Mercruiser 3.7 Build, 1970 Cj5? Part 2, Fab And Adapting!

Is the T90 ideal? Probably not. But I have four wheeled the snot out of mine for 18 years, behind a 225 V6. 1st& reverse are pretty strong, 2nd& 3rd less so. I would not hesitate to use one in a small lightweight vehicle with a smaller engine, if that was what I had and was on a budget.

 

I am curious . how do you plan to address starter on this motor

 

I would make the it the same as a sbc for the bore of the pilot bushing so it can be changed easily in the future then have a pilot bushing made the same as the short t90 to sbc kits. Then a change to a sm465 or t18 in the future will be simpler.

I measure 6.75" from the back of the input bearing retainer to the tip of the shaft on the left overs from my long input swap
Tip length for the bearing surface is basically 1"
tip dia for the short shaft is .625
Not exactly close to your specs. Hopefully we can get confirmation.

 

I have 2 options.
1- use the original, and notch the bell.
2- use a int scout starter, no bendix support.

 

6.75 , not deep enough in crank.I got 6-7/16 to end of crank. Extended bush might work?
Benn looking at pilots, they make all kinds.
.628 ID x several different OD is common.
1.73-1.76 would press in flywheel?
Still researching this.

 

I was looking at my sm465 with bellhousing while measuring the old t-90 and the Chevy transmission with Chevy bell has the input shaft about a quarter inch past the engine to bellhousing mounting surface.
20181024_163958 by Joe with a jeep, on Flickr (there are more pics of measuring)

 

What's the stick out on the 465?

 

Remember, a guy on Hamb milled 5/8 off back,so input would go deeper in crank.

 

The sm465 has a 6.5" stickout and my bell is 6.25" from engine to transmission.
This puts the pilot bearing contact area .75" into the bellhousing and .25" outside of the bellhousing
This matches what I found at Novak
The Novak Guide to the GM Muncie SM465 Transmission
The long t90 and thick adaptor puts the input shaft in the same position as the sm465 but the pilot bushing is different.

 

Started on the head.
Read up on 460 head work.
3 of the exhaust ports have an extra hole next to guide that needs filling.
460 read recommended 5/16 -24 set screw.
I drilled,taped ,red loctite,and installed deep in hole.
I started blending around the valve seats.
More to come.

 

On the left, mahle, gasket set and rings, Clevite inserts 228$
On right, water pump gasket and seal kit, Sierra. 58$

And was thinking while driving today(285mile route), bout pilot extension?
Remembered this thing during teardown.
Might make a pilot holder, if that becomes necessary?

 

I know from folks the run these engines that they highly recommend the head gasket be only OEM Volvo Penta. The aftermarket and label branded head gaskets don't work well. I know Mahle is a good brand, but I am using Volvo Penta for at least the head gasket.
-Donny

 

That is the coupler- it's the means of attaching engine to outdrive. If it is useable to you in the project, then you might need to leave the studs where they are in the crank.

I believe the coupler serves as a slip joint of sorts for the driveshaft as well as a means of absorbing shock from the outdrive. Between the inner spline and the external casing is a mass of dense rubber.

 

Yes I've ordered a merc head gasket also.
Block and crank going to mach shop this week, while I'm still working on head.

 

1 cyl done.
Exhaust hump gone.
Ports, gasket matched .
Sharp edge around top of seats ,blended in.
On a 460, this is worth 20Hp, I'm figuring on bout 10?

 

That’s a start but get some tootsie roll barrels and smooth that all out.

 

I see one replaced intake seat. You really need to watch out for nicking those seats. That means you have to either replace that seat too, or you end up with a pocketed valve if you try to grind out that seat.
-Donny

 

Looks like that chamber on the right is toast already...

 

I would stick in some valves before doing any work in the combustion chamber. Also I would have that head checked for cracks before all the time consuming work is done. Resurfacing that head right?