73T 2.4L engine woes...

[jmorris3]

Well at Road Atlanta last weekend I finally zinged the motor in the practice session sunday morning. I went one more lap and all seemed fine. I looked over the car between practice and qual and found no issues, so I went to qualify as normal. 4 laps in coming out of T7, the motor bogged real bad, power came back and then bogged again. I pulled into the pit and headed to my paddock spot. I found oil leaking out of the left bank and dripping onto the header and decided my weekend was done since the race was only 1hr away.

I should also note that the motor has 83,xxx miles on it and I have put about 22 race hours on it in the past year. During the weekend the car ran right around the 250^ mark, but oil pressure and oil level were both fine throughout the weekend.

I did a compression test on it last night and got these results:
1. 120 psi
2. 90 psi
3. 120 psi
4. 120 psi
5. 120 psi
6. 120 psi


Obviously something is going on in the # 2 cylinder since I finally found that that is where the oil is leaking from as well.

Could the oil leak be a rocker arm issue. That is what happened to a friend of mine with the same motor but 3,000 miles less during the same weekend.

I plan on doing a leak down test this afternoon as I have just found a place that carries the tool.

Any suggestions on what could be wrong? Worn rings? leaky valves? cracked jug? Rebuild time?

The motor has always pulled strong until this happend, I know it's tired, but it has always ran great.

Thanks for the help!

[Bobboloo]

When you say zinged do you mean you over-revved?
If so, I'd pull the valve covers and check the rocker arms and shafts on #2.

[jmorris3]

[i]Originally posted by Bobboloo
If so, I'd pull the valve covers and check the rocker arms and shafts on #2. [/B]

Yes, I over-revved it. I shifted from 4 to 3 instead of 4 to 5 going down the back straight at Road Atlanta, I was passing one car and a faster car was trying to over take me....one of those racing things I guess....

What should I be checking on the rocker arm and shaft?

[Bobboloo]

See if they are cracked or broken. With an over-rev you get valve float. With valve float the piston can hit a valve and either bend it or cause it to break the rocker arm or shaft. The leaking oil you have might be the result of a broken shaft since they seal the oil in the cam towers. Hopefully this is all it is since it's an easy fix that can be done with the motor in the car and is relatively in expensive.

Worst case scenerio is a bent valve and damaged piston but first check out your rocker shafts and arms. If they are damaged replace them and do another compression test. You may have dogged a bullet.