1275 crank casting #?

[aeronca65t]

Wow...that is really *trick*. Still, I'd want a good scatter shield, just to be on the safe side.

My Dad used to work in a place where they re-welded and ground Caterpiller 'dozer crankshafts while they were still in the block....but those things only turn about 800 RPM when they're screaming (and they were only doing the journals).

 

[Hap Waldrop]

Nial, it got a serious scattersheild. It was a wild job even for me, then only reason I ever considered it, was for the dirt track engine builder who literaly had did this dozens of times. Believe me I had my doubts, in the end it was the customer's choice with all liabilty lying on him, but so far it's worked out fine. It's fairly an elaborate process, the crank has to be brought up to temp, then 4130 weld applied, but only a little bit at a time, it probably weat through the cycle a dozen times, the the machinist had to mahine it to exactly mock the original flywheel hub. This engine won the Walter Mitty this year, both the enduro and the sprint race. Overall this de-stroked engine makes very little sense, but I kept it together for the customer, just an example of the wild stuff floating around at a HSR race, 1380/5 speed cars are quite common there, that's why I'm looking forward to busting their butts with a .040" over 4 speed car /bcforum/images/%%GRAEMLIN_URL%%/smile.gif

I've found out, pretty much anything can be fixed and be as good as new, most of the time, this type work is crazy expensive and reserved for much rarer stuff than our little cars, but there are people out there who can weld a Bugatti block back together from two pieces and you never know it and it perform as new, but they are for the "bluebloods" for sure.

 

[DrEntropy]

Yeah, me too Drew... and I don't even HAVE a Spridget! /bcforum/images/%%GRAEMLIN_URL%%/wink.gif

 

[Bugeye58]

Hap, what do your 1275 rods weigh? With the "Hybrid" rule in "H", I may have to reevaluate my approach.
Jeff

 

[JerryB]

"""""fact if I stumble across a EN40B, I sell them to the Spridget freaks, who pay big money for them, """"""

I always get a kick when I see the scramble for an EN40 steel crank......going on 30 years old and just like an old hooker you dont know where she's been or how hi the miles are.

Its geting so nowadays that at the end of the day and after PROPERLY prepping and heat treating, for just a few $$ more a Moldex piece looks better and beter pricewise.

 

[JerryB]

"""""""floating around at a HSR race, 1380/5 speed cars are quite common there, """"""

Brings new meaning to the phrase "Vintage racing"!

That crank was evidently done right at the onset....with the two dowel pins as shown in the recreation. Huge amount of second harmonics....maybe the bolts loosened up or failed??

Hap....you mentioned Ti retainers for big springs in another post...and that "you had only one set".....you do know the source?....if you need it and the # let me know and I can PM you the details.

 

[Hap Waldrop]

Jeff, as for the rods weight, still heavier than the Carrillos, but we can't use them in SCCA LP anyway, The stock 1275 rods start out out roughly 685 grams per rod, and we gotten mostly 100 grams of them, it all depends on the cores, the heaviest ones still weight about 600 grams when done.

Jerry, yes the last EN40B crank I had was still std./std, straight, mag checked and polish and a guy paid me $600 for it, and I let him have it /bcforum/images/%%GRAEMLIN_URL%%/smile.gif A customer at the runoff this year gave me a tote full of 1275 cores for future engine projects, and he has 3 EN40Bs in there. On the retianer we had them made by a racing buddy in the Charlotte area, but I might look you up if I need some more. I buy oversized valve spring for the vintage and F-prod 1275, and use alloy retianers, I got a good source on them as well I would share with you, he like to sell some volume, he offer both the alloy retianer and a steel retainer, you have to enlarge the spring pocket, but I have a buddy who lets me bottow his tool for that, do on the mill, real easy job.