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A flywheel issue

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PR-Chapin

Member
Hi. New to the forum and have a challenging and complex issue to deal with. Need some expert advice. I have an older 1974 Chrysler 318 on a 270 outdrive in a 24' Fiberform. The 318 went belly up a few years ago (camshaft issue) and I'm finally trying to get it back in the water. I picked up a nice 360 Chrysler Marine engine from a 1977 boat for a good price. Just one problem. The bell housing on the 360 will not match up to the 270 outdrive. I cannot switch bell housings because the 318 has a smaller flywheel (122 tooth) and bell housing won't fit over the 360 flywheel (160 tooth). So I'm thinking about changing flywheels. In vehicles this is a bit complicated because those 360 engines were externally balanced and 318 was internally balanced. It requires modifying the 318 flywheel to meet the counterbalancing needs of 360 engine. I have the blueprint for machine shop to make that modification but I have some concerns before proceeding further. First, is a marine 360 externally balanced? Given the higher RPMs of marine engines, is it possible that they were designed internally balanced? Second, the flywheel on this marine 360 is quite large (160 tooth compared to 130 or 143 tooth for most vehicle flywheels) and heavy and though it has a large hole drilled right through middle of radius and a couple of smaller ones partially through the rim (which seems to indicate balancing in the flywheel), they seem to be in strange locations for typical 360 vehicle flywheel counterbalancing. Can I make the old 1974 318 flywheel and bell housing work with 1977 360 engine? Thanks.
 
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The 360 fly wheel is unique to that engine. Assume the bell housing are the same. I also believe the LH engine mount moves back a couple inches. Search the threads this has been covered before...
 
300hb said:
The 360 fly wheel is unique to that engine. Assume the bell housing are the same. I also believe the LH engine mount moves back a couple inches. Search the threads this has been covered before...
Click to expand...
<br><br>I have no idea how to do a search.  The bell housings are quite different which is why I'm having the problem.  Because the 1977 360 flywheel is larger, the 1974 318 bell housing won't fit over it nor will starter line up (also two entirely different starters for 160 vs 122 flywheels).  I want to put both the bell housing and flywheel from 318 into 360 so it will mate to my outdrive.  I believe the "uniqueness" your talking about is the 360 being externally balanced flywheel while 318 is zero balanced ... that's the case for vehicles anyway.  I need to know if the marine engines were made differently (this one is NOT reverse rotation).  Engine mounts for both are identical.  It's no problem relocating the 360 fore or aft as needed.  Mounts are lag bolted into wooden hull supports running parallel in that direction.  But I can't see how that will be an issue since the 360 block, mounts, bell housing, and exhaust would all be identical to the 318 I pulled out of the boat providing I can get the bell housing and flywheel matched to 360.  The only adjustment I can see for these mounts is up and down and in and out.  I planned to simply shift the identical mounts from 318 to identical block of 360.<br>
 
360 fly wheels are all external balanced whether marine or not. You maybe on the right path having the flywheel made to make it work although
you'll probably be the first to ever do it but may not have a choice. By the time they replaced the 340 with the 360 and all it's idiosyncrasies they
weren't using Volvo drive anymore but only 90% sure on that. No one probably really knows anymore but you can try asking Dave at Hurrikain.com
Just curious what drive was in the 360 boat...???

As for the mounts, I just threw that out there because the 340 definitely were diff from the 318 but wasn't sure about the 360.
That would be the least of your problems anyway.... IDK about the jibberish either....
 
Just to wet the appetite for all you Chrysler marine aficionados out there (you know who u r) Chrysler designed and built their own stern drive called the '300'
but alas it was only in production for 3 or 4 yrs before the end...300.jpg

.... and here's the man who designed it....

https://jonesfh.org/obituary?id=316452
 
The Volvo Penta drive is superior to that of the old Chrysler stern drive. That is a plus in your favor.

There is another way out of this if you are not able to find a smaller flywheel for the 360.

Find a 360 Chrysler Marine Engine "inboard" style Borg Warner flywheel cover (bellhousing is an Automotive term).
The BW 360 flywheel cover should accept the larger flywheel!

Example only (this one is GM)
Borg Warner flywheel cover.jpg
Note the industry standard Borg Warner 6 bolt pattern.



Next..... find a Borg Warner -slash- Volvo Penta PDS adapter housing. PDS = primary drive shaft.
(not as easy to find, but they are out there)
Disassemble and install new PDS bearings/seals.

BW to VP adapter housing.jpg

Note the matching Borg Warner 6 bolt pattern.


When the BW flywheel cover and the Volvo Penta PDS adapting housing are mated, you will end up with the same geometry as with the 318 AQ series Volvo Penta flywheel cover and PDS.

When done...... your 360 will mate up to your Volvo Penta 270 stern drive.


NOTE: whether you find a smaller 360 flywheel or not, there is a one-time alignment procedure that will be required when installing the new engine.
It involves triangulation using the six flat spots between the transom shield and the PDS adapter housing.
Let me know if you need info on this!



.
 
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This site is not user friendly! Twice I have been sent into the Twilight Zone and lost long replies.

The 360 engine was supposedly mated to a 280 Volvo but I think it must have been a Chrysler 300. It's a 1977 model and former owner said the outdrive had hydraulic trim and 280 did not. Might explain why this flywheel cover does not mate to my 270 outdrive.

Thanks for the Borg Warner conversion idea but I don't think I'll have the clearance for aft mounting starter to flywheel housing cover. I'll check. Already located two flywheel covers but no luck yet finding the conversion adaptor to my outdrive. I might have trouble finding a starter anyway as this 360 flywheel seems to be unique with 160 teeth. Vehicle 360 engines were 130 or 143. I have no idea why Chrysler would have made the flywheels for marine engines so much heavier and larger diameter with more teeth (it's just under an inch wider than my 318's 122 tooth flywheel but MUCH heavier). Apparently weight and diameter difference is not a big deal according to the guys over on Moparts forum. Hot rod guys make the conversion all the time.

Also just thought of something: Isn't that starter mounted on the Borg Warner flywheel cover to accommodate right hand rotation? Both my engines are left hand rotation with their starters mounted on opposite side of the housing.
 
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I think your custom fly wheel is a great idea. Trying to find this and that for Chrysler's will take forever.
Come to think of it my 340 fly wheel is anchor too... I forgot how thick it was. You going to use a newer gear
reduction starter...???

Volvo's will always have parts availability which is why I have a collection of 300 drives...
Does the guy still have his...???


Jack
 
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PR-Chapin said:
This site is not user friendly! Twice I have been sent into the Twilight Zone and lost long replies.
Look at the bottom left corner in the text field.
You should be able to invoke the "restore previous".

The 360 engine was supposedly mated to a 280 Volvo but I think it must have been a Chrysler 300. It's a 1977 model and former owner said the outdrive had hydraulic trim and 280 did not.
Not so!
Volvo Penta did offer an AQ series 280 with power trim...... it was the 280PT.

Might explain why this flywheel cover does not mate to my 270 outdrive.
How is it not mating?
Please post a few photos of the flywheel cover and stern drive for us!

Thanks for the Borg Warner conversion idea but I don't think I'll have the clearance for aft mounting starter to flywheel housing cover.
When/if you were to find a Chrysler B/W flywheel cover, look closely for an opening for a low mounted I/O starter motor.
Go back to post #7 and look at the GM B/W flywheel cover. It has both.

Already located two flywheel covers but no luck yet finding the conversion adaptor to my outdrive. I might have trouble finding a starter anyway as this 360 flywheel seems to be unique with 160 teeth. Vehicle 360 engines were 130 or 143. I have no idea why Chrysler would have made the flywheels for marine engines so much heavier and larger diameter with more teeth (it's just under an inch wider than my 318's 122 tooth flywheel but MUCH heavier). Apparently weight and diameter difference is not a big deal according to the guys over on Moparts forum. Hot rod guys make the conversion all the time.

Also just thought of something: Isn't that starter mounted on the Borg Warner flywheel cover to accommodate right hand rotation?
NO.... the Borg Warner Inboard flywheel cover's starter motor location works for either a Std LH Rotation engine, or a REV RH Rotation engine.


Both my engines are left hand rotation with their starters mounted on opposite side of the housing.
Please explain.... better yet..... post some good pictures!
Click to expand...
 
I would think the amount of "unbalance" needed for the 318 neutral could be determined from the 360 wheel.
If your shop is able to do that, make sure you indicate the bell in also.
 
300hb said:
I think your custom fly wheel is a great idea. Trying to find this and that for Chrysler's will take forever.
Come to think of it my 340 fly wheel is anchor too... I forgot how thick it was. You going to use a newer gear
reduction starter...???

Volvo's will always have parts availability which is why I have a collection of 300 drives...
Does the guy still have his...???


Jack
Click to expand...

It appears my 318 starter is gear reduction but I'm not sure if it's marine ... maybe truck? Doesn't look marine-ish.
 
RicardoMarine said:
...................
Click to expand...

The bolt up pattern to outdrive for the 360 flywheel cover does not match my 270 Chrysler/Volvo. The bolt pattern and sealing ring for 360 are narrower. Same number of bolts and in all other ways appears to be the same (e.g. bellows diameter are the same). Deceived me when I bought it because just looking at it I was sure the flywheel cover would bolt up to my 270 outdrive. Close but no cigar. Another interesting thing is that it appears the 318 flywheel's yoke ring for holding sealing donut in place is pressed on whereas the 360 flywheel housing is all one single cast piece.

I do not see anything but aft pointing starter mount on the Chrysler Borg Warner flywheel cover. See attached photo from e-bay.
View attachment 18580

I would be surprised if this 360 was hooked up to a 280 Volvo. First, I believe Chrysler dumped Volvo in 1976 and switched to their own 300 (I think I read that somewhere). Second, from looking at all the images I've been able to find of 280 Volvo, it sure looks like they used identical transom plate. This flywheel housing's sealing ring assembly is too small for the 270 opening so I presume it's also too small for 280 plate as well?
 
Chrysler has been using gear reduction starter motors since the late 50s.
While I’m not a Chrysler Marine expert, I would not be surprised to see that the marine industry followed suit.


.
 
RicardoMarine said:
Chrysler has been using gear reduction starter motors since the late 50s.
While I’m not a Chrysler Marine expert, I would not be surprised to see that the marine industry followed suit.


.
Click to expand...

The interesting thing is the 360 had an obviously non-gear reduction straight shaft starter with remote solenoid. Given the dog-leg in the 318 starter (with solenoid attached), I'm sure it's gear reduction. If the 360 used a starter without gear reduction, that might explain its 160 tooth large size flywheel. Never thought of that but it's probably the explanation for difference in flywheels ... or part of the explanation anyway. Thanks.
 
He wrecked the outdrive (whatever it was) and left the boat stored in a barn for several years till he could get time and money to fix it. In the meantime a family of raccoons took up residency and destroyed everything in the cruiser, even the headliners. He pulled the engine and took the rest to scrapyard.
 
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PR-Chapin said:
The interesting thing is the 360 had an obviously non-gear reduction straight shaft starter with remote solenoid.
That would be an old Bendix style starter motor. Heavy, amp hungry, slow spinning!
You will want to make a door stop or an anchor from that one! ;)

Given the dog-leg in the 318 starter (with solenoid attached), I'm sure it's gear reduction.
Yes, if the center of the armature and the center of the pinion gear are offset from one another........ it will be gear reduction.

If the 360 used a starter without gear reduction, that might explain its 160 tooth large size flywheel. Never thought of that but it's probably the explanation for difference in flywheels ... or part of the explanation anyway.
Possibly!

Thanks.
Click to expand...

mcomm said:
The singular issue here is the 122 tooth flywheel being neutral balance. There is an aftermarket "balance plate" that many people are satisfied with that will make your conversion quicker and cheaper. Use all the existing parts you already have. Loctite might be advisable.

https://www.summitracing.com/parts/...MI87zkpar93AIVj5V-Ch1NggHTEAQYASABEgLBRfD_BwE

The notation in the ad says this:
QuickTime balance plates are made from high-quality, zinc plated H-60 steel. They are used to fit between the crankshaft and flexplate to correctly balance your vehicle's engine without resorting to a big, heavy flywheel. Quick Time offers several models to choose from for your engine.

A flex plate is used with an automatic transmission Torque Converter.

Then if you go on to read the Qs and As...... it does allude to using it with a flywheel.

Your call!
Click to expand...


I would still like to see a few photos of the stern drive and stern drive components!
 
Okay, exactly what do you want to see? The stern drive is laying in my grandson's red wagon right now with cover off. Cover is in the bag of parts and holding screws, bolts, etc. The transom plate is just a 270 Chrysler. Perhaps you'd like to see the 360 flywheel housing next to 318 housing? Both flywheels are removed right now and I can take a photo of them together I guess. They are unremarkable except for size difference and a rather large (counterweight?) hole drilled through the 360's.

I am surprised modifying the flywheel hasn't come up here before. It's fairly common in the hot rod crowd and a number of after market outlets sell lightweight pre-drilled flywheels to accommodate the mating of 360 to 318 transmissions. Unfortunately they are almost all 130 or 143 tooth flywheels. One supplier in Australia sells 122 tooth flywheel with 360 counterweight but its seven hundred bucks (Australian $) plus shipping. The slant six also had 122 tooth flywheel but only ten inch and mine is 12.3" . I emailed them asking for diameter and got no reply. Not that I was very seriously considering spending that much anyway. A thirty dollar counter weight balancing plate is on its way here now. It's fitted to the crank's six bolt pattern and sandwiched between the crank and flywheel. It's received good reviews from everyone who's tried them. If I can find a 360 crank and connecting rod somewhere I'll take them down to machine shop and have him spin up the balancing plate and flywheel attached on balancing machine to see how it looks. I'm not going to tear down my engine just to get at those parts.
 
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PR-Chapin said:
Okay, exactly what do you want to see?
Any photos would be helpful..... the more/the better!

The stern drive is laying in my grandson's red wagon right now with cover off. Cover is in the bag of parts and holding screws, bolts, etc. The transom plate is just a 270 Chrysler.
If you DO indeed have a Volvo Penta drive, Chrysler simply put their name on the Volvo Penta transom shield.

Perhaps you'd like to see the 360 flywheel housing next to 318 housing?
Yes!

I am surprised modifying the flywheel hasn't come up here before.
Chrysler Marine Corp has been out of biz for years.
The boats with Chrysler engines and V/P stern drives are rather rare these days.

It's fairly common in the hot rod crowd and a number of after market outlets sell lightweight pre-drilled flywheels to accommodate the mating of 360 to 318 transmissions. Unfortunately they are almost all 130 or 143 tooth flywheels. One supplier in Australia sells 122 tooth flywheel with 360 counterweight but its seven hundred bucks (Australian $) plus shipping. The slant six also had 122 tooth flywheel but only ten inch and mine is 12.3" . I emailed them asking for diameter and got no reply. Not that I was very seriously considering spending that much anyway. A thirty dollar counter weight balancing plate is on its way here now. It's fitted to the crank's six bolt pattern and sandwiched between the crank and flywheel. It's received good reviews from everyone who's tried them. If I can find a 360 crank and connecting rod somewhere I'll take them down to machine shop and have him spin up the balancing plate and flywheel attached on balancing machine to see how it looks. I'm not going to tear down my engine just to get at those parts.
Be patient...... perhaps a few of our Chrysler Marine experts will come along and offer some advice.
Click to expand...
 
RicardoMarine: It is definitely a Volvo-Penta outdrive with Chrysler name on the transom shield. I have bought parts for it before and it matches the V/P schematics.

I have a very large boat in pieces in my driveway. I'm not going to wait long :) Winter comes early up here in Canada.

The 318 vehicle automatic has zero balanced flexplate/torque converter instead of zero balanced flywheel. Essentially the flywheel and flex plate/converter perform the same function, delivering engine power to the vehicle/boat driving unit (transmission or outdrive). The same amount and placement of counterbalance is necessary for the same conversion from 360 engine to 318 driving unit no matter if it's standard or automatic. The same counterweight placed in the same position (end of crankshaft) should work for both auto or manual or boat transmissions. At first I was questioning the pressure of clutch on vehicle flywheel with conversion plate between it and crank but the plate's surface spans the surface of crankshaft bolt up face so I see no reason for the pressure to be lopsided. Anyway, I'm not dealing with a vehicle. The guys over at Moparts who have tried the plate say no problems with 360 engines. Vibration free.

You have to wonder why Chrysler went back to the bendex style starters for this marine engine especially if they'd been using gear-reduced starters in vehicles since the 1950s. Are they more durable? Strange.
 
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Okay, here's some photos.

First, flywheel covers, left is 360 and right is the boat's 318 I want to replace it with.
flywheel covers outside.jpg
flywheel covers inside.jpg

Now the flywheels: 360 engine's with 160 tooth on left and 318's with 122 teeth on the right
flywheels.jpg

And here's the transom shield
transom shield.jpg

I have also started a new thread re the exhaust swap with photos in it you might be of interest. Thanks again for your help.
 
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That clears up an mystery for me .... I got a Chrysler/Volvo bell housing off of a guy rather than see it thrown away but
at least now I know it's for a 360....!
 
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PR-Chapin said:
Okay, here's some photos.

First, flywheel covers, left is 360 and right is the boat's 318 I want to replace it with.


View attachment 18590

If the PDS is equipped with a pilot nose (as I think I'm seeing), you will need to install a crankshaft pilot bushing. Do NOT operate without one!



And here's the transom shield
View attachment 18592

That is a 270 shield. Note the smaller rubber bumper and the single relief.
Click to expand...
 
I know I have a 270 outdrive NOT a 280 outdrive or 300 outdrive which is why I want to use the 318 bell housing and flywheel instead of the 360's. The drive shafts (spindles?) for both bell housings are identical and recess the same distance from flywheel cover base into crankshaft. I can see no reason why any adaptor or bushing would be needed. If the old 360 flywheel cover worked on its 360 marine engine, why wouldn't the 318 flywheel cover work on it too if they have the same drive shaft?
 
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PR-Chapin said:
I know I have a 270 outdrive NOT a PDS or 280 outdrive or 300 outdrive which is why I want to use the 318 bell housing and flywheel instead of the 360's. The drive shafts (spindles?) for both bell housings are identical and recess the same distance from flywheel cover base into crankshaft. I can see no reason why any adaptor or bushing would be needed.
Click to expand...


No offense....... it would be very helpful if we used the correct marine terminology.

Volvo Penta PDS = primary drive shaft. This is the shaft that is housed within the flywheel cover! It connects the engine to the stern drive universal shaft and transmission.

Bell housing is an automotive term...... the equivalent in the marine world is a "flywheel cover".

Borg Warner = the industry standard shaft splines that engage into the Borg Warner drive coupler.
Borg Warner drive coupler = the flywheel mounted spring-dampened drive unit that couples to the PDS. It will look similar to an auto clutch disc that is minus the friction material.

Pilot nose = the forward portion of the PDS that is forward of the Borg Warner splines.
Pilot nose bushing = the bronze bushing that inserts into the AFT most area of the crankshaft. It is NOT an adapter.
It is absolutely necessary as to center and support the front of the PDS.

NOTE: If the PDS is supported by 2 ball bearings within the Flywheel Cover, then it will NOT have a pilot nose. (again, I could not tell from the photos)


I'm trying my best to help you. I simply ask that you try to use the Marine terminology so that we can better communicate. No offense!
 
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This will help explain the single bearing PDS w/ pilot nose -vs- double bearing PDS w/o a pilot nose.
Either one connects to the Borg Warner drive coupler in the same fashion.

Again..... if single bearing PDS w/ pilot nose, the crankshaft bushing is required as to center and support the front of the PDS.
If double bearing PDS, the bushing is not required.

View attachment 18606
 

Attachments

  • PDS double and single bearing explained.jpg
    PDS double and single bearing explained.jpg
    23.9 KB · Views: 53
Hi again. You will have to bear with my ignorance of marine mechanical terminology. Acronyms fly in one ear and out the other with me. If I inadvertently say bell housing you know I mean flywheel cover. It shouldn't inhibit our dialogue. I'm doing my best.

Both flywheel covers are single bearing. I can feel the bushing in the 360 crank with finger but NOT the 318's crank. Not sure what the story is there. Consequently I checked for slop in the PDS on 318 flywheel cover (see, I got it right this time!) and there appears to be a bit compared to 360s which is pretty tight. Presumably I should change bearing and seal? Any advice on how to do that?
 
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PR-Chapin said:
Hi again. You will have to bear with my ignorance of marine mechanical terminology. Acronyms fly in one ear and out the other with me. If I inadvertently say bell housing you know I mean flywheel cover. It shouldn't inhibit our dialogue. I'm doing my best.
That's good. It will help not only me, but others as well!

Both flywheel covers are single bearing. I can feel the bushing in the 360 crank with finger but NOT the 318's crank.
While you have the PDS out for bearing replacement, fit it into the bushing for a test. It should be snug. It does not need lubrication since (unlike a car/truck) it does not spin within the bushing.

Not sure what the story is there. Consequently I checked for slop in the PDS on 318 flywheel cover (see, I got it right this time!) and there appears to be a bit compared to 360s which is pretty tight. Presumably I should change bearing and seal?
Yes, a failure here can cause very expensive damage. I have repaired many over the years.


Any advice on how to do that?
Yes.... you will need a looooooong needle nose pliers with the tips modified. The tips will be tweaked inwards a bit so that they can grab and hold within the two large snap ring eyelets.

You will first sacrifice the AFT seal so that you have access to the snap rings.
Once both snap rings have been removed, the PDS is free to come out AFT.

The bearing is most likely an industry standard 6206. If there is no grease port in the FC, then it will be a 6206-2RS.
If it is a 6206, the AFT seal will be a 35x62x7mm Timken or TCM.

If you need more info, do a forum search...... I have posted on this many times.
Click to expand...
 
I have a pair of snap ring pliers with multiple attachments somewhere. Hopefully they will reach. If not I'll get down to el-cheapo tool place, buy a sacrificial pair of long needlenose pliers, and go to work on them with grinder to make them fit. Both flywheel housings have grease fittings. If the bearings are the same (and I suspect they are), then I'll simply swap the 360's PDS shaft into the 318 flywheel housing. I'm 100% sure they are the same (same length, same teeth, same crank bushing). Will still need to buy seal of course. Thanks for that heads up and providing the numbers (makes it quicker for me to acquire). You undoubtedly saved me a lot of trouble down the road! I'll probably need some help triangulating the 360 engine once it's back in the boat but I'll get to that bridge when ready to cross it. Looks like the flywheel balancing issue was fairly easy to resolve. However, a quick question on that: are the marine connecting rods the same as typical vehicle? The Mopar hot rod expert I talked to here yesterday felt they probably are the same but Chrysler did make some special high performance factory 360s with thinner connecting rods that balanced up differently. I know the marine engines have timing chains like those hi-performance engines which is giving me some second thoughts on the adaptor plate route ... though the guy seemed very reassuring it would work.
 
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