New Mummert Crankshafts


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By Y block Billy - 10 Years Ago
http://www.jalopyjournal.com/forum/attachments/castcranklr-jpg.2717595/

I imagine a custom set of rods, pistons will be needed with the use of this, what else to consider John???? Cam, Girdles etc???
By John Mummert - 10 Years Ago
Billy, the plan at this point would be make some 3.61" stroke. This is the same as our regular stroker cranks. We have pistons for that stroke and off the shelf rods. This would eliminate the need to find a 312 crankshaft.
We will likely end up with 3.68" stroke in the future. We would supply the rods for that combo.
If there is sufficient demand I would probably do some 3.75" stroke crankshafts but pistons would be custom due to low demand.
We haven't put girdles on our 2 drag engines. Stock caps with ARP studs. John Hildebrand's engine has maybe 150 runs without problem.
By D Woodruff - 10 Years Ago
Please some more information. Y Block Billy where did you find this? John 312 or 292 main journals? Availability? Details please. I looked on John's site and Jalopy Journal to no avail.
By D Woodruff - 10 Years Ago
Ok I found the post in another thread on this site, Thanks.
By 2721955meteor - 10 Years Ago
John Mummert (10/1/2014)
Billy, the plan at this point would be make some 3.61" stroke. This is the same as our regular stroker cranks. We have pistons for that stroke and off the shelf rods. This would eliminate the need to find a 312 crankshaft.
We will likely end up with 3.68" stroke in the future. We would supply the rods for that combo.
If there is sufficient demand I would probably do some 3.75" stroke crankshafts but pistons would be custom due to low demand.
We haven't put girdles on our 2 drag engines. Stock caps with ARP studs. John Hildebrand's engine has maybe 150 runs without problem.

Coming near your location in nov. could i come see your operation ,if yes  please send your adress and phone #. cliff frome surrey bc canada. ct1940@shaw.ca
By Y block Billy - 10 Years Ago
So your telling me the 312 cranks I have been saving will be obsolete POS's?? LOL! On another note, Ted once mentioned to me that the steel cranks revved up slower due to their weight but is that so whereas they dont have the center counterweights? (Correct me if I misunderstood Ted)
Will the prices of stroker kits change with one of these new cranks?
By John Mummert - 10 Years Ago
Billy, the C1TE steel cranks are heavier than an EC 272-292 crankshaft even though they don't have center counterweights. The rod journals are solid on the steel cranks which explains some of the extra weight. Where is the rest???
Don't expect China prices on these cranks. The raw castings cost more than a finished 350 scrub chinese crank. Machine work on this side of the Pacific pond is not subsidized by our gov't, in fact, work of any kind is discouraged.
 I wouldn't throw away any 312 cranks just yet but they aren't getting any easier to get. Many are .010-.020 or .030" undersized. Some are cracked. Some get broken in shipment.
I would prefer to make 292 main journal cranks due to the limited supply of standard size 312 main bearings but I'm certain some people will want 312 mains.
By Glen Henderson - 10 Years Ago
I assume that we could get these drilled for a FE or other SFI flywheel or flexplate and machined for a different damper, such as scrub?
By Ted - 10 Years Ago
Y block Billy (10/3/2014)
...... On another note, Ted once mentioned to me that the steel cranks revved up slower due to their weight but is that so whereas they dont have the center counterweights? (Correct me if I misunderstood Ted)
Bill.  No misunderstanding on your part.  Add this to what John has already brought up.

The steel crankshafts are indeed heavier than the fully counterweighted cast crankshafts.  Part of this is simply due to the cranks being designed for the HD trucks with heavier rotating assemblies and the need for stronger crank snouts.  While the steel cranks are quite robust, the excess in weight tends to make them a less desirable choice in an all out normally aspirated performance application.  Where a supercharger is involved, then the additional snout strength of a steel crankshaft tends to overcome any detriments in the actual weight.
 


By John Mummert - 10 Years Ago
Glen, to some extent the bellhousing you are using will determine the flywheel that can be used. The FE ring gear is larger than a Y-Block so the starter won't line-up if a Y-Block bellhousing is used. The people that I get flywheels from make SFI f/w's so I should be able to get them with stickers, don't know what addition cost would be. I haven't heard of anyone getting grief over the flexplate in the C-4 kit but I'm certain a really picky NHRA inspector might complain.
We have made a crank with a snout that was scrub where the damper registers and Y-Block for the timing gear. There's only about .004" difference in diameter but the damper keyway is also different size.