Welcome to our resource for MG Car Information.



MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - TD & TF Air Cleaners

I remember reading this post before and now in the archives, it got me thinking, (bad idea)? I think the way we take care of our cars and where most of us drive them, no Matthew I'm not including you! Grin, a stock element in the air cleaners should be very sufficient without going to and modifying super high tech elements to fit. Example, my 1993 custom pickup has 250,000 miles on it, driven in all kinds of weather, many gravel and dirt roads and pulling loaded car trailers across the US many times. The engine has never been apart and now uses about one quart of oil in 4,000 miles! Point being, I have always used standard element air filters, nothing high tech, but the best rated oil filters. I feel excellent oil filters, frequent oil changes and analyzing the used oil are much more important in our cars than high tech air filter elements. My TF has the standard air filter elements.
Paul S Jennings

The major argument in favor of modifying air filters is to increase the amount of air available to the engine at all times. On a TD, the stock intake system was, by all accounts, extremely restrictive (search the archives, there is plenty about this). The most popular choice of modifications, as far as I can see from reading these threads, has been for TD owners to add two Vokes air filters (or two other pancake type filters) and replace the single oil-bath filter and intake manifold. These filters came standard, I believe, on later TDs and TFs, but were not available on my stock 51 TD.

I went another route. And did so by accident; my engine was burning rich and having significant running problems, and I found when I took off the stock air filter that the engine ran MUCH better. (Later, I discovered that most of my carburetion/engine problems disappeared when I removed washer #33; but that is covered in another thread.) At the time, I reasoned that if it ran nicely with the air filter off, but badly with it on, then I needed to do everything possible to reduce air intake restrictions.

After researching air filters and looking for the least restrictive possible filters, I replaced my air filter with two British made Ram-Air filters, which are pancake style filters offering considerably more breathing area than standard pancakes (at around the same cost). Instead of offering filtration around the circumference of the pancake, they offer air filtration over most of their area. They are used in racing applications where minimum air restriction is the absolute goal. And they claim 40% improvement over the market standard K&N filters.

I think that no matter how much care you take with every other aspect of an engine, if it is gulping air because of intake restrictions, it will never run as well as it should, and that's a bad thing. I'm not looking for extra performance, merely an engine that isn't choking on its own design restrictions.

So far, I am very pleased with the filters and will keep them. The engine sounds much happier with them!

Regarding your point about oil and oil filters; my TD had no oil filter, and the very first thing I did was install one of Bob Grunau's excellent spin-on oil filters. You are correct, clean oil and a good oil filter are the first and best line of defense in keeping an engine running well!
Geoffrey M Baker

I like these for their shaped groundplate:

Has anybody tried these?
Willem van der Veer

Willem, I think for a TD they might work very well, but look a little too thick to mount on the front carb on a TF. TFs are a pain. JMHO. PJ
Paul S Jennings

Geoff - a minor point: the oil bath cleaner was standard on all TD's, while all TFs all had the Vokes pancakes. No TD came with Vokes or any other pancakes from the factory. Earlier Mark II TD's came with the stock oil bath air cleaner and air intake pipe, later Mark II's had a larger air intake and oil bath. The smaller one CERTAINLY strangled the engine; dunno about the later one. I don't have a flow-meter...

Tom Lange
MGT Repair
t lange

Tom, I guess I saw a picture of a Mark II with Vokes additions and assumed they might have been stock. Have yet to see a Mark II in real life...

I should add, anybody interested in Ram-Air filters can check them out at:

They come in a wide variety to fit SU H2s, H4s and have generic "blank baseplate" models you can use to make your own. They also come in a variety of thicknesses; I used a set of the thinnest (25mm interior height) to fit my TD. I agree with Paul, the filters mentioned by Willem look too thick to fit on a TD, not sure about TFs.
Geoffrey M Baker


Which Ram-Air filter did you use? Their website lists so many filters that I can't find anything usefull quick, so I thought I'd try the lazy way first.

Maybe a picture please?
Willem van der Veer

Willem, this should work:

Choose the 25mm internal height version, the others may be too thick.

I should point out that I screwed up and bought the HS4 versions, which I then had to take some sheet aluminum, rivet it over the old holes, and drill new ones, but the HS2 should fit our 1.25 inch carbs correctly. You may also find that the way the filter fits may not work for you and thus have to - again - rivet over the existing holes and drill holes that will work for you. My H4's I had to turn 90 degrees so that the ovals were narrowest in the vertical dimension; otherwise they overlapped in the middle by a quarter of an inch. The H2's being (I believe) a tad smaller, they may not have this problem at all. Remember also, you either need to bend the radiator stay bar slightly............

Geoffrey M Baker

Here's a pic of the filters on the engine

Geoffrey M Baker


Thanks for the link to Hi-Flow. I've been looking for just that sort of thing to replace the oil bath - paper filters with a shaped inlet. I've contacted them to see if they have one that will fit a TD with H4's.

There is an interesting series at the following MGA site (click the arrows at the bottom of the page to keep reading):
J Barry

As I discovered through experience, the standard TD air cleaner can cause the engine to run rich. However, this is not because of the design, but rather because over the years owners have over-tightened the wing nut on top. Often this has crushed the cover down sufficiently to partially close off the air passage. Turning the cover over on a can (to provide support) and gently tapping the center will open up the airway so the airflow is no longer so restricted.
Lew Palmer

Lew: That's a great discovery. It fits into the 'fix it, don't improve it' philosophy of mine.
Chris Couper

This is what I had to do to get the filter to fit on my carbs, just rivet some aluminum to the baseplate to cover the holes, and cut my own holes. This way I could have the filters in a vertical rather than horizontal configuration, which wasn't really possible. However, the H2 filters are possibly smaller and may not need this modification.
Geoffrey M Baker

I was faced with the same decision as most owners with cars previously owned by several others, whether to keep the cobbled together filters or try to find originals. Mine had Vokes pancake filters with window screen for the element. Originals are hard to find and perform poorly so my solution was to create something completely different. The manifold is made from TIG welded 6061-T6 structural aluminum with a high capacity K&N filter. No restriction whatsoever. Not for the purist obviously. Neil

N.W. Dwyer

Do you think it is the air intake pipe, or the oil-bath that is more restrictive?

Tom Lange
t lange

I don't know but the pipe doesn't seem big enough, and those turns must interfere with air flow. All I know for sure is she sounds much happier without the oil bath and manifold. Starts instantly, too.
Geoffrey M Baker

I have been told that every 90 degree turn in the intake passage between the filter and the head can reduce air flow by 30%.
If this is true then the TD air filter manifold reduces air flow by between 60 and 90 percent.
I replaced 2 old style screen filters with an original intake filter manifold with a K&N filter. The engine sounded starved, ran very rich and smelled pretty bad to anyone behind us. Went back to the screens and the engine settled right down, smoothed out and was no longer stinky rich.
Hope,that helps.
Norm Peacey

Norm, you talking about two filters in the TF?
I had been thinking about adapting a K&N to my Vokes in the TF, but may now give that up. The original filters seem to do a decent job for my 1,000 miles a year.

'54 TF
T Norby

This thread was discussed between 16/05/2014 and 21/05/2014

MG TD TF 1500 index

This thread is from the archive. The Live MG TD TF 1500 BBS is active now.