Need more HP 90/115/140

[Dhadley]

Re: Need more HP 90/115/140

The 60* 150 is an outstanding choice. Excellent carb'd motor.

 

[WillyBWright]

Re: Need more HP 90/115/140

Jimbo, go to the BRP website (like I did) and look at the 1989 90 pistons (like i did) and the 1989 140 pistons (like I did) and you will see that the pistons ARE DIFFERENT (like I did).
(I already knew because I know the difference between a Looper and a Crossflow.)
Standard 90 piston 393271 = Crossflow
Stbd standard 140 piston 432970 = Looper
Port standard 140 piston 432969 = Looper

Crossflow pistons are the same for each side. The tops of the pistons kinda remind me of the Prudential Rock. Looper pistons are different for each side because of the skirt porting, and the tops are slightly domed. There is no skirt porting on crossflow pistons. The heads for each are designed accordingly, and the block porting for each is also designed accordingly. Cubes are the same because they have the same bore and stroke. But internally, they are completely different. Crossflow cylinders have intake porting on one side and exhaust porting on the opposite side. Loopers add intake porting on the top side. That's how they get 140Hp out of a 90Hp block. The main (but not nearly only) difference between the 90/115 and 120/140 is the carb throat diameter, or more precisely the venturi diameter. You cannot make a 90 into a 140, but you can make it into a 115.

When I started doing this, that 1989 was still ore in the ground, as were motors ten years older. Willy B Right!

(If I ever use a term like Young Whippersnappers, someone please shoot me. )

 

[jimmbo]

Re: Need more HP 90/115/140

Billy Be Wrong. What are you babbling about?

you said
"Originally Posted by WillyBWright
Same cranks and rods, yes. Same pistons, no. 85s to 115s are crossflows and 120s to 140s are loopers."

I said
" wrong

1977 thru 1984 99.6 cu.in. crossflow 140hp"

 

[Chinewalker]

Re: Need more HP 90/115/140

The only 140 OMC offered in 1989 was a blooper, not a crossflow...
- Scott

 

[jimmbo]

Re: Need more HP 90/115/140

The only 140 OMC offered in 1989 was a blooper, not a crossflow...
- Scott

I've never said otherwise.

The thread is labeled "Need more HP 90/115/140", which is what the 99.6 crossflow block is well known for.

The question was...

"Can anyone tell the the diffrence between 90/115/140 I was told it was only the carbs. I need a little more giddy up with out having to buy a new motor or rig. Right now I have a 1989 90 V4 VRO. Could I take this motor and turn it into a 115 or maybe even a 140 . Thanks"

It sounds like the person is asking can a 90hp be hopped up tp be a 140hp. A 90hp, whether it is crank rated(pre 1985) or prop rated(post 1984) can be turned into a 140, crank rated mind you.


As for the BRP website parts lists. I am not questioning the charts regarding the 1989 model year comparing crossflows to loopers. But I have noticed oddities in the lists, usually in older model years. Things like: where 2 or 3 different horse power ratings from the same size engine, every part is identical, no differences at all; Cases where the parts were different from one year to the next, the BRP sites says same part number. Maybe BRP is trying to reduce service parts inventory...

Now I'm babbling...

 

[Dhadley]

Re: Need more HP 90/115/140

Yes, the 110, 112 and 115 (after 1985) were all the same and rated at the prop. And they are basically the same as the 140's in 1984 & earlier. The variation in the "advertised horsepower", whether it's crank or prop rated, is the 10% rule set by the NMMA.

Yes, you can turn a 90 hp crossflow block into a 1984 140 or a 1985 115. It takes some machine work but once the block is stripped it's really pretty simple.

Will you see a difference between a 1989 90 and a 1989 115? Probably not unless you have a performance hull. Especially if both are set up at 5500.

Would I personally take apart a perfectly good running 90 to make it into a 115/140? Probably not on a recreational boat. Would I make a 90 into a 115/140 if it was apart already? Absolutely. It's not that big of a deal to do the porting and cut out the center rib in the exhaust. Would I square the ports, scollop the block & pistons? Nope, not worth it.

 

[rlee6427]

Re: Need more HP 90/115/140

I have an 1983 v4 90hp johnson
I looked at all the schematics and
it looks like that the pistons are the same
there are only a few differences between the 90 and the 140
can you guys double check me and tell me what you think.

 

[Chinewalker]

Re: Need more HP 90/115/140

RLee,
Lots of small differences as outlined in previous posts. All doable, but there is no bolt-on and go way to bump your 90 to a 140. Only way is to completely rebuild your 90 to 140 specs – opening up the porting, bigger carbs, exhaust tuner, etc.
- Scott

 

[rlee6427]

Re: Need more HP 90/115/140

any suggesions on where to find the parts that I need.

 

[brisboats]

Re: Need more HP 90/115/140

Try Ebay lots of V-4 carb sets there the 135hp heads come up often too.

brian

 

[gotboostedvr6]

Re: Need more HP 90/115/140

i have a full 140 conversion gotboostedeg@gmail.com

 

[avenger90]

Re: Need more HP 90/115/140

i have a 1983 90hp which did a piston ring recently and got myself some other parts so i can get a bit more hp from it
i got 2x225 carbs on a 140hp intake with boysen reeds and a 140hp exhaust housing with all block fillers for intake and exhaust and shaved 140hp heads with 30 tho pistons. i'm leaving the standard cylinder ports and was wondering what sort of power this would make. should i get the ports opened up same as the 140hp power head to help make use of the bigger carbies?

 

[jimmbo]

Re: Need more HP 90/115/140

i have a 1983 90hp which did a piston ring recently and got myself some other parts so i can get a bit more hp from it
i got 2x225 carbs on a 140hp intake with boysen reeds and a 140hp exhaust housing with all block fillers for intake and exhaust and shaved 140hp heads with 30 tho pistons. i'm leaving the standard cylinder ports and was wondering what sort of power this would make. should i get the ports opened up same as the 140hp power head to help make use of the bigger carbies?

Welcome to the board Avenger.

Well, unless you change the porting of the 90, adding bigger carbs and exhaust tuners isn't going to help one bit. In fact it will run worse than before. About the 225 carbs, since the 225 was a looper I doubt very much they will even fit a 90hp crossflow. The carb will fit a looper 140 intake, but then the looper intake will not fit a crossflow block.

 

[avenger90]

Re: Need more HP 90/115/140

the intake and carbies are off a custom super strangler apart from the exhaust which is a crossflow.
maybe at this stage i'll just fit the high comp heads and reeds
only thing i can find that changed between the 90 and 115 was the carbies...was there anything else?

 

[jimmbo]

Re: Need more HP 90/115/140

Porting is different on the 90 and 115. The 115 and the 140 had the same porting. Being that some of the 115s were crank rated and later ones were prop rated there are differences in exhaust systems. crank rated 115s had the flat exhaust cover, while the prop rated 115/112/110 had the bubbleback exhaust of the crank rated 140s. For all purposes the crank rated 140 and the prop rated 115/112/110 are the same engine.

 

[avenger90]

Re: Need more HP 90/115/140

those parts i was getting didn't happen the seller lost interest and hasn't answered his phone again...oh well
anyway picked up an 83 140hp and a 72 125hp and the 140hp is all good apart from missing carbies and the 125hp overheated and melted a piston
i was looking up specs on the carbies off the 125 and they seem to have bigger jets than the 140hp...is this correct?
the 125hp has the flat exhaust so i'm assuming it had the bigger carbies to make more than the 115hp.
also if i was to fit my 90hp carbies to a 140hp block would i starve it and kill it or would it just not rev as hard

cheers

 

[bob01081969]

Re: Need more HP 90/115/140

You want power go to this web site buy there V4 set up billet heads and their MAD FI then spend more money and buy a 16 inch mid section lets see hmmm right now were @ 5500.00 plus and it's still the same motor but if you want hp buy a new etec 115HO for around 7800.00 I am not being rude or a smart ***** just letting you know by the time you make a lot more power it will cost you more $$$ and with a new motor you will enjoy years of fishing, but unless your a person that likes to work on your motor more than fishing don't mess around to much you will reget it I hope you don't take this the wrong way. I run a 1988 V4 2.0 140 hp on a 16 ft ranger and I am adding a set of head from a 1987 1.8 140 I might get 2-3 mph maybe 300-400 more rpm but thats it. I want the MAD FI but not for power but better fuel metering. Hope this help.

 

[bob01081969]

Re: Need more HP 90/115/140

sorry here is the web site http://www.madefi.com/

 

[jimmbo]

Re: Need more HP 90/115/140

Not a lot of parts will swap between a 72 125hp and an 83 140. They do share the same displacement but the blocks are different and will not swap. As for the jets in the carbs, they might be bigger, but the air bleeds might be larger too. Lots of things affect the fuel delivery curve of a carb. Putting the 90 carbs on the 140 will give you better bottom end but the engine will be a little asthmatic at higher rpm, might even do some damage.

 

[avenger90]

Re: Need more HP 90/115/140

thanks, i'm not after big power but while i have the 90hp apart and require 1 new head...why not fit 140hp heads and so-on. maybe i won't get heaps more power but on such a little boat i will notice any extra power. if i could afford new i would buy new but boats are my second hobby to cars so this is on the back burner untill it gets a bit warmer. my turbocharged v8 ford is getting the attention now.