Hi!Today my "engine to z-bar stud" broke. I will get a new one in a week or something like that but I need to drive the car home from the shop.Do you know the thread size of this stud? I didn't find any information about this. I will try to buy a bolt with the proper size, cut the old stud, weld the new bolt to it and make sure it's the same Overall lenght of the thread and the "ball" the goes into the Z-Bar. Please let me know the thread size if you know it Thank you!Chris
Chris, the thread size is 1/2"x 13 threads per inch.,. if possible, get a short 1/2" "coarse thread" bolt about 2" long (about 50mm) and grind the bolt head as required to fit into your "Z" bar socket.,. you'll need a nut to lock the bolt to the block.This will work for you until a replacement gets to you or buy 2 bolts and have a welding shop weld up the broken one.
When The Flag Drops.,. The Bull ***t Stops.,. P. Engineer, Engine Builder
tuff is totally right.. i have used allen head bolts also.. one time with a stack of washers above the jam nut but below the head.. with only 3 that were the proper size for the z bar tube.. the rest were smaller.. this worked great for months till i got around to finding a replacement z bar ball.. please.. check your motor mounts.. if your motor mount is broken.. or ???the engine can lift up and snap the ball off the stud.
i have never seen one break. check out the clearances. your z bar should wiggle side to side around 8 mm. if its too tight it might cause probs.
Thanks!!! The engine mount is not broken but it's bad, you're absolutely right!What kind of mount works best for me? (some drag strip use..)I found a solid mount, a stock mount and a polyurethane mount. What type would be best? And how difficult is it to change them?I'll just drive the car home with the repaired stud, without big accerleration, don't want the engine to move and brake the repaired stud on the way home After that I'll wait until the new parts arrive, change the Mounts, put in the correct stud for the z-bar and make sure there is 8mm clearance (there was some clearance from what I could see before, I guess the engine mounts caused the problem)
there are lots of ways to lift the engine to change the mounts.. these are one way to lift it safely if you use the tool as designed...this is an earlier version of the same brand tool.. i actually have this one and use the heck out of it.. i have been drooling over the twin hook version.. note that the wooden blocks seem to be rolling over.. and the legs are almost out past the safe point.. try not to abuse the tool like this.
I cannot use such a tool on my fenders... maybe I'll lift it from underneath if I can find a good place.Thank you for the Information!I'm now curious what engine Mount I should order.. I don't really like the idea of a solid mount.. I think it's better with rubber or poly.... What do you think?
Yeah I think those lift bars would be sketchy on anything non-unibody. Strut towers can take the weight, fenders and fenderwells not so much. Theres a small spot on the front corner of the block that I normally lift at. Of course once you lift, its important for safety to BLOCK the engine from falling while you work. Even if you use a cherry picker to lift, you need to support the engine in the raised position. The hardest part of doing mounts for me, is probably carving out the rubber that blocks the bolt heads once the mount gets old. Yours may not be that way.I would choose poly engine mounts.
I hope they will come out easily. The poly's are more stiff I guess, but they will last longer? Solid mounts won't be used, that's for sure now. My car is now at home, the clutch linkage works again. This is the new engine to z bar stud: We cut the stock one, drilled a hole, put in the new bolt with the same thread, welded it together and cut it to the proper length. I will change it to a new one when we do the engine mounts but it looks very strong to me the way it is now.If the engine mounts weren't bad I'd probably keep the stud the way it is
I believe poly would last longer based on the fact that plastic generally outlasts rubber. I haven't used poly engine mounts, they were not yet available last time I did that job on mine. However I did use poly control arm bushings. From that, I learned about how poly can be damaged by contact with other fluids such as oil, ATF, power steering. If something leaks on the plastic mounts they won't last long. Aside from that, the potential for squeaks isn't an issue with rubber but is with plastic. Probably a non-issue with engine mounts. I would imagine that the poly mounts can withstand a lot more exhaust heat over time, as well.Sounds like a good fix on the stud, that should last awhile!
hello chris;your engine has only been in a short while, how can a mount be bad without being broken?you can put a 2x4 under the oil pan off to one side. it must be longer than the flat part of the pan.unbolt the motor mount on that side.jack it up as far as needed and replace.leave bolts slightly loose and do the other side.you should chain your engine down on the drivers side if you use a stock mount other than gtojacks. leave a little bit of play in the chain. old racers trick.the urethane mounts frequently increase vibration. i do not like them for that reason. f
For the record, the pic of the repaired stud popped up after I replied. I kinda don't like the looks of the fix, what will it tighten against with the tapered weld surface in the way? Any way- thats a good point about vibration. And about a supplemental engine restraint or torque chain. Chains can rattle though, I've made a slotted metal bracket for that once before and limiting travel helps a lot. Just so the slack pulls out of the restraint before the mount does, it doesn't matter what its made of as long as its sturdy enough. Just consider where the force will go and design it accordingly.Mounts are different on the Grand Prix, thats probably why I couldn't get poly ones.
After that we worked on the welded part to make it even around the thread. Its just a sollution to drive the car home and back to the shop when the parts have arrived! I have to agree, the stud will now take more load on the thread.. The engine mounts havent been replaced, I think one is broken of has a least a deep cut, the other looks better. I'll replace them with stock mounts (rubber) and do it like you said.Thanks for the Information!By the way.. before this "accident" the stud wasnt fully tightened because the 2 seats and spring were missing at the frame side stud. It would have fallen off if it was tight, that probably broke the stud, the broken engine mount made it even worse. When I think about it.. this little stud had a hard life and didnt give up for a long time I didnt really know how bad the linkage was but I already ordered the parts.. bad timing for the stud to break, in a week the parts would be here in Austria anyway.. The only thing I knew was that it will need overhauling so I ordered all the parts with my next order I had to make.