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MG MGA - MGA vs Modern highways

My 58 MGA motor and cooling system is in top condition, as is the 4 speed transmission. I have limited my driving to rural roads at 40-55 mph, with an occasional boost to 60-65mph for short distances. My question concerns driving the car at high speeds (65-70 mph)for an extended time of say 2 + hours on the expressway. Other than the obvious high revs, is there any reason to fear this level of constant speed with a standard 1500 motor?

Fran
F Valenzano

I have driven my 1500 for full days at 70mph+. While it is not as enjoyable as driving 50-60, no harm is done to the car if the car is well sorted to begin with.

Drive away. but be prepared for the beating from wind and noise.
Chuck Schaefer

Fran,
Remember that these cars were designed to run at Sebring and LeMans and did well there. Yes, they are older now, but the running gear was well over-designed in most areas because they were planned for high speed distance races. These are tough little cars.
Cheers,
GTF
G T Foster

From my experience the B-series engine will sit at 3000 to 3500 RPM all day. Last summer, when it was unusually hot in the UK, getting up to your USA temperatures, I drove my car down our M6 and M40 motorways between 70-80mph for about 5 hours with one required natural break, plus a drink and a sarnie. The engine did not miss a beat and the temperature remained rock steady at about 180.

Okay, I do run the 1800 version, 5-speed box and 3.9 diff, but the revs were above 3000 all the way:

70mph = 3300rpm
80mph = 3750rpm

Steve
Steve Gyles

A few years ago we drove our car (1500) down to Italy and back. No problems with the car although it did drink even more water than we passengers did.

No overheating even at 36 celcius air temperature, but we did need to check the water every morning.
Dan Smithers

Be conservative, keep the tach under the red line, and drive forever.
Barney Gaylord

I agree. I try not to stay above 4000 for too long, but it cruises nicely above 3500 with no complaints at all.
Mark J Michalak

Fran, fit a 3.9 B diff, electronic distributor and 40k coil from Pertronic. Plug gap at 34thou and drive all day at 3500 RPM ( peak torque ) at 70 MPH plus. A standard A in good condition with good compression will pull a 3.9 diff with ease. On a long hill shift to 3rd at 3000 revs and go for it. !... Sean
S Sherry

Thanks guys,

I will, as they say in the USA, put the pedal to the metal and give her a go!

BTW I am running a Pertronix electronic distributor and a 40K volt coil.

The plug gap at 34 thou? Sounds scary, can you tell me more? Dynamic timing?

Fran
F Valenzano

Hi Fran, 34 thou is fine as long as the rotor is not the rivited type. Pertronic rotors are quality items. I run iridium plugs ( they require about 5K less voltage )and set the timing at 12/13 static but check there is at least 32% at around 3500 rpm on the mechanical only. Works well for me. Sean
P.S. use Hi octane gas ,less carbon build up and can take more timing. Cheaper in the long run
S Sherry

Steve,
What's a sarnie??????
Gordon Harrison

Gordon

Sandwich.

Steve
Steve Gyles

We run our '62 MKII 1622, with the original bottom end and pistons, but with rebuilt head, on the highway holding 3750 rpm which works out to about 65 mph according to the GPS, with bursts up to 4200 to pass. . We've done up to 800 miles per day at that speed, with (knock on wood) no problems thus far since the head rebuild back in 2005 - about 24K miles.

Of course, Barney has been known to go a bit faster, especially while passing (see the photo below from his website (http://mgaguru.com/pic89/trmont.htm)

- Ken

Ken Doris

I too, have been using Hi-test fuel for the last few years. Don't notice any difference in power but the car definitely runs cooler. Installing an early “B” 3.9 pumpkin is an inexpensive way of making an MGA an even nicer road car.
David Werblow

For all those who worry about overheating; check out the temperature gauge on the picture posted by Ken.
Don't worry, be happy!
Lindsay Sampford

None at all. I have driven mine at a steady high speed for hours on end in the heat of the summer in southern France and had n issues at all, except having to reset the points at the end of the 9 hour journey. I surprised many of the french drivers by sailing past them on the autoroute
dominic clancy

This thread was discussed between 02/03/2011 and 05/03/2011

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