Ted

I'd also be interested in a drilled girdle, so add my name to the list.

Thank you

Missouri Mike

I'd rather be lucky than good.................

    but good ain't bad!!

Thanks Ted. Any rough estimates for final product?

 Seppo from Järvenpää, Finland
www.hollowheads.net (just click the hole in the head to proceed)

I’ll be aiming for the end of October at having some girdles ready for machining/drilling.  I figure another two weeks after that to finish girdle machining.  Once I get an initial price for the material for the girdle blanks, I can give a price for the girdle and another price for the stud kit.  Steel prices being in a constant state of flux prevents an accurate price estimate at this time.

Lorena, Texas (South of Waco)

Hi Frank,

I see your point but I have always heard that the reciprocating acceleration loads of the pistons et al were actually higher than the firing and compression loads.  If this is so then the crank is accelerating and decelerating as it rotates even without the firing loads.  The very purpose of the flywheel is to smooth out these accel/decelerations which it does by applying a reverse torque to the crank as the crank trys to accelerate the flywheel.  This torque must be at a maximum at the rear main since this is where the total inertia of the crank and recip masses is at a maximum (relative to the flywheel). 

But the burden of my question concerning other engines with or without girdles was to see what real world experience is with engine/crank failures

Also the purpose of the girdle is "to stiffen up the bottom end" or to say a bit more technically to keep all the main bearings on a common centerline.  This would seem to be just as important for the rear main and where it may be a greater problem since the rear main has to deal with the imbalance of the flywheel as well as the crank loads.

Doug T

The Highlands, Louisville, Ky.

Doug,

     Couldn't resist. I don't follow your reasoning on the rear main at all. There is torque or twisting force on the main, but the stiffness of the cap wouldn't affect that either way.

     Since the torque is applied in eight bursts, (as each piston fires) the maximum torque it sees is the same as all the other journals except, of course the front main, which sees none. Obviously the frequency increases front to back. The rear main and the front main would probably see less distortion from the firing because they only deal with two pistons on one side of the bulkhead. I think the biggest issue with the cranks is probably the overlap of material between the main and the rod journals. The smaller that section is the more likely breakage will occour. I suspect most of the block issues result from the loads caused by the cranks imbalance at higher RPM. That load is not happening in one direction but all around the circumfrence. Obviously that force changes with RPM and amount of torque applied to the piston weight. Blah, blah.. 

Frank/Rebop

Bristol, In ( by Elkhart) 

While I'm not using a girdle yet, I am using main studs which required some clearancing of the seal retainer and the use of a torch and hammer on the oil pan to make dimples. I do not recall how close the dimples came to the pan bolts. It's fine for the clearance required for the stud but with a girdle, it will need enough clearance for the nuts. If it does not block the pan bolt hole, a sufficiently long spacer and bolt can be used to clear the dimple. If that is not sufficient, then the girdle can be extended to provide new pan holes, which will require cutting and welding panels to make the pan fit and making a gasket, and the girdle can be fastened to the block with some countersunk head screws at the rear to provide a flush mounting surface and no interference for the pan or girdle nuts. And now to get out of any familiar territory for me, maybe a less conventional method can be used, instead of main studs through the girdle, how about drilling the girdle for tension screws at maybe 45 degrees to intersect the main cap at each end. If something like this is done it may fit an unmodified pan but will probably require that that main be machined with the girdle and those screws in place, but maybe that's required anyway.


Lawrenceville, GA

Hi Ted,

This may be a little academic for me but I would be interested in at least knowing what it would cost with all the studs and hardware.



Also I would like to start a little discussion as to how and why to put studs and the girdle on the rear main. It seems to me that the rear main and the cheek of the crank to the rearmost throw is the most highly loaded material in the entire crank. This is where all the energy leaves the engine to go to the flywheel and onwards. This is also the area of the crank that has the material removed when stroking by reducing the throw's journal diameter. So if the crank will benefit from having more support, it seems to me that this area is where it is needed most. What is the experience with other engines?



If this can be incorporated by a rework of the pan sheet metal this would be a pretty easy to for most of the serious guys to do. But what about the rear main seal, is this likely to be a problem? Also is there any difference between a 312 and 292 with regards to a girdle? Finally would it be possible to incorporate say 4 threaded holes in the girdle to support a windage tray?

Doug T

The Highlands, Louisville, Ky.

Ted, is this going to happen or do we have to go to plan B? Don't mean to hurry you, but .

 Seppo from Järvenpää, Finland
www.hollowheads.net (just click the hole in the head to proceed)

Thanks Ted. For some reason I had convinced myself the girdle was the boat type. Looks great! Can't wait to hear it run. Lets see some BIG numbers now. Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

AH! Chuck, now we all know what your got!!

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia