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Flywheel mystery


fireguyfire

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Long story to get to my question so I apologize up front!

im getting close to finishing the restoration of my 1958 Fargo Sweptside truck, one of less than 10 that came with a v8 engine.

The original engine and transmission were in the truck when I bought it, but the engine was badly seized so I had to have it bored out, pistons made for it, etc.

That process took a year and a half and while they was going on I took the flywheel clutch and pressure plate to a local shop that has been servicing stuff like that for 100 years. The ground the flywheel and pressure plate and refurbished the original clutch disc to new; that was over a year ago.

 

I finally got to the point recently where I could mate the transmission back with the engine and drop it into the fully restored truck frame. When I pulled the engine from the engine stand and went to bolt on the flywheel, I was stunned to find that the flywheel bolt pattern is a circular 8 equally spaced, and it also has non threaded holes meaning it has the clipped head bolts and nuts to hold it onto the end of the crank.

The end of my crank has a 6 bolt pattern that is not equally spaced, with 2 of the holes obviously closer together meaning the flywheel can only go on one way. Also, the end of the crank flange holes are threaded to take bolts, no nuts needed.

This engine and transmission were together when I bought the truck and I have absolutely no idea how I can have a flywheel that doesn’t match my flange now.

I thought perhaps there was a chance that I got the wrong flywheel back from the shop by accident, so I called them and they don’t have any record of a mixup where someone else got the wrong flywheel (mine) by mistake.

Luckily I have 2 flathead 6 parts trucks here (non Sweptsides) and one has the same 3 on the tree transmission that is in my Sweptside so I pulled the transmission to get a look at that flywheel, and it has the exact same one that I have, 8 bolt equally spaced around tge circle with clip head bolts and nuts.

 

So I have absolutely no clue how this can be unless the engine shop put a different crank in the engine?

 

My question is, we’re there 2 different bolt pattern on flywheels of this vintage?

 

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What engine is in the Fargo?........is it a Plymouth based polysphere?...........when the engine was reco'd is there any chance that the crank was swapped or was the flywheel swapped when it was reco'd.........the crank from a later A series Poly or LA Series 318 wedge can be used in the early polys but has a different flange..............I'm getting a pre 62 poly rec'd at the moment so am curious as to whats happened here.........regards from Oz........andyd 

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I'm not an expert on truck motors and flywheels. But I do have info on some early V8's. But in order to help more info is needed. Which V8 engine is this ? A Poly 318, early hemi or a B engine ?

 

The pattern on the crank and the flywheel obviously don't match. Somehow your parts got mixed up, the 8 bolt pattern would be similar to those on a 230 flathead. 

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1 minute ago, fireguyfire said:

So if indeed I have a later crankshaft, would the matching later flywheel interchange, meaning would the diameter , ring gear etc be the same?

would the older pressure plate and clutch disc bolt up?

 

None of that matters, the flywheel is now physically closer to the block than it was originally, which means the bell housing is too deep and the clutch assembly won't work.  Your machine shop screwed you.

 

https://poly318.com/poly-318-crankshafts-transmissions/

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If its a 313 then its an A series Polysphere...........does it have the distinctive "sawtooth" shaped rocker covers, and I think either the crank OR flywheel has been swapped by the reconditioners who didn't have the correct parts or didn't realise there are differences.....Fireguy........can you post a pic of the rocker covers or the whole engine..........thanks.........andyd 

Edited by andyd
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Yeh!!!.......thats a Plymouth Polysphere........looks nice..........now if only we can answer your original issue............check out Snipers 318 Poly Crankshaft Link............it has the answer I think to this issue........my money is on the engine shop swapping in a later 1962-67 crank with 6 holes whereas as you still had the 8 hole original flywheel............as mentioned check Snipers Link especially pics 2a, 2b, 2c...................andyd

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Fireguy...........how are things going........or not?.........have you had any joy with dealing with the engine machine shop?......I hope I havn't added to the confusion...........andyd

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Howdy!

I spoke with the owner of the engine shop, and he fully admitted that they have made a mistake and that they will fix it at their cost.

He remembers my engine well and said there was another guy named Todd that had a 318 engine in at the same time as me and is sure that they used his crank in my engine. The crank has been ground and balanced etc for my engine, so he is thinking about how they can make my original 8 bolt flywheel fit my now 6 bolt flange. I also mentioned about the option of using a later 318 6 bolt flywheel, but then you have to swap the ring gear for the original 172 tool one.

We are just starting down the road of how to fix this issue, and I will keep updating here what winds up being the solution.

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Fireguy...........sounds like the machine shop owner is a decent guy for that admission.............have you read the Link that Sniper posted?...........I've printed it out, its long, 34 A4 size pages but its got some really good info and it maybe worth getting a copy for the machine shop.................it maybe also worth them or you contacting Hot Heads as they are quite experienced in essentially doing the opposite, ie, mating early Hemis to late transmissions and may have some advice regarding the opposite as that is essentially what has to be done now..........there are various crank flange/flexplate adaptors available plus as the Sniper Link mentions other factors such as the location of the bellhousing locating dowells may or may not need to be taken into account...........good luck with it all, I will keep checking on your progress & sending positive thoughts.......regards from Oz..........andyd.  

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1 hour ago, fireguyfire said:

Howdy!

I spoke with the owner of the engine shop, and he fully admitted that they have made a mistake and that they will fix it at their cost.

He remembers my engine well and said there was another guy named Todd that had a 318 engine in at the same time as me and is sure that they used his crank in my engine. The crank has been ground and balanced etc for my engine, so he is thinking about how they can make my original 8 bolt flywheel fit my now 6 bolt flange. I also mentioned about the option of using a later 318 6 bolt flywheel, but then you have to swap the ring gear for the original 172 tool one.

We are just starting down the road of how to fix this issue, and I will keep updating here what winds up being the solution.

Be sure he understands the problem with flywheel fitment doesn't end at the number of holes.   The crank is also too short and could (likely will) result in the pressure plate and throwout bearing failing to meet up properly.   And the starter isn't in the right place, fore and aft due to the flywheel being too close to the block.

 

The ideal solution is replace the crank.   Surely the other engine is not yet installed, maybe the shop can do a recall.

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Yes, they are a mopar specialty engine shop that has been around for 70 years so they will definitely understand the can of worms they have opened that they will have to make right 

unfortunately I picked this engine up from them over a year ago and didn’t think to check the crank bolt pattern before I put it on an engine stand and covered it up while I restored the rest of the truck, so the other crank is long gone

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