Sign up to occasional emails

Saturday 3 November 2018

Austin Healey 100 Crank damping issues

Recently we were contacted by Michael who has written an interesting blog about the crankshaft breakage problems in Austin Healey 100s.
Here's a selection of his blog post all of which you can find HERE

'“Cumulative Fatigue Failure for Dummies”
I broke a crankshaft while racing my 100S and that experience always haunted me because original 100S engine blocks are extremely rare and I knew that I had been very lucky not to have destroyed mine with that “blow up”.
Over the years I had encountered many cases of 100 crankshaft failures and it was the fear of another in the “S” that caused me to study the issue. The conclusions arrived at and described below prompted me to build a very special competition engine for the car which you can read about here.
WHY DO AUSTIN HEALEY 100 CRANKSHAFTS BREAK?
The Austin Healey 100 engine was actually developed from a 1929 Chevrolet design and several aspects of the design contribute to the crankshaft failure problem, these include:
  1. The engine size which at 2660 c.c., is around the upper limit of what is optimal in an automotive 4 cylinder unit.
  2. The relatively spindly forged steel crankshaft which has no “pin overlap” and is only supported in 3 main bearings
  3. The extremely big and heavy flywheel necessitated by the engine design.
To understand why these 3 aspects of the design are major issues it is first important to understand some less than common engineering terms and concepts.
CRANKSHAFT ROTATIONAL SPEED OSCILLATION.... FOLLOW THE LINK TO READ MORE. 
We think that an engine should be tested on a dyno machine with the AH 6 cylinder damper on it. If such a test shows that vibration in the engine is eliminated from 0-3000 RPM then the 6 cylinder damper is working.
At HDR we are working on developing rubber repairs for all these flat dinner plate style dampers. 
Starting with Jaguar and Wolseley models.

1 comment:

  1. You have good articles here! If anyone here looking for loan @ 2% rate in return to buy home or other financing needs, I want you to contact Mr Benjamin On 247officedept@gmail.com Also On Whats-App + 1-989-394-3740When I was introduced to Mr. Benjamin, I was entering the market as a first time buyer. Naturally,my needs were a bit different and I had loads of questions. Before he sent me my pre-approval letter, he called to speak with me about what it meant and what could change. He made himself available to me at pretty much any hour via email and texts. He was very responsive and knowledgeable. He’s also very straightforward. I explained to him what my expectations were in terms of closing time and other particulars. He said he would meet those expectations but he surpassed them. I closed so quickly my realtor and the seller of course were excited about that. But as a buyer I appreciated being walked through the process of Mr Benjamin loan offer. From pre-approval to closing- the journey was so seamless and I consider myself lucky because I’ve heard horror stories. I recommend him to anyone looking for a loan. Everything was handled electronically expediently and securely   

    ReplyDelete