Upgrading Evinrude 88 SPL E88TSLEOC Crossflow-flatback?

hanslanda

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Afternoon yall,

Been reading around the fourms and was wondering if anyone could help me clear up a couple questions. I have a E88TSLEOC and from what i gather its a Crossflow Flatback variant. I read quite a bit about people putting on a bubble back exhaust from different models as well as a larger carb with reeds. My question is, do these options exist for the 88 SPL as well? Might be a break-down project i consider next down season up here in wisconsin.


High compression heads? What year/model
Larger 1-5/16" carb? Year/model?
Bubble exhaust, plates as well? Year/model?
Reeds? Type, intended for year/model?

I'm going to keep digging for information but anything on the above would be super appreciated guys!
 

jimmbo

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Adding the larger carbs and the bubble back without changing the port timing and size is not going to do much, in fact it may perform poorer than the engine currently does. All the pieces need to be there for it to work properly. There is also some machining in addition to the Porting needed to be done as well

Replacing your powerhead with a complete post 84 115hp, or a 78 - 84 140hp powerhead, would probably be the easiest and the least expensive way to 'hop up' your engine

Besides, you're only looking at 5 - 6 mph difference between your 88 and a prop rated 115
 
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hanslanda

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Adding the larger carbs and the bubble back without changing the port timing and size is not going to do much, in fact it may perform poorer than the engine currently does. All the pieces need to be there for it to work properly. There is also some machining in addition to the Porting needed to be done as well

Replacing your powerhead with a complete post 84 115hp, or a 78 - 84 140hp powerhead, would probably be the easiest and the least expensive way to 'hop up' your engine

Besides, you're only looking at 5 - 6 mph difference between your 88 and a prop rated 115


Alright that's quite different from what iv'e read but ill bite.

If i'm looking at an entire powerhead swap is there anything stopping me from putting on a 92-94 90deg looper powerhead well other than maybe space? Do the 90deg engines even fit the same footprint of the compact 60. Crowley lists those at 140hp. I think 115+ would be a great pep to my 17' Glastron. I imagine this 88 will get me going high 30's to low 40's, and 5-6mph might be huge down in that range.
 

flyingscott

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What do you have that is a 60 deg V? All crossflows and the early loopers are 90 deg Vs and no I do not believe they interchange. Go find a 110/112 hp motor they are common and cheap and are basically rebadged 115 motors.
 

hanslanda

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What do you have that is a 60 deg V? All crossflows and the early loopers are 90 deg Vs and no I do not believe they interchange. Go find a 110/112 hp motor they are common and cheap and are basically rebadged 115 motors.

Ahh this has been confusing me. All the Xflows are 90 deg and the loopers are 60? Do i have that correct? Is it as easy as swapping a 115 powerhead onto the mid section? What am i looking at in terms of wiring and electrical challanges?
 

racerone

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No there are 90 degree loopers as well !-----A 115 crossflow will fit on your 88 model.-----Only requires wiring changes if newer that a 1996 model.
 

jimmbo

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By Porting a 88 block to the 115/140 specs, machining the block for the bubble back manifold, using the 135/140 heads, the bigger carbs, and the stuffers in the reed plate, you can convert it to the prop rated 115/crank rated 140. Not doing it all may provide a less than satisfactory outcome.

All the crossflows are 90 degrees. There are 90 degree loopers, and there are 60 degree loopers. You can not put a looper power head on a crossflow midsection, nor can you put a 90 degree looper power head on a 60 degree midsection, and vice versa.
90 degree crossflows 1978 and newer:
85
88
90
100
110
112
115
140
90 degree looper:
120
130
140
60 degree looper:
90
115
 
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hanslanda

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Roger that. Sourcing Crowleys lists of powerheads we'd be talking a 1992-1998 V4 Crossflow Bubbleback then? That is what it lists for a 115 crossflow. They show the 115 go all the way back to 1978 but with changes inbetween. I think i need to start staring at service manuals. For the record im going to run this 88 at least next season with this work not being until the season after. Im in super early stages of research.
 

hanslanda

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All the crossflows are 90 degrees. There are 90 degree loopers, and there are 60 degree loopers. You can not put a looper power head on a crossflow midsection, nor can you put a 90 degree looper power head on a 60 degree midsection, and vice versa.
90 degree crossflows 1978 and newer:
85
88
90
100
110
112
115
140
90 degree looper:
120
130
140
60 degree looper:
90
115

Thanks Jimmbo! Looks like i'm flat out limited to running a 115 crossflow. Whats some of the best places on the internet to source stuff like this? Is the wiring (CDI ignition timing) anything like that affected?
 

jimmbo

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78 - 84 engines are crankshaft rated. In 85 OMC switched to prop shaft rating. Yes there were changes made, mostly linkages, Ignition and choke/enrichment systems.

The 115 goes back to 1969, though don’t expect interchangeability with the later versions
 

racerone

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There was a 115 HP motor offered in 1968.----Limited production.-----I would like to get one of those.
 

jimmbo

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Based on the 89.5 in. block with the 4 bbl carb. I didn’t mention that one as it wasn’t part of the regular lineup
 

hanslanda

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Based on the 89.5 in. block with the 4 bbl carb. I didn’t mention that one as it wasn’t part of the regular lineup

What do you guys consider a good place to acquire older hardware like this? Would the wiring/harness on my 88 work for the 115? I would have to think timing may differ.
 

jimmbo

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The 68 115 has nothing in common with any of the later 115s, or any of the later V4s, except a few bolt/nuts.
 

flyingscott

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You will also need new carbs for a 115 motor. The 90 hp ones will not run correctly.
 

racerone

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The 68 model 115 HP ( limited edition ) sure has an interesting gearcase.----I would just like to get that gearcase alone.
 

jimmbo

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The 68 model 115 HP ( limited edition ) sure has an interesting gearcase.----I would just like to get that gearcase alone.

Snooping around the Dealers back yard about 30 years ago I stumbled over one of those engines. At the time I wasn’t aware of the Limited edition and thought WTF, A weird looking 100. Then I took a good look at the gear case and it was, Oh. That one had two driveshafts in the case if I recall. The 2 blade Props had lots of Rake
 
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racerone

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Correct------ 2 driveshafts and 2 pinions in the gearcase.------Spells " go fast " I think.
 

jimmbo

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Correct------ 2 driveshafts and 2 pinions in the gearcase.------Spells " go fast " I think.

I thought it spelled "Less chance of Breaking during the Race":rolleyes:

Probably a lot of both, as the case was was quite narrow where the shafts were, so they had to double them up

Made for a no Reverse and No Neutral kind of Boating, half of Merc's Imfamous Silent Neutral
 
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