chrysler 140's

[thompy]

in buying a 20 ft. banshee tunnel, and by brother has a couple 140,s one is in good shape 140-145 comp the other ran good but know there are alot of hours on it, and needs parts for the cdi that were robbed for the other engine.
now i would like to rebuild both engines and run twins, any tricks as far as cleaning up ports and castings, reed valves, and are props available above the 19 pitch, these are 78-79 motors, are these through exauste[props]. i will run one motor till they both get a RB

 

[thompy]

Re: chrysler 140's

seems to be very little info on the 140 hp motors, could anybody give me a name to a chrysler guru, thank you

 

[huskerdaninva]

Re: chrysler 140's

Try Franz at FranzMarine@aol.com He is very knowledgeable.
Dan

 

[thompy]

Re: chrysler 140's

thanks husker

 

[Frank Acampora]

Re: chrysler 140's

The 140 is one of the better engines Chrysler made. It is big bore-3.375, and long stroke-2.875 so is a combination of 120 and 125 engine set-ups. It is relatively potent--I had an 18 foot closed bow Renken that did 42 MPH, but will not stand up to a Merc 140.

You can port them, but best not to port the exhaust side, only the bypass. They will gain a little power but the three cylinder engines respond better to porting.

You can add aftermarket reeds like Boyeson or-- I forget the name--fiberglass reeds.

If you replace the 1.7 to 1 lower unit with a 2 to 1 ratio lower, you will get a bit better performance.

Props are available in 21, 23, and 25 pitch but the 23 and 25 are difficult to find. Some Merc props from small merc lower units will fit too. Note the 25 pitch bronze Merc racing prop in the photo.


Attached are a couple of photos.
That boat is a 21 foot cuddy and on a good day will run 39 MPH

 

[thompy]

Re: chrysler 140's

thanks Frank thats the kind of info im looking for

 

[thompy]

Re: chrysler 140's

the Banshee, he still has to pull his stuff off it, should have it by next weekend

 

[Frank Acampora]

Re: chrysler 140's

It is so frustrating: I write a long reply and the damn board cuts me out and of course deletes it. So now I write a short one and edit it 5 times.

I didn't fully read the first post. With that Banshee hull, Run the engine high. the water intakes are in the gearcase bullet so you will be able to get it up on the transom. Try Franz and see if he has a 12 X 21 stock Chrysler stainless cleaver prop. That prop can be run high. It will probably give you 5900-6000 RPM, maybe more. (Yeah, Yeah. I know the factory rating is 4500-5500, but you can't go fast without going fast.) Don't bother with an aluminum prop. It will cost you at least 400 RPM.

If you do decide to port the block, do not port the exhaust side. You will actually lose power. This is because the exhaust ports are about 120 degrees open while the crank is 90 degrees apart. #2 and #3 fire next to each other and into a common exhaust chest. Gases blow back during the 30 degree overlap. If you have a way to isolate the cylinders, then feel free to port the exhaust. Proper porting adds about 5-10 HP per CYLINDER.

Look again at the first photo. See the exhaust holes drilled above the cavitation plate? Four on each side. There is room for more but be careful where you start so you don't drill into the oil chamber. They only add a little relief and are noisy, but on your hull, everything counts. If you do drill the holes, mine are 3/8 inch chamfered with a 3/4 countersink. Shaping them this way increases the capability for gas flow even though the hole is the same size. If you do, please use a template--I used perforated angle to space the holes--make it look nice. Professional!

If I remember, they made the 140 for a number of years and in both two piece and one piece lower units. The one piece is about 2-3 MPH faster. Neither is thru-hub exhaust and neither is dual exhaust. The only exhaust exit is through the snout behind the prop.

 

[thompy]

Re: chrysler 140's

thanks again Frank, I'm not looking to go nuts on this ride but if I have it apart I will clean it up, 2&3 sharing the same exhaust chamber, is a copout on the corporate level, so on the transfer ports did you drop the intake or just match the dimensions of the original O ports, I've done a bit of porting on snowmobiles and bikes, and have been impressed with what a little dremeling can do. anything to clean up in the crank area to transfer ports?
the Banshee has a 16" setback on it so I'm glad the Chrysler has a fairly low water P.U.
this is going to be a family boat, some towing and fishing to go along with seeing what it will do, so i guess a jack plate will be in order to swap out props for the intended use of the day
so what kind of RPM will these motors take before self destructing through crank harmonics.
i was working on a CobraJet project that needed a complete rebuild and this was a deal i couldn't pass up to get on the water now. thanks again Frank, you have cleared up my major concerns and questions and got my mind going in the right direction

 

[Frank Acampora]

Re: chrysler 140's

I keep the port timing the same but just square them to increase possible gas flow. I have not yet, but will on the next engine experiment with through the piston skirt additional porting to increase the area of the bypass channel.

The bottom of the bypass ports are blinded by the piston at bottom dead center however, I fair the bottoms so that the gas flow "sees" a bigger port and is directed a little better directionally into the combustion chamber.

As far as RPM, with a 2.875 crank throw, they are probably good up to 10,000 (remember a properly built Chev 283 could turn that high without the oil pan looking like a sack of walnuts?)but above 6 the reeds are probably going to flutter or float so useable power is probably developed at say, less than 7000. My stock 125 is turning 5900 and still seems strong. Someday I will experiment to see what she can actually do before the power curve drops radically.

 

[thompy]

Re: chrysler 140's

i would think the Boyseen reeds would take more RPM but have read if you have a lean low idle they can get eaten, when the engine sneezes, how many reed packs on the 140, i dont imagine you could get much over 7500 with out a tuned exhaust anyhow

 

[Frank Acampora]

Re: chrysler 140's

Four cylinder engine, four Vee blocks with reeds on both sides. Five petals each side. Some came with a block of five petals, some came with a block of four and a single reed petal. Reeds and reed blocks are the same for all 3 and 4 cylinder engines earlier than mid 1990s. After then, Merc changed to rubber covered reed blocks with four square end petals on each side. They are more responsive but slightly thinner than older round tip reeds. They appear to not last as long and shed petals now and again, whereas the older ones will last (apparently) forever.

Boyeson is the same reed set for all four cylinder engines prior to the Square end reeds. That is, order reeds for a 105 through 150 and they will be correct.

Personally, I have done some engines with Boyeson reeds and I was not really impressed by them--appearance, not performance. Can not comment on performance as I have no direct comparison. Not much plastic for 125 bucks ( and price has probably gone up)

 

[thompy]

Re: chrysler 140's

i would think you would pick up a little bottom end torque with some on top end as well with them beeing a 2 stage reed, mabey ill just save my money

 

[Frank Acampora]

Re: chrysler 140's

Chrysler did offer a water cooled tuned exhaust on their racing 150. It was two pipes and manifolds that took the place of the exhaust cover and separated the cylinders. VERY sharp looking, sticking out the side of the engine cover. Last set I saw went for 1600 bucks with the racing lower unit on ebay. Too rich for my blood.

Remember: You have a 50 year old design, straight cross flow engine. You can make some improvements, but there is not a lot you can do with it.

 

[thompy]

Re: chrysler 140's

I've seen some pics of that set up, don't think people would appreciate the noise level on those, nor myself but they do look cool, is there anything that can be done to have a true trim setup on these

 

[thompy]

Re: chrysler 140's

well i finally got my banshee home, pressure washed it and going to try and hand buff it and wax it, wish i had a buffer, plenty of oxidation will take some pics if i dont fall asleep[3rd shifter] or get rained on

 

[thompy]

Re: chrysler 140's

after a little cleaning, tomorrow i have to pull the tanks and clean them, and vac out the needles

 

[thompy]

Re: chrysler 140's

well i pulled the tanks and flushed them, installed all new hose, tank selector valve and squeeze bulb, along with new front seats, need to get the carpeting back in and make a rear seat, and get up north to pickup my engine, kind of tied up with replacing my house's roof. wish the color of my seats matched a little better

 

[thompy]

Re: chrysler 140's

well i finally got one of the 140,s have a few issues to work through, first how hard is it to change the lower unit, the skag on the one I'm using is broken off, then i need a new steering helm joint and last but not least is the ignition on this one died at one point, my brother swapped out distributors, but now the timing belt is riding high and rubbing the flywheel, so im getting there

 

[thompy]

Re: chrysler 140's

A couple pics