Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Exhaust Manifold Bolts

The helicoil repair went very well. The kit came with a dozen coils, the insertion tool and the tap. Very straightforward. I may just do the other exhaust manifold as well as it has been removed a number of times and the softer aluminum is not holding up at all well to the rusty steel studs. The ARP studs are a beautiful hard stainless finish compared to the stock studs. The 3/8" jetnut is also MUCH easier to attach a socket to in that tight space.

I did the same repair with a time-sert, 3 years going strong.

After promising myself that I would finish out the motor with new studs it came to pass. Went on a short ride yesterday and ran into a severe pocket thunder storm. Received more water than I liked even pulled over with a golf umbrella covering the cockpit. Turned around when it lessoned and made my way home. Put it in garage and saw that another stock manifold stud had left the building. Today I removed the other stock stud with great difficulty. Tapped the two holes, inserted the coils using high temp loctite, then the new studs and added the jet nuts without loctite. They are hard enough to remove as is.
I think I would like to not worry about this anymore.

I am hopefully reviving an older Thread to learn how you guys got the lower rear cylinder exhaust manifold nut retaining plate bent back out of the way? Not sure the name of that stinking plate but I sure as heck won't use it again! I managed to get the other three nuts to a point where I will be able to turn them but the locking plate on the lower passenger side is a real buggar.

Suggestions?

LightSpeed, sorry. That was the stud that mysteriously disappeared so was not an issue. If I remember correctly when I had to do the other side so ling ago I used a narrow wood chisel to get in there and start it.

Thanks Michael, I tried that, I tried a long sharpeded screwdriver and it didn't budge because it is bent around two faces of the nut. I can get under on face but not the other. At this point I am considering using a Dremel with a burr grinder, like a dentist, to carefully carve away the offending piece. Why MMC thought it necessary to bend that plate around two sides of the nut is beyond me.

UPDATE: I carefully cut the locking plate away from the nut on the exhaust stud. It worked and I was able to remove the nut. What was interesting when I removed the nuts was the bottom nuts were fairly tight where as the top nuts were almost loose and took little pressure to unscrew them.

I believe that Morgan added the locking plates AFTER Charles Morgan & wife did their cross-country journey in the USA with a fresh M3W from NY city. They lost a manifold bolt somewhere in the California desert and it was no joy. Both of my locking plates are busted and in the bottom of one of many tool boxes. I went with the ARP studs and the Jet nuts and have not had any of them leave...

Thanks for that Michael, it explains the overkill.

I will replace with JetNuts and a wee dab of anti seize. The studs are in excellent condition.

Thanks for he suggestions. One more step done in engine removal.

See if you can get hold of the silver plated Jetnuts/Kaynar nuts. These are corrosion resistant & rated up to 800F (426C) so ideal for our application.



The size we use are 5/16"-24. Available from LAS Aerospace in the UK.

Thanks for the information Bunny, order placed👍