Building a 140; questions

[merc644]

I am gathering enough spare parts to build my first Chrysler outboard (a 140) and have a few questions.
What made up the difference between the 135 powerhead and the 140? Were there other differences, ie could a 140 powerhead mount to a 135 leg?
Also wondering if the 1985 Force 125 was just a prop rated 1984 Chrysler 140 - were they identical motors? I have found an identification tag on the top inside of the leg but is there a separate id for the powerhead? Thank you!

 

[Frank Acampora]

Re: Building a 140; questions



First two photos are my 140, third photo is my 105. These engines use a one piece lower unit because 1. It looks better, and 2. It is about three MPH faster than the two piece lower.

The 125 is NOT a re-rated 140. The 125 has a 3.3125 bore and a 2.875 stroke. The 140 has a 3.375 bore and a 2.875 stroke. Chrysler used four variations of bore and stroke to develop from 90 to 150 Horsepower. For example: my 105 (which was later de-rated to 90) used a 3.3125 bore and a 2.80 stroke. The 120 was the same as was the 150. The 115 was like the 135. The 125 was the ONLY engine to use a 3.3125 bore and 2.875 stroke.

The 135 has a (I think) 3.375 bore and a 2.80 stroke. Aside from that, port timing is slightly different on each engine and that is primarily what sets the horsepower. Later Force 120s were the same bore/stroke. After Merc got their hands on them, they changed all engines including 2 cylinder 40 and 50 HP to 3.375 bore but kept the 125 at 3.3125.

All three and four cylinder engines use the same mounting bolt pattern and all will fit on the same leg EXCEPT the Force 70 and 75. As a matter of fact, All these engines will mount on either a two piece lower unit midleg or a one piece lower unit midleg. There is no ID for the powerhead BUT: Sometimes there is a stamped number on the block up top on the port side near the head. If you can find a number and can get to Merc, they can look it up in their database and tell you year and HP.--even for Chrysler blocks.

 

[merc644]

Re: Building a 140; questions

Thanks so much Frank for the information. I?ve heard a lot of poor and negative information regarding these motors and its refreshing and encouraging to hear someone knowledgeable about these motors. Those are awesome looking motors. I also hope to have a finely polished motor when I am done.
Last fall I purchased a well used and somewhat abused 1977 Conqueror. The cowl on the motor that came with the boat had been repainted/stickered to say ?Chrysler 140 Charger?. Along with the boat came a parts motor. The motor on the boat (which said 140) has a 135 lower unit according to the serial number tag. The spare motor was a 115. According to the previous owner he needed to ?fix? the powerhead since the pistons melted. I think he swapped the powerhead from the 115 to the 135 leg. Thus my question. Unfortunately he also melted the top two pistons of the ?new? powerhead. I understand 2 stokes enough to know that I need to richen the exhaust slightly and use octane boost or premium fuel. The previous owner ran full out on regular fuel that I suspect was not carefully mixed either.
As I understand, the only way to really know what powerhead I have is to measure bore and stroke(?). Since port timing is different between the 135 and 140, I guess I should be looking for a 140 motor or block prior to doing any work.(?) I was also wondering if there is any internal difference between the regular 140 and the Charger 140? Sorry for the long note, I have lots to learn about these.

 

[Frank Acampora]

Re: Building a 140; questions

Melted pistons are almost always because of a too lean setting of the carb low speed needle. These engines are about 9-1 compression and premium fuel is NOT necessary. It is, actually a waste of money. If you read some of my other posts, you will see that the low speed needles are always at manifold vacuum and always delivering fuel. Thus: If they are set too lean, the engine will also run lean at or near full throttle and preignite/detonate.

IF you can find an intertech manual, all carbs are listed along with correct high speed jet size. It would be useful to check these on your carbs.

The 140 engine block also internally had a splash of either red or green paint on the bottom of the bottom cylinder. If the block is off the leg and the exhaust downtube / match plate assembly is disconnected you can see this paint. The 140 was the only engine with the 3.375 bore and 2.875 stroke. There is no difference between any engine labelled "Charger" and the regular. Chrysler used the word charger and also the word "Skier" quite frequently. It was simply marketing.

Five horsepower is not a lot. It will translate to maybe 1 MPH more. Since you already have the 135 block, why not use it? Bore the bad cylinders. If the bottom two are good, it is not necessary but if you feel like it bore all four. Put in aftermarket pistons (I like Wiseco because they ar easy to install) and you are ready to go.

As an extra, before you ask, you can NOT bore out a 3.3125 cylinder to make it a 3.375. They use different sized cast-in sleeves. Although .040 pistons are offered, factory recommends only boring a MAX of .030.

 

[merc644]

Re: Building a 140; questions

I had read somewhere an advice to retard these motors from 32 deg. to 28, no reason was given but I assume it had to do with pre-ignition. I had thought to use premium and richen the carbs but am grateful for you sharing your expertise. Thanks also for the clarification regarding the Charger moniker. I will keep a lookout for a 140 block but if none comes up very soon I will rebuild the 135. Was thinking to use the Wiseco forged pistons as added insurance but I am guessing the forged pistons will give a little less holeshot.(?)
Was also wondering about the 150 ? was that only the stacker motor or was there a 4cyl 150hp regular production motor available from Chrysler? I have seen pictures of the Stacker motor but have never seen any other 150?s. Thanks again for the excellent information!

 

[Frank Acampora]

Re: Building a 140; questions



Here are some more photos. Note my 105 is stickered "Charger" I believe they took names from the car line--Challenger, Charger

Hole shot is a function of low end torque and horsepower available. Wiseco forged pistons have no effect on holeshot. Oh, OK---they do have less ring drag than stock so there might be some immeasurable improvement in holeshot. Timing was originally 32 BTDC but in late '70s or early '80s they reduced it to 30 BTDC because of low quality marina fuel. If you intend to only use pump gas it can be set at 32 with no harm.

You will find many opinions about Wiseco pistons. Some swear by them, some swear at them. But undoubtably, the forged pistons are stronger. Personally, I like them and have a set in my 140. I think you can now get them with the skirts coated with an anti-wear plating which also reduces friction.

I have never seen the 4 cylinder 150 in person. I do know that both it and the 135 came with stacks. These stacks last year went for 1600 bucks used on ebay.

Once you get that Challenger together, post a couple of photos and go over to The Chrysler Crew outboard marine website. They love them over there. It was a very progressive hull back then, and I like them as othe peoples boats. But for my own boat, I don't particularly care for the shape. I passed on a couple of cheap ones on craigslist.