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Transmission overhaul, turns into supercharged 383 stroker build

elyon

elyon

1/2 ton status
Joined
Feb 16, 2012
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Location
Eastern NC
So my rebuilt TH400 failed. I think it was due to blocked cooler lines. The torque converter was pushing forward into the dust cover under load and in the process ate my thrust bearing and crank. Pulled the engine to replace the crank and found oil in #5 cylinder. Pulled the head and found a blown head gasket, worn ring lands on top, lose valve guides, exhaust valves hammering the seats. Instead of a new 350 crate engine, I elected to have my engine rebuilt as a 383. Supercharger going back on making about 5 lbs. of boost. Lunati supercharger cam going in to compliment. 8.7:1 compression ratio, Hedmann full length headers, water methanol injection.

Can you say "excited."

This thing should make some decent torque.

Also have a new Tactical Armor Group multi carrier sitting on a pallet to be mounted. Only took 9 months to get it!!! They build a nice bumper, but will string you along forever in the build process. They live up to their reputation unfortunately.

image.jpg
 
Home made.

Green PVC from Lowes for the filter housing. Spectra conical filter lives inside. Rubber boot is a reducer also from Lowes. The rest is all Spectra stuff. Stainless line is water/methanol feed.
 
Very nice, I want to do the same thing and haven't seen anyone's setup. Would you mind takig some pictures?
 
I'll try to remember when I get home. Out on the road right now.

The pipe is a short green section of 8" I think it was. I used a green drain grill plate that fits the pipe section and routed the center grll section out of it and used the outside flange to mount it. Cut n 8 inch hole out between the lights and radiator. Fabricated an 8 inch circle plate with 3 legs attached and mounted that between the grill and radiator support to block any large debris from entering the housing. I used a metal paint roller strainer again found at Lowes to fabricate an 8 1/2 inch circle to cover the intake whole between the housing and radiator core to keep big bugs and such out. It is a diamond patterned strainer they come in different sizes and I found a small one to cut up. The rubber reducer is slightly larger than 4" inches on the small end, but I found the one of the rubber couplers from Spectra slipped right inside making a perfect fit. There is a short, I want to say 6" section of pipe inside the reducer that the Spectra filter clamps to.

It was a pretty easy fabrication and has held up very well. It flows well. I was going to go with a snorkel but ARB engineering could not tell me how many CFM it flowed so that was out.
 
There is a flex coupling at the top that you can see. I found the other type was too stiff for the whole set up. Engine torque kept pulling the pipe apart. No problem now...
 
dang, thats gonna be fun to drive. lets see that bumper!
 
Engine was stared on Friday. Cam has to be broken in and timing dialed in as well. Think we are going to put a larger trans cooler in and bypass the smaller internal one in the radiator. Bumper is still sitting in my friends warehouse waiting on me. Going to China on Tuesday. Back in 10 days. Hopefully get it mounted and some pictures taken then.
 
New 383/rebuilt TH400 and...... Tactical Armor Group multi carrier

Finally got my truck back from the shop. Thought I would post some pics of the rear bumper. The bumper is well built. The tire carrier is too low for me, but I will remedy that. The latches are pretty well put together. The fuel can shelf was cobbled together. It isn't even plumb. One corner dips down. I think for the money though it is a good buy.

Only thing is, customer service was the pits. They advertise 2 to 3 months. This one took 9 with some proding. My front bumper took about 6. You have to "NOT" be in a hurry if you order from them. You will get all kinds of stories about where your bumper is in production.

It is really a shame......

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Sexy bumper! On a side note, be sure and check the line pressure of the 400 trans with a gauge at wide open throttle. It should be 175 to 200 psi, even with a shift kit/pump mods etc. If you are over that by much the pressure could be pushing on the converter and this can wipe out the crank thrust. I have probably only seen a handful of truly "Ballooned" converters, though they do get the fair share of blame. The high line pressure is the real culprit, check it soon so you don't harm that sweet new engine.:waytogo:
 
Thanks for the heads up. I had them put an external trans cooler with new lines and fittings up front. Not that the one in the brand new Griffin radiator was bad mind you. The guys at the shop just convinced me to put a larger cooler on.

Now for the bad part. Picked the truck up on Friday. This morning, taking my children to school, got out of the neighborhood and it did it again!!! Shifts from first and then tries to lock up. I don't get it. It would motivate in first so I limped back home and called a tow truck. Back to the shop........

On Friday when I picked it up, it felt like it was slightly shuddering in first, but I was listening and feeling for anything. After a few miles there was a squeaky sound that started up. Sounded kind of like a hampster treadmill. It increased with RPM. Yesterday I took it to get inspected and made no noise what so ever. This morning, no noise, just broke down again.

Frustrated.
 
Got my truck back yesterday. The second gear sprag clutch had destroyed itself. Wish I knew exactly why. It will be a while before I trust it. Now to dial in the carb. It was pretty close when the engine was a 350. Now that it is a 383 with a different cam and larger valves, it goes very lean when the secondaries try to open. It has a massive flat spot.
 
Crazy stuff happens. Probably from improper assembly. The th400 in my burb is original and has 230k miles on it. They can be trusted!
 
A TH-400 is a great trans and should give long service life. The intermediate sprag came in two basic flavors, the earlier dog bone style is easily converted to accept a sprag element with 34 of these little dog bones instead of just 17 as the stock trans used. The later transmissions (73 and newer for the most part) used a spring and roller style of sprag like the turbo 350 trans. This sprag was not as durable in high performance use though they seldom fail in most stock/near stock applications. It is commonly agreed that in applications exceeding 450-500HP/TQ that the 34 element sprag design is the way to go for best results. It could be your builder did not have the best sprag for your application and its shortcomings came to light after the initial drive.
 
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