Logo
FULL SITE MENU

more power from my mercruiser 260

Check w/your insurance co. to see if they have access to newer salvaged boat engines from a boat that had hull damage.
 
87concord said:
One piece rear main seal blocks and two piece rear main seal blocks use different flywheels, couplers and bell housings. The later model one piece rear seal uses a different bolt pattern on the flywheel which requires you to use a bravo style bell housing and triangular style coupler. The bell housings between the two are very close but a triangular coupler won't clear inside the older bell housing (ask me how I know this, lol). Other than that everything else will change over. Except for the circulating water pump, you will need the new style with longer necks to clear newer style composite timing cover
Click to expand...

ok I found a new coupler that will allow you to install a 1 peice rear seal motor where a two peice motor was . and it is round not triangular. from basic power and the part number is mal9-72500 would this allow me to install the vortec motor?
 
I have seen early 2 pc rear main flywheels and newer 1 pc rear main flywheels both with threaded holes to run the same triangular coupler.

I was able to use a 1998 triangular coupler on a 1981 motor, as my 81 motor had the same holes so look for those threaded holes before you bother with a new coupler.
 
barrylee66 said:
ok I found a new coupler that will allow you to install a 1 peice rear seal motor where a two peice motor was . and it is round not triangular. from basic power and the part number is mal9-72500 would this allow me to install the vortec motor?
Click to expand...
hystat said:
I have seen early 2 pc rear main flywheels and newer 1 pc rear main flywheels both with threaded holes to run the same triangular coupler.

I was able to use a 1998 triangular coupler on a 1981 motor, as my 81 motor had the same holes so look for those threaded holes before you bother with a new coupler.
Click to expand...
I'd also check, but I think that hystat is on the right track here.
The triangular style drive coupler fastening/attachment method has to do with the perimeter bolt pattern on the flywheel itself..... not the crankshaft flange bolt pattern!
IOW, the same perimeter bolt pattern that allows for the automotive type clutch pressure plate attachment.

Example: the AQ series Volvo Penta uses a Borg Warner drive coupler (similar perimeter bolt pattern attachment) that fits onto either flywheel (i.e., pre- 1987 and post 1987).
I would think that this would also apply to the larger 168 tooth flywheel (that Merc uses)....... either pre- 1987 (2 pc seal) and/or post 1987 (1 pc seal).

Perhaps take the triangular drive coupler with you when you look at flywheels. :)


************************

Barry, just curious............, earlier you said that you had some decisions to make.
Have you made a decision re; piston selection and the Quench or Squish effect -vs- the non-quench full dished pistons?
Are you finding any "Nay-Sayers" or any "Yeah-Sayers" for this?

Again, just curious!

.
 
The round donut style coupler won't work on a vortec engine because it uses the center bolts that go into the crank and the bolt pattern is different on new vs old fly wheel, I think the triangular coupler will work on either but you have to make sure it clears the bell housing.
 
87concord said:
......... I think the triangular coupler will work on either but you have to make sure it clears the bell housing.
Click to expand...
I believe that you mean Flywheel Cover!

images





Here is the triangular drive coupler.

463916658_tp.jpg



Here's a Merc Bell Housing..... aka Gimbal Bell!
bellhsga.jpg
 
Back
Top