Quote:
Originally Posted by PanozDuke
Kel,
Great photo. I think he likes you. I also think you are going to be busy.
The idea of shot peening the main webs is great- hadn't thought of that, but it should be a help.
Keep us posted on both projects, Ari and the Crimson Kiwi.
Mike
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Mike, I started thinking about the utility of shot peening when looking at the failure mode in the block below. I am thinking of shotpeening a band of approx 1" from the bottom of the no's 2,3 & 4 webs up. I have read a few engineering papers on the value of shotpeening cast iron and this varies significantly depending on the grade that you are working with. Seems that you could expect an improvement in fatigue life of 10 - 30%. I think that this in combo with removing all stress risers (sharp edges etc) will help.
There will certainly be need for care when shotpeening the webs though as they are not very thick. Shot size and peening pressure will need to be well considered. There is also a possibility that this process may affect the main bearing bore alignment.
I am going to talk to a local Ford specialist race shop to discuss where they normally see cracks originating in these blocks so I can work out whether the shotpeening idea is worthwhile. Next job will be to find a skilled operator that can be trusted to do the job and at a reasonable price.
I am not so trusting of these blocks though, that I wouldnt run a main girdle. I really think that any 347 application will benefit from a girdle and at less than $200 it seems a cheap way to add some strength to a marginal block arrangement. It is worth buying some girdle kits just to get the ARP main stud kit that comes with them (I think mine is a Probe kit and it came with ARP stud set up). This will also help to stabilise the bottom end of the engine.
Next job is to haul my engine out and strip it down to get the block crack tested to see how it has held up to the 6 hour beating that it got.
Kel.