Engine Guru's...need your oppinion!

[AllZWay]

I put in another engine I bought used without much information known about it.

The engine itself sounds great.... as long as you don't listen to exhaust from the rear of the car.

As the exhaust exits, it sounds just like it has an exhaust leak around the exhaust manifolds. However, it only sounds this way at the back of the car. Under the hood, the car runs and sounds perfect. No miss, no knock....just nice and smooth from idle to redline.

Dad and I reset the valves tonight hoping to mabye find the cause of the sound or stop it, but adjusting the valves had no affect on the exhaust sound.

Throw out your oppinions. I am kind of leaning to maybe a burnt valve...what do you think?? The problem with this theory is that the engine sound so good.

I am close to pulling the heads now and will likely miss Hallett, since my schedule is pretty filled between now and race weekend.

[Casey_SS]

James - sorry to hear this. You're right - could be a burnt valve or hole in a piston. A compression or leakdown test would confirm / deny this theory before you go to the trouble of pulling the heads though. Is it throwing any codes? If you can get a datalog (there are several free programs out there for OBDI) that would also be helpful....a burned valve or piston should show up as a big difference in O2 readings from side to side. Happy to look through the logs for you if you're able to get them.

[AllZWay]

Thanks Casey.... I am going to do a compression test, but it will probably be on Monday before I get a chance to get back to work on it.

I have a 93 computer so I can pull codes and nothing other than the egr codes were showing.

The car seems to run so smooth is what is throwing me off on a burnt valve or piston... I would think it would have a slight miss.

[Adam Ginsberg]

If the compression test comes back normal (or relatively normal).....RACE IT!

[Casey_SS]

x2!

Heeeyyy.....waaaaiiittt a minute....you're not trying to pull whole that McLaren / Redbull F1 thing where the exhaust gas generates downforce but sounds all weird are you? GLENN.....GLENN!!

[marshall_mosty]

+3!!!

If it's an "unknown", it's a ticking time bomb!!! RACE IT LIKE YOU STOLE IT!!!

[AllZWay]

If the compression test comes back normal (or relatively normal).....RACE IT!

The thought has definitely crossed my mind. I just wonder what would happen if it is a burnt valve.

[Fbody383]

I am close to pulling the heads now and will likely miss Hallett, since my schedule is pretty filled between now and race weekend.

Wouldn't think it would run "well" and have no codes with a hole in a piston. There have to be enough parts floating around this group, besides how hard is it to put the top end of the motor back together? Glenn can change the valve springs out in about an hour.

Come race the thing.