MGA MGA Destruction-More

[aeronca65t]

I thought I'd let you see some more detailed results of catastrophic failure on a 1600 cc BMC "B" series engine. This engine was in my friend John's vintage racer MGA. I posted a note about it before, but these are much better photos.

The link below shows photos of the post-mortem.

https://vintageracer.tripod.com/mga-engine.html

You may recall that I actually caught the engine failure on camera (he had just passed me when it failed). If not, you may want to you click on the video link (below), and slide to about 1:20 and watch, you'll see it.....followed by a view from his in-car camera of the same failure.

https://www.youtube.com/watch?v=gBFWSNiRVc8

John description of the damage:

"The centre main is still attached to the crank but no longer to the engine. Part of the torque reaction of the sudden stoppage was absorbed by the bell housing which reacted by cracking all the way around!"

Sample photo:

 

[rick_ingram]

Ouch! :frown:

 

[DrEntropy]

Full blown NASTY, that.

 

[JPSmit]

it'll buff out

 

[DNK]

I'm with JP, just might take a little extra elbow grease

 

[JPSmit]

I'm with JP, just might take a little extra elbow grease

and maybe some JB weld and you are good to go

 

[Silverghost]

I'm with JP, just might take a little extra elbow grease

and maybe some JB weld and you are good to go

<puts a buy order in for JB Weld stock.....!> :laugh:

 

[Silverghost]

I just got a PM from the Mythbuster guys, they say: :thumbsup: :thumbsup: Nicely done!

 

[Stewart]

"My old man is a television repairman, he's got this ultimate set of tools. I can fix it."

 

[billspohn]

Been there, done that, never used that weak crankshaft again. The 1622 is much better.

 

[PAUL161]

Nial, What Rs was he turning when that happened? PJ

 

[aeronca65t]

Paul: He told me he was keeping things at 6500 or under. The engine has at least 20 weekends on it, so it may have been a combo of loose bearings and general wear-and-tear.

Bill: This car is supposed to be an early MGA 1600 (but it has 4-wheel disks :shocked: ).

I think it's probably the 1588 motor. I was not aware that 1622 (Mk II) crank was better; that's good to know. I owned a 1500 MGA ages ago, but I'm more of an A series guy these days.

<span style="font-style: italic">Interesting Fact</span>-BMC had originally considered using the A series in the MGA and having the bigger B series engine as an option.

 

[PAUL161]

Nial, Is there a restriction on using the 1800 series blocks? Just curious, as 4 mains should hold up better than three, and if I'm not mistaken, the cranks are inherently stronger. PJ

 

[aeronca65t]

The 5 main bearing, 1800cc MGB engine is not allowed in MGAs for vintage racing.
Even John's 4-wheel disk addition is not really correct for his car. But it's not a huge deal, performance-wise. He gets beat by a very well-driven, drum brake 1500 MGA all the time.

In all honesty, our club (VRG) is a bit more even-handed about modifications. I believe they'd let an 1800 MGA run in our events......but in the faster class, against TR4s, 911s, etc.

The club also makes allowances for rookie drivers and tends to group cars with equal lap times in groups....rather than just big-bore and small-bore.
There were two MGBs with rookie drivers racing in my class at Watkins Glen. But several other MGBs with experienced drivers in the faster class.
Most drivers in our club "get" the fact that we're just racing for fun anyway, so it works well.

 

[billspohn]

Bill: This car is supposed to be an early MGA 1600 (but it has 4-wheel disks :shocked: ).

I think it's probably the 1588 motor. I was not aware that 1622 (Mk II) crank was better; that's good to know. I owned a 1500 MGA ages ago, but I'm more of an A series guy these days.

The 1500 and 1600 shared the same (weak) crank, while the 1622 was a different stronger crank. The 3 main MGB is the most durable 3 main of all with the sole exception of the Twin Cam, which was built to turn 7000 RPM in stock form.