85 hp or 140?

[wayneo99]

Been using this site for a few years and its great!

I have a 1979 85 johnson knock on wood it runs good, leaky trim pump and lower unit but i can manage that,

Just bought a mid 1983ish 140 for the lower unit.

it has very similar parts and block style but a few differnet things like

the primer system
larger exhaust plate
Voltage regulator? on top of block between heads.
same internal block parts or different animal internally?

my major question is.... is there a MAJOR difference in performance between the 140 and the 85? my 85 is on a 17 montauk it shoots out of the whole and flies right along.


thanks guys

 

[emdsapmgr]

Re: 85 hp or 140?

Both engines are 99.6 cubic inches and use the same pistons, cranks. If you put the two engines on identical boats and raced from a dead stop-both engines might have similar holeshots. Almost immediatedly the 140 will start to walk away from the 85-big time. The 140 has larger carbs, special tuned exhaust, intake filler blocks, higher porting and higher compression heads. It will swing a larger prop size and will eventually leave the 85 in the dust.

 

[wayneo99]

Re: 85 hp or 140?

Emd
Thank you for the information
I used the top secret file to determine the gear case interchangeability. I plan on swapping the lower unit.
Do the lower units have the same gear ratio?
If the gear ratios are the same thing I assume I will use the same prop im using in my 85

 

[emdsapmgr]

Re: 85 hp or 140?

Most of these V4 crossflows have a 2:1 gear ratio. At least from 1982 they do. There are some exceptions. In 1977, the 85/115 gear ratio was 13:26, the 140 gear ratio was 13:25. Slightly taller ratio on the 140. Either one will surely work with your 85, though you may have to switch a pitch on the prop if you have one of these 77 140 gearcases. One other thing. The mechanical shift gearcases from 73 through 77 all use the belcrank shifting lever under the bottom carb. The 78 and later don't. The 73-77 cases shift backward from the 78 and up.

 

[wayneo99]

Re: 85 hp or 140?

the 140 is a confirmed 1983.
im going to put it on my 1979 85
should be good to go

I will be compression testing the power head today and keep you posted
thanks

 

[jimmbo]

Re: 85 hp or 140?

Both engines are 99.6 cubic inches and use the same pistons, cranks. If you put the two engines on identical boats and raced from a dead stop-both engines might have similar holeshots. Almost immediatedly the 140 will start to walk away from the 85-big time. The 140 has larger carbs, special tuned exhaust, intake filler blocks, higher porting and higher compression heads. It will swing a larger prop size and will eventually leave the 85 in the dust.

The 85 will have better holeshot than the 140. The larger carbs, porting and the tuning of the exhaust move the peak torque and hp higher in the rpm range but lessen it at lower rpm. The 140 will be behind the 85 for several seconds until it gets higher in rpm where its torque increases. In theory, on identical boats loaded equally, the 140 should be about 11mph faster.

 

[wayneo99]

Re: 85 hp or 140?

Compression is even on all cylinders @90-95 psi
Great spark
Carbs Have been sitting for a few years I'm sure they'll need to be cleaned
Drive shaft oil seal leaks real bad
Not sure about the prop shaft seal yet
Definitely a good parts motor or spare power head if my 85 blows up

 

[wayneo99]

Re: 85 hp or 140?

ok guys both engines have broken rings and banged up heads. Im thinking about rebuilding the original parts motor 83 140.
the heads look different than whats on the 85hp. since one side is beat up from the broken ring where can i find the proper head for the 140? are those specific heads to the 140?

I have to talk to a few local machine shops to see if they can bore it out etc. anyhting specifc to look for in their services.?

 

[Chinewalker]

Re: 85 hp or 140?

If you're looking for heads, you want ones with sequential casting numbers. The casting numbers will be in a small rounded area on the outer face of the head. Getting sequential head numbers will assure you get matching heads. A long-established marina may have a graveyard. Showing up at coffee time with a box of donuts might get you a pass to the graveyard to poke around for parts. Failing that, they show up on eBay, too...

I would take the block to a marina and see who they send them to. Most do not do them in-house.

 

[V153]

Re: 85 hp or 140?

Seems to me the logical choice would be to rebuild the larger newer 140. 55 additional hp is hard to argue with. Your 85 is definitely crank rated hp. The 140 may or may not be prop rated hp, depending on who ya ask. Plus it's a year before VRO which is probly a good thing.

I recently replaced an '86 90 (prop rated hp) with an '83 140 (?). Bears mention the 90 was 'breathed' on a lil. Bored .030, 140 carbs, some porting, aftermarket reed kit etc. The 140 is bone stock but has increased my top end from a lil under 55 mph to nearly 63?!

Far as holeshot goes this thing comes outa the hole like a freakin ballistic missle. No offense Jimmbo but the 140 will smoke a 85/90 on a bad day. Ironically the 140 spins the same props @ a lower rpm? Still tryin to figger that one out ...

 

[phillnjack2]

Re: 85 hp or 140?

This seems a bit strange the engines both being same size.

i always thought that this is the size of the engines

V4 1632 cc platform, 85/88/90/100/115 HP

V4 2000 cc platform, 120/130/140 HP


this would make them very different.



phill

 

[V153]

Re: 85 hp or 140?

If you say so Phill. But here across the pond the 85-140hp use the same crankshaft, piston, & connecting rod assy etc. I'd love to hear all about where your 388 additional cc's of displacement come from?

As was correctly mentioned earlier the hp increase is the result of bigger carbs, higher ports, and tuned exhaust.

 

[McGR]

Re: 85 hp or 140?

I think Phil is comparing later model V4 crossflow displacements to the large 90 degree V4 looper displacements.

 

[V153]

Re: 85 hp or 140?

I think Phil is comparing later model V4 crossflow displacements to the large 90 degree V4 looper displacements.

My bad. I thought we were talking about '79-'83 Crossflows ...

 

[emdsapmgr]

Re: 85 hp or 140?

The heads for the 83 140 hp crossflow are different and unique to that engine. You can check out the factory parts lists to compare parts between the two engines on the web: epc.brp.com. The factory will suggest that a damaged (pitted) head should be replaced. That will be difficult, since these heads are NLA and somewhat rare anyway. Look for one of these two heads for your 83: 326503 starboard, 326502 port. Your 79 head is of similar size and shape, but will yield about 10 lbs less compression than the stock 140 head. You can do some scrounging around on ebay and see what you can come up with.

 

[wayneo99]

Re: 85 hp or 140?

do i need a matched pair? or can i reuse the one good side and find another?
what would good compression be for a 1983 140

 

[phillnjack2]

Re: 85 hp or 140?

sorry guys, must of got looper and cross flow mixed.

 

[Chinewalker]

Re: 85 hp or 140?

Yes, you can use a mis-matched pair, as long as the one you replace your chewed up one with has the same, sequential casting number. Look at it this way, you've got all winter to find one as the heads are among the last parts you'll install on a rebuild...

 

[wayneo99]

Re: 85 hp or 140?

POWERHEAD from 140 is almost offof the mid section 2 bolts to go.

so far this is what it looks like

2K for a complete refurbished short block from outboard exchange, i reinstall accessories and put back on midsection.

I send block to machine shop to have it honed or borred out for 350 plus a piston and gastket kit for 1k and replacement head for 100.

then i reassemble powerhead and the acccessories and put back on midsection about 1500
plus misc extras, carb kits etc..

plus i may get a credit for my old v4 blocks

there may only be a difference of 200-300

i will keep you guys posted

 

[wayneo99]

Re: 85 hp or 140?

this may become my build thread

how many bolts to remove powerhead

i removed the pann mounts plastic shroud and 3 long bolts below on each side.
cant seem to see anymore that look like they go into the power head
thanks