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  Identifying OMC V4 Loop-charged and Cross-flow Engines

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Author Topic:   Identifying OMC V4 Loop-charged and Cross-flow Engines
laserguy posted 06-30-2014 12:42 PM ET (US)   Profile for laserguy   Send Email to laserguy  
How to tell OMC V4 loop from crossflow at a glance

Is is easily possible to tell an OMC V4 90-degree loop-flow from cross-charge at a glance in the 90-HP and 115-HP models? I know they overlapped in production. Various V4 cross-flow outboards were produced from 1968 to 1997. Loop-charged V4's went into production in 1985 and continued until 1998. 60 degree V4's began production with the 1995 model year.


Can you tell them apart at a glance, especially from a photo?? The sellers never seem to know.

I know the bore spacing on a loop-charged engine is 4.750 inches. The cross-flow engine is 4.125 inches. For identification purposes, this is also the distance between the spark plugs, if you're there in person. The implication is that the engine is taller. Can you see that when examining the cowling?

I assume all 88-HP Johnson or Evinrude engines are cross-flow? The bigger V4 120 and 140-HP I believe stayed cross-charged; or, switched later?

It's easy to tell the 60-degree from the 90-degree models, but can you distinguish between the 90-degress versions on sight when shopping for a used boat?

Thank you.

laserguy posted 06-30-2014 12:47 PM ET (US)     Profile for laserguy  Send Email to laserguy     
For completeness sake, the original V4 series was made from 1958 to 1968. It looks quite different from later models and all 1958-1968 models have exhaust gases exiting through the cavitation plate. Through-the-prop exhaust wasn't available on the V4 engines until 1969.
seahorse posted 06-30-2014 01:05 PM ET (US)     Profile for seahorse    
The crossflow V-4 has the trim switch on the stb. side and the motor cover has 2 latches in the back.

The looper V-4 has a port mounted trim switch and a single latch on the back.

seahorse posted 06-30-2014 01:07 PM ET (US)     Profile for seahorse    
The 90 and 115 looper V-4 with the 60° block and OIS ignition came out in 1995.
seahorse posted 06-30-2014 01:34 PM ET (US)     Profile for seahorse    
All crossflow V-4's have their thermostats located at the bottom aft of the powerhead connected by molded rubber hoses.

The looper V-4's have thermostats at the top of each cylinderhead and no molded "heater hoses" at the bottom of the heads.

laserguy posted 06-30-2014 01:49 PM ET (US)     Profile for laserguy  Send Email to laserguy     
Seahorse, thank you.

I had not noticed a single cowling latch on a 90 degree block. Do you have photos? Is the latch in the middle or to one side?

The 60 degree profile and cowling are very distinctive though.

ALAN G posted 06-30-2014 08:15 PM ET (US)     Profile for ALAN G  Send Email to ALAN G     
Laserguy/Seahorse, I have a 1989 120 HP Johnson Looper. But contrary to Seahorse's input, It has the trim switch on the stbd side, and has two latches in the back and one on the front.

Not sure it is worth the effort, but searching each model years' parts listings should answer your questions on telling the difference between the two types. I don't ever recall seeing an OMC 90 degree V engine without two rear latches.

Al

contender posted 06-30-2014 08:31 PM ET (US)     Profile for contender  Send Email to contender     
SeaHorse, I have a 1985 140 looper, no trim switch on either side of the engine, I also have a double latch (motor cover) in the back and one in the front, the thermosats are on top of the heads...
Teak Oil posted 06-30-2014 09:20 PM ET (US)     Profile for Teak Oil  Send Email to Teak Oil     
Loopers have larger gearcases (usually) and have V4 embossed in between the cylinder banks when the cowl is removed.

The loopers also appear a little taller to me

seahorse posted 07-01-2014 01:06 AM ET (US)     Profile for seahorse    
Y'all are correct about your findings.

My initial explanation was in regards to the very first sentence in the original post - "Is is easily possible to tell an OMC V4 90 degree loop from crossflow at a glance in the 90HP and 115HP models?"

My answer was intended only for the 90 and 115 loopers and crossflows.

seahorse posted 07-01-2014 01:11 AM ET (US)     Profile for seahorse    
My 3rd answer applied to ALL V-4's from the 1958 50hp original crossflow V-4 to the very last of the carbureted V-4's
laserguy posted 07-03-2014 06:29 PM ET (US)     Profile for laserguy  Send Email to laserguy     
Thanks for the updates.

I recently saw a 1993 Johnson 120 for sale. I believe it is a larger V4 crossflow block, supposedly 2.0L vs 1.6 L for smaller V4. Is that correct? Did this size ever go to loop charged?

There are 4 model codes for 1993 120 Johnsons: J120LET, J120LAT (Presumably long shaft) and J120XET and J120XAT 25" shaft.

Thought I understood OMC V4 models but the 120/140 models add complications.

Teak Oil posted 07-03-2014 08:54 PM ET (US)     Profile for Teak Oil  Send Email to Teak Oil     
No, that is a looper. All the crossflows were 100 cubic inches.

The looper has more top end pull and weighs about 40# more.

The crossflows were 85, 90, 100, 110, 115, 130, and 140 hp.

The loopers were 120 and 140 hp.

Teak Oil posted 07-03-2014 08:56 PM ET (US)     Profile for Teak Oil  Send Email to Teak Oil     
88s and 112s were crossflows too
contender posted 07-03-2014 09:12 PM ET (US)     Profile for contender  Send Email to contender     
And I think I lucked out as well, my lower unit on the 140 looper looks like a v-6 unit...
seahorse posted 07-03-2014 10:41 PM ET (US)     Profile for seahorse    
The 130 was a looper, not a crossflow
Binkster posted 07-04-2014 08:59 AM ET (US)     Profile for Binkster  Send Email to Binkster     
Not to get too far off subject, but will a later model V4 powerhead bolt onto a 1961 Evinrude 75hp V4 lower unit. The reason I ask is I have the above motor installed on my antique 1959 Sea Fury runabout that I run at the AOMCI meets. Its in very good condition, last year I had the gearcase rebuilt with new gears and a short shaft driveshaft, and removed the spacer. It will run about 40mph, and I am looking for more speed. I know 1968 was the last year for this design powerhead, I assume a 100 hp '68 V4 powerhead would bolt up but I would like to get a 130 or 140. Is that possible?
Other than carbs what is the difference betweem the 75hp 1961 V4 75hp and the 1968 V4 100hp.

rich

Peter posted 07-04-2014 09:34 AM ET (US)     Profile for Peter  Send Email to Peter     
"The crossflows were 85, 90, 100, 110, 115, 130, and 140 hp."

If you go back further into the 1970s, the cross-flows also has 125 and 135 HP ratings.

contender posted 07-04-2014 06:28 PM ET (US)     Profile for contender  Send Email to contender     
you left out 120
contender posted 07-04-2014 06:32 PM ET (US)     Profile for contender  Send Email to contender     
Bink I would look on line at boats.net, you can get an exploded view of both engines, see if the gaskets (power head to midunit) match and possibly bolt up...
seahorse posted 07-04-2014 09:11 PM ET (US)     Profile for seahorse    

...but will a later model V4 powerhead bolt onto a 1961 Evinrude 75hp V4 lower unit?


Sorry, but ain't no way !

Binkster posted 07-05-2014 12:34 PM ET (US)     Profile for Binkster  Send Email to Binkster     
Well, I figured that, but thought I'd ask anyway. I'll take contenders advice and see if the powerhead gaskets bolt up between the 100 and 75 hp from the sixties.

rich

seahorse posted 07-05-2014 12:55 PM ET (US)     Profile for seahorse    
1968 would be the latest V-4 to bolt up to the original 75hp midsection.
laserguy posted 07-12-2014 08:31 AM ET (US)     Profile for laserguy  Send Email to laserguy     
"posted 07-03-2014 08:54 PM ET (US)
The crossflows were 85, 90, 100, 110, 115, 130, and 140 hp.
The loopers were 120 and 140 hp."

Thanks Teak Oil. Loopers should also include some 90 and 115, also?

Were any other horsepower ratings loopers?

seahorse posted 07-12-2014 09:21 AM ET (US)     Profile for seahorse    

There were the commercial series loopers that came in 105 and 125 hp sizes. They have a W in the model number.
laserguy posted 07-16-2014 12:26 PM ET (US)     Profile for laserguy  Send Email to laserguy     
I guess the original question still stands. Ca i visually tell the difference between a V4 90 degree looper from crossflow at a glance.?
seahorse posted 07-16-2014 02:32 PM ET (US)     Profile for seahorse    

Flywheel shape and nut size

thermostat location - top of heads or at base

water hoses at bottom of cylinderheads

Letters V-4 cast into exhaust cover

4 all black plastic individual carb bodies in looper, 2 aluminum bodied 2-barrel carbs on crossflows

Motor cover physically larger and more "squared off" looking on looper

starter held on with 4 bolts on looper, 2 side bolts and 1 forward facing bolt on X-flow

Freddy posted 07-19-2014 01:42 PM ET (US)     Profile for Freddy  Send Email to Freddy     
laserguy, you might enjoy this link.

http://continuouswave.com/ubb/Forum4/HTML/006497.html

laserguy posted 07-23-2014 05:48 PM ET (US)     Profile for laserguy  Send Email to laserguy     
Thanks for the update and the link. I assumed the cowlings had to look different. I need to find good photos, but Google Images hasn't been trustworthy about the model shown.


Peter posted 07-24-2014 06:49 AM ET (US)     Profile for Peter  Send Email to Peter     
Evinrude never made a 120 HP cross-flow. So run a Google image search for "Evinrude 120" and then one for "Evinrude 115". You should be able to see the difference in the cowling shapes between the two.
laserguy posted 07-26-2014 09:19 AM ET (US)     Profile for laserguy  Send Email to laserguy     
Found an online copy of the 1995 Evinrude catalog at this link.
Interestingly there are no V4 loop charged engines in the catalog at that year. Even the Jets and the commercial models are crossflow. They did of course have the 60° blocks. Was information I had about V4 loopers produced until 1998 correct always only Johnson???


http://issuu.com/liquidnirvana/docs/1995---evinrude-outboards--x---wm-

seahorse posted 07-26-2014 09:24 AM ET (US)     Profile for seahorse    

In that brochure the 130, 115, and 90 hp models are V-4 looper engines

seahorse posted 07-26-2014 09:30 AM ET (US)     Profile for seahorse    

I forgot to mention that the V-4 105hp is also a looper.

They also have some cross-flow model V-4s in the catalog and you can tell when kind of engines by referring to the specification pages near the end of the brochure.

laserguy posted 07-28-2014 03:57 PM ET (US)     Profile for laserguy  Send Email to laserguy     
RE: 1995 Catalog
Page 6: has only 60 degree loopers
Page 9: 90/115 HP 60 deg ocean pro loopers
page 14: 115 Intruder 60 degree - diff gearcase?
page 15: 90/115 60 deg loopers and 90/115/85 (tiller) crossflow (see chart lower right portion of page)
Page 28-29: SPL crossflows
Page 30: V4 Jets are 80 HP apparently crossflow,105 jet is V6.
seahorse posted 07-28-2014 04:27 PM ET (US)     Profile for seahorse    

Laserguy wrote:
quote:

Interestingly there are no V4 loop charged engines in the (1995) catalog at that year.

You missed page 15 for the 90° V-4 looper 130hp and page 31 with the 125 Commercial model 90° V-4 looper.

Of course all the 60° block V-4's are in the catalog are loopers, too.

laserguy posted 08-10-2014 11:35 AM ET (US)     Profile for laserguy  Send Email to laserguy     
Thanks for the help. The carburetor difference between the plastic carburetor in the aluminum carburetor has been an easy way to tell them apart. All I need is a clear photograph of the engine with aCal it off to make that determination.

Almost every 80s or 90s engine I've looked at, interestingly, has been a crossflow.

laserguy posted 08-10-2014 11:42 AM ET (US)     Profile for laserguy  Send Email to laserguy     
"aCal it" should have read Cowling. Stupid Siri.
laserguy posted 08-16-2014 01:08 PM ET (US)     Profile for laserguy  Send Email to laserguy     
Do I care if it's loop charged?

Bottom line question do I even care about the difference? It seems the features and technology other than the charging itself is about the same. All the fancy ignition OIS and other goodies seem to be on the 60° motor.

In the small sampling of the 90 deg V-4's I've seen for sale, 100% have been crossflow based on the identification information provided in this discussion.

Maybe I shouldn't even care about the difference??

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