Jump to content

Need a bit of help. Engine, trans install help


Recommended Posts

Ok I did an engine swap z24i to z24i, nothing too complex.


Anyway the good starter grinds and won't engage. It was new on the blown motor. Works fine and both spins and pops out engaged on the ground.


Now. The blown motor was a manual trans that did not have a large spacer between the engine and flywheel.


The new motor was an automatic and did have the spacer. I did not use the spacer because the manual didn't have it.


Am I going to have to drop the trans or is there anything else I could do? Could I put two washers between the starter and the block to see if it would hook up like that?


Of course you really can't see anything because of the manifold.


New/old motor spins freely and I pulled the exhaust side plugs just to try with no compression.


Also the first two times I bumped it when I finished installing it, it did turn the motor.

Link to comment
  • Replies 16
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Well after googling some more, it seems autos have the spacer or it is welded on to flywheel. Manuals do not. I cannot find anything specific for a 720 though.


I am using the work flywheel on both but am aware of the difference

Link to comment

After working on it till it turned into an oven in the shop, I might have an idea on the problem. I think I have rust in #4 cylinder. The motor turns with a few fingers till it hits a certain point then it takes a slight bit of pressure to go through it.


I am going to borrow a camera tomorrow and look before I try any further.


It will now turn about one full revolution before the starter kicks out and grinds

Link to comment

The automatic flexplate requires a spacer between it and the crankshaft. Additionally, there a spacer on the transmission side of the flex plate. This front spacer aligns the torque converter to the center line of the crankshaft. This will space the starter ring on the flexplate to the rear away from the starter about 1/8". Thus if you don't have it, the flexplate is not only too close to the starter but the torque converter can easily be off center. Without the two spacers the flexplate mounting bolts may also be bottoming out into the crankshaft before the flexplate is tightened in place. I would fix this first before worrying about any 'rust' in the cylinder. 




spacer2.jpg This goes on the end of the crankshaft. The round part in the middle supports and aligns the torque converter. The torque converter is NOT aligned by it's 4 mounting bolts.

  • Like 1
Link to comment

Just to clarify, you're using a manual trans? No spacer if manual trans.


Rust in the cylinder is death for a motor. RIngs rust and leave pitting in the bore, which is going to cause blow-by. Also, the rust damages the rings by similar pitting. If there is a lot of rust and you crank it hard, you can break a ring. Then there's the question of why the rust was there in the first place. Was it from a previous blown head gasket or leaky intake? Or was it from improperly storing the engine when it was out? Who knows?


At this point, the motor is in, so nothing ventured, nothing gained. Squirt some WD40 in the cylinders and rock the motor back and forth until you can do a full rotation. Spin the motor with the starter, but with the spark plugs out to blow out all the crap. Put the plugs back in and see if it will run. Maybe you will get lucky, maybe not.

Link to comment

Yes I used the manual trans with no spacer. There is very little resistance but it is there. I have a standard length ratchet on the nut and it goes from about 2 fingers pressure to a bit more but not much. I am just running through ideas as to why the starter jumps out after about one engine revolution. Plugs are out, Marvels Mystery oil in.

Link to comment

Condensation? Maybe, but doubtful. I don't know what the climate is where the engine was stored, but it would have to have been stored for a very long time (years upon years) for any sort of condensation to actually cause a stuck piston.


If the motor spins a full rotation and you're having that starter issue, the starter may be faulty, or the ring gear on the flywheel. Or maybe the flywheel isn't seated on the back of the crank properly.


So the engine does turn a full rotation? And when you say nut, are you referring to the bolt in the center of the crank pulley?

Link to comment

Yes the 27mm one on the crank. I guess I will try a new starter. Maybe it is, I have no idea how much it was tried to crank after the hg blew on the old motor but that motor never successfully drove. The kid that rebuilt it never could get it to run right.

  • Like 1
Link to comment

Manual... somehow it sounded like an automatic. That spacer may have to be pried off or the standard flywheel does not seat properlu over the end of the crankshaft.


I haven't seen an engine yet that takes uniform pressure to turn by hand or wrench. Even with the plugs out.


Take the starter out and watch the flywheel while someone turns it. Does it wobble???? The starter ring gear is not welded on and if dropped can move it.

Link to comment

Sorry for All the confusion. The truck is a manual. The new engine was an automatic. The auto flywheel was removed and the manual installed.


Will post when I get new starter in. Small town, I have to order everything

  • Like 1
Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

By using this site, you agree to our Terms of Use.