I have a 2006 A6 with the following mods:
Larger Cam
Headers
Exhaust
Ported Heads
ProCharger D1 Supercharger

A couple of months ago, I reduced the size of the pulley on the supercharger and increased boost from 5 pounds to about 9pounds. I was making 605 RWHP on the dyno (this is an automatic, so its not too shabby).

Heres a little confession, I'm not mechanically inclined. In fact, this is my first experience with a high performance car, so its all new to me I'm embarrassed to say this, but I dont know anything about engines and what little I do know, I've learned from the performance shops, I've taken my car to (I dont even know what a stroker is, yes its a sad fact, and Im ashamed).

However, you dont have to be a mechanic to know when you broke something. During a hard run (in full boost), I heard a loud pop, and the car began to back-fire. I drifted to the side of the road and had my car towed home.

I had a mechanic come to my house and without pulling the heads, hypothesized that I had some major internal damage, as the engine makes a loud, "clitty-clack" noise while running (coming from the #7 cylinder). There was no visible damage to the exterior of the block.

Well, rather than pulling the engine out and trying to rebuild something that will inevitably fail again, I elected to be patient and save up for a new forged small block, that can handle all of the other mods I've already had done.

The only problem was coming up with the money and more importantly, convincing my wife, who already wants me to sell the car, because she says I've already spent enough money on it. The situation became heated and it came down to either my wife or my vette. Well, as crazy as this may sound, I chose the vette and the wife went to her moms
(yes, I love that damn car).

Anyways, after a couple of weeks, my wife came back and I'm happy to report things are fine between us now. However, the vette is still out of service, but I'll have the money to fix it next month.

So, heres my question... My budget is $8000 or under (to include labor). What is the most bang for my buck in terms of a short block, for this application. I'm not some rich guy that can afford to replace engines, like sneakers. No, this is a one time deal, so I want something reliable, and of course, if I can squeeze a few more ponies out of it too, then all the better.

What are my options? Please help me out guys, all of your input is appreciated.

 

Assuming you did not ruin your heads, do a forged 6.0L - reuse the crank, add 9:1 compression forged pistons, Compstar rods and a clutch. Then go to 10 psi. You will probably make about the same power, but with much better reliability.

 

just curious, did you have a knock sensor and an intercooler and how many miles were on the motor ? BTW, with John, it would be a lot more reliable. I hope you didnt get any metal fragments in the head unit of the blower, it is oil fed right ? That sucks, I am glad you got things worked out on both ends !

 

If the block isn't wasted, you save a bunch. Have a reputable builder go .005" over on the block, add forged pistons and rods, balance and assemble.

Including removal and installation you should beat your budget by a good margin.

 

All I can say is, damn good choice!

 

I have no motor advise for you but I wanted to ask you about your trans. Were you having any issues or was it working okay? Do you still use the stock tune for the trans? Do you have any drivetrain upgrades or is it all OEM? What are your wheel sizes with all that monster power?
I'm just asking as some people say the A6 is not reliable in the high power range and you are way above that number.
Sorry to hear of your problems but it's good you got the go ahead to rebuild

 

Dude....my advice is to get a real good lawyer and then go to school for high performance racing...I have been there and done that and even have the shirt to show for it!!!!!

Oh ended up marrying the lawyer just in case!!!

 

If your short on cash? and your marriage is on the rocks because of a car?

Got to be honest and say put a stock motor in the car and enjoy it as it was designed from GM..

Sell off the supercharger to foot the bill for part of the cost of a new stock Motor..and save your marriage..

(Just kidding)

Call ECS or AA Andy or who ever has a great reputation with superchargers and ask them to build you a reliable motor... or as charlie recommended?

Good luck

 

I feel your pain. Not about the car, because that has never happened to me, but about your wife. My wife used to bitch at me about spending money all the time. Well, now shes my ex wife, and I couldnt be happier. What you should do is add up how much every pair of shoes and every purse she has costs and give her the total. Also, with most women, its not so much the money spent on the car as it is the time you spend with the car. I have had a few girlfriends get jealous because I was "spending too much time on my car". Anyway, good luck with the rebuild

 

So what "is" wrong with the engine,and "how" did it happen?

 

Get Meth, and wideband next time.

 

Curious about that too. Did you drain the oil and look for metal and parts....cut open filter too? I broke a rocker stud on another small block and it made all sorts of racket. Simple $15 fix and I was off to break something else. Yours does sound much worse but if your block is good it shouldn't cost you nearly that much to pull it and go with forged internals. I guess your out of warranty huh?

 

The reason it happened was this; one, to much boost for 10.9:1 comp.
Second, cast pistons, and third and most importantly, The stock intake LS2 manifold is a big reason for your failure. Under boost air is thrown to the rear of the manifold the last runner is No# 7 is goes lean and there goes your cast piston. Adding boost like you did just made it happen earlier. Most stock block blown motors will not live a long life. Like people have said on this thread you need forged internals and a lower compression.
Then your good to go.

 

So I'm not alone!

 

First of all good move with the wife. There are over 3 billion women in the world today and life is just too damn short to pick one of them and then let her run your life.

Secondly, I have blown up 4 motors, 3 of which were on forced induction. #1 was stock, N/A. It spun a rod bearing. #2 was boosted, stock, blew a head gasket. #3 was boosted, 3 layer stainless steel head gasket, blew a piston ring. #4 was boosted with a fully built race engine, all forged internals. It melted a piston. The moral of the story?
The strongest engine in the world will fail just as quickly as a stock engine when made to run with an improper tune. The FIRST thing you need to do, before you even think about putting another dollar into your car, is figure out what failed, how, and WHY. I am willing to bet that the tune was a bit to agressive for the octane level and running conditions. A completely non tune related failure would be, say, a bent rod, or maybe a spun rod bearing with no evidence of detonation. I am willing to bet that you detonated and blew a piston ring.
Get yourself a compression tester and do a comp. test. This should show the blown ring, unless you bent a rod, spun a rod or crank bearing, or blew a head gasket, which are possibilities too. A "lack of mechanical strength" failure can only be remedied by stronger parts or a decrease in cylinder pressure (less power). A failure induced by detonation or excessive EGTs will NOT go away just because you built a stronger motor. I wish I knew that before I put several thousand into my previous car.

As far as WHAT to do... I, personally, would call up several tuners and engine builders to get their opinion once I knew what happened to the car. Then based on their advice I would plan my next move. Without consulting the forum experts, I will say that my usual plan of action for a mild boost motor (9psi is not much; I was running 22PSI on 93 octane in a 9:1 compression engine) is to buy a set of forged pistons and a 3 layer stainless steel head gasket, buy the factory service manual, and do the install myself. Since you are not mechanically inclined, you may want to have someone do the install for you. If you end up doing rods, try to find some moly coated stainless steel rod and crank bearings; Calico makes them, amongst other brands. Those are indestructible and well worth the investment if you are taking the rods apart. Another good investment for a boosted motor are ARP Head Studs. Those are FAR stronger than the head bolts the engine comes with from the factory, and will not stretch under boost. Head bolt stretch is a guaranteed way of blowing head gaskets.

Good luck, and let us know how it turns out!

 

WOW!! Thanks for all of the great advice folks! I'll try to respond to all of you:

john_sblendorio: Thank you! Great advice and at least I know where to start.

G Alex: No, I didnt have a knock sensor. The engine had 36,000miles. As far as an intercooler? I think you're referring to the blower, right? If so, yes the pro-charger is intercooled. The blower wasn't damaged, it has its own independent oil source and doesnt use the oil from the motor.


C_Williams@RPM Externally the block looks pretty good. If I can re-build it with forged internals and save money, then all the better. Is there a difference between rebuilding my block and just buying a forged short block? Whats better?

EuroRod Thank you!

sampson Well, brotha I'm happy to report that I was using all of the stock OEM parts on the tranny and never had any issues. I never took the car out to the track or put slicks on it. However, I did drive this car pretty damn hard. I'm not the kind of guy that baby's his vette (not that theres anythng wrong with that). I just like to drive hard and fast, frequently hitting the red-line, while paddle shifting (which explains my inoperative motor, I guess). The tranny held up pretty good. Due to all of the mods, I had a custom tune done, but I'm not sure if they tweaked anything on the tranny, in terms of the tune. I run 20" tires to the rear and 19" in the front. The tires spin, so this reduces the load on the tranny, or so I'm told. Thats why I never put slicks on.

srpbaer Thanks for the advice brotha. :-)

JerriVette Brotha, when you posted that response, I almost thought my wife had become a forum member and was posting on my thread! Listen, my wife hasnt worked in 6 years (since we got married). She putt, putts around in a new lexus, lives in a big house and buys whatever she wants without any resistance from me. I work my ***** off, to support her and my kids and all I ask (since sex ended years ago) is to drive around fast, every once in a while. Its the only car we have where I can get away from it all. Its a two seater, so the sound of my kids crying in the backseat, is non-existant, because they dont ride with me. Also, since the car is so damn fast, she gets scared being in it, so she never rides with me either and thus her whining little voice is eliminated as well. The faster the car is.. the better chance I have of riding solo, thus I have a supercharged vette. Some guys turn to girls, alcohol, or drugs to escape. I turn to my vette. So, this is why my wife gave me lip about fixing it. The night my vette was towed home, she was on top of the world and even laughed about it. Well, I told her I was going to fix it and thats when we decided to go seperate ways. I figured, if a woman is wanting to leave me, because of a car, I dont need her in my life. So, I asked her to leave me the kids and my monkey (sorry had to throw that in, if you've seen walkhard, you'll get the joke) and go to her moms. after a couple of weeks, she came around though, (after I took away her lexus, of course). Suddenly, she was a sweetheart again. Amazing how that works, when you turn it around on them? She came back, apologized and everything is cool now.

UmCanesZ06 I agree, women want to be the center of attention and its possible for them to get jealous over you spending too much time wth anything (or for that matter having fun, when they arent). I had a chopper and had to sell it, cause according to her, I cared more about it than her. I had a Cessna airplane and again had to sell it for the same reason. She was trying to pull that same crap with this vette, but this time, I put my foot down and laid down the law (tactfully of course), and told her how its going to be. Yes, my cahonies finally dropped and I became a man.


1bdasvt:[/B] Well, I'm asking a stock engine to do twice the power it was designed for. Thats what happened brotha.

vr6aaron Thanks brotha

pwoolford yes, brotha I'm out of warranty. I purchased an after market warrantly that goes to 100,000 miles, (this car has 36,000). However, I found out that they send out an adjuster, so I thought forget it. I wont even try to do a claim, cause the adjuster will see all the mods I did and laugh at me.

andreas g Great input! The mechanic that came out to look at my car told me the same thing.


10ring Nope, I feel your pain too.

 

PowerLabs: Wow! brotha! Four engines! I thought forged motors were bullet proof, so I still run the risk of towing my car, even with forged internals (yikes, definately something my wife can never hear). 23 PSI of boost is insane man! Holy jeepers! Great advice though and I'll definately take it all to heart. As far as the comp test, the mechanic did one when he came out and said I didnt have any loss of compression.

As far as the tune... Man, where do I begin? This car was taken to five different shops from Nevada to Texas, to Utah and finally California. Every shop made the car run a little better, but the one in california, did the best, in terms of the tune. The last shop increased the timing to I beleive 17 degrees. They said the lifters were starting to float above 6500 RPM, so they programmed the rev limiter to stop at 6500RPM. This was at the same time that the pulley size was decreased and boost increased to 9psi. The car ran good for two months. The elevation in my hometown is 4800'. I blew up my motor in Indio, CA where I think the elevation is close to sea level? I had just put in some octane booster and one quart of marvel mystery oil. 10 minutes later, on the interstate..kaboom! And I was calling for a tow. I dont know if any of this has anything to do with my engine failing, but I thought I'd throw it out there anyway.

 

1. Get the forged internals

2. Go back to the bigger pulley

3. Get a conservative tune.

4. Have fun and you should have no problems, if all is done correctly.

 

When I was married & had a vette, she bitched! Now instaed of giving her 100% of my paycheck, she gets 20% for my son. Tell her to share your passion or leave & pick one of the other 3 billion gals! I did.

 

If your short on cash? and your marriage is on the rocks because of a car?

Got to be honest and say put a stock motor in the car and enjoy it as it was designed from GM..

Sell off the supercharger to foot the bill for part of the cost of a new stock Motor..and save your marriage..

(Just kidding)

Call ECS or AA Andy or who ever has a great reputation with superchargers and ask them to build you a reliable motor... or as charlie recommended?

Good luck and it sounds like you got a good plan..