View Full Version : Alloy Valve Covers and breathers

12-28-2007, 12:09 PM
I've one of the aftermarket (big 3) alloy valve covers and the filler cap has a very small breather hole (1/16th in.) compared to the stock TR3 breather/filter unit.
I'm thinking about removing the cap assembly on the alloy cover and welding an aluminum plate with neck to utilyze the stock breather cap.
Does the engine require the stock open breather or will this just be esthetic?

12-28-2007, 12:22 PM
Open breather on the TR3 or any TR2-4 with the road draft tube installed on the block (just behind the fuel pump). You can get a nice chrome one from you FLAPS.

12-28-2007, 12:31 PM
"You can get a nice chrome one from you FLAPS."

Peter, what does that mean?? I can get a chrome breather/filter that will fit the aftermarket cover from where? BTW the aftermarket cover has a 2 1/4 in opening for the screw in cap and all of the normal aft breathers are about 1 1/4".

12-28-2007, 02:30 PM
Mine (TR3A stock cover) came with an aftermarket oil breather that fits the stock cover. I guess I wrongly assumed that your aftermarket cover had the same style oil filler/breather but it sounds like yours is just a cap.

On the TR4A, it has a closed system with a PVC and a slotted oil cap and pin hole (for moisture?) like yours. It also has a breather tube on the side of the cover that attaches to the PVC and does not have a road draft tube.

But on an open system like the TR3, there is no breather tube on the valve cover since it "breathes" through the roaddraft tube and the breather/oil fill.

Whew, you probably already know all this.

SO, on your new alloy valve cover, you will need a way for it to breathe as well. (assume you already know this too).

It sounds like the cover you have is for a later model TR engine. Does it also have a tube in the side above the intake? If you purchased this cover specifically for a TR3, ask your vendor if they have a proper breather available.

Your options are to purchase a bolt on breather (Offy style) the bolts to the side of the allow cover but looks "different" IMO. Also you can get a K&N rear end breather - looks like a mini air filter and attach it to a
breather tube on the side (like the 4A).

You also may be able to get a breather from one of the speedshops like jegs, summitracing, speedwaymotors dot coms that fits the 2-1/4" filler hole.

12-28-2007, 03:02 PM
Thanks Peter, I did know about the dif systems and was just wondering if there was a quick cap replacement but I don't think there is at that size. Sooo....
I'm going to weld up a plate and neck in alluminum and weld it to the large opening (once removing the steel cap neck) and utilyze the stock breather cap

12-28-2007, 04:31 PM
I have an original Triumph finned alloy valve cover. I think it was an option. I don't want to start a debate. Anyway, it's probably similar to the one the Big Three sell.

I just looked at oil caps at a Pep Boys or equivalent until I found one that looked like it would fit, and it did.

FLAPS had me stumped for the longest time because, being somewhat of a worldly man, I misinterpreted the word the F stands for. F is for Friendly! The rest is Local Auto Parts Store.

12-28-2007, 05:00 PM
What kind of opening did it have (triumphtune)? The aftermarket I have has a 2 1/4 inch necked deal similar to a radiator and haven't found any breathers compatible with that.
I've noticed the TR3/4 offenhauser alloy covers came with a proper breather on them. Now that's a period correct item I'd pay a bit for but it's hard to switch one ally unit for another considering the cost.

12-28-2007, 05:18 PM
My valve cover doen't say "Triumphtune", it just says "Triumph" in script with the World logo on a plate riveted to the cover top.

I hope you will forgive me for not braving the cold to go out to the Lab to measure the opening. I do remember that it has two "ears". The cap turns 1/4 turn to lock, similar to a radiator cap. The neck of the cap has to be long enough for the ears to reach through the thickness of the alloy and I will estimate that at about 1/4", maybe 5/16".

I will measure the opening tomorrow if the question hasn't been answered by then.

12-28-2007, 06:32 PM
FLAPS had me stumped for the longest time because, being somewhat of a worldly man, I misinterpreted the word the F stands for. That's OK; I've got some stores like that in the neighborhood too !

Me : I'd like four Bosch WR7BP spark plugs please.
Droid : What car is that for ?
Me : Triumph TR3A
Droid : What year is that ?
Me : 1959
Droid : Triumph ? Who makes that ?
Me : Triumph
Droid : No, I mean who made the car ?
Me : Standard-Triumph
Droid : What was the name of the company that made the car ? You know, like GM or Ford ?
Me : The company was called Standard-Triumph and they later became part of British Leyland.
Droid : We don't carry parts for that car.

Andrew Mace
12-28-2007, 06:47 PM
Droid : We don't carry parts for that car.
Me: I don't carry cash for this sort of store. /bcforum/images/%%GRAEMLIN_URL%%/smirk.gif

I have a small, local NAPA store near me. Despite the sometimes young age of the clerk du jour, I've never yet failed to get help, and no clerk has yet even blinked when I asked for things like Lucas generator brushes (yeah ... warehouse ... be here in a day or two)! And, when I ask for Champion L87Y or equivalent, they don't pester me for the application. I just find it odd that any store of that kind would not do whatever it takes (within reason) to make and keep a happy customer! After all, odds are someday you'll walk in needing brake rotors for your '02 Corolla or whatever....

12-28-2007, 07:28 PM
Flaps had me cold.
At the local Checker the guys like the TR3 (small town) and enjoy seeing if anything is listed computer wise. About as far back as the cp goes is 63 but it does list Triumph and parts.

12-29-2007, 02:03 PM
I have a local NAPA about 2 blocks from my front door. I'm on a first name basis with most of the counter help. One of them has a 1962 Buick with the 215 V8 and he likes to help find cross referenced parts for my TR8. The local Checker and CarQuest guys are pretty good too. My worst experience has come from Autozone. I was once told by an Autozone droid that my TR6 had the wrong engine in it when I asked for 6 spark plugs. He would only give me four plugs and refused to give me the other two as "I didn't need them". His 'manager' wasn't any better and claimed that their computers are never wrong. Thats a good one! To be fair to Autozone... that hasn't happened with everyone of their employees, but it has happened more than once. I think they teach their employees to never trust the customers 'knowledge' of their own cars and to always believe the company computer.