I took my vette to get a Dyno tune at Hesco in Birmingham to optimize the performance. After the initial dyno test he came back with the graph showing 290 HP and said it was running rich. So then he spent several hours tuning and came back showing 319 HP but the engine had a knocking noise. He said this was due to an excessive amount of oil in the engine causing damage. He also stated he had a hard time getting the AFR correct.

The engine was inspected and pistons #7 & #8 were dark when viewing from the bottom, cylinder #7 would not hold compression, a small piece of aluminum was on the #7 plug and the carb power valve was broken. Currently the left head is being pulled for further inspection.

How do you think Hesco should handle the cost of labor and parts?

 

I think they should take cash, check or credit card.

 

Sorry about your miss fortunes.

 

Who put the excessive oil in there.


It´s not their fault your engine fell apart.

 

Dynos can be the end of even a slightly worn engine...i dont go anywhere near them. A local rice burner shop here had some souped up thing on the dyno, engine built by owner. It all looked good until the dyno operator let off the gas and all the rods fell in a heap on the dyno floor.

 

Sorry about the broken engine, but why would the dyno shop cover the repairs?

 

It would be hard to prove but if they ran it too lean it IS there fault.

A shop worth it's salt would take care of it. If they are not offering good luck.

 

Except the guy said it was running rich.

 

This is my first experience with dyno tuning so I am getting an expensive lesson and hopefully it helps other members.

I checked the oil before leaving, added a ½ qt and verified the level. My thoughts along these lines are I would expect the mechanic to verify fluid levels before, during and after loading up the car on a dyno.

The mechanic mentioned while tuning he did get the AFR up to 15 but he was not able to set it as desired. He also mentioned the carb (AED 650HO) had an unusual configuration. I gave him the number to contact AED and he called them to discuss the customizations they perform on Holley carbs.

A nagging thought is the mechanics said it sounded “healthy” when I pulled up and after the initial dyno test everything was running good. It was only after the tuning is when the failure occurred.

I am interested how other dyno shops have handled similar cases.

 

Specks of aluminum on the plug porcelain or tiny black specks on the porcelain are the first signs of detonation. Don't know if what you saw fits the bill.

 

Sorry, but it is your cost. Why would think the dyno shop should rebuild your engine? I am sure they have print out of mixture rates as well a the AFR. Your engine was put on a WOT run for several runs at maximum RPM and resistance. Why did you have it dyno'ed in the first place??

 

Not the dyno shop's fault... sorry.

Avoid dyno shops unless you can stand there and watch everything... even then, never let them "drive"

 

oh man,
I can't begin to tell you how sorry I am to hear that your engine is trashed. your car is a beauty.
I do believe that they should offer to help you in some way, even though they probably don't accept responsibility for engines that are being run on the dyno.
heres why I think so.
1. engines don't make oil. you checked your oil earlier. and added a part of a quart. if you mistakenly added it( which I doubt), that's not enough to damage your engine. I think the dyno tech is making an excuse there.
2. the small amount of aluminum stuck to your spark plug is direct evidence that this cylinder was running way to lean. ( cylinder temps go way high under lean conditions causing pistons to burn.)
although its possible that his o2 sensor is reading wrong causing him to try over and over to get the mixture leaner. check the piston tops for burned areas to verify.
3. your power valve in the carb got trashed because of a backfire.
it happens with holleys and holley clones, its a weak point in the design of the carb. there are mods that can be done to prevent this.
so, the long and the short of it is this...
they can't guarantee that an engine wont come apart on the dyno because they cant know what shape the inside of your engine is in.
but in your case they share some culpability due to the fact that he didn't check the oil level before he ran the engine and because it looks like he overly leaned the mixture.
that being said, you are really at their mercy, on this one.
just be nice when you talk to the manager of the place and maybe they will accept some of the responsibility and try to help , but, they probably will not. good luck

 

When power valves tear they pour fuel into the induction system. If three or two cylinders show signs of Dentonation then more than likely these cylinders had intake track leaks. Like I said before I'm sorry for your misfortunes. Good luck on your next project.

 

Sorry about your engine but they are not responsible for your engine, read the bill, it probably states this fact.
Look at it this way, if they where to be held liable then everyone would go to the dino knowing there engine was about to blow up.
Or its like your doctor giving you a stress test, run as hard as you can but if your heart blows up, O well, you failed, there not liable for your heart attack even though they told you to do it.

 

As a dyno operator.............. It is always a scary thing to load motors harder than they ever will on the street or the track.

They don't owe you anything IMO.

It is just a sad fact of life that motors expire on the dyno, drag strips, or the Auto - X courses

 

It's always a crap shoot to run a well used engine on a dyno to it's max. limit. I don't think they owe anything. If you know the oil level was correct, then the oil story was something to direct the blame at.
A fresh engine on a dyno can let go too.

 

The shop doesn't owe anything. I would never let any of my machines out of my site. If I can't participate then no business from me.

 

Really???? We own a marina, if a customer wanted to follow every single moment we are working on their boats/engines, it would be the last time. Honesty goes two ways, if you don't trust anyone, then do it yourself. Go ahead and buy thousands of dollars of equipment and tools every year. Plan on stocking 10k to 20k of parts on hand also. How would you like someone watching every single thing you do, and also commenting on every single item. Oh, also second guessing what ever is wrong. Geeeez, Al

 

if it was running too rich that might be the reason there was too much in the crankcase. dosent make sense.