How to Reduce Blow-By? (modded engine question)

[xBrent92]

So my engine is further modified and has blow-by smoke and oil coming out of the exhaust.
At first the engine had a HUUGE amount of blow-by you would swear James Bond him self came by with his smoke screen.

So I used the governor hole as a vent,drilled it open just a tad more, and the blow-by substantially decreased but is still there. Wondering if i should have a bigger crank-case vent?

I did feel the pressure coming out of that governor hole/vent during cranking and a good amount of pressure gets pushed out of that hole. It's like releasing the compression from a compression tester at about 50psi in pulses.


I feel like I may have solved my own problem (at least partially) by typing it out So I may just fabricate a bigger vent somewhere.
So what do You say? I've heard about gas-porting before I knew what it was about. And low tension? piston rings.

Most likely more to it than i want to spend my money on.

 

[xBrent92]

Here's the current setup. The vent is only 1/4 inch. ..going to a gatorade catch bottle lol.

Sorry about the Ginormous pic. Will do better next time if needed.

 

[xBrent92]

Just thought i'd add it ONLY blows smoke when I come far off of idle.
So.. like I said earlier.. I'm pretty sure I answered my own question with needing a bigger vent.

Either way, this is what i'm up to at the moment. Along with a couple other special things.

 

[trinik7597]

If you have smoke and oil coming out of the exhaust chances are either your rings are not clocked right . Or your rings did not seat during break in even mild builds with no block vent will not smoke and blow oil out of the header . If you used synthetic oil during break in that could do it too ..

 

[xBrent92]

If you have smoke and oil coming out of the exhaust chances are either your rings are not clocked right . Or your rings did not seat during break in even mild builds with no block vent will not smoke and blow oil out of the header . If you used synthetic oil during break in that could do it too ..

I haven't had this problem with the .290 cam.Did break-in with conventional then switched to synthetic, then back to conventional 10w-40 but \/

I'm no longer mild. I'm now pushing a much higher lift. (See pic)
Those are 18# springs. I know I need stronger springs. Also the valve lash is in check.

 

[Prowler08]

i believe you have other issues besides venting... usually if you have too much crankcase pressure it will show at sidecover/gasket issues, or crank bearing seals leaking...

Also look at your head gasket by the oil galley ...they are prone to leaking/blowing there and leaking oil in the combustion chamber...

 

[xBrent92]

i believe you have other issues besides venting... usually if you have too much crankcase pressure it will show at sidecover/gasket issues, or crank bearing seals leaking...

Also look at your head gasket by the oil galley ...they are prone to leaking/blowing there and leaking oil in the combustion chamber...

I have had a minor side-cover leak for a while but mainly due to gasket damage from taking off and putting it back on repeatedly during my cam installation and clearance tests.

I need to put another hole in it anyways So guess we'll see what the outcome is.
and head gasket may have a super duper minor leak.

 

[CarPlayLB]

I have had a minor side-cover leak for a while but mainly due to gasket damage from taking off and putting it back on repeatedly during my cam installation and clearance tests.

I need to put another hole in it anyways So guess we'll see what the outcome is.
and head gasket may have a super duper minor leak.

Wowzers! Did you re-use the head gasket too? Cheap ain't fast, fast ain't cheap! Your breather goes to a soda bottle? With no vent? You leak oil from the side cover? A "super duper minor leak" will stay that way for a very short time. Combustion will eat it up. What kind of torque wrench do you have?
Buy a complete gasket set and redo your motor. While you are there, check and see why the rings are not sealing

 

[trinik7597]

You are worse than a mild build Brent . You have an ignorant build .. it's not crank case pressure . First of all you can not run more than a .275 lift with the hemi head with out issues that need to be addressed . And the reuse of stock gaskets that are junk to begin with is just a common no no ..

 

[xBrent92]

I'll just leave this pic here and back away.

 

[CarPlayLB]

I'll just leave this pic here and back away.

That proves nothing! I can do that with an HS30!

 

[xBrent92]

So I just drilled another 3/4" hole and guess what.... almost zero blow-by.
Not only is the throttle response much harder, but almost zero blow-by. It kinda hurts me to hear the engine rev so hard. But hey...power made.

 

[CarPlayLB]

Sorry Bud, no one else here measures success with blow by!

 

[minibikin']

.275!


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[FirePowerMinis]

You didn't reduce blow-by, you vented it. Leave the valve cover off, which based on the rusty rockers, you've tried, and it should rev like a Top Fueler.

Between the questionable hardware selection, reuse of gaskets and obviously absent grasp of internal combustion process, there's little doubt that you've merely crutched an ailment you created. It's likely that the head gasket is queefing combustion pressure, which is much higher than cranking pressure, in to the oil return. The only other likely scenario is that one of your random over-jetting tries has washed down the walls and ruined ring seal.

Real builders have pounded these for a decade or more and don't need to make them look like Medusa.

 

[CarPlayLB]

LMAO! Thanks FPM! :laugh:

 

[neo71665]

medusa, roflmao


Honestly dude you are cutting your leg off at the knee to stop your foot from bleeding. I'm the king of reusing parts I can (and prolly shouldn't) and make my own gaskets more often than not on non critical parts but the head gasket isn't something to do that with and expect good results.

 

[xBrent92]

You didn't reduce blow-by, you vented it. Leave the valve cover off, which based on the rusty rockers, you've tried, and it should rev like a Top Fueler.

Between the questionable hardware selection, reuse of gaskets and obviously absent grasp of internal combustion process, there's little doubt that you've merely crutched an ailment you created. It's likely that the head gasket is queefing combustion pressure, which is much higher than cranking pressure, in to the oil return. The only other likely scenario is that one of your random over-jetting tries has washed down the walls and ruined ring seal.

Real builders have pounded these for a decade or more and don't need to make them look like Medusa.

Good stuff ^
Already has started to look like Medusa.
With all that being said..Could I enlarge the hole inside the cylinder head above the intake rocker and be fine? :

Ok. Even though I rather make FelPro gaskets i'm guessing aftermarket fiber is the way to go.
Along with going back to conventional 10w-30 to re-seat the rings. The over-jet is due to an over-sized pilot jet with under-sized needle.

.275!


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This is starting to make sense now lol.
Just as I think i start to get into the advanced stuff..then the really advanced stuff.. then comes the engineering-level type of advanced stuff. Intriguing, it is.

 

[minibikin']

Just a tip, there is no reseat. Once the cylinder is glazed, you're done. It needs to be properly honed and fresh rings. Checking ring end gap and clocking/staggering the rings is a must.


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[Cuda54]

With all of the blow by I am with minibikin'. Time for new rings and honing and some new gaskets while your at it. Make sure to use regular oil for break in too. Did you replace the rod and flywheel? If not time for that to before it flies apart. You might want to recheck your jetting to see if it is right. What does your plug look like is it all black?