Seized rebuild engine :(

Finished my rebuild yesterday (1.8l type 4) and had it threatening to start on the bench last night until the battery died and it was just clicking. It took a few times and just about fired so I know it was running ok-ish. Had a few flames from the exhaust as the timing obviously wasn’t right so gave in for the night and put the battery on charge.

Gone back to it this morning and the whole thing is completely seized solid. The starter is spinning off the gearbox, so that’s fine, but the whole thing is rock hard from the flywheel back so the starter is just hitting the wheel and doing nowt.

I’ve taken the rocker covers off and all valves are shut, so I’m thinking something on the camshaft timing gears has come loose/off/broken and jammed it all up, but that’s nothing more than guesswork! I’ve taken plugs off and the barrels aren’t full of oil so it’s not hydraulic seizure.

I’m absolutely gutted, first time I’ve attempted anything like this and it’s taken me months to get to this point as it’s at my in laws house so I can’t get here very often. Really don’t relish the thought of having to pull it all apart and start again. It won’t be as lengthy this time obvs as there’ll be nothing seized on and no parts to wait for, but still...!

any thoughts on other things to check before I have to go back to square one again .

 

Will it turn with a spanner?

 

No, neither from fly wheel end or with a socket on the fan

 

All the valves can't be shut.

 

All the springs are up, rockers are solid

 

What was the cam and crank end float when you rebuilt the engine?

 

i didn’t measure it, the shafts were the originals so I replaced it all as was, same size shims etc but can’t recall now what size

 

So you didn’t renew the main or cam bearings?

 

Underneath the crank bolts , see if it turns

 

i did, stupidity on my part not to recheck end float

 

will have to wait for next weekend now but will have a crack with that, cheers

 

I’m a bit confused by this. How can the cam end up in a position where its not opening at least one valve? There’s not a point in a normal engine rotation where all the valves are closed is there?

 

I thought the same. I can’t imagine a position on the cam where everything’s shut.

What position are the pushrods in?

 

I would take the rockers off, I bet it turns then. You messed up somehow setting the gaps. Maybe a few pushods fell out of the cups and it's all jammed up.

That's my guess. Just a guess. It accounts for the flames too.

If that's right it's easy fix and no harm done... probably.

 

that’s what makes me think the timing gears may have sheared or the keyway come off or something. Beginners guess though!

 

Good shout, will try that first. Gaps were set to (from memory) .6 and .8

 

That would have made an horrendous noise though wouldnt it. I cant imagine that happening without you noticing

 

My guess was that you were setting the wrong ones for the position of the engine. If you start off at TDC 3 instead of 1...easily done, @jameswick89 did the same the other day setting HT leads out after his rebuild.

 

that’s entirely possible.

 

saying that, cranking by hand before the gearbox went on, the valves were all bouncing around perfectly happily. Maybe not necessarily in the right timing, but when two were open, two were closed. Whereas now, all are closed