My new 347

[CDW6212R]

I'm hoping the next build lasts for years. It sounds kind of like the machining was poorly done, like the main bores were not honed true and/or the clearances varied a lot journal to journal. A bent crank would do that but that's very unlikely compared to sloppy machine work. I don't want to condemn the shop but the symptoms sound scary for a recently built engine.

Did the crank move much front to back, that the trans needs some extra checks(pump gears etc)? Hopefully the trans and TC had nothing to do with the engine issue.

 

[Dono]

Yup, with that thrust bearing wore out to nothing, there was a boat load of play in the crank.
I'll be taking all kinds of measurements before the motor goes in. Also, I'll be checking crank play after the motor is in.

 

[CDW6212R]

The crank thrust damage issue used to be rare ages ago, it seems to have come up more in the last ten years than it ever did before. The newer transmissions after the first four speed automatics seem to have critical TC and pump installation issues, special tools etc. With older automatics, and the AOD/AODE/4R70W, they are all fairly simple to install. The pump is easy to install, and the TC is just slightly tricky to get it seated all the way in. Once in though, there is and has to be plenty of play front to back of the TC.

The studs that mount the TC to the flexplate should easily push back into the flexplate and pull out to put the nuts on. I don't know how much less play is there when the TC is not engaged all the way, but I suspect it's so little that the studs won't push back through the flexplate at all. That's the TC forced forward up against the flexplate, which pushes against the crank(thrust bearing).

I'm not trying to beat a dead horse, but I think a lot of newer wrench turners don't know these simple details. I think a lot of people are learning things on their own instead of having more experienced help from friends etc. Hopefully many of these build threads online do point out these details which experienced people take for granted. I've forgotten a lot of details, and have to go slow for any project so I can figure things out again.

 

[Dono]

Im hedging that this last motor install I didn't have the TC seated all the way against the trans as I am loosing (lost) patience with this whole thing. I have not had thrust bearing issues previously. Taking a few months off is a good thing. In a few weeks we will be out of the cold weather (at least hovering around freezing) and I'll get started. Maybe tonight I'll pull the TC off the Trans and start assessing damage/clearances.

 

[CDW6212R]

Hopefully the main pump is okay. The gears are an easy $20 pair to buy new, the pump I think I saw for under $120 when I was browsing recently. I was hunting for a new planetary set of parts for an AODE(close ratio(2/3 are closer together)).

 

[vroomzoomboom]

as i had mentioned, i do believe if you didnt have it seated all the way in, the truck shouldnt have moved. maybe take the tc to trans tec and see what they say. they will be able to spot a problem a lot easier then you or i would. that and they are just down the road form you as well.

 

[Dono]

TC to flex plate has 15/16 of an inch. Spec is 1 inch.
Its a bit tight

 

[Dono]

TC pilot spec is 1/8 inch doing this. I have .004 ( 1/25 of an inch).
This might be ok if the crank pilot hole is deep enough.

The tc to flex mount is out by 1/16 inch. That could be a bit tight. I'll be asking more questions about this.

All the splines on the Transmission look fine. I emailed this info to my engine guy. Neither of us want this to happen again. He's a great guy, but its far cheaper to not see him again.

I'm thinking the TC is ok, as of all the times the motor has come out, this is the first thrust bearing issue.

 

[Dono]

After numerous emails to transman304 with pictures, the conclusion is that the transmission did not cause the thrust bearing failure. I'll just have to be careful with my measurements and make sure that the torque converter will need to be pulled slightly forward when it bolts to the flex plate. Thank you transman304 for all the help.

My pistons are in. Wiseco 4.04 boost pistons with a GFX ring package. They are things of beauti. It was explained to me that you can tell its a boost piston because the top ring is set lower on the piston. They sure are light.

The machinist thinks he might have to take a few thou off the top of the pistons since the block is already zero decked and he will want to re-deck the block. He's not sure yet.

Since the pistons were hitting the crank before, he will assemble the short block, make sure it rotates without anything knocking in to anything else, check all clearances, shave top of pistons as required, balance and re-assemble.

Machinist says he doesn't want to see me again until I phone him and ask to have him build me a different motor for something else. lol.

 

[CDW6212R]

Sounds great. When he's test fitting and adjusting clearances, include the piston to head distance. That's the quench which has a lot to do with power, efficiency, and avoiding detonation. Too much or little is not good, hit the middle range and it helps in all ways. About .030-.040" is what I've read of a lot. Most people don't even measure or consider it.

 

[Dono]

I'm impressed with the attention to detail. I understand that you pay for the time spent, and I'm ok with that also. As long as there is value for the money spent.

 

[CDW6212R]

It does sound like you found a good shop to build the engine.

 

[4pointslow]

The pistons were hitting the crank?

 

[Dono]

Yup
I'd never heard of that before. machinist showed me the bottom side of a couple of piston skirts, and then held the rod against the crank showing how the piston was hitting.

 

[4pointslow]

Wow!
I have seen where an engine ingested water into the intake and when over top of the piston caused a hydro locked condition and bent a rod.
That caused the rod to be too short and the crank hit the bottom of the piston. Some shatter and a couple were at low rpms so they just locked up.
Your engine was a stroker kit or short block? That means someone put together a crappy kit without checking to make sure it would all fit together?
Where did it come from? Was it from Summit Racing?

On a good note it sounds like you have a shop that really knows their stuff and has an eye for detail, since they noticed all that.
That should be helpful in getting this engine right this time. With less rotating resistance you should have more power too!

 

[Dono]

Yea, I'm comfortable with the shop and their attention to detail.
I did ask about bent rods, and they had already measured them up. No issue there.

The short block came from Ford Strokers. The motor was apart aster the initial startup when the oil pump drive gear sheared, but I can't see the parts changing and causing pistons hitting the crank. I'm not exactly sure what happened and can't point any fingers, but it does look like the block could have been machined to better tolerances and better attention to detail should have been taken at some point.

 

[Dono]

I stopped by the machine shop today. The machinist found a couple of rods that were clearly bent. This is obviously from when I hydro locked the motor going down the 1/4 mile track way back when. Frustration sets in.

 

[4pointslow]

Oh No!

 

[vroomzoomboom]

If you need more don, let me know

 

[Dono]

Yup, 4pointslow called it.

2 rods with a very slight 'arch'.
Funny thing is, quite a few miles wen't on that motor while it had the bent rods. lol.

Best to get it all fixed up properly before trying again. Its at least a few more weeks away from getting it back home to complete final assembly and drop in.