Ever heard of an engine siezing up like this?

[josh817]

So Dad and I built a U20 motor for a customer and we go to put it in the car. Now, we know it spins, because we spun it before we put it in. Every time we did something major like add pistons and rods, put head on, connect timing chains, install flywheel, we spun the motor to make sure we don't have any screw ups. Admittedly, it is a tight motor. The rear seals are particularly tight, even though we oiled them. That's ok though, the motor spins freely. So we stab it into the car, make sure it spins, it does. We proceed onto hooking everything up. We're at the point where we now need to get the points to the open position or something Dad said. I don't know how to work a points style dizzy but that's what he said. We want to use the points first to get the engine running and then we will install electronic ignition.

 

So, we put a socket onto the crank, it won't turn. I go "oh that's because we have the spark plugs in", take them out, still nothing. Its out of gear mind you. So we decide ok well lets try rocking the car while its in gear to see if it moves at all. Still nothing. The wheels were sliding on the ground, that's how stuck it was. So here we are going what on earth is happening?! I think maybe its something that's connected to the crank in some way, so like the water pump, the alternator, the starter. I remove those, still nothing. I have now undone everything, ready to pull the motor back out. I then remembered, we spun the motor over, with the jack under the tranny. We had the motor in its mounts and bolted up but the jack was still under the tranny. I then remembered, Dad said "that tranny mount is probably toast" when he saw the engine moving around when we rocked the car, you know like it torques to one side.

 

Has anyone ever heard of a tranny sagging, so maybe the input shaft is in a bind with the crank? I'm thinking maybe when we took the jack out, the tranny drooped a little from its dead mount. Doing this sort of thing:

 

I was thinking no that can't happen because the bolts from the tranny to the block are tight, holding it together. I honest can't think of anything else guys... Everything is off the motor, no valves are colliding or anything. The only thing I can think of is that its in a bind somehow with the tranny or the motor somehow froze up like... over night..?

 

We will trouble shoot further tomorrow. I'm clueless right now though.

Edited April 13, 2010 by josh817

[rturbo 930]

No real advice for you, but that sounds very similar to what happened to my friend. Rebuilt his motor, and I forget how he found it, but he went to turn it over, and it didn't. Tore it apart, put it back together, made sure it turned over, put it in the car and... you guessed it. He had a shop rebuild it the third time, don't think I ever found out what the problem was.

 

Just like yours, it happened literally overnight.

Edited April 13, 2010 by rturbo 930

[Nizm0Zed]

(i had about 3 times as much written up, but the more i think about it, it doesnt appply)

 

 

maybe look at the flywheel? to see if there is something binding against it? is the starter fitted in place yet?

 

something isnt right, yea you can have a tight motor, but if its real hard to turn over by hand there is an issue somewhere.

consider how much power is going to be lost from the motor to overcome its internal friction?

 

Its a strange one, i would be very keen to hear what has caused it.

[josh817]

Nothing is up with the flywheel that I know of. I installed the flywheel, turned the motor. Then put motor into car, turned it. Then when everything is hooked up, it won't turn. I suspect it has something to do with the jack that was propping up the tranny a little or something, because the motor did turn when it was in the car! Thats how we check if its engaged. Turn it out of gear, put it in gear, make sure it doesn't turn. I tried turning the motor over with nothing installed, just the blocked, mated with the tranny, and it won't budge.

 

Tomorrow we will loosen the bolts joining the two together, and prop the tranny up a little, maybe it will turn.

[hoov100]

Nothing is up with the flywheel that I know of. I installed the flywheel, turned the motor. Then put motor into car, turned it. Then when everything is hooked up, it won't turn. I suspect it has something to do with the jack that was propping up the tranny a little or something, because the motor did turn when it was in the car! Thats how we check if its engaged. Turn it out of gear, put it in gear, make sure it doesn't turn. I tried turning the motor over with nothing installed, just the blocked, mated with the tranny, and it won't budge.

 

Tomorrow we will loosen the bolts joining the two together, and prop the tranny up a little, maybe it will turn.

 

The schwartz is telling me, that your input shaft is bottoming out on the crank bushing? (the little bronze thing, that the input shaft slides into on the back of the crank)(or your input shaft is cocked/bent and is causing the clutch plate to jamb on the sides of the pressure plate.

Edited April 13, 2010 by hoov100

[josh817]

The schwartz is telling me, that your input shaft is bottoming out on the crank bushing? (the little bronze thing, that the input shaft slides into on the back of the crank)(or your input shaft is cocked/bent and is causing the clutch plate to jamb on the sides of the pressure plate.

I hope the shaft isn't bent... We inharreted this project, with the motor out of the car, taken apart... I guess we'll find out...

[hoov100]

I hope the shaft isn't bent... We inharreted this project, with the motor out of the car, taken apart... I guess we'll find out...

 

Could you move the engine forward enough, so that the input shaft is completely out of the clutch? if you can get the input shaft completely out of the clutch, you can try turning the motor over. Also when you have them separated, put the car in gear and push the car forward, to see if the input shaft spins without excess binding.

[FlatBlack]

I had a real "doh!" moment this winter when I put my new clutch in.

 

I accidentally grabbed the wrong bolt while under the car and put the starter bolt into the slave cylinder bolt. I didn't realize what I'd done until I pulled the tranny again

 

It caught one of the edges of the pressure plate when I tried to start it and slammed into the bolt. Put the car in neutral, tried to roll start it and the tires slid on the pavement like you said. Is there any way the pressure plate is catching on the bellhousing?

[jeffer949]

Maybe the clutch is to big and is hitting the bellhousing?

[thrustnut]

I had a problem like this with a Bronco. I had the tranny rebuilt and after re-attaching it to the engine and keying the starter...nothing. I tryed to turn it over by hand and no go, so I unbolted the bell housing bolts and the torque converter bolts and lifted the tailshaft aligning it as best i could and actually herd somthing pop, slid the tranny back in, tightened it down and everything worked perfect. I don't know what made the pop noise, but somthing was misaligned enough to keep the engine from turning over. I also had a similar problem with the Z, the engine was hanging up on one of the ring gear bolts that was too long. I agree with pulling the tranny off and spining it through by hand, then re-installing it. Take it one step at a time, there's not that much going on back there, shoulden't be that hard to find.

 

Good Luck!

[Mike kZ]

I think your tranny is messed up. When I first drove my Z with the T56 in it, I backed out onto the street, put the the lever into first, let the clutch out and it stalled. Every gear I tried, it would stall. Turned out reverse and I think 6th gear jammed together inside the tranny, but the lever moved freely in all gears. Did you try connecting the clutch peddle, then push in the clutch, and see if the motor turns?

[rturbo 930]

Update: My friend's problem was that two of the rod ends were swapped somehow.

[jasper]

Many good suggestions here.^^^^

Make sure BOTH ALIGNMENT DOWELS are present. Shaft centerlines are important.

 

I've also seen clutch discs installed backwards, locking up the clutch.

[josh817]

Alright well Dad jacked up the tranny at different points and still nothing. We will pull the motor tomorrow, make sure it spins freely, go from there I guess. He thinks that maybe one of use spun it the wrong way on accident at some point in time. Maybe like when we were under the car so our right is actually left, I don't know. He thinks maybe a timing chain is stuck. I said well if it spun backwards, and it got stuck when we tried to spin it forward, shouldn't it still spin backwards then...? And it doesn't spin either way.

 

Clutch may be installed backwards, that's a good thought. There were no markings on the clutch, and the paper it came with showed a picture which resembled the same way most clutches face, so we did that. I would think however that the motor would still spin when its out of gear. Alignment dowels were there, all 3 I think it was. Proper clutch, correct size and correct input shaft spline count.

 

We have no slave cylinder installed so the bolts can't protrude.

 

I guess we will have to see. An incorrect clutch or locked up timing chain is easy to fix with the motor out. Dad is getting all pissed because he's getting into the "fast money", quick turn around, crap. Its really starting to piss me off the route he is going. If something is wrong with the car, he buys the part to fix it. We told the guy it will be this much to rebuild the motor and get it in the car running. The internal conflict is that because he told the customer a set price, that is our budget. Of course, Dad needs to make money off this just as much as I do, even though its my project, because the car is taking up a spot in the shop. This means he marks up the parts prices, and pulls that from our budget. Any money left over from the budget, is my profit. So the problem is, he is more than willing to go out and replace everything on the car to make it pristine, despite the fact that the task is to rebuild the motor and have him drive off with the car, because every part Dad buys, he makes money, yet I lose money. Point being, I don't think I'm even going to see $400 in my hand when everything is done here. If I don't get at least $400 for the work I did (complete rebuild, lighten, balance, and polish rods and pistons), I think I'm finding somewhere else to work.

 

Sorry, just had to rant a little. This project is becoming overwhelming.

Edited April 14, 2010 by josh817

[MONGO510]

You said this was a U20 engine. The U20 engine was installed in the Datsun 2000 Roadster and had a 5Spd trans behind it. The Roadster 5 Spd was notorious for getting jammed in to 2 gears at once when it was speed shifted. Once it was locked up the only way to free it was to take the trany apart and replace the spring lock pins in the shift rails.

Don't ask how I know! LOL

This may be your problem. See if the engine will spin with the clutch pushed in. If it will you found your problem!

 

Mongo

[josh817]

You said this was a U20 engine. The U20 engine was installed in the Datsun 2000 Roadster and had a 5Spd trans behind it. The Roadster 5 Spd was notorious for getting jammed in to 2 gears at once when it was speed shifted. Once it was locked up the only way to free it was to take the trany apart and replace the spring lock pins in the shift rails.

Don't ask how I know! LOL

This may be your problem. See if the engine will spin with the clutch pushed in. If it will you found your problem!

 

Mongo

Some good advice. You're filled with U20 knowledge! Would it still roll if it did that because the car can still free roll... just not in gear obviously. I don't think there is anything wrong with just the tranny... The car rolls, goes in every gear, etc. Its something to do with the motor or the two together. I highly doubt just the motor because when we built it, everything spun freely. Unless if it froze up somehow but I can't fathom that because I am notorious for using all the assembly lube and STP...

[woldson]

We have no slave cylinder installed so the bolts can't protrude.

 

So you can not disengage the clutch for a test?

[woldson]

One last thing, is the rest of the drive train hooked up? EBrake?

[josh817]

We have no slave cylinder installed so the bolts can't protrude.

 

So you can not disengage the clutch for a test?

That is correct, we couldn't engage the clutch.

 

So, I pulled the starter completely, motor doesn't turn. I pulled all the bolts holding the tranny to the motor, still doesn't turn. Pulled the motor, motor turns outside of the car no problem. We can spin the input shaft with our hand when its out of gear, and when its in gear, we can push the car and the input shaft spins. I looked on the clutch and there are no scratches or anything... I don't understand. Dad is now determined to replace the tranny mount, and then replace the tach and its cable. So much for just "rebuilding the motor". Of course, the guy won't pay for it separately, its all part of our tight budget, meaning, he gets money for marking up parts, and I lose money. Nice. This will be the last job I do, as part of his shop. I'll use this money to buy my own metric stuff, and continue onto any other motors (doubtful) by myself.

Edited April 15, 2010 by josh817

[woldson]

Input shaft bent? Any metal shaving on piolt, clutch disk splines or input shaft?

 

Something seems amiss here. I would leave it apart and cogitate, measure, cogitate, repeat.

 

This tranny was mated to that engine before and moving, correct?

 

Starter gear moves freely? The nose of the starter does not show scraches? Fly wheel the same?

 

You have such a big bind that it really dose not seem that it would be just a tight fit of the input shaft. Did the tranny and engine mate up together with out much trouble?

 

 

Did the alignment of the tranny and engine cause a bind on any other parts of the drive line, check Ujoints.