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Discussion Starter · #1 ·
Hello everybody. I am new to this forum and definately appreciate all the info here. I have searched (maybe not enough) but I haven't found any info on converting a 3406B white motor from an intercooler to air to air. I am looking at an inframe and would like to do something around 625hp as in ynot's iron set list. (I know the list is for a C) Is the ATA conversion worth the cost? I would think that I would need to do it just to get that kind of HP out of my motor. I have a 1979 KW ex-hood and would probably need to go with a new radiator to make room for the ATA. Thanks
 

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Get a serial number to be sure, but if you have a 7FB it already has decent parts in it to get to 625, and for packaging concerns the current cooler that is on it will handle that without trouble.

Converting to an air to air is not that hard though, they make plates to block of the water ports that feed the cooler, and the air to air manifold will bolt right to the head. I have the plates and the manifold if you are really interested PM me.
 

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Cody is spot on about your current set up being able to handle 625hp, and IMHO the small gains in ATA is offset by all the cost and aggrevation. I'm pretty sure you would have to change radiators, and then the conversion plates and all that Cody spoke of plus the air charge system, this is to just to convert it. If you check the archives on this and other boards, and mechanics, and drivers or owners, you will find a list of hose&clamp problems along with punctured or seperated air charge radiators, which will give you alot more headaches than with what you have now. Good luck, and I love the X hooded A models.
 

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Discussion Starter · #6 ·
If my current set up will go 625 (at the flywheel) then that's good news. This motor was new from CAT in 1982 to replace the 3408 and has about 500K on it and has never been opened up except for rods and mains at 350K. I'm not too worried about doing the conversion as I might do a new radiator anyway, but no need for extra aggravation. Thanks
 

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The iron set list is for a dual scroll C, As the other guys said a 7fb should get you there with just settings, Going from JWAC (jacket water after cooling ) to ATAAC (air to air aftercooling) is a trade off, jwac is quicker spooling and can be more effective in warm weather. Air to air is good for heavy haul etc
 

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You're right - I hadn't thought about quicker spooling. I just assumed ATAAC was always way better because it's the industry standard.
The radiator, cooler, water and air piping from a Cat equipped FLD 120 transplants perfectly in a W900A. Plus the extra 25-30HP is a plus, too. You have to remember, you are going from coolant temp air (190) to around 110 degrees intake air. I installed ATAAC on my W9A, and it made a tremendous difference. Absolutely no modification other than moving the bottom two mounting bolts on the radiator farther apart by about 3 inches.
 

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The iron set list is for a dual scroll C, As the other guys said a 7fb should get you there with just settings, Going from JWAC (jacket water after cooling ) to ATAAC (air to air aftercooling) is a trade off, jwac is quicker spooling and can be more effective in warm weather. Air to air is good for heavy haul etc
I saw an increase in spool up when I did my ATAAC. Have you ever looked inside the JWAC? Theres alot of restriction going through the cooling fins.

Just an opinion...
 

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I saw an increase in spool up when I did my ATAAC. Have you ever looked inside the JWAC? Theres alot of restriction going through the cooling fins.

Just an opinion...
there is no replacment for real world data , Maybe the quicker spooling JWAC
was because of a quicker spooling ARR, when the ATAAC became common,so did some polution controls. Yours is real world experience wiht the same engine.
 

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Sledman - What years of FLD 120's will work for the ATAAC transplant?
Late nineties, through 01, maybe 02 appear to be the same. I used the upper and lower coolant pipes, and ATAAC pipes. All worked beautiful. The lower pipe actually comes off the engine, and runs under the frame out to the radiator. It was almost like it was made for it.

Like I said, the lower mounting bolts are 3-4 inches closer than the A model mounts are. Remove the lower mounting bracket, drill new holes, tack weld the bolts in. All worked perfect.

One more thing.....the new cooling system held ALL of the coolant. Even with the JWAC gone. Never ran hot...ever.
 
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like the forum I too have a 3406b model water jacket after cool and I want to convert it to air, Cody mentioned that plates are needed to cover the water ports, I need an ata housing, an air charge cooler, piping, and? Any advice in letting me know what all is needed for the conversion is much appreciated. Thank you in advance
 
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