MCX knock sensors and drain plugs

[jwroblew]

I want to add ball valves on the block drain plugs were the knock sensors go. If I put a tee there, with the knock sensor on one end and the ball valve on the other, will the sensor still work properly?

[Timr245]

Well when I bout my 08 X-2 they were unplugged laying in the hull from winterization, and someone put the wrong older style gm sensors in the holes. Not wanting to mess with them til after the season I simply plugged them in and left em lay. Boat ran fine all summer so I assume doing what you want wont hurt a thing. I myself just did it, if I could figure out how to get a pic on here I'd show ya what I did.

[Timr245]

This what I did on both sides. ALL stainless ran about $110. You can skimp on valves if ya want, but that's not my thing.

[Rossterman]

I'd be careful modifying as folks have shown. Knock sensor retards the timing to prevent internal engine damage from pre-ignition. Making a change to location or laying in the bilge means you no longer have this protection for the engine.

In the old days, it wasn't uncommon for engine "pinging" to damage an engine if not addresse. Had a old neighbor that ran cheap gas in his mid 70s car and would hear it pinging all the way up the hill to his house. Told him he better run a higher octane gas but was too cheap to spend the $. Engine went ~ 2 years before it failed

[horseshoept]

I would be worried something like that would break off while in use.

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[carracer]

[ATTACH]102556[/ATTACH]

This what I did on both sides. ALL stainless ran about $110. You can skimp on valves if ya want, but that's not my thing.

Will you please post your parts list I am certainly interested in this idea. My concern is over the years the block threads will wear out and then what.... your idea will fix that concern.....


TKS..........

[FrankSchwab]

My concern is over the years the block threads will wear out and then what

Well, put Brass plugs in the holes. The likelihood of Brass wearing out the cast iron of the engine block is about nil. After 100 years of removing/replacing the brass plugs, they'll wear out and you can replace just the plugs.

I'm not a fan of these kinds of drain valves. When I pull my drain plugs, I normally have to stick a screwdriver in the hole to knock the scale loose before the engine will drain correctly. With a valve in place, you'd never be able to do that.

[FrankSchwab]

My concern is over the years the block threads will wear out and then what

Well, put Brass plugs in the holes. The likelihood of Brass wearing out the cast iron of the engine block is about nil. After 100 years of removing/replacing the brass plugs, they'll wear out and you can replace just the plugs.

I'm not a fan of these kinds of drain valves. When I pull my drain plugs, I normally have to stick a screwdriver in the hole to knock the scale loose before the engine will drain correctly. With a valve in place, you'd never be able to do that.

[mikeg205]

Well, put Brass plugs in the holes. The likelihood of Brass wearing out the cast iron of the engine block is about nil. After 100 years of removing/replacing the brass plugs, they'll wear out and you can replace just the plugs.

I'm not a fan of these kinds of drain valves. When I pull my drain plugs, I normally have to stick a screwdriver in the hole to knock the scale loose before the engine will drain correctly. With a valve in place, you'd never be able to do that.

Frank - didn't know you were that old..

[FrankSchwab]

Frank - didn't know you were that old..

Get off'n my lawn! Go on, get outta here!

Dang whippersnappers!

[mikeg205]

Get off'n my lawn! Go on, get outta here!

Dang whippersnappers!

[André]

... When I pull my drain plugs, I normally have to stick a screwdriver in the hole to knock the scale loose before the engine will drain correctly. With a valve in place, you'd never be able to do that.

That X 100!!!

[Spork]

[ATTACH]102556[/ATTACH]

This what I did on both sides. ALL stainless ran about $110. You can skimp on valves if ya want, but that's not my thing.

I guess buying a new engine when this one detonates to death is your thing...

I would be VERY concerned that the knock sensor is not operating as designed. With your knock sensor not properly mounted on the cylinder block the sensor can not detect vibrations thus can not adjust timing and reduce spark knock. Some knock sensors are mounted in different locations but the manufacturer tunes them for specific installations. This modification is a very bad idea...

[mikeg205]

I want to add ball valves on the block drain plugs were the knock sensors go. If I put a tee there, with the knock sensor on one end and the ball valve on the other, will the sensor still work properly?

I spent some time thinking about this... why add a valve? The cooling system is not under and real pressure. I addition the knock sensor does not need to be over torqued. I put a keep a little anti-sieze on threads and install and torque an 1/8th of a turn - just tight enough to keep it from turning itself out.

Always need a wrench to remove that 1/8th of a turn...

I also agree with James... adding the other parts can change resonance of engine block - thus allowing for sensing errors. The knock sensor is a very sensitive microphone...

I would not do it.

[Indyxc]

[ATTACH]102556[/ATTACH]

This what I did on both sides. ALL stainless ran about $110. You can skimp on valves if ya want, but that's not my thing.

This can be a very bad idea. The resonance frequency of the knock sensor is matched to the knock frequency of the engine at that location.

Move the sensor away from the block, and essentially dampen the frequency with the stainless steel fittings, and you are possibly shifting the frequency of vibration at the knock sensor.

This is a very similiar knock sensor,

http://delphi.com/pdf/ppd/sensors/et_broadband.pdf

It all depends on how the frequency was shifted and dampened. I personally wouldn't do it.