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Good pick on the motor. The fso 6406 is a good transmission. I have read that they upped the torque specs on it to 860 ftlb. Nice looking engine. I think my trip to get my rto 6610 transmission was 1500 miles :).

Cj
 

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Discussion Starter #22 (Edited)
Thanks CJ, you are correct about the Eaton. There is a FSO-6406a (600 something torque) and a FSO-8406a (800 something torque) from what I’ve read they hardened the parts more for the 8 model but it actually all looks the same
 

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Hmm... I haven't heard the hardened internals - transmissions already sport hardened internals for wear resistance, but the parts manuals list the same parts for both transmissions. My understanding was that the transmission performed so well Eaton reevaluated it and upped the torque specs. If ever if get tired of the 10 speed I'll find an fso 6406 for my truck.

Cj
 

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Discussion Starter #25 (Edited)
CJ, What do you have a 10 speed behind? What I read about the Eaton was they cryo froze the parts resulting in 30% more strength over regular hardened but that was just hearsay in another forum, might not be true but I do know cryo treat does result in 30% more strength
 

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Rp,

The 10 speed is stashed behind the 7.3 in my 97 F350 :). Hmmm... my research on the cryo treatment has indicated that absolute strength may go up a bit, but the real advantage is that the parts have lower internal stress over all.

Cj
 

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Discussion Starter #27
That’s a cool swap CJ! Must’ve been a cool trip to go get the 10 speed. And overall the Eaton 6 speed does seem like it’s a good set up
 

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Discussion Starter #29
I’ve been researching my options for a transmission set up. Would love to have a sae 2 housing and flywheel but I have a sae 1 so keep an eye out for a 2. I found a place that sells sae 3 housings for $400 but I don’t think that’s gunna work with a Eaton trans since they come with sae 2 bells.

Then on to my next question.... using and Eaton transmission I could get an adapter to bolt the sae 2 transmission bell to the sae 1 housing on the 8v53 which is the easy part, I just need to figure out somehow which flywheel I will need. There seems to be a lot of used flywheels for sale (71 series which the 8v53 uses). So if anyone knows what flywheel to use( pot style or flat) to get an Eaton to work I am all ears. Seems like I might be looking something that’d work with a 15.5” clutch.
 

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I'm guessing on some of this... but with an sae 1 I think you have to go with a matching flywheel to engage with the starter. An sae 1 to 2 adapter is not a bad idea, but it will mess with the pilot bearing spacing. Perhaps a spacer between the engine and flywheel, but then you have to figure out the starter. The Eaton with work with either a pot or a flat... the 7.3 in my truck has a flat flywheel with a pull style clutch and the V504 Cummins I own has a pot style with a push style clutch behind it. Both have RTO 610/6610s behind them.

Cj
 

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Discussion Starter #31
CJ, the specs on the adapters I’ve seen show you can get a zero offset or a small offset if desired. And you are correct about the flywheel/starter setup, so I am willing to get a sae1 flywheel to work with my sae 1 housing as long as I can find a clutch set up. The engine uses 71 series flywheels so there got to be some clutch/transmission set up out there
 

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Discussion Starter #35
If it breaks it breaks. Although The engine was built 60 years ago and if it were to break I think it would’ve happened long before it wore out the loader that it came from. Kinda like the year 2000ish Cummins 53 blocks, some cracked but by 2010 they were saying if yours hadn’t cracked yet it probably won’t.

I really came to post that I’ve made progress on my transmission stuff. Through wayyyyy to much time staring at pictures on the web I’ve found the style of flywheel I need and it can be had for $300 in good used condition with the pilot bearing(making it easy to find the bearing part number). I found that it uses a 14” pot style Eaton clutch and after skimming a bit I think the fso-6406a runs that clutch. I’m gunna pull the trigger on that flywheel so I can get this engine to run first and then go about the transmission hunting. Like I said before my engine came with a flywheel on it, a sae 2 with 14” pot but I suspect this to be just one the previous owner slapped on it while it was lying around because the engine has an sae1 housing. I’m excited
 

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Discussion Starter #36 (Edited)
Also while I had the valve cover off tonight that there seemed to be 4 exhaust valves per cylinder. The ID number in the block stated this is an N engine for naturally aspirated. There is another code on ID charts for a “4 valve head” so I assumed that meant the N engine were 2 valve heads but mine is a N engine with 4 valve heads. What’s up with this. These heads look like they’ve been on this engine for a very long time. Did 8v53N eninges come with 4 valve heads or did someone a long time ago swap out the 2 valve heads for some 4 valve. Another thought is that because the 8v53 engines came with 71 series blowers they needed 4 valve heads to get the gases out faster.

  • Edit: even funnier is the fact the engine ID number says 5803 when it should say 5083 but maybe it’s a 60 year old typo.... 5: 53 series, 08 8 cylinder, 3: fan to flywheel. My engine has the 08 backwards.
 

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8v53s didn't come with 71 series blowers! They came with 8v53 blowers. Also I don't know of a 53 series head with less than 4 valves per cylinder.
 

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Discussion Starter #38
In Griggs write of 53 series engine he talks about two valve heads along with ID charts showing them. And as far as the blower on my 8v53, yes technically it is an 8v53 blower it just has more in common with the 71 series than it does a 53 series.
 

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In Griggs write of 53 series engine he talks about two valve heads along with ID charts showing them. And as far as the blower on my 8v53, yes technically it is an 8v53 blower it just has more in common with the 71 series than it does a 53 series.
OK, I had never heard of a 2 valve 8v53 and I still don't know if one was ever produced
I have an 8v53 blower, it is a lengthened version of a 6v53 blower, not much in common with a 71 series other than it is a Rootes type blower
 

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Discussion Starter #40
OK, I had never heard of a 2 valve 8v53 and I still don't know if one was ever produced
I have an 8v53 blower, it is a lengthened version of a 6v53 blower, not much in common with a 71 series other than it is a Rootes type blower
You’re right on the blower, I just had a Detroit expert stop by and he said it is indeed a special blower built for the 8v53 although it had spiral suckers in it and a forward mounted govener with a 71 intake all common with the 71 series.

Thank you for clarifying with me
 
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