C2 Engine Install

[Richard H.]

Well, just when you thought you were finally there.....! The new engine is in the 66 427/390. It started right up. After a few minutes of running, there was a very high pitch whistling sound coming from the back of the block. I have been told that this is an indication of a bad main bearing, however this engine was supposedly REBUILT by Performance Engines out of Nebraska. Please say it isn't so!!!!

Does anyone out there have any insight as to what other problem it could possibly be. It would be great if it were something simple?????? I have had good luck with Performance Engines up to this point and since I did pay quite a bit of money for this rebuild, I find it hard to believe the main bearing could be the problem. Maybe I am still to naive!!!!

As always, your assistance is always greatly appreciated.

Thanks alot.

Deb

[David D.]

Re: C2 Engine Install

Deb. A very high pitched whistling noise is usually a vacumn leak. A bad main bearing usually sounds like a muffled knock, not a whistling noise. Dave

[David D.]

Re: C2 Engine Install

Deb. A very high pitched whistling noise is usually a vacumn leak. A bad main bearing usually sounds like a muffled knock, not a whistling noise. Dave

[Joe L.]

Re: C2 Engine Install

Deb-----

1965-66 Chevrolet big block engines require a special rear camshaft bearing and/or camshaft if the engine lubrication system is to operate properly. For these engines, the rear camshaft journal has to be grooved and/or the rear camshaft bearing has to be grooved. If at least one of these is not present, the engine will be starved for oil and I would not be surprised if the rear main bearing was the first thing to go. I'm NOT saying that this is what happened here. It's STRICTLY a possibility.

A lot of folks don't know about this peculiarity with 65-66 big block engines, especially younger folks who might not even have been born yet when these engines were popular and might rarely ever see one these days. I certainly hope that "Performance Engines out of Nebraska" is not one of the unenlightened.

[Joe L.]

Re: C2 Engine Install

Deb-----

1965-66 Chevrolet big block engines require a special rear camshaft bearing and/or camshaft if the engine lubrication system is to operate properly. For these engines, the rear camshaft journal has to be grooved and/or the rear camshaft bearing has to be grooved. If at least one of these is not present, the engine will be starved for oil and I would not be surprised if the rear main bearing was the first thing to go. I'm NOT saying that this is what happened here. It's STRICTLY a possibility.

A lot of folks don't know about this peculiarity with 65-66 big block engines, especially younger folks who might not even have been born yet when these engines were popular and might rarely ever see one these days. I certainly hope that "Performance Engines out of Nebraska" is not one of the unenlightened.

[Richard H.]

Re: C2 Engine Install

Dave:

Let me rephrase what I stated before. I'm so upset right now I can't even think straight.

The noise can be heard best while laying on your back under the engine. It is high pitch but maybe it is more like a screech then a whistle. The noise comes and goes. It is not continuous. At first I thought it may have been a throw out bearing, but this is also new. My neighbor said something about it being the rear main. With this additional info, I am assuming we can eliminate the vacuum leaks (we did check for these from the beginning).

Any more assistance would be greatly appreciated. I am about ready to throw the towel in!!!!!!!!

Thank you all so much.

Deb

[Richard H.]

Re: C2 Engine Install

Dave:

Let me rephrase what I stated before. I'm so upset right now I can't even think straight.

The noise can be heard best while laying on your back under the engine. It is high pitch but maybe it is more like a screech then a whistle. The noise comes and goes. It is not continuous. At first I thought it may have been a throw out bearing, but this is also new. My neighbor said something about it being the rear main. With this additional info, I am assuming we can eliminate the vacuum leaks (we did check for these from the beginning).

Any more assistance would be greatly appreciated. I am about ready to throw the towel in!!!!!!!!

Thank you all so much.

Deb

[Richard H.]

Re: C2 Engine Install

Joe:

I knew you would come to my rescue!!!!!

The engine was built by Hi-Performance Restoration, Inc. out of Springfield Nebraska. We bought it in Bloomington. They are at Bloomington and Carlisle every year. As far a being young, not to be disrespectful, but Ron Bockerman appears to be in his late fifties. They specialize in Corvette restorations. Has anyone heard of them? They appear to be very reputable.

Are you telling me I need to tear the engine down to see if there is an oil groove in the cam shaft? There is no easier way?

I will be waiting for your response.

Thanks so much.

Deb

[Richard H.]

Re: C2 Engine Install

Joe:

I knew you would come to my rescue!!!!!

The engine was built by Hi-Performance Restoration, Inc. out of Springfield Nebraska. We bought it in Bloomington. They are at Bloomington and Carlisle every year. As far a being young, not to be disrespectful, but Ron Bockerman appears to be in his late fifties. They specialize in Corvette restorations. Has anyone heard of them? They appear to be very reputable.

Are you telling me I need to tear the engine down to see if there is an oil groove in the cam shaft? There is no easier way?

I will be waiting for your response.

Thanks so much.

Deb

[Joe L.]

Re: C2 Engine Install

Deb-----

Well, the first thing that you might do is ask them. If they say right of the bat that they know about the cam bearing/journal differences and they used the correct components, you can PROBABLY discard this notion. On the other hand, if they "waffle" or say something like "all big blocks are the same and use the same bearings", then there is cause for concern.

To be honest, I think that the high pitch sound that you are hearing is unusual for a bearing noise, but I think that it's possible. Speaking of "throwout bearings" (actually "clutch release bearing") they can cause a high pitch sound for at least a couple of reasons even if they are new: first, there may be insufficient freeplay. You MUST have sufficient freeplay or the bearing can be destroyed quickly. Second, the bearing could have been installed incorrectly so that the above-condition exists even if there is freeplay. The "tangs" of the spring riveted to the clutch release fork must be within the groove of the bearing. This manner of assembly is not necessarily intuitive, so it's a common "stumbling block".

[Joe L.]

Re: C2 Engine Install

Deb-----

Well, the first thing that you might do is ask them. If they say right of the bat that they know about the cam bearing/journal differences and they used the correct components, you can PROBABLY discard this notion. On the other hand, if they "waffle" or say something like "all big blocks are the same and use the same bearings", then there is cause for concern.

To be honest, I think that the high pitch sound that you are hearing is unusual for a bearing noise, but I think that it's possible. Speaking of "throwout bearings" (actually "clutch release bearing") they can cause a high pitch sound for at least a couple of reasons even if they are new: first, there may be insufficient freeplay. You MUST have sufficient freeplay or the bearing can be destroyed quickly. Second, the bearing could have been installed incorrectly so that the above-condition exists even if there is freeplay. The "tangs" of the spring riveted to the clutch release fork must be within the groove of the bearing. This manner of assembly is not necessarily intuitive, so it's a common "stumbling block".

[Clem Z.]

Re: C2 Engine Install

the grooved cam and the special rear cam bearing only effects the oil to the lifters and valve train. it will not do anything to the rest of the engine.look into the hole in the rocker cover where you put oil to see if the top of the engine is getting oil. i would be of the line of thought that if you still have oil pressure and hear no knocking noise it is the clutch TO bearing. did you put oil in the trans before starting the engine.

[Clem Z.]

Re: C2 Engine Install

the grooved cam and the special rear cam bearing only effects the oil to the lifters and valve train. it will not do anything to the rest of the engine.look into the hole in the rocker cover where you put oil to see if the top of the engine is getting oil. i would be of the line of thought that if you still have oil pressure and hear no knocking noise it is the clutch TO bearing. did you put oil in the trans before starting the engine.

[David D.]

Re: C2 Engine Install

Deb, Ron re-built a 66 427/425 for me about 5 years ago. He knows about the grooved rear cam bearings. Do you have the dust shield on the bellhousing? If it is, it could possibly be hitting the back of the flywheel. To find out, just remove it, start the engine and see if the noise disappears. Dave

[David D.]

Re: C2 Engine Install

Deb, Ron re-built a 66 427/425 for me about 5 years ago. He knows about the grooved rear cam bearings. Do you have the dust shield on the bellhousing? If it is, it could possibly be hitting the back of the flywheel. To find out, just remove it, start the engine and see if the noise disappears. Dave