C6 flexplate vs 94 IDIT

hexpheen

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Hi all,

I'm swapping a 94 IDIT into a 88 E350 N/A IDI. I'm keeping the C6 in there now.

I bought a flexplate for the IDIT instead of using the C6 flexplate because I read the IDIT flexplate was built heavier to compensate for the turbo-engine rotating mass.

When I removed the old engine and had access to the C6 flexplate, it was much heavier than the brand new ATP flexplate I got for the IDIT.

Also, on the n/a idi the flexplate didn't have a reinforcement ring, the IDIT shop manual has the ring mounted after the flexplate.

Any help or advice on what flexplate to use for mounting a 94 IDIT to C6 is appreciated!

Pictures included. NA/C6 flexplate on left , ATP flexplate and reinforcement ring on the right.

-hex
 

hexpheen

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IDIBRONCO

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I'd use the C6 flexplate and harmonic balancer. Im pretty sure that the balancer is different too. If I'm wrong, I'm sure that someone will correct me.
 

cpdenton

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C6 flywheel is much heavier, but balanced differently.

The flex plate for the IDIT is the only option you can run on your IDIT engine. It is lighter but balanced with a heavier weight on one side. They will bolt up to the c6 torque converter for sure(my truck was flexplate to c6 when I bought it) as long as you use the 1 inch spacer between the flywheel and crankshaft.
 

IDIBRONCO

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See? It didn't take very long for someone to correct me. Thanks cpdenton. I'm not the most up to date on the factory turbo engine balancing.
 

hexpheen

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Wow! You guys are on your game!

Thanks cpdenton. The idit supplement manual has the spacer ring after the flexplate...you're saying I should actually use it as a spacer and put it in between crank plate and flexplate?
 

cpdenton

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The spacer makes up the distance added by the transmission adapter plate that adapts the international bolt pattern to the ford transmissions. The older c6 flywheel made up the distance without a spacer.

It goes like this,

crankshaft,
1 inch spacer,
flexplate,
ring that acts to spread the bolt torque(like a washer),
then bolts.

Be sure to use sealant on the bolts too as the holes in the crank go through to the crankcase.
 

hexpheen

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Cheers mate!

Thanks for the help and thorough response. I understand now.
 

FORDF250HDXLT

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The new flexplate you bought.That's not part # Z-344 by any chance?

I ask because this statement is 100% accurate:

The flex plate for the IDIT is the only option you can run on your IDIT engine.

and last I knew,the aftermarket didn't make a turbo flexplate.The ATP Z-344 I was able to use as replacements for my trucks due to them being M code/non turbo blocks.Those flexplates are not balanced correctly for the turbo crank.
 

riotwarrior

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I beleive the c6 plate could be balanced for turbo engine...but just use the plate u got as previously mentioned
 

hexpheen

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Hi FORDF250HDXLT, yes that is the flexplate I intend on using. Even with the added weight of the factory spacer/reinforcement ring with the new flexplate - it is noticeably lighter than the NA C6 flexplate. This is what through me off since I was expecting the IDIT flexplate to be more heavy-duty.

Here's the ATP link with specs/application guide: Z-344
 

FORDF250HDXLT

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It's not about heavy vs light.It's about how it's balanced.As you can see here,the flexplate for the 7.3l IDI N/A cannot be used on the 7.3L IDI Turbo engine.The same applies for ZF5 trans flywheels.


full


The balance between the two engines are drastically different.All becomes very clear when you compare N/A & Turbo engine cranks.I'll see about adding a pic to my albums so I'll have it handy as well.

Added:
full


It's not just cranks but the factory turbo engines used a bit more heavier duty piston with larger wrist pins as well.The whole rotating assembly is of a different balance.Install that N/A flexplate and it will eventually lead to engine failure........who knows how long it might last until it sounds like the engine in my little honda civic did on my last road trip.......it wasn't pretty.:D

Last I knew,the only way to replace a flexplate for the oddball/less common, factory turbo engine,is to source one used.Since they only made the optional engine for two years ('93 & '94) it can be tricky.Then to make it tougher,you'll need to source it from an engine someone is willing to part out and or swap to a manual trans.How many can be left after 20 years? No doubt half or better have probably been long since tossed into the salvage yards.Of the other half out there,those are probably backed with manual transmissions.Of the other 1/4,those might still be on the road.The few of those that are not,the owner may not wish to separate parts from.I don't envy you.Good luck!
 
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cpdenton

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Here is the only difference between a factory turbo flexplate and a non turbo flexplate. See the weight on one side? Turbo flexplate is on the top.


This is why you can not use the flexplate you have bought if you truly have a factory turbo spec idi.

You can make sure that you have a factory turbo block by looking at the engine ID number next to the IP tower. A turbo spec engine will start with 7.3T and a non turbo idi will start with 7.3D.


http://s478.photobucket.com/user/cpdenton/media/1442019835.jpg.html

Here is a comparison of all the parts that are different on a turbo vs non turbo of the exact same year block.

http://www.oilburners.net/threads/photo-comparison-of-factory-turbo-parts-vs-na-parts.74367/
 
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cpdenton

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Not to push anything, but I do still have that flexplate from the turbo IDI.

Sold the rest of the internals a while back.
 

hexpheen

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Well.....this just got more complicated. I wish the ATP site didn't list the turbo IDI as an application then for that flexplate.

Yes, I have a factory turbo block. Verified with the block code.

How about this ebay find?
http://www.ebay.com/itm/1994-Ford-F...ash=item3d3a168a2d:g:fhkAAOSwT-FZC8ex&vxp=mtr

I'm assuming the C6 isn't going to the really care about which flexplate is there - we're mostly concerned about the balance of the engine rotating assembly.
 

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