that spin the turbos. The wastegate does two things, one is the most obvious in controlling the amount of boost by bleeding off exhaust gasses as the pressure meets a pre-set level, but it is doing so not by relieving boost, but by bypassing the exhaust that spins the turbo.

And to be certain I understand the mechanics of this, the wastegate does absolutely nothing until the boost has exceeded the rating of the spring. Up to that point, all exhaust is routed through the turbos. Is that correct?

Bob K · 01-28-2011, 07:51 PM

Quote:

Originally Posted by Rich Z

And to be certain I understand the mechanics of this, the wastegate does absolutely nothing until the boost has exceeded the rating of the spring. Up to that point, all exhaust is routed through the turbos. Is that correct?

I found this Rich.

http://en.wikipedia.org/wiki/Blowoff_valve

**Rich Z** · 02-03-2011, 03:05 PM

Well, I honestly would like to think that no news is good news, but somehow I just don't think that will be the case here....

My luck just hasn't been flowing in that direction.

The last I heard from Aaron was that he was going to try a new wastegate that he has in the shop.

**Rich Z** · 02-03-2011, 05:57 PM

Well Aaron called me today with good news and the usual bad news.

The incorrect MAF that Chris Harwood put in my car was affecting the tune, so he had to get the correct Z06 version.

Aaron straightened up a lot of the plumbing on top of the engine so it should look a lot neater now.

He found that the wastegate problem was caused by a vacuum hose melted through that was laying against a header.

The turbos themselves now appear to be leaking oil. He checked the scavenge pump and it appears to be working properly. So no telling what happened now....

The oil pan leak still needs to be addressed (which means pulling the engine) and he's going to look into the reverse problem with the transmission.

I swear, I feel like I'm at the 2 yard line and I'd be a fool to just give up being this close. But then when I cross those two yards, there is ANOTHER two yards to go. Then another. And another.... Yet suppose I am REALLY REALLY at the two yard line and I give up then?

I swear, if I retain my sanity after all this, it will be a bonafide miracle. Or maybe I have already lost it? How will I know? Maybe continually thinking I am at that two yard line is a sign?

navy2kcoupe · 02-03-2011, 06:42 PM

Rich, the more I read this thread, the more that I think that ALL of the problems you're seeing are as a direct result of Mr. Harwood. Don't beat yourself up over a past decision, and be EXTREMELY grateful that Aaron is diligent enough to find and fix all of them. The only really "bad" news is that you wind up paying twice. This thread is more of a damnation of Mr. Harwood than anything else, and eventually you WILL have a beast that's worth having.
Andy Anderson

CorvetteJohn · 02-03-2011, 07:58 PM

Pan oil leak. You mentioned that the pan bolts were stainless and that the allen heads were rounded out.. I am wondering if it would be possible to drill the heads out enough to silver solder or braze a short bolt onto them and then turn them out without removing the engine. Only you know if there is enough clearance to do this.

**Rich Z** · 02-03-2011, 08:25 PM

Quote:

Originally Posted by CorvetteJohn

Pan oil leak. You mentioned that the pan bolts were stainless and that the allen heads were rounded out.. I am wondering if it would be possible to drill the heads out enough to silver solder or braze a short bolt onto them and then turn them out without removing the engine. Only you know if there is enough clearance to do this.

It looks pretty tight in there with the engine sitting on that cradle. I'm sure you would have to drill through the cradle to get to some of the bolts. With the block being aluminum, I'm guessing that aaron doesn't want to risk stripping out the threads. If I remember correctly, Harwood had to cut slots in the bolts holding the timing chain cover in place as those bolts were rounded out as well.

But even after the bolts are out, I'm not sure how easy it would be to get to the oil pan gasket. Aaron wants to put a sealant on both sides of them (like in the old days when we used to use Permatex on all of the gaskets. If this had been done originally, quite likely I wouldn't have an oil leak there right now.