Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Standard Vanguard Engine Head Torques

Just rebuilt the engine on a 1953 SV engined flat rad +4. I have gotten water in the oil with two different head gaskets. I have the original engine with Standard Vanguard head. I got the car from a friend who also has a 1952 Morgan +4 and both blocks were cracked in the same place (sort of above where the drain spigot goes). I suspect that this was because he torqued on TR2 and TR3 heads to the block with 100 ft/lbs (standard for TR) while my Standard Vanguard manual says to torque on heads to 60 ft/lbs. I had my block crack stitched together at locknstitch.com and they told me that the stitch is stronger than the original cast iron now. I tried using a racing composite head gasket from Moss thinking that it might seal better. Still got water in the oil. The bottom of the liners are sealed tight too and I doubt that it could be the figure-of-8 gaskets with Wellseal. I've checked cylinder liner protrusion and they are all .003". Is anyone running a SV engined Morgan with the head torqued on to 100 ft/lbs? Any problems. Any other ideas?

I expect you have already checked that the liner protrusion is fairly even around each individual liner by measuring each liner in at least 4 places (after trial assembly and torque up with an old gasket)

Apparently it sometimes happens that the block around the studs can become raised if the head has been over torqued or if the studs were not seated deeply enough in the holes. Is the block itself perfectly flat?

You could also try the TR Register forum and search 'liner protrusion' or similar

Have you checked the cylinder head in case it has warped? Given the head is a fairly substantial casting, I would not have believed it possible until 11 am this morning when my cousin brought round a Ferguson tractor cylinder head for checking on my surface plate, we found it to be distorted!

Arwyn

How many times has the head been torqued? I think maybe its time to remove all the studs and replace with the heavy duty ones that Moss sells. I can only think of what kind of nightmare to have a stud shear where it enters the block. Good luck.

No idea if the block is warped. Never considered it. TR3 studs won't go into a Standard Vanguard block. Different diameters and very different lengths. Turns out that the SV head studs are the same as a 302 Ford. I used ARP studs.

if you havent then defonatley check the deck, touurghley, i have found blocks that apear to be flat with the threads pulled up a little high. if it is only a small amount you can get away with countersinking the deck at the head studs. On later triumph engines it is not uncomen to take out the top few threads with drill. This results in the stresses beeing placed deeper into the block and helps you get a higher torque on the headstuds when trying to get engines to seal when running higher compresion ratioes.

You can allso work wonders with a good flat oil stone and a large glass of good scotch on decks that resemble the sea. though its obveousley best to get the deck skimed if needed.

Allso, are you re tourqueing the head studs a few times after instalation? dont go to far though as you can esaley overtourque a stud even with a wrench set at the desied value....

I ran a Vanguard bottom end under a TR head for one race only. It was a disaster, but i needed the championship points at the time so it was worth the chance.

As you have already found out, the Vanguard studs are smaller diameter than the TR, so the torque value is going to be a lower figure . Yes you are still holding the liners down with the head , so it is likely to be higher than other models , but don't overdo it , or you will pull the stud out of the block, and then you will have to take the head off again.
I suspect that torquing down the Vanguard head to 100/105 lbs ft might have contributed to the problems, but I doubt it will be the root cause. Did you check that all the studs are really tightly seated in the block? If they have been over-torqued it is possible they have been loosened and this will not help with the sealing

As Arwyn points out the iron head on these engines is a big chunk of metal, BUT they can and do warp quite easily if you run them dry of water. You will be most unlucky if the block is warped, my experience would suggest about 100:1 , but it is worthwhile checking with a straight edge , if only to eliminate it from the diagnosis.

The other lesser point is the seating of the liners on the figure of 8 gaskets. Are you very sure that these were done correctly, as the smallest of errors here ( e.g.:nipped or protruding edge) will give rise to leakage and water loss.