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MG MG Y Type - Radial tyres for YAs

I am a new YA owner.
I’ve seen the information on fitting radials to YBs but no mention of YAs.
Is there any reason why this could not or should not be done?
Apart from better road-holding on radials, a slightly larger tyre of either sort would give a welcome reduction in engine revs
Are the rims suitable?
Is there enough room under the wings particularly if slightly larger section tyres were used?
Is the pre-war suspension suitable?
I know that they would not fit in the spare wheel compartment without deflating, but electric air pumps are so cheap that this is hardly a problem.
From data on the Web from Dunlop and Vintage Tyres at Beaulieu I calculated that the largest available radial is a 185R16 Michelin X which reduces the engine revs by 3%.
The largest cross-ply is the 650 x 16 WW which gives an 8% reduction.
As you would expect, the cross-plies are narrower for the same size, presumably because they flex more at the road, so they are likely to allow the largest reduction in revs.
If anyone wants the data in an Excel Workbook I will E-mail it on request.
Come on you experts, should we do it?
Michael Nicholson

155 section tyres will fit in the tyre box (at least it will on my YB - I believe both are the same size). Some types of 165 tyres will not go in without deflatiom though. Radials do improve the ride but my experience gives no reason to go above these sizes.
ian thomson

Yes! The tire-question again! I, too struggled with tire-dilemma's. There are several interesting threads in the BBS-archive.

Some disconnected ramblings:
PRE-WAR SUSPENSION? Go wash your mouth! The YA was one of the first British cars with independent front-suspension and rack & pinion steering; state of the art 50's engineering, sir! The Y may look pre-war, but isn't! You may want to fit an YB or MGB front-stabiliser.

The YA-rims are 3.5 in width, much to narrow for 185 radials. Some Australian posted information about fitting Lada Niva rims to the YA centres to overcome this problem, he uses 175/80x16" radials, a size which I can't get in the Netherlands.

The YA tyre-box is narrower than the YB's, that has 5.5x15" tires, I have trouble sliding in the spare 5.00/5.25x16 of my YA, but I fear the body has sagged over the chassis.....

My front wheels have ancient Dunlop 5.5x16's which I'm going to fit to the back, to decrease the engine revs.
Otherwise I'm going to stick with oldfashioned tires; they look better and with the limited mileage driven in good weather I'm not so concerned/bothered about roadholding or comfort, I get that enough in modern cars.

Greetings,

Willem Y5888
Willem van der Veer

Hi Michael

If you are a new Y owner I would suggest just go gently for the time being and enjoy the cross plys. I thought about it when I first got my YA and I have to say that I actually enjoy the retro experience of the Cross plys and am a great fan of them now. You just find that you are driving a little slower and more cautiously - and that is not a bad thing.

Frankly there are down sides such as your oddometer and speedo will be miscalibrated etc. and frankly I couldn't be bothered after a bit to change. While I can get the cross plys (and it is easy for me being only 15 miles from Beaulieu) I frankly wont change.

My ZA is also running cross plys too.

Paul
Paul Barrow

If you really do enjoy driving your Y, then radials are the way to go. I have retained a set of Standard wheels with cross-plies for the once a year "Display Day", but for "Sunny Sunday" driving my YA will only ever have radials - I value my life and my passsengers lives (not to mention the car) more than that original feel of cross-plies.

If the radials only save you once, you will be forever wiser for the effort. The roadholding and safety are just far superior. You are kidding yourself if you think that driving slower on cross-pliess will save you from the other nut behind the wheel that expects your Y to brake and stop like his Fiesta/Astra/MX-5 or whatever.
Tony Slattery

Should we do it? No.

Why? Two reasons, in my personal view.

1) The Y's suspension was conceived in 1937 (this is the date on the relevant patents), long before radials were available. A car's handling and cornering depend on many things (slip angles, roll behaviour, suspension bush compliance, damping efficacy etc), and it is highly doubtful to me that simply introducing strange new tyre characteristics is therefore safer.

2) Radials look ugly on a car of the Y's design, particularly if they are oversized. Ever seen a Citroen DS on crossplies?

Thinking about it, if you want to raise the gearing, there is a conversion using a 5-speed Ford Sierra gearbox available. Better brakes? Just machine the suspension uprights to accept MGB discs and calipers. 46bhp not quite enough power? Pop in a Ford Zetec... you see where this is leading, though not too seriously. My vote is to keep things original and enjoy our cars as they were.

Tim Griggs

Tim,

Although I agree with your comments, I do think the suspension would be up to it, if you don't overdo the size of the radials (i.e. 175/80R16)?

I also think it would be safer because of better grip when braking in a nasty situation. But I'd rather not think about safety because then I would desperately miss safety belts and view the protuding steering wheel and nearby windscreen as potentionaly painfull....

Can you be save in a YA?

(maybe I should have said state of the art BRITISH 50's engineering?)
Willem van der Veer

Willem

On the question of safety, can you be safe in a modern car? My view is very simple - you will be as safe as you are prepared for the actions of other drivers. The more you are conscious of the capabilities and limitations of you and your car, and also of the total inadequacies of those around you you will be safe (or at least as safe as you can be) in any car. Better to keep things totally original in my book - because someone spent a lot of money and time designing them to be as safe as possible at the time. I appreciate things have moved on since then, but that has not changed the fundaments of the engineering you are driving - therefore I prefer to know and love what I have than mess around changing everything then relearn everything again.

Call me old fashioned, and my theory is easy to counter, but it is only my view! Hope it helps your dilemma.

Paul
Paul Barrow

Paul

I have been driving my YT since 1961 and switched to radials long long ago. Here in California many of the concrete highway surfaces are grooved to help rain run off. However, here they run the grooves parallel to the direction of travel. This has a distinct tendency to cause a sudden unannounced change in the direction that you are travelin which can be quite disconcerting as you suddenly find yourself part way into the adjacent lane. Once I switched to radials I never again experienced this phenomenon.

FWIW

Larry
49 YT
Larry Hallanger

The ifs on the 'Y' type was originally designed for the Morris Ten series 'M'. The M.G. Ten designed at the same time in 1938 was to have a cart-sprung solid front axle. The M.G. Ten became the 'Y' series after the war and it was fitted with IFS, the Morris Ten got the solid axle instead. The suspension system on the 'YA' was then used on the YB, YT, TD, TF, slightly modified for the MGA and again for the MGB.

It is a pre-war suspension system, and used a crude lever-arm damper as its upper location, ( hence the 1990s MG RV8 updating to a coil-over-damper system, it too used the basic 'Y' ifs...)

It was designed for cross-ply tyres, but copes very well with radial ply tyres. The MGB was sold using radials, and its suspension design and geometry is almost identical. I would suggest the fitting of the later MGB GT V8 inner wishbone rubber silentbloc bushes, they last much longer than the rather feeble early MGB 'tophat' ones that the 'Y' uses.

The tyres to use on the YB are those fitted to some 30 million VW Beetles, they are the same size. Radials do make the steering much heavier, but improve the roadholding, tyre life and ride quite a bit. ( Note that it is the cross-ply that causes the car to side-slip easily in the wet, not the ifs design. Radials cure this.)

Neil.
Neil Cairns

And another thing...

Radial ply tyres run at a reduced radius, they sit much lower on the road. This effects the whhels diameter, and makes its effect smaller by almost an inch. This makes the speedometer read fast, and slighlty improves acceleration.

Neil.
Neil Cairns

We also looked long and hard before we replaced our tires last year. I finally went with Coker Bias ply. changing the rims to fit the available radial tire or change the suspension to a YB type just did not feel right to me. Cost was also a factor. As I set here in my office and look out at the YA sitting in th driveway with the new Wide White walls I still think we made the right choice.
Rob R.

If radials were available when the Y-type was in production, you can bet it would have used them. I also believe that there would have been no significant suspension changes because of the tires. Changing to a higher-quality tire will vertainly not lower the safety level of the car in any way so long as you are installing a similar size. The added benefits of course will be much improved traction and braking and well as added stability.

Tim is obviously a purist and I certainly appreciate that, but where do you draw the line? Should you not install seat belts because it may lead to a V8 engine? I think that a minor, non permenant change to a vehicle which will improve performance and potentially safety as well should not be scrutinized. I used to be a purist in every sense, but I've come to believe there are things worth changing and noone besudes me seemed to care anyway!
Steve Simmons

I have used my YA with Dunlop cross-ply tyres (or should I say tires?) for the past 12 years and have been extreamly satified with the performance, I am about to replace 2 of them again with Dunlop cross-plys, they suit the A and B roads in the UK and they also look right on the Y, radial tyres never will look correct {but white wall tyres, yuk!)
I am not a purist I would rather see a car being used daily using alternative parts if the correct ones are not available, but cross-ply tyres are available.
I enjoy the experience of driving a 1947 car the way it was in the 40s not a modified version that never was.
stephen randle

I can't argue with your last statement. There is nothing quite like stepping back in time with a purely stock vintage automobile.
Steve Simmons

Did you spot the deliberate mistake at my start of this thread? I put "more" instead of "less" for the flexing of cross-plies.
No-one seems to have answered the practical questions, so I asked Vintage Tyre Supplies. They recommended only going up one size to 5.5 x 16 on the 3 inch rims (according to the YA data on this web-site, not 3.5 inch as Willem van der Veer said.)This makes all the radials look unlikely, and the extra flexing assuming one could get a 5.5 inch radial would lower the gearing even more.The smallest appears to be 175mm which is almost 7 inches.
So it looks like 5.50's for me if they will go in to the compartment.
Michael Ncholson

Micheal,

We all make "deliberate" mistakes, don't we? Sorry for that!

I was going on memory and didn't consult the data, so it must be 3".
Willem van der Veer

This thread was discussed between 04/12/2003 and 06/01/2004

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