TR2/3/3A Intake/Exhaust Manifold Replacement

All,

Finding some time to work on my '59. It has been very hard starting and the last time I had it running a friend noticed an exhaust leak from the exhaust gasket. Since I am just starting my learning process I thought why not dive in. I managed to get the carbs and manifolds removed yesterday.

In the process I found that the lower front manifold stud had been broken off by the PO below the level of the head right where the leak was coming from. I was unable to remove it using a reverse bit or EZ out, but I did manage to get the hole drilled out and re-tapped it for the original stud size. I have never done anything like this before, but i think it will work. If not, I guess I will have to try a helicoil or something else.

Anyway, my question is on the best way to clean to gasket surfaces and what parts to replace. Again, new to this so please pardon the newbie questions. Do I just scrape the mating faces to get it clean? What tool should I use to make sure I do not do any damage?

I am planning on ordering the combination intake/exhaust manifold from Moss unless there is a better option. Should I replace all the studs, washers, nuts, etc? I broke one study that connects the manifolds together so I know I am going to replace those. I also need the four gaskets that go between the carb and intake manifold. Is the insulating block that goes there a consumable item or just re-use the ones i have.


Any other advice before I place my order? Thanks for the help!

Seems like you are right on track. I only replace fastenings that are broken, badly rusted or stripped. I also re-use the insulators unless there is something visibly wrong. I clean with a sharp scraper or whatever seems to work. Tom

FWIW, I've left out those connections between the manifolds for.many years. It might make the engine just a little.slower to run smooth without the choke after a cold start, but not enough to worry about IMO.

Loctite makes a product called "Chisel" gasket remover that helps sometimes. But on cast iron, I just use a steel gasket scraper and a bit of care.

On an engine new to me, I also like to remove all the studs and lightly rub a flat machinist's file around to pick up and remove any high spots. It's very common to find the surface distorted just a bit around the studs, which can make it harder to get a good seal.

All new lock washers of course. Reusing nuts & studs is OK as long as you've got the right ones and they are in good nick. Make sure the nuts spin easily down the studs. Sometimes the threads distort and create a tight spot which can lead to leaking gaskets.

On the outermost exhaust studs (the ones with no bridge pieces), I find that it helps to add a heavy flat "setup" washer between the lock washer and manifold.

I seem to recall that someone was selling "improved" gaskets for TR3s, which I believe were a bit thicker. Not sure if they are necessary or useful, but someone may know or have experience to share. Could not find info when I searched this morning. Maybe they were Remflex? Cheers, Mike

mgedit said:

I seem to recall that someone was selling "improved" gaskets for TR3s, which I believe were a bit thicker. Not sure if they are necessary or useful, but someone may know or have experience to share. Could not find info when I searched this morning. Maybe they were Remflex? Cheers, Mike

Click to expand...

I think Moss sells them...are these them?

https://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=56707

Cheers
Tush

Searched some more. Believe the ones I was thinking of were the Remflex ones ...

https://catalog.remflex.com/TRIUMPH_Exhaust_Gasket_p/20-001.htm

Cheers, Mike

You may also want to contemplate match porting the manifolds to the cylinder head while they are removed.

Yesterday on a high-speed dash up I-19 I blew out the gasket between the exhaust manifold and the down pipe. The nuts (which may be 50+ years old) came off the studs easily - because they were brass and extra thick/long.

I mention it as brass nuts (some in long lengths some not) are what I use and are worth seeking out IMO.

Great advice all. Thanks. I placed an order with Moss for all the miscellaneous parts including their heavy duty gasket. Not sure if it is much different from the Remflex one, but at this point I will give it a try. Why are their two gaskets? I assume you just stack them on top of each other?

Brass nuts are an interesting idea. Something I would just find locally or would that be a special order item from somewhere?

I will do some research on port matching. What is it? Why is it needed? Where does one get it done and how much does it cost?

Thanks again!

When I told my.local auto parts store / machine shop I wanted 3 nuts to replace those on the lower part of my exhaust manifold on my spitfire, they handed me the brass ones... So I would suppose any decent local shop would have them

The manifold/head gaskets only serve two cylinders each, so it takes two gaskets to cover all 4. Why they did that, I don't know. I'm guessing it made the gaskets easier to manufacture.

The brass nuts for the headpipe/manifold joint are actually as original and available from the usual suspects. TRF P/N 108951 But they are also used on some American V8s, so readily available at FLAPS.

My experience was that ordinary steel nuts work almost as well, when used with a generous coating of copper-based anti-seize. The problem I had was that the exposed threads on the stud would corrode from exposure to salt on the roads combined with exhaust heat. About the only thing to do then is to let the nut bind and pull the stud out; then replace both nut & stud. Use plenty of anti-seize on the other end of the stud, too.

I wouldn't bother with port matching on a street engine. Without testing on a flow bench and making other changes at the same time, you'll probably make things worse rather than better. Bigger is not always better, especially when talking about a local area of a longer pipe (the path from carb opening to combustion chamber) at lower rpm; and it's not practical to make it smaller. Even Triumph went smaller on the TR4A, as part of their exercise to improve mid-range power.

Port matching is a comparatively simple procedure ,opposed to porting where the ports are usually enlarged and not recommended on some engines.
Most cast manifolds have mating port openings that will not perfectly match the cylinder head ports...This is particularly important for the intake manifold.
Port matching can be DIY using some marking material and a die grinder type tool.
Camano Island looks to be a beautiful place to live.