Classic/Antique Car Repair: 79 midget clutch problem, mg midgets, clutch disk

Question
I have a 79 midget that the moter went bad , it is a 1500. I found a good used one and replaced it runs fine. My problem is that now my clutch will not dis ingage. i tried to bleed it with no luck. bought a new slave cylnder and got a little pedel but not enough to disingage. ended up shiming the rod from inside the slave cylnderand works better but still do not have enough peddle.it will disengage now but if i let off the peddel at all it engages instentley.Dont kno why changing the engine would cause all these problems. never opened the system. if you have any ideas please help. Thanx BOB

Answer
Hi Bob,
The 1500 (Triumph Spitfire)engine used in the late MG Midgets always had clutch travel problems even when it was in the Spitfire. As for why just changing out the engine would make it on the edge. Did you use any of the components from the new engine, ie, flywheel, pressure plate, disk ?
Another possible problem is when you separate the engine and trans, and reassemble. It is easy to slightly warp the clutch disk with the trans input shaft. This makes the disk wobble slightly and thus makes the pressure plate need to retract further to disengage. Add this to a system that was designed "on the edge" of having enough travel to start with and you have problems with clutch release.
Other things to look at are, the clevis pin on the master cylinder rod is soft metal and will ware groves in it thus giving you less travel. Bleed the clutch system (be sure to us DOT 4 fluid).
The shimming of the slave cyl. rod was a common practice in the dealership and a good method of correcting a problem.
As long as you don't have gear clash going from neutral to reverse at a low idle, you may want to just drive it for a while to see if it improves. If it does improve over time it would indicate the disk was slightly warped due most likely to a input shaft strain during replacement of the engine.
Only quick sure cure I seen was a boring out to a larger size mastercylinder piston. This was done by one of our customers, but I don't know what kind of piston he used.
good luck, let me know.
Howard