I've used many pairs of either with no problems. They are made by Dennis at American Hot Rod Parts who makes his products for the foreign market, Australia and New Zealand and others who have much more stringent testing than the US. Either one is a good choice. Today if I were doing a spring behind the axle even though I've been successful using perches I would do a fabricated mount.
Investment cast is also know as the lost wax process. Oversimplified it is when wax model of the part is made usually in an injection mold. This wax model is then dipped in a ceramic slurry followed by coating with a very fine sand then dipped in the slurry again and coated with the fine sand until a ceramic shell of sufficient thickness is achieved to form a mold. The mold is then put in a oven to melt the wax out of the mold. You now have a cavity that resembles the part you want. The mold is then typically heated and the desired alloy of metal poured into the cavity. After solidification and cooling the ceramic mold is broken off the cast part. Investment casting offers several benefits. You tend to get a very smooth surface finish of the casting with few surface defects. Molds can be poured in a normal atmosphere or in a vacuum for very clean parent metal in the part with very little porosity. The list goes on but it is a superior process to sand casting. However it is labor intensive and usually expensive. A lot of aircraft/aerospace parts for turbine engines are done this way. Forgings are strong because there is a directional flow of the microstructure of the metal when struck or pressed in a die. Although investment casting is superior to sand casting there is no direction flow of the alloys microstructure. With all this said the only way to know which is the right process is with a stress analysis of what is going on in use. A study would be extremely expensive. What happens in most cases is the part is simply built over size the parts original confirmation to handle any situation. A investment casting may be perfectly fine however I would think a replacement part made with the same process as the originals would be better.
Nosworthy? My roadster suspension was manufactured by him here before he moved to the US. All shiny stainless and still is operation more than two decades later after plenty of road testing in all conditions.
These perches are from Bert's Model A, they are advertised as forged. Can't say where they were made also can't say for sure how they fit a 2 1/4 boss, mine is 2". modelastore.com/index.php?route=product/product&product_id=3231
I have been conversing with Pete and Jakes a bit, and what they say is wishbones will break the perches. He said it happens a lot, and the adjustable perches are what is needed to fix it permanently (or hairpin 4 bar). He said it allows more flex, though I'm not as convinced, (from the break area) but would have to see them in person & in action to know for sure. He said they will have them in stock soon and sounds like may send them out as a replacement, but will see how that progresses.
Hot Rods have been running split wishbones with spring over the axle fronts for about 80 years without adjustable perches. I've always considered them a crutch? If the front is set up right from the beginning with no spring bind and tie rod ends on the bones there should be minimal stress. I like to use split 32 bones or split 35-48 bones as they are long enough for minimal stress. Most front ends have a vertical movement at the axle end of about 1.5 to 2 inches going down the road not 6 inches. Just my opinion, but what the hell do I know?
Yep. Any adjustability in locating devices will twist the spring one way or the other to make those adjustments.
I agree, I was just surprised they would readily say that they see this all the time. I'd want to try beefing them up, use different steel and process if I was the one making them and they were breaking all the time.
Here is an explanation of how to build it correctly (or incorrectly). https://www.hotrod.com/articles/easy-solution-complicated-suspension-problem/
Casts parts will have a very thin 1/16” mold line Forged parts will a 1/4” wide forging mark. You can see the differences on crankshafts and connecting rods.
Correct me if I'm wrong guys but I don't think " stainless steel" can be " cast"....I also don't believe " stainless steel " has the capability to be as,strong as high carbon or chrome molly steel....
Casting of stainless steel is commonly done. https://intercast.com/2018/04/17/deciding-stainless-steel-casting-cast-iron/
Speaking of forging, unscrupulous people can forge the look of a forging in a casting. And dishonest/ignorant people will sell them as such.
I seen it asked, but didnt see a response. What is da actual torque spec on da perch nut? Thats all was looking for when i found this thread. I never imagined a perch breaking. Little do i know. Ha.
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