110 hp exhaust baffle plates missing?

[peter wickham]

Iassume baffel plates would normally bolt somewhere in here and mine are missing? Will it make much difference if i dont fit them. I dont have them, or now what they look like or how they fit. The motor is only used for short fishing trips obout 10 km on a 4.5 metre fg runabout and i dont need 110 hp but its what i have until I can upgrade. It uses fuel at about 1ltr per km. Would missing baffle plates cause poor fuel consumption?

 

[racerone]

Re: 110 hp exhaust baffle plates missing?

You can see the 3 holes per side used to mount those filler blocks.------These block are part of the " tuned " exhaust.----May affect fuel consumption a bit but not much.--The 90 HP block does not use those filler blocks.-Run it the way it is.---These V-4 crossflow engines are a simple / low cost / easy to maintain package.---Not sure why you would want to " upgrade " from that.

 

[peter wickham]

Re: 110 hp exhaust baffle plates missing?

Im confused now. Is it 90 or 110 the seriel number indicates 90 but was told its 110 because it has a domed exhaust cover plate?

 

[racerone]

Re: 110 hp exhaust baffle plates missing?

There are many parts on these motors that are interchangeable and for many years.-----Maybe someone installed the bubble back thinking / hoping for a magic horsepower increase.If you post a picture of the intake ports I can maybe tell if it is a 90 block.-Intake ports on the 90 were smaller than the 110 model.

 

[peter wickham]

Re: 110 hp exhaust baffle plates missing?

Is there another way to tell

 

[V153]

Re: 110 hp exhaust baffle plates missing?

Looks more to me like a 140 block. Note the cut-out in the ridge (to the far right in the pic)

 

[racerone]

Re: 110 hp exhaust baffle plates missing?

These blocks look similar for many years.------------No telling what has been done if you are not the original owner !!!!

 

[peter wickham]

Re: 110 hp exhaust baffle plates missing?

OK thanks for the help I'll put it back together with new gaskets and a good clean up and go fishing.

 

[V153]

Re: 110 hp exhaust baffle plates missing?

'Less my eyes are real bad it appears you have the cut-out, like the one pictured below. The 90 & 115 block does not have that cut-out.

It wont hurt your motor to run without the stuffers. In fact there are some who say it'll increase your top end by a couple hundred rpms. Others claim it has a negative effect on midrange acceleration.

Regardless, this is what they look like: Part # 323461(2)

 

[V153]

Re: 110 hp exhaust baffle plates missing?

Regarding fuel economy:

These things were never considered 'gas sippers'. Particularly at high rpm. Don't have my metric conversion chart handy but don't be surprised if that motor burns 9 or 10 gal per hour at wot.

 

[V153]

Re: 110 hp exhaust baffle plates missing?

What is your model# btw?

 

[emdsapmgr]

Re: 110 hp exhaust baffle plates missing?

My understanding is that the cutout of the rib in the exhaust chest came out when the OMC first upped the hp rating from 135 hp to 140. That's part of where the 5 hp increase came from. Should have first appeared on the 140 blocks in 1977. It is fairly easy to add that cutout if the engine is ever apart for overhaul. Another part of the increase was the intake filler blocks on the 115 and 140 in 1977.

 

[V153]

Re: 110 hp exhaust baffle plates missing?

My understanding is that the cutout of the rib in the exhaust chest came out when the OMC first upped the hp rating from 135 hp to 140. That's part of where the 5 hp increase came from. Should have first appeared on the 140 blocks in 1977.

My bad emd, forgot they stopped making the 135 in '76.

 

[Bosunsmate]

Re: 110 hp exhaust baffle plates missing?

A litre per kilometre is quite reasonable for that motor.
Be careful you get the right exhaust gasket for your set up, the wrong one will allow water into the cylinders right through to the intake manifold

 

[peter wickham]

Re: 110 hp exhaust baffle plates missing?

The model number indicates its a 90hp 1988. Have just been given a 1987 90hp for parts and will take the flat exhaust cover from that and fit to my boat motor. I have ordered the exhaust gaskets for a 110 hp as i was told it probably was 110. Will they fit to the flat exhaust cover. Also I would like to know more about how and where the wrong exhaust gasket can let water into the cylinders through to the intake manifold?

 

[emdsapmgr]

Re: 110 hp exhaust baffle plates missing?

A 110 set of manifold gaskets will be the wrong ones. The 110 engine uses one 317955 and one 323469 exhaust manifold gasket. The 88/90 hp model uses 2 pcs of 317914. A water leak in the exhaust manifold gasket won't let water into the intake manifold. It leaks water into the exhaust chest. When a cylinder opens for the exhaust stroke, water in the chest can get forced back into an exhausting (open) port due to the exhaust compression from nearby cylinders. An engine might seem to run ok with a little water in the cyl, but too much and it will put out the fire in that cyl, causing a miss.

 

[peter wickham]

Re: 110 hp exhaust baffle plates missing?

Great information thanks

 

[peter wickham]

Re: 110 hp exhaust baffle plates missing?

Have just removed an 1987 90hp exhaust plate and that has no cutaway and smaller exhaust ports. So maybe someone has changed the power head.

 

[V153]

Re: 110 hp exhaust baffle plates missing?

Your powerhead is a 140. As evidenced by the cut-out. Why would you wanna restrict it with a 90hp flat-back exhaust?

There is a quarter size plug on top of the port cylinder bank. What is the number stamped in it?

 

[peter wickham]

Re: 110 hp exhaust baffle plates missing?

I thought it was a 90hp which has been modified and as i dont need the extra power and was going to fit the flat back exhaust. also domed exhaust was hard to get off and probably harder to refit. Also see photo is this the quarter size plug on right looking from back of motor