4

I just finished building my own engine stand, however, I have (yet another) problem to solve: in the original Czechoslovakian manual I see the factory stand holds the engine from a side, holding it by two tabs it has at the bottom where the oil sump gets attached, and in the middle of that side by a threaded hole between cyls #2 and #3, but not passing through. The issue is that hole has some weird diameter and threading: a spark plug looks to have the same diameter, but the thread is like 1.25 however it fails to be such when I use the threads gauge.

As the engine will build up a lot of weight when adding its pieces (the head is cast iron, for instance), I'm concerned about that hole or any invention I can make with it. I thought about re-threading it to whatever the spark plug is, and then weld a rod to an emptied spark plug to make it a stub...could work but...

Question: Can I hang the engine by its rear side, the side that has the flywheel, the side that attaches to the gearbox, using the same studs it goes there? Would that hold the engine ok for assembling it? Or any other suggestions :)

Remember, engine block is aluminum.

Engine: Skoda 120 Estelle, 70's, RWD, rear end mounted.

enter image description here

EDIT: the stand they show in the original manual

enter image description here

EDIT: so I got scared with the idea of hanging the engine from its rear side: the stubs there are mere M8, maybe they are just for attaching the gearbox but I don't want the risk of breaking something there. This is the stand I made, and a pic shows how I resolved the hole problem by using a spark plug.

enter image description here

  • Do you know how much the expected total weight is? – Zaid Mar 12 '17 at 15:40
  • No Idea, not in the czech manual nor in Haynes...I'm thinking 350 pounds, sort of standard for 4 cyls small car engines. – Aram Alvarez Mar 12 '17 at 18:14
2

TL DR: You should have no issues.

Almost every engine stand I've dealt with and/or used is designed to support the engine from the back side of it where the transmission connects to it. There should be more than enough support at the transmission bell housing mounting points to support the engine off of the stand. You'll want to ensure you have long enough bolts to have full engagement into the threaded holes. The bolts should extend into the holes by at least 3/4" (~2.5cm) ... this is at a minimum. You'll want to ensure there are at least three mounting points, but four preferably. Ensure the bolts hold the arms tight against the block. If it is at all lose, you stand the risk of pulling the threads out of the block.

The biggest reason why you'd absolutely want to mount it from the back end of the engine is because you'll need to rotate the engine during assembly. You cannot do this if you have the engine mounted by its side.

  • I just uploaded an image of the stand they show in the original manual: the engine is secured by side support holes and can rotate as you can see. Well, I finally made a head for the stand I did, for this kind of engine support. The problem I had with the center hole and its odd threading/diameter I solved it by re threading it for a spark plug :) I'll post photos when I start the "journey" next week. – Aram Alvarez Mar 11 '17 at 19:07
  • Your question, though, asks if you can support it from the rear. There should be no issues hanging it from the rear of the engine, whether it's an aluminum block or cast iron. The metal is more than capable of standing up to the weight and will support it without issue. – Pᴀᴜʟsᴛᴇʀ2 Mar 11 '17 at 19:29
  • @Paulster - with the depth required for bolts as per "The bolts should extend into the holes by at least 3/4" (~2.5cm) ... this is at a minimum." the limit I use is the depth should be 2.5 times the root diameter - there are publications that give more precise information such as Giek Technical formulae and it depends on the materials and pitch and depth of thread. – Solar Mike Mar 12 '17 at 11:49
1

I would say yes, but use most, if not all the studs as using just 1 or 2 may crack the casting. The disadvantage will be your access to fitting the flywheel and clutch. The factory mounting points are usually placed to allow robots to do assembly. So, after your edit, the answer still stands. :)

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.