How uniform are the mounting bolt holes on different blocks?


(Erica Moss) #1

My 3.8 E-type engine will be coming out for service in the near future and Mr Wigton has kindly offered to fabricate a bespoke stand for it based on this photo from the UK list. It looks like in the front it’s using the mounting bracket hole for the generator/alternator. I’m not sure what it would use on the other side, oil galley hole?

If he finds say a 4.2 block to work off of, what are the odds that the hole placement will be identical? I may just have to take good measurements of my own block.

Thanks!


(Ian) #2

I know the 240 , 3.4 , 3.8 and later 1975 XJ6 3.4 holes are in the same place so chances are 4.2 are the same !


(Rob Reilly) #3

I wouldn’t have thought the trouble and expense necessary. Here is my XK120 engine on a 4 wheel 1000 lb capacity stand from Harbor Freight.


Don’t buy the 750 lb 3 wheeler, that’s for 4 cyl engines, too tippy for a 6.

But to answer your question, only the early XK120 block lacks the front engine mount holes. All others have front mount holes, and all have the rear holes for the bell housing.


(Erica Moss) #4

Maybe they’ve improved but I had the same stand 18 years ago the last time the engine came out. The problem wasn’t lack of stability but rather the fact that it was near impossible to turn. When the job was done and it was disassembled, the swivel tubing was massively galled up despite being well lubed. A stand such as the one in the photo keeps the entire thing balanced around it’s center of gravity.


(Rob Reilly) #5

Maybe you got a bad one. Mine is more or less on the c.g. as best I could guess it, and of course the c.g. changes when you add parts, particularly the crankshaft. I only turned mine a couple of times.


(Erica Moss) #6

It’s CG in one direction, but there is a massive amount of weight sticking out front which torques that swivel joint down in front and up in back. I have to imagine the one in my photo could be rotated with one hand. Mine wouldn’t turn at all and I finally had to resort to using the crane to lift and lower it.


(Paul Wigton) #7

Frankly, the one you posted has the CG too low: with the head on that will be a bit of a bear to turn. I’d fab it so the pivot points would be closer thefreeze plug’s plane.


(Rob Reilly) #8

Yes, its easier if you lift up on the front of the crankshaft, sorry I didn’t say it, thought it was obvious.


(69 FHC ) #9

My engine stand came from Northern tool about 15 years ago. The problem I observed with it is the OD of the tube the engine is attached to is a bit over 1/8" smaller than the ID of the tube it goes through. This results in most of the load of the engine being concentrated on two points, A and B in the below drawing. That make it very hard to rotate the engine unless one lifts the engine enough to lessen the weight on those two points. To resolve this I smoothed the OD on the inner tube and used a brass sheet to make a bushing that fills the annular space.


(Erica Moss) #10

I agree! As is it would be better than an end hanger but if it could sit higher that would balance it even better. That would require welding much longer mounting brackets off the square frame at an angle. It could weaken it.


(Paul Wigton) #11

Indeed: I had a tall jack stand (that I just sold to @Craig_Balzer1) that i would put under the nose of the crank, and I could spin the heaviest engine with a 3 foot cheater bar.

Including the 1250 pound Auburn engine!


(Erica Moss) #12

I was solo the first time and my arms aren’t long enough :laughing:

I could request help this time, but it’s coming out for a new seal and timing work so the crank will be coming out. I may relent and default to the cheapo solution though if this becomes too much headache.


(Erica Moss) #13

I think mine had a similar issue. I don’t think it was 1/8" play but it wasn’t a smooth slip fit either. Why they can’t make these joints more robust is beyond me. Maybe instead of trying to reinvent the wheel I should focus on just replacing/improving the swivel joint on an existing one.


(Larry velk) #14

I made all sorts of contraptions to work on and move the engine. The stand is a custom made one with a precision fit of the tubes (by the tool and die brother in law) - he made it in high school some 45 years ago. Two hoists help.