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727 auto won't bolt back onto to 225 /6
https://slantsix.org/forum/viewtopic.php?t=47930		 Page 1 of 3
Author:  Vanopolis [ Fri Feb 17, 2012 10:40 am ]
Post subject:  727 auto won't bolt back onto to 225 /6
I have been at it for hours, I just did an engine swap and I cannot get the 225 to flush up with the trans. Is there a thread on this I can't find.
Any helpfull words would make my day
Author:  SlantSixDan [ Fri Feb 17, 2012 10:59 am ]
Post subject: 
What year is the engine you've installed? More specifically, what year is the crankshaft?
Author:  Fopar [ Fri Feb 17, 2012 11:57 am ]
Post subject: 
Is the convertor fully seated? It should be back about 1/2" (measured across the mounting blocks) from the edge of bellhousing.

If the crankshaft has a small pilot hole for the convertor and you are using a later big snout (pilot hub) convertor, it won't go together.

Richard
Author:  Vanopolis [ Fri Feb 17, 2012 3:19 pm ]
Post subject: 
The new engine is out of a 66 dodge truck /6 and my tranny is original 727 auto in a 69 a108
I've got 1/2 an inch of depth from the face of The bell housing to the blocks on the converter, but when I get the thing lined up and the pegs in their holes and some bolts threaded the converter won't turn so I don't go any tighter as to not bend anything.
Author:  SlantSixDan [ Fri Feb 17, 2012 3:27 pm ]
Post subject: 
Quote:
The new engine is out of a 66 dodge truck /6 and my tranny is original 727 auto in a 69 a108
There's the trouble. Through 1967, the crankshaft counterbore inner diameter on the slant-6 engine was 1-1/8" diameter, and so was the torque converter nose outer diameter. Starting in 1968, the counterbore ID and torque converter nose OD were increased to 1-1/4".

For this reason, a 1968 or later torque converter cannot be mated to a 1967 or earlier crankshaft. The other way round (1967 or earlier torque converter with 1968 or later crankshaft) can be made to work by using a spacer ring between the early small-nose torque converter and the late large-bore crankshaft. However, there is no way to adapt the large late torque converter nose to fit in the small early crank counterbore.

At the same time, the splines on the back of the torque converter (and on the transmission input shaft) were changed.

For this reason, a small-nose 1967 or earlier torque converter cannot be installed on a 1968 or later transmission, nor the other way round.
Author:  Reed [ Fri Feb 17, 2012 3:43 pm ]
Post subject: 
Cheapest and easiest solution to this problem is to pull the 66 motor back out and swap cranks with the 69 motor. Be sure the 69 crank is in good shape.
Author:  Vanopolis [ Fri Feb 17, 2012 3:46 pm ]
Post subject: 
So I can't get a new converter that will fit?
The new engine is a good rebuilt motor that's bored .030 over and possibly an upgraded cam, I would like to not have to tear the thing apart.

Also my original motor seized up and it's not the head, something in the bottom end failed at idle just after an oil change. Maybe a bad oil pump? Who should I go thru to get a new cam that's not to spendy?
Author:  Reed [ Fri Feb 17, 2012 4:04 pm ]
Post subject: 
I have heard people have had custom torque converters built that will mate a late trans to early engine, but I don't know how expensive that would be.

Provided the 69 crank is in good shape, it wouldn't be too difficult to pull the pans, pull the vibration dampener, pull the timing chains, unbolt the main bearing caps and con rod caps (KEEPING THEM MARKED AND IN THE PROPER ORDER ACCORDING TO THE MOTOR THEY CAME OUT OF), and swap the crank from the 69 motor into the 66 motor. It would only cost you time since you already have all the parts. Just inspect the 69 crank for wear and journal condition, and correct as needed.

Swapping cranks will be cheaper than finding someone to build you a custom torque converter.

Oregon Cams has good prices on custom ground slant six cams, but you can use the cam that is in the 66 motor.
Author:  Vanopolis [ Fri Feb 17, 2012 4:30 pm ]
Post subject: 
Thanks, I'll be tearing it all apart then. :?
Author:  Doc [ Fri Feb 17, 2012 4:37 pm ]
Post subject: 
Measure the hole in the back of the crank and the "hub" on the converter to confirm that this is the real issue.

I have had the crank's pilot hole machined-out on a number of engine's that had this issue... but the crank has to be out to do that.
DD

Image
Author:  Romeo Furio [ Fri Feb 17, 2012 5:14 pm ]
Post subject: 
Hughes did a converter for me at a cost of 300 bucks for a 904>Should be in the ball park. Well worth the money.
Author:  Vanopolis [ Fri Feb 17, 2012 5:24 pm ]
Post subject: 
If the front and back seals look good can I just slap my other crank in with just new bearings?
Author:  DusterIdiot [ Fri Feb 17, 2012 5:56 pm ]
Post subject:  But...
Quote:
Swapping cranks will be cheaper than finding someone to build you a custom torque converter.
Between the time to pull it all apart, and the price of gasket kits, then having to measure to make sure that the bearings are correct rod/crank to Rod/Crank, having to degree the cam in,etc... he should not have a problem getting a custom convertor made, there a few good tranny shops in the Portland/Vancouver area.

2 cents

-D.Idiot
Author:  Reed [ Fri Feb 17, 2012 7:09 pm ]
Post subject: 
Hmmmm. Maybe I am just too cheap for my own good. :wink: :lol:
Author:  SlantSixDan [ Fri Feb 17, 2012 10:16 pm ]
Post subject: 
I cannot imagine putting a worn crank into a freshly rebuilt engine. That just does not seem like a wise way forward to me. If the problem is indeed crank/torque converter mismatch, then the right way forward is to machine the crank counterbore OR have a customer converter made OR swap in a '68-up engine.
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