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Help with blow by


Woc123

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I want to know if the set up it has is right it has the crank case hose is going to a T then one hoes is going to the carburators and another hose is going to the hoes that goes to the head cover is that right or do they need to be individually and it doesnt have a pcv valve either i think the set up is wrong

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It sounds like both the valve cover and his crankcase breather are both feeding a single hose that is routed to the air filter housing. Sounds...custom.

 

You could always just remove the hose from the air filter housing. Route it down below the truck and let it vent to atmosphere. No sense in crudding up a nice Mikuni by blowing oily shit all over it.

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Thats exactly how it is mainer311 i dont know if thats how it should be or if the guy who had it before me ran it like that but to me it doesnt seem right . So your saying the hose that goes to the crank case just route it down below the truck?

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The valve cover hose is supposed to go to the air filter housing, the engine case breather tube is supposed to go to the PCV valve, the hoses are routed this way to keep the engine case/block clean(PCV valve) and to filter the air when the valve cover outlet sucks in air like when under acceleration.

The way you have it now will release any pressure created by blow-by to keep the blow-by from blowing your seals out and making it leak oil everywhere, but your oil will not last as long and the inside of the block will build up this layer of crud and make it a dirty mess when it is torn down, I have seen heads that had this brown/white gooey oil crud on everything when the valve cover was removed because the engine didn't have a PCV valve.

It has been a long time since I seen that gooey crud as that was when they didn't have PCV valves on engines, all gas engines have them now and have had them since the late 60s, back then one was lucky to get a 100,000 miles out of an engine, now 300,000 miles is not uncommon.

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Yes. Excessive pressure/smoke under the valve cover, sometimes thought to be caused by worn rings when it’s not.

 

No...

Valve seal, worn guides, worn seats don't create blow-by.

They will create smoke out of the tail pipe,

but that isn't blow-by.

 

There is no pressure at the valves that can in any way produce pressure in the head (and crankcase, as they are connected by rather large passages).

The intake valves will only create a vacuum, and that draws oil into the intake port when guides/seals are shot, and why an engine with worn out valve seals will smoke, especially at idle, and when slowing down, using the engine to brake, as when down shifting before a corner.

 

 

..... the inside of the block will build up this layer of crud and make it a dirty mess when it is torn down, I have seen heads that had this brown/white gooey oil crud on everything when the valve cover was removed because the engine didn't have a PCV

 

I haven't run anything crankcase related to a manifold, air cleaner, or carb in years, and I don't get any white crud in my engines.

Normally, white/brown crud is from minor head gasket leaks, and water mixing with the oil.

 

Maybe it's because I live in Texas, and condensation never builds up in an engine due to dry air, and mostly warm temps.

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So your saying the hose that goes to the crank case just route it down below the truck?

 

No, you want to keep the crankcase and valve cover hoses where they are, and remove the hose from the air filter housing. You still need to vent the upper and lower chambers, but you can do so by dumping the pressure to atmosphere down below the truck instead of back into the carb(s).

 

EDIT: I just noticed your location. Bakersfield, CA? If so, I'd be hesitant to mess with anything CARB related. Commiefornia isn't very car friendly. 

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