150 Johnson Pyrometer

[DieselDood]

Hey guys,
If you couldn't tell my the user name, I'm a diesel freak.

One of the big tools we use to know how close to the ragged edge we are is a Pyro.
I just picked up a 150hp Johnson (crossflow), and while I'm not looking to make it the fastest thing in my bass club... I may play with it a little. (bigger carbs, intake stuffers and bubble back)

Does anyone use a pyro to help tell if it's going to lean? Or maybe a wide band O2?

I hate the idea that the only way I can tell if this thing is running right is by the color of the spark plugs. That doesn't do me any good when I'm fishing a tourney and I'm 10 miles from the landing running WOT...

Thanks!

[Motv18]

Yep, both.

mainly the racers. As boats need to run 11:1 ish or full power to maintain speed due to the drag from water.

that lends itself to just reading pistons and plugs. Without having to worry about coasting it letting off to go the speed limit.

it is more accurate and could save money if you can optimize fuel consumption.

[DieselDood]

Awesome. Now for the fun question....

Where is the best place to install such things on a CrossFlow?

My main concern is... well these old motors are getting harder to come by, and if lets say... I have one cylinder lean out, I would see it on the Pyro and the Wide Band. I could shut it down or at least back it down to save it. Rebuilding carbs, quick, easy and cheap. Rebuilding a motor isn't. LOL

Thanks!

[Machinist76]

Following.
I plan to install a 4 channel gauge on my 3.0L for two EGT and two CHT

[powerabout]

Awesome. Now for the fun question....

Where is the best place to install such things on a CrossFlow?

My main concern is... well these old motors are getting harder to come by, and if lets say... I have one cylinder lean out, I would see it on the Pyro and the Wide Band. I could shut it down or at least back it down to save it. Rebuilding carbs, quick, easy and cheap. Rebuilding a motor isn't. LOL

Thanks!

very hard to catch a 2 stroke underload with a raised egt, it goes bang before you know in most cases
Good tuning tool for modded engines, get a baseline when its stock and mod from there
I have not done it but would think in from aft in the exhaust adapter just below where the powerhead bolts on.
I'm sure Racer knows so hopefully he might jump in with some numbers as well?

[DieselDood]

very hard to catch a 2 stroke underload with a raised egt, it goes bang before you know in most cases
Good tuning tool for modded engines, get a baseline when its stock and mod from there
I have not done it but would think in from aft in the exhaust adapter just below where the powerhead bolts on.
I'm sure Racer knows so hopefully he might jump in with some numbers as well?

Really? I'm surprised you wouldn't see a 50-100degree rise in EGT temps. Although I've never ran a Pyro/EGT on a gasser.

Although that should show up on the wide band pretty clear I'd think. (at least once you know what you see for a "normal" reading)

I was thinking they would go into say the exhaust plate, but the lower housing makes more sense I suppose as that is where the exhaust combines and is headed out.

On the diesels we try and stay as close to the head as we can, but where things are still combined... and before the turbo for the most accurate reading.

Humm... some good food for thought here.
There is one gentleman in my area that is well known, but last time I reached out to him he didn't reply (looking for parts). I don't like bugging someone I don't know well, but I may reach out to him again for this. I'm guessing he's done some things along these lines before.

Being I already have one motor to rebuild, I'd rather not make it 2, if you know what I mean!

Thanks
Josh

[Dave Strong]

Your best off reading plugs and pistons, as was said most times by the time you see an issue on a egt it just tells you your cooked. In a lake boat you reading 3 cyl at a time and probe placement has a huge effect on temp readings.


Dave

[David - WI]

A "knock" (detonation) sensor would be the most useful. https://www.summitracing.com/parts/cei-102001

One problem with EGT's is that EGT goes DOWN once the engine starts to knock, even though the piston is melting from being too lean. Plus you don't have to "read" the knock sensor or try to figure out why it's going up (or down) like an EGT, just recognize the red led is "danger".

[DieselDood]

A "knock" (detonation) sensor would be the most useful. https://www.summitracing.com/parts/cei-102001

One problem with EGT's is that EGT goes DOWN once the engine starts to knock, even though the piston is melting from being too lean. Plus you don't have to "read" the knock sensor or try to figure out why it's going up (or down) like an EGT, just recognize the red led is "danger".

That's interesting! I didn't think of it that way!
Diesels knock all the time.. if they don't... they aren't running! LOL

Won't you pick up anything on a Wide Band O2 either? I'd think since you'd be lean on one cylinder, you'd see that on such a small displacement. I'm just guessing though.

[powerabout]

the 02 sensor doesnt last long with oil on it.
Yam actually had one on one model

[David - WI]

I have a wide-band O2 setup and thought about running it on my outboard... but I think the sensor will end up getting submerged in water and I don't think it will like it. I'm not sure, never got that far (trying it).

And then you have to make sure all the sealants, oil, etc on these old motors are O2 sensor safe, I guess?

[powerabout]

I have a wide-band O2 setup and thought about running it on my outboard... but I think the sensor will end up getting submerged in water and I don't think it will like it. I'm not sure, never go that far (trying it).

And then you have to make sure all the sealants, oil, etc on these old motors are O2 sensor safe, I guess?
I think you need to put it in a tube so exhaust doesnt blow on it

[Dave Strong]

I think you need to put it in a tube so exhaust doesnt blow on it

They tend to work better when they are in the exhaust flow.

Dave

[David - WI]

Keep in mind too, that knock is "instant" meaning you get the reading immediately... not after the probe heats up.
If it gets lean it will knock... but also if the fuel (octane) is bad or you have too much ignition advance, etc.
I think the knock sensor gives you the "broadest" picture of impending doom... it would be my choice. :cheers:

Knock is always bad... 1100F EGT can be good or bad, EGT going up can be good or bad, EGT going down can be good or bad depending on what load, rpm, throttle opening, etc are at that moment. You have to think a lot about what the EGT is telling you, and you have seconds to do it.

[DieselDood]

I like the knock sensor idea. The one that was posted above is just to read an existing sensor, but I'll dig into it some more and see what I can come up with.

EGT can be confusing I agree. But I'm used to looking at that and knowing what is "normal" (which could be abnormal on gas) and knowing what to do. On diesel we can run 1250 and less. 1250 is the max... and beyond that you better not be there long. BUT they come back down fast. Pistons are huge and heavy. I'm sure a small engine like this wouldn't take as much heat before things go badly.

[powerabout]

Not so sure how hard it is to get a knock sensor to work?
I thought its lots of time on a dyno tuning the software so it knows what a knock sounds like?

[DieselDood]

Not so sure how hard it is to get a knock sensor to work?
I thought its lots of time on a dyno tuning the software so it knows what a knock sounds like?

In the Auto industry they have been used for MANY years, so that part has already been established. It's basically a pezio electric sensor that when it picks up a knock through abnormal vibrations sends a small voltage to the computer, or in this case a gauge.

What he is saying makes perfect sense. Some tweaking and tuning may be needed, but the theory behind it is sound.

Although you may be right on needing a dyno to actually tune it in.

Humm... Maybe I will just run it till it blows up... rebuild it and do it again... LOL JK

[powerabout]

In the Auto industry they have been used for MANY years, so that part has already been established. It's basically a pezio electric sensor that when it picks up a knock through abnormal vibrations sends a small voltage to the computer, or in this case a gauge.

What he is saying makes perfect sense. Some tweaking and tuning may be needed, but the theory behind it is sound.

Although you may be right on needing a dyno to actually tune it in.

Humm... Maybe I will just run it till it blows up... rebuild it and do it again... LOL JK
you cant hear a 2 stroke detonate like a car engine so its not that easy
We would all be using them if it was an easy install...

[David - WI]

Oh brother. :rolleyes:
You can hear a 2-stroke detonating on the dyno or at 120mph on a snowmobile wearing a helmet, if you know what to listen for.
The "learning" and "filtering" is mainly a 4-stroke thing... valve & lifter noise that two-strokes don't have. But really the thing is, Mercury uses knock sensors on 2-stroke outboards (see #18) http://www.marineengine.com/parts/mercury-outboard-parts/v200-efi-25l/1b227000-up-usa/cylinder-head

[Dave Strong]

Oh brother. :rolleyes:
You can hear a 2-stroke detonating on the dyno or at 120mph on a snowmobile wearing a helmet, if you know what to listen for.
The "learning" and "filtering" is mainly a 4-stroke thing... valve & lifter noise that two-strokes don't have. But really the thing is, Mercury uses knock sensors on 2-stroke outboards (see #18) http://www.marineengine.com/parts/mercury-outboard-parts/v200-efi-25l/1b227000-up-usa/cylinder-head

And how many Lazer EFI's have melted down with that feature? Carb motor with plug checks with each mod and leave it rich you good to go. Drag racing jetting on the edge looking for a tenth of a second maybe. Lake boat no need, buld it safe and use proven mods. You start trying crazy stuff you will wind up with a big box of toasted aluminum and no amount of sensors will prevent it. I have my own box of shame that shows how fast sh*t happens in a 2 stroke.


Dave

[baja200merk]

The big dogs have a probe in each cyl through a rifled head arid then use a ecu like link emtron motec etc. which monitors it 1000 times a second and can pull Timing or add fuel to each individual cyl. It’s a pretty crude way to tune especially without a dyno.

my 12valve has been over 2000* in short pulls before I built the compound turbo setup :D

[H2OPERF]

Save your self some time pick up an 83-85ish 235hp powerhead and adapter and go from there, it will be a world of diff from the 150 and they can be found cheap. These motors need to be run well on the rich side with 93 min octane even on stock compression to be rally safe. The deflectors hold heat and will melt the corners off in a milisecond so if you do much with compression your gonna need better fuel and more of it with less timing when the rpm starts going up..

[DieselDood]

my 12valve has been over 2000* in short pulls before I built the compound turbo setup :D

Ya... been there... many times on my 12v.. lol More than I should admit to really. Somehow #6 has stayed in good shape....

My worst was not letting out racing a guy up hill pulling 20k. Crested the hill (won) looked over to the pyro pegged, and started coasting down the other side... it was a solid 15 seconds before it came off the peg.... I thought for sure it was done for!

[DieselDood]

Save your self some time pick up an 83-85ish 235hp powerhead and adapter and go from there, it will be a world of diff from the 150 and they can be found cheap. These motors need to be run well on the rich side with 93 min octane even on stock compression to be rally safe. The deflectors hold heat and will melt the corners off in a milisecond so if you do much with compression your gonna need better fuel and more of it with less timing when the rpm starts going up..

I'm looking for such a thing that isn't already blown up.... so far no such luck. I've got one running 150ish (cover says 150, tilt tag shows 175, water pump is 83ish, and I haven't figured out which power packs it has yet... or pulled the heads)
I have another 175 that needs a rebuild. Someone before me rebuilt it and shouldn't be touching wrenches.... (4 different bore sizes, rings installed wrong causing a cracked sleeve, and another piston melted)

[H2OPERF]

There's a seadrive on ebay but its in NC, kinda far lol.. as you may know the last few years (87-89? dont remember when they droped it) of the 175hp was the 235 big bore bubble back block..

[rjdubiel]

Find a 235, or I can sell you a nitrous system!
459874
459875

[FORBESAUTO]

From my experience, I’ve found that my behind tells something’s about to go south before I see anything on a gauge. I used to run pyros and swapped them out for dual water temp gauges. I felt the engine bow up and could get out of it and shut it down way before I noticed an EGT issue. Yeah, there was damage, but not catastrophic. It happens so fast with these things is hard to totally dodge it regardless if the tune is right. Like stated earlier, set her up a tad on the rich side and make sure advanced timing is right on all cylinders and enjoy it. When your tail says what was that? Get out of it and shut it down as fast as possible :eek:

[DieselDood]

Find a 235, or I can sell you a nitrous system!
459874
459875

I'm thinking the Nitrous may be tough to hide from the Bass inspectors..... LOL

[racervboat]

I'm thinking the Nitrous may be tough to hide from the Bass inspectors..... LOL RJ will give you a package deal on all his omc crossflow v-6 stuff so you will have plenty of stuff to blow up.:D

[rjdubiel]

I got 3 flatback powerheads, all running. carbs, heads mids, lowers. all sorts of junk I cant give away!

[racervboat]

There ya go diesel your dialed in now.:D

[racervboat]

I got 3 flatback powerheads, all running. carbs, heads mids, lowers. all sorts of junk I cant give away!Sure ya want to trust egt's on that brand new 245hp powerhead this spring ?:D

[rjdubiel]

Sure ya want to trust egt's on that brand new 245hp powerhead this spring ?:D

Don't worry, I know a guy that will put sleeves in all day. I just gotta buy beer!

[racervboat]

Can weld up those windows as well too.:cheers:

[gfinch]

Drilled head studs. All tips installed at the same height in each port. All exposed tip type. O2 works. Really need EFI and a true dyno.

[DieselDood]

I got 3 flatback powerheads, all running. carbs, heads mids, lowers. all sorts of junk I cant give away!

Well we may have to talk then! Especially since you aren't all that far from me! I'm about 10min from Faribault on Hwy 60 in a little town called Morristown.

[DieselDood]

Don't worry, I know a guy that will put sleeves in all day. I just gotta buy beer!

That may be the biggest thing I'll have to chat with you about. All the machine shops around me don't know how to do a crossflow anymore (if they ever did)
I have a 175 block that needs 4 sleeves.

[mrichartz]

I got 3 flatback powerheads, all running. carbs, heads mids, lowers. all sorts of junk I cant give away!

Give away!? just have to ask the right person hell would have definitely been in line..lol



Michael

[racervboat]

That may be the biggest thing I'll have to chat with you about. All the machine shops around me don't know how to do a crossflow anymore (if they ever did)
I have a 175 block that needs 4 sleeves.Missed that were just in the north metro area.

[mrichartz]

Find a 235, or I can sell you a nitrous system!
459874
459875

Nitrous!,? ....:D

[racervboat]

Give away!? just have to ask the right person hell would have definitely been in line..lol



Michael You still are.

[racervboat]

Nitrous!,? ....:D Yep we are having a hard time blowing it up-timex thing I guess.:D

[mrichartz]

Yep we are having a hard time blowing it up-timex thing I guess.:D

That's got to be fun when adding lots of power and not blowing up..and easy enough add a bigger shot till it does.. lol....how big of a shot?

[racervboat]

Nitrous!,? ....:Dhttps://youtu.be/XDeDfmkYhbA

[racervboat]

https://youtu.be/XDeDfmkYhbA 50hp for now got bigger jets,went from 87mph to 93mph in 6-7 secs.

[mrichartz]

https://youtu.be/XDeDfmkYhbA

Nice to have a Dyno handy..really want Dyno mine..nobody around here has one at least that works over 250hp


Michael.

[rjdubiel]

https://youtu.be/XDeDfmkYhbA

That old flatback did 87 on the viper before nitrous, ran 93 with nitrous but never strung it out, pulled it off and put a merc on last summer. Basically stock motor, just some 235 heads and 1 3/8 carbs. It will pop if we cut back on fuel with the wet shot.