Bell Housing - Merc 250 vs 292

[brodie123]

Hi Everyone.

My boat used to have a 165HP L6 250 engine but was toast and tossed.

I have a 292 L6 to install and is ready to go 100% except for the bell housing which does not fit - I thought they were supposed to be an exact match.

I need to identify what bell housing part # to get. The engine mount bolt holes are 15" apart center to center.

Can anyone help? Any other info needed?

Chris

 

[kenny nunez]

I have re used the flywheel housing on several 250-292 conversions. Try to post a picture of the fitment problem.

 

[brodie123]

I have re used the flywheel housing on several 250-292 conversions. Try to post a picture of the fitment problem.

Thank you and will do but in short, the bell housing I have (4 various ones) will not fit over the flywheel. I will see if I can get their part # and post. Perhaps the correct bell housing got tossed by accident.

 

[brodie123]

Thank you and will do but in short, the bell housing I have (4 various ones) will not fit over the flywheel. I will see if I can get their part # and post. Perhaps the correct bell housing got tossed by accident.

The part # on the housing I have is 63530 which I "think" came off the 250 but does not fit over the 14" flywheel.

 

[Scott06]

The part # on the housing I have is 63530 which I "think" came off the 250 but does not fit over the 14" flywheel.

Not 100% sure on this but I think you need a 153 tooth 12.75" Diameter flywheel like this

McLeod Racing 450300 McLeod Nodular Iron Flywheels | Summit Racing

Free Shipping - McLeod Nodular Iron Flywheels with qualifying orders of $109. Shop Flywheels at Summit Racing.

www.summitracing.com

in that listing gives stock GM part number it replaces. I assume the 252 flywheel was smaller as I thought GM didn't use bigger wheels until later?

Somewhere around 1981 Merc changed the flywheel cover and the rear mount spacing where it attaches to inner transom plate. You may be able to use a later flywheel cover ( for example my 2004 cover fits a 14" flywheel) but depending on what transom you are mounting it to may have another issue... also starter bolt pattern is different between the two flywheel sizes... again not 100% sure just recall seeing these things on here over the years

 

[brodie123]

Not 100% sure on this but I think you need a 153 tooth 12.75" Diameter flywheel like this

McLeod Racing 450300 McLeod Nodular Iron Flywheels | Summit Racing

Free Shipping - McLeod Nodular Iron Flywheels with qualifying orders of $109. Shop Flywheels at Summit Racing.

www.summitracing.com

in that listing gives stock GM part number it replaces. I assume the 252 flywheel was smaller as I thought GM didn't use bigger wheels until later?

Somewhere around 1981 Merc changed the flywheel cover and the rear mount spacing where it attaches to inner transom plate. You may be able to use a later flywheel cover ( for example my 2004 cover fits a 14" flywheel) but depending on what transom you are mounting it to may have another issue... also starter bolt pattern is different between the two flywheel sizes... again not 100% sure just recall seeing these things on here over the years

Thanks. If I swapped the flywheel - not sure how that would work - the starter would then be out of alignment. Surely there is a housing for this? I really don't want to have to swap my gimble and mount.

 

[kenny nunez]

Since the 292 flywheel studs are 1/2” and the 250 are 7/16” the easiest cure is to drill out the 250 flywheel and coupler. You will need some special lock nuts that are 5/8” hex and 1/2” 20 to mount the flywheel and coupler. They are available from some specialty venders. Also available from some new old stock from Mercruiser. Another way is with stepped studs that are 1/2” 20 X 7/16” 20.

 

[Scott Danforth]

the 250 and 292 have different balance

get the right 153 tooth flywheel for the 192. they are cheap at rockauto.

 

[brodie123]

Hi Everyone.

My boat used to have a 165HP L6 250 engine but was toast and tossed.

I have a 292 L6 to install and is ready to go 100% except for the bell housing which does not fit - I thought they were supposed to be an exact match.

I need to identify what bell housing part # to get. The engine mount bolt holes are 15" apart center to center.

Can anyone help? Any other info needed?

Chris

Is there any way for someone to provide me with the part # of the correct pre alpha flywheel bell housing for the 250? I think I need to validate what I have.

 

[Scott06]

Is there any way for someone to provide me with the part # of the correct pre alpha flywheel bell housing for the 250? I think I need to validate what I have.

part number one https://www.marineengine.com/parts/...u-5178958/flywheel-housing-and-engine-support

 

[kenny nunez]

When switching to a 292 you will need a new fuel line since the fuel pump is in a different location, the alternator belt adjusting strut needs to be lengthened and you will have to cut the exhaust hose and extend it about 1.5” with either stainless or copper tubing.
I have done this conversion over a dozen times using the original flywheel.
When these engines were used they were only mounted to the #2 Mercruiser drive platform and a completely different set up.
Depending on your boat sometimes the oil pan may have a clearance issue.

 

[brodie123]

When switching to a 292 you will need a new fuel line since the fuel pump is in a different location, the alternator belt adjusting strut needs to be lengthened and you will have to cut the exhaust hose and extend it about 1.5” with either stainless or copper tubing.
I have done this conversion over a dozen times using the original flywheel.
When these engines were used they were only mounted to the #2 Mercruiser drive platform and a completely different set up.
Depending on your boat sometimes the oil pan may have a clearance issue.

Thank you. The 292 came with a 14" flywheel which I believe to be 168 teeth. But I think what is needed for the marine application is the 153 teeth version??? which is around 12" my concern is how will the starter then fit? If the flywheel is 1" away it won't reach the teeth. See image.

 

[Bondo]

Thank you. The 292 came with a 14" flywheel which I believe to be 168 teeth. But I think what is needed for the marine application is the 153 teeth version??? which is around 12" my concern is how will the starter then fit? If the flywheel is 1" away it won't reach the teeth. See image.

Ayuh,..... That's why Chevys run one of 2 starters,.....
The staggered bolt pattern like yers, 'n the straight across for the small flywheel,.....

Is yer block drilled for both starters,..??
If not, you need to find a MC-1 bellhousin'/ flywheel cover for the big flywheel,....
It can be from an I-6, or a V8,....

 

[kenny nunez]

It is not hard to drill the hole to mount the starter. Flip the engine over mount the straight bolt pattern starter, be sure it is square with the engine and with some drill guides drill and tap the hole.

 

[Scott Danforth]

the 292 should have 3 mounting holes to cover both flywheel sizes with the GM starters as Bondo points out.

 

[brodie123]

As always, I appreciate the great advice I get here.

I got a 153 tooth flywheel and a new starter - all fits now including the bell housing.

I ordered studs but they are too small. I see now that the 292 has larger bolt holes so I will have to get new studs and drill the flywheel/coupler to suit.

I ordered 1/2"-20x1/2"-20 studs (2" long) Can anyone confirm that this is correct?

thx!