454 blow by.

[jroberts88]

I am working on a 454 and was wondering something. There is what appears to be white smoke coming out of the breathers on the valve covers(yes both of them).

To check if it is blow by.

Pull dipstick and smell. should smell like gas.

To check if it is a bad head gasket.
Oil be milky.

Is that right? and/or is there another way to tell what it is with out pulling the motor apart.

That is what i am thinking i will have to do.

 

[Don]

I would start with a compression check may be bad rings

 

[73 Sanger Flat]

Need to really do a leak down test and a compression test .. If your oil is milky it could be a few thing . Like you said head gasket  also could be a cracked head , cracked block and also could be just an intake gasket leaking .

Normally blow by is caused by the rings not sealing good .. I had this problem a few times and once was the rings and the other two times I knocked a hole in a few pistons . Most likely not your problem with your engine .

I would start by getting a leak down gauge and start there .. the white smoke coming out of the breather is an indication of water somewhere , unless it is just contaminated air from the crankcase blowing bye and catching oil with it and it looks like water .

Is this engine a stock engine , slighlt modified  or High Performance like 12 to 1 and higher compression . Also need to know what type of exhauset you are working with , could be sucking water up the exhauset and back into the engine and getting water that way .. Way to many varibale to try and disgnose with the info you posted ..

Like I said , first thing I would do is a Leak down and Compression on all holes ..

 

[jroberts88]

Yea I didn't think of those tests. I was just thinking of what could I see right away. Its in a vehicle.

Thanks for the help. Ill let ya know what I find.

 

[Becket]

Yea I didn't think of those tests. I was just thinking of what could I see right away. Its in a vehicle.

Thanks for the help. Ill let ya know what I find.

is it using water? Any Steam or sweet smell from the Exhaust?

Also, Pressure up the Colling system, see if it leaks off.

 

[jroberts88]

I am going to get the compression tester and the leak down tester this weekend and dig deeper into it.

the oil does seem to be clean looking but does have alittle gassy smell to it. normal or not normal?

 

[Becket]

I am going to get the compression tester and the leak down tester this weekend and dig deeper into it.

the oil does seem to be clean looking but does have alittle gassy smell to it. normal or not normal?

Older oil can have that smell, Be sure to pressure up the Cooling system, if it dont hold pressure then you can start looking for where it is going, Head gasket, cracked block........Ect.

How many Miles on this Engine?

 

[73 Sanger Flat]

If the oil smells like gas , it could be the  carb  flooded over and the excees fuel went past the rings and into the pan at one time ,

Blowby does smell different because it has all the nasty contamintaed oil and gasses in it when it is pushed out the breathers from the inside the engine . .. A little blowby is OK , the PVC will handle some of it , but if it is exceessive ,you have a problem some where .

 

[jroberts88]

Okay well i had done a compression test and i get 120 across all cylenders. leak test is fine also.. so i am officialy lost.

The block is the first year they went to fuel inject.  And if i remember correctly the heads dont flow that much air.

This is what has been done """"454 freshly rebuilt with dated receipts, MSD 6AL box, MSD distributor, Edelbrock airgap intake, Edelbrock 750 carb, headers, mild cam, high volume Melling oil pump, Moroso aluminum water pump""""

 

[Becket]

Okay well i had done a compression test and i get 120 across all cylenders. leak test is fine also.. so i am officialy lost.

The block is the first year they went to fuel inject.  And if i remember correctly the heads dont flow that much air.

This is what has been done """"454 freshly rebuilt with dated receipts, MSD 6AL box, MSD distributor, Edelbrock airgap intake, Edelbrock 750 carb, headers, mild cam, high volume Melling oil pump, Moroso aluminum water pump""""

How much run time on the Engine? What kind of Oil did you use when Breaking it in?

 

[jroberts88]

I am unsure as to either.

I had gotten the engine after the rebuild was done and unsure as to how many hours are on the engine.

 

[Don]

1.When you did the compression check did you hold the throttle open and how many revolutions did you turn the engine on each hole to achieve 120psi should be no more than 3
2. How did the engine run at idle rough or smooth could you smell excessive gas while running I don’t think the two issues are connected to the same problem

 

[jroberts88]

1.When you did the compression check did you hold the throttle open and how many revolutions did you turn the engine on each hole to achieve 120psi should be no more than 3
2. How did the engine run at idle rough or smooth could you smell excessive gas while running I don’t think the two issues are connected to the same problem

no on the throttle.
But it took between 2-3 turns.
The engine runs smooth at idle and no i could not smell an abundent smell of gas while running.

I did find out that the engine was rebuilt at Davids machine shop in houston.

 

[Don]

I would retry a couple of the cylinders with the throttle open and see if the consistency changes
Do you know if the engine has been run hot?

 

[jroberts88]

I would retry a couple of the cylinders with the throttle open and see if the consistency changes
Do you know if the engine has been run hot?

no i do not know if it has or hasnt. Would that make a difference? I know that could cause cracking but if that was the case wouldn't the machine shop catch it?

 

[Don]

Has this motor had blow by since it was rebuilt?
If you run one hot enough it will collapse the rings and may are may not crack a head or blow a head gasket I've had them go both ways
Even one collapsed ring will make a lot of blow by

 

[jroberts88]

Has this motor had blow by since it was rebuilt?
If you run one hot enough it will collapse the rings and may are may not crack a head or blow a head gasket I've had them go both ways
Even one collapsed ring will make a lot of blow by

Per the guy that i had gotten it from yes it has had blow by. but the machine shop said "That all chevys have blow by. its normal." <-- I call BS.

 

[Don]

that is BS in this case I would start with the rings I have never built an engine that had blow by from the start

 

[jroberts88]

that is BS in this case I would start with the rings I have never built an engine that had blow by from the start

So a rebuild is in order..

So the question is this. Wouldn't that show up in the compression test.?

 

[Becket]

Has this motor had blow by since it was rebuilt?
If you run one hot enough it will collapse the rings and may are may not crack a head or blow a head gasket I've had them go both ways
Even one collapsed ring will make a lot of blow by

Per the guy that i had gotten it from yes it has had blow by. but the machine shop said "That all chevys have blow by. its normal." <-- I call BS.

Horse Shite, Sounds like the Rings did'nt take, Re-Build time..........