Questions about compatibility ...

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notpaul

notpaul

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Hello, all!

So ... I am trying to locate a good 225 motor to replace the one in my 1976 Duster, that has a cracked block. (Manual transmission)

I tried a block from a '63 ... but after getting everything ready to install, my mechanic informed me that the lower end did not properly mate-up with the transmission & starter from the '76. (There was some disagreement online about whether or not it should have worked ... but at the end of the day I had to go with the guy turning the wrench.)

I have tried to research the issue ... but there seems to be inconclusive detail regarding which years, serial numbers, etc should work with my vehicle.

I have several leads on running motors, but before I go to the trouble of fetching one, I want to know if there is any simple and fool-proof way to check a motor and verify it will work with my vehicle (& tranny).

Thanks!
 
find one from the same era - 68-76

The counterbore in the rear flange of the crankshaft was a 1 1⁄4-inch diameter until 1967. For 1968, it was enlarged to 1 1⁄2 inches. This difference has implications when swapping engines and automatic transmissions across this date line.
 
Does this car have the 3 speed or the '3 speed + Overdrive 4th' trans?

What are the problems exactly?
- Starter not lining up with the flywheel ring gear?
- Flywheel not centering properly on the crank shaft?
- Or are there other trans to block mating issues?

The above register hole change is for the auto trans....but the same change also involved changing the flywheel centering hole; both changes occurred in the 67 to 68 year change over.

You may be able to just change the flywheel to an early one and be OK. The early crank has a smaller centering ring for the flywheel. There were also 2 different flywheel outer diameters and different ring gears in the early years; the smaller one (with the 130 tooth ring gear) should match up with your later gear reduction starter.
 
Does this car have the 3 speed or the '3 speed + Overdrive 4th' trans?

What are the problems exactly?
- Starter gear hitting the flywheel ring gear?
- Flywheel not centering properly on the crank shaft?
- Pilot bushing not the right size?

The above register hole change is for the auto trans....but the same change also involved changing the flywheel centering hole; both changes occurred in the 67 to 68 year change over. And I think the pilot bushing size may have changed.....

You may be able to just change the flywheel to an early one and be OK. The early crank has a smaller centering ring for the flywheel. There were also 2 different flywheel outer diameters and different ring gears in the early years; the smaller one (with the 130 tooth ring gear) should match up with your later gear reduction starter.
 
You stated you tried another block, just the bottom end,whole engine?If you
have a cracked block the crank is still ok unless a thrown rod was the reason, but that
is an option to swap cranks if yours is forged not cast,which was phased in late '76.
You have two areas of concern w/the older crank;
The hub diameter is .250 smaller as mentioned above,which a
competent machine shop could make a press in ring to remedy.
If the crank on the new(older) engine came from an auto equipped
car, the pilot bushing hole is often not final sized for said bushing.I have
put pilot bushings on a lathe and made them fit the undersized holes on
smallbocks before,again a machine shop can do that for you.
If you have a late /6 with a cast crank,the stamped numbers on the pad by
the alternator will have 225E, the "E" is for a cast crank unit.The damper on cast is
different as well the crankpin dimensions,so only swapping w/other "E" stamped.
The light duty clutch was 9 1/4,the heavy duty 10", I honestly don't know
if the cast engines used a non-neutral flywheel or not,another member may know
that for certain.It is not mentioned in the performance books as such.
 
I am not aware of any non-neutral dampers for inline 6's or 4's; it would not normally be ever necessary the way inlines are balanced (though they might exist, 'specially with big diesels). And not for the /6's. Ditto for flywheels for the /6: neutral balanced.

The later cast crank damper wold be designed a bit differently because the torsional vibration's that the damper is designed to suppress will be different for the cast material. They can interchange, but just won't be optimized for crank vibration damping.

So, OP, tell us where the interference is, and waht exact parts you are using from the '63.... complete block and crank, flywheel, or what?
 
nm9stheham said:
I am not aware of any non-neutral dampers for inline 6's or 4's; it would not normally be ever necessary the way inlines are balanced (though they might exist, 'specially with big diesels). And not for the /6's. Ditto for flywheels for the /6: neutral balanced.

The later cast crank damper wold be designed a bit differently because the torsional vibration's that the damper is designed to suppress will be different for the cast material. They can interchange, but just won't be optimized for crank vibration damping.
Click to expand...

Chrysler says, "they should NOT be swapped" in the performance manual,and
I see no reason to .Use the balancer that belongs w/the crank,but that wasn't the real
issue.I know inlines are "naturally" balanced,but they still have counterweights,so cast
may have still needed help. Either way,the key is ID'ing his orig. mill as cast or not,as
He will not be able to swap cranks if it is.
 
Thanks; the Pioneer catalog (which I consider to be reliable) shows the same PN for all years of the /6, all the way up through '87. I have wondered why they could not be swapped and the vibration range of the design is all I could come up with. I am 99.9% sure that the cast crank is neutral balanced just like the forged ones; the counterwieghts are there to balance the throws, not the rotating weight part of the rod/piston assemblies, like in a V8.
 
To the OP, I have successfully driven a standard pilot bushing into an
unfinished sized pilot hole, but it swedged it and I was unable to install the trans
even w/o the clutch installed.I don't know if that's a testament to My bushing driving
skills, the bronze oilite bushings conformability,or both. The upshot is it is possible,but
won't work,so that needs to be checked. Also the OE flywheel will bolt rite on,but will
not be accurately centered w/o the spacer ring,it MUST be centered.
I don't understand how the starter issue came about,unless you're mixing
the OE bellhousing w/ another flywheel ,or vice versa.You can't.
We would appreciate an update whenever You are able,and I hope We've
been helpful .

:coffee2:
 
My only thought on the flywheel and starter was that he got a 141T flywheel for the older direct drive starter with the '63 block, rather than the more modern 130T flywheel for the common gear reduction starter.
 
I have a good running 225/3 speed in a 80 duster if you want to go that way
 
nm9stheham said:
Thanks; the Pioneer catalog (which I consider to be reliable) shows the same PN for all years of the /6, all the way up through '87. I have wondered why they could not be swapped and the vibration range of the design is all I could come up with. I am 99.9% sure that the cast crank is neutral balanced just like the forged ones; the counterwieghts are there to balance the throws, not the rotating weight part of the rod/piston assemblies, like in a V8.
Click to expand...

I have swapped dampers between cast and forged crank slant six engines, with no problems, with running. Where you have problems is with the timing marks. There are at least three different locations, and each needs the corresponding damper, or the damper remarked.
As for pioneer's catalog, it has several issues for slant six parts. The first is the timing mark issue on the dampers. Also it shows the same flexplate, for all year slant six engine with a 904. That is not correct, the center hole changed size in 1968. That is the flexplate pioneer has available. They have none that fits the 60-67 slant six engine.
 
Thanks Charrlie; I never have looked at the flexplates they offer, just the dampers.

It sounds like the dampers for 273/318/340.... the 340 was different (for the heavier crank than the 273/318) but everyone lists the same PN for them all. I suspect the aftermarket ones are 'close enough' that no one notices any crank vibrations despite different harmonic ranges, and that may even extend to the OEM's. And I don't recall ever having found an early damper for the SBM's with the mark over on the passenger side from the aftermarket sources (....but I may not have looked hard enough).

Edit: And fof course, I just found one for the pre-70 SBM!
 
Well,the performance manual made a point of stating not to swap dampers,and
emphasized the word NOT, but I've never examined or tried a cast crank damper to see
what difference if any existed.Timing marks aside,of course,which have to match the
cover in use.
The upshot is this. Unless the older engine came w/a flywheel,and it was
for the 9.25" clutch, and he has the housing and flywheel OE
for the 10" HD slanty clutch (likely w/a four gear),the only thing to prevent the trans
from going in would be trying to use the mis-matched parts or the pilot bushing issue.
And since notpaul has disappeared from this thread, it's dead w/o any feedback
from him at this point. So d5667 wherever you are in relation to OH, that is good to offer
if close enuff, if the OP resurfaces he should consider that.
And there might be a member here interested in the '63 mill,so......
 
Yes, it goes back to that manual statement, K6. One thing about a damper tuning that everyone needs to keep in mind: I expect you would never, ever feel it external the engine as the torsional vibrations are in the range of hundreds of cycles per second, and are waaaay higher than our normal tactile feel ranges (especially through the butt LOL). . It is not like an engine imbalance, where the frequencies are in the few 10's of cycles per second. The only way anyone at our level of engine operation and design would readily suspect/know that they had the wrong damper tuning is to run it hard and eventually suffer crank breakage.

If anyone is interested, here is a great white paper on dampers; it makes some great points on when dampers can be sub-optimum and the cranks survive, like normal, lower RPM usage, or infrequent high RPM operation.

http://www.bhjdynamics.com/index.php?main_page=page&id=4&zenid=9kf5edqg8r6bfnrqegd409akp0
 
I know what the Mopar performance manual states, about the slant six dampers. In my opinion it is wrong. They just took the correct info for the V-8 engines, and someone writing the slant six manual, used the same info, incorrectly. If you read the slant six racing manual, carefully, you will find a few of these situations.

PS:the forged and cast crank dampers, do have a slight difference in total weight. I don't remember which is lighter, but only very little. On a crank balance machine, there was no difference, in the balance. I am thinking the difference is the "rubber". which after all these years, would not be the same as originally made, or where the "mass" is located with respect to the center.
 
Other differences would be where the TDC marks are. I also have dual groove dampner that weights twice that of a single groove dampner.
 
kesteb said:
Other differences would be where the TDC marks are. I also have dual groove dampner that weights twice that of a single groove dampner.
Click to expand...

I'm pretty sure the multi groove dampers are truck units. I have one with three grooves. Some of the truck part books have different part numbers, depending on whether auto, stick, or what engine options.
 
Roger, Charrlie. I was gonna ask if you had a variety. If I ever make that FL trip, I need to stop by and pester you on this and other topics.
 
Killer6 said:
Chrysler says, "they should NOT be swapped" in the performance manual
Click to expand...

That book is full of all kinds of funny jokes. Oops, but they're not jokes, they're errors of fact. Lots of them. :-(

It's not a reliable source. Never has been, and even less so now since a good chunk of what used to be decent info in it is now badly outdated as the parts and options available are different now than they were when that book was written.

In actual fact, they're not all alike, but there is cast/forged-crank overlap in the application of the Slant-6 crank pulley assemblies.
 
slantsixdan said:
That book is full of all kinds of funny jokes. Oops, but they're not jokes, they're errors of fact. Lots of them. :-(

what used to be decent info in it is now badly outdated

In actual fact, they're not all alike, but there is cast/forged-crank overlap in the application of the Slant-6 crank pulley assemblies.
Click to expand...

Lol, but usually they're so bad you can spot them a mile away,wrong app, procedure
etc. if you know what you're doing. Unfotunately things like that,small details while it
may turn out to be harmless,can bite the unwary if it is not. I guess to be fair there is
a lot of material in totality in those manuals,and reviewing/editing them may have been
a bit much for those charged w/the task.Still.............
The good thing about them being outdated, is the fact that someone cared enuff to
render them so, but the factory has abandoned /6ers, 2.2-2.5ers,and soon anything
that isn't a GenIII Hemi it seems.
The OP hasn't revisited his own thread,and the cast damper I mentioned only IF
he was swapping , and IF it was a cast unit he wouldn't be anyway,but only he knows.
Or his wrench,......... Helloooo????
 
Hello, again!

Sorry to have been slow to reply ... December is my busiest month of the year at work, and there were a lot of responses to read through. As far as the specific issues with the '63 block, I need to ask the mechanic again (it has been several months).

I do have the smaller diameter clutch.

Having read through the replies ... it seems - as they say - clear as mud! :)

Sounds like my 'path of least resistance' will be to find a motor from close to the same time period ... and cross my fingers?

I have looked at buying a reman short block ... but can't seem to get a good report on the available sources. (Example ... there is a place in Texas called MAABCO ... but they seem to get a LOT of complaints about quality, support, etc). At this stage, I would be fine purchasing the short block, but I want to ensure the money is well spent.

d5667 mentioned having an '80 motor ... anyone want to weigh-in on whether any compatibility issues would have cropped-up between '76 nd '80? (Oh, and where are you located, d5667?)

I *DO* appreciate the advice ... and will ask the mechanic this week for some more detail.

- notpaul
 
Welcome back! OK, question list;
Is your "tech" re-using your OE flywheel,bellhousing,clutch & starter team?
If so,you should be having NO starter problems,even w/the large hole
flywheel just on the bolts for centering.(which you should NOT run w/o
a snug centering ring).
Did the '63 mill come from an auto or stick car?
If it came from an auto, see pilot bushing ref. above.
If it came from a stick,is he trying to use a mismatched
flywheel if it came w/?
OK, those are the basics,we've covered the mismatch hub issue above if the
'63 eng has not had the crank changed to a '68 and up,you know the drill.
I'm sure there are plenty of members w/ 225's out there, shouldn't be a
problem finding a '68-early'76 forged,or late'76-& up cast crank eng. to match.If it
comes to that.
:coffee2:
 
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