Exhaust valve question for Briggs Intek 20hp

namari

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I just did a rebuild on an Intek MOD: 331777 2372 G5, CODE: 110502ZD. The retailer that sold me the camshaft sent me the wrong part, but it looked very close with the exception that I had to cut out a slot for the pump stem. Anyway, I get it all put back together and there is too much compression, like the ACR is broken. I set the exhaust valve lash to release enough pressure to start and run the machine. Doing so allows it to run nice, full throttle, idle, no backfiring etc. But it's nowhere near spec and I'm just wondering what the negative effects might be in leaving the lash set hard like that on the exhaust side? It's been a long day, and I'm a little tired, so forgive the question if it's dumb. I am planning on tearing the engine back down and putting in the correct cam. Just looking for some of the experts to chime in on the ill mechanical effects doing this. Thank you all!
 

bertsmobile1

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The ACR generally works on the inlet valve now days.
Totally wrong for the engine but EPA regulations as apparently the assive amount of unburned fuel released by the ACR will cause your kids to grow 5 heads , lawns to grow upside down & the world as we know it to cease to exist.
 

Tinkerer200

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"The ACR generally works on the inlet valve now days."

The compression release of most B&S engines has utilized the Intake Valve for many years, years before the EPA entered the picture. You need to carefully adjust the Intake Valve, I have detailed Instructions for setting it correctly plus I can send you a Service Manual for your engine IF you like. Address below, put in proper format and remind me engine model number and what you want.

Walt Conner
wconner5 at frontier dot com
 

namari

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Thank you guys for your responses. My specific question: "What are the negative effects on the machine from permanently setting your exhaust valve slightly open so as to relieve crankcase pressure when the ACR is not working properly?" has yet to be answered. I know that there would be a loss of compression, but the machine has plenty of compression to run. I'm looking for the long term negatives. Anyone? Thank you!
 

primerbulb120

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Your exhaust valve would get burned up.
 

bertsmobile1

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Why you would want to do this is beyond imagination
And if you have to ask this shows you have no idea about internal combustion engines
So go ahead with the self reassuring opinion that you know more about the engine than the engineers who made it.
 

Tinkerer200

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Thank you guys for your responses. My specific question: "What are the negative effects on the machine from permanently setting your exhaust valve slightly open so as to relieve crankcase pressure when the ACR is not working properly?" has yet to be answered. I know that there would be a loss of compression, but the machine has plenty of compression to run. I'm looking for the long term negatives. Anyone? Thank you![/QUOT

Seems to me it is self explanatory, you said you got a new camshaft then you need to see why the ACR is not working on your new camshaft. Would you loosen the spark plug to relieve compression? Makes as much sense as cracking exhaust valve open.

Walt Conner
 

namari

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Thanks again everyone for chiming in. primerbulb120 nailed it. Your exhaust system, muffler and all would eventually get red hot and burn up. Good discussion!
 
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