65 Hipo Engine Balance

[S412gofast]

Was the design requirement of the 289 hipo hatchet counterweight being incorporated to the hipo engine to avoid hitting this dynamic system's natural frequency harmonic within a normal operating rpm range?

[pbf777]

     I think the additional "hatchet" was necessary as simply a counter-weight sum to offset particularly the heavier connecting rods; this being the expedient process as otherwise a different crankshaft casting would have been required to provide this.

     The vibratory "critical" frequency is the point at which things when agitated reach a harmonic sync, and if components remain in operation at this frequency of motion, parts begin to suffer fatigue failures at alarmingly short operating durations, so best avoided.  The sum of the hatchet's effect on the entirety of the mass in motion it's attached to, doesn't seem to be great enough to really effect that which we are referencing as the 'critical' here.   

     An example of what this 'critical' is that we are referring too is: a simple bell that rings, the ringing is the bell vibrating do to the agitation created as it is struck by the clapper, and changing the size (mass) of the bell changes the vibratory effect (sound as heard).   

     And, it is probably the incurred fatigue in this vibratory action (ringing) that led to the cracks the Liberty Bell 

     Scott.

[gt350hr]

   It was to counteract the heavier rods ( big end weight) It was also used on other "non production" engines like the Tunnel Port 302 and Boss 302 T/A engines.

[J_Speegle]

For a little look inside the process - at least for a few years prior - the first four minutes cover the engine casting, measuring and testing of a typical engine at that time. Have pictures from other years but unfortunately can post here

https://www.youtube.com/watch?v=e_aRxkRCXD0

[pbf777]

   It was also used on other "non production" engines like the Tunnel Port 302 and Boss 302 T/A engines.

     Randy, did these engines with the crankshaft (C7FE ?) bearing the heaver counter-weights and the addition of the center weight also still require the hatchet?   

     Scott.

[mygt350]

Is it true the hipo crank was a slightly better quality steel than a non-hip engine would receive? Assume the Brunell hardness test was only done on the HiPo crank and flywheel version of the 289 due to the anticipated stress the engine would receive. Assume same casting just better iron/steel?

[sg66]

Is it true the hipo crank was a slightly better quality steel than a non-hip engine would receive? Assume the Brunell hardness test was only done on the HiPo crank and flywheel version of the 289 due to the anticipated stress the engine would receive. Assume same casting just better iron/steel?

There is a post on the HiPo site from Bob Mannel June 6 2007 about the cranks https://hipo-mustang.com/user-post-list/1706-bobmannel/?pageNo=13

In short, he spoke with someone who used to work in the foundry who claims they tossed in some extra nickel and manganese but has no documents to verify it.

The testing was not a Brinnel test which is pressing a ball bearing into the metal and measuring the indent.  V8 front spindles have this test mark on the rear side, not sure about others.

The rear journal of the crank is polished and according to Bob's source, the inspectors used this to count or estimate the grains in the iron. I used to have a link to site showing the tool and grid used for this type of testing but don't know where it is now. You can get an idea of what it looks like here on page 16 https://www.thaithavorn.com/pdf/microstructure.pdf

[gt350hr]

   With all due respect to all involved , ( including Mr Mannel) the material spec for the HIPO crank did not include nickle . The spec included chromium and manganese to create "nodular" iron. This increased the ductility ( ability to flex without cracking). For MANY years people have used "high nickle" yet Ford never used it. The same material was used for 428 cranks . "N" diff cases and "some" 427 FE blocks and other things too. GM used nickle but Ford didn't.
    Randy

[sg66]

   With all due respect to all involved , ( including Mr Mannel) the material spec for the HIPO crank did not include nickle . The spec included chromium and manganese to create "nodular" iron. This increased the ductility ( ability to flex without cracking). For MANY years people have used "high nickle" yet Ford never used it. The same material was used for 428 cranks . "N" diff cases and "some" 427 FE blocks and other things too. GM used nickle but Ford didn't.
    Randy

Thanks Randy. After all these years, it would nice if someone had HiPo and non-HiPo cranks tested to see what the metal content of each is. There are non destructive tests like this which would indicate any difference in nodularity but having cranks and access to a testing facility or University lab are easier said than done. https://youtu.be/FIORrrCbLbo?t=149

[Bigfoot]

  For a slow typer you sure are flowery.

        45 years ago I was at Holman Moody in Charlotte. I watched a guy assemble a Boss 429 short block. He opened a brand new box of TRW pistons and put them on the rods and eventually into the block. I questioned him about not balancing or even checking the piston weight of the assembly. His response was "what goes up and down isn't as important as what goes 'round" . "If you want to make an engine shake , pull a plug wire" . "All them pistons still weigh the same!"  His name was Robert Yates (rip). I learned something that day. balancing to a "quarter of a gram" may be fine for a Swiss watch but an automotive engine doesn't care.
   Randy

Learned something. Thnx

[mygt350]

I see the small ballbearing indentation on engine side of a known 65 Hipo flywheel. Have a 65 Hipo crank but have never really looked for any hardness test marks. So the Hipo crank used same mold as the standard 289 crank, but was ground and polished to a higher standard and the metal was mixed with a dash of chromium and manganese to create a "nodular" iron crankshaft. I do remember someone telling me if stand hipo and standard crank on and and tap snout with small hammer, the HiPo crank would "ring" much different that the standard crank.

[gt350hr]

   If you "pitch" sensitive , yes the HiPo crank does ring a little higher  , but not like steel. You can also look for orange paint on the next to last counterweight , or the leading edge of the last counterweight being polished as already mentioned. The other thing not mentioned is they usually have fewer "drilled holes" in the counterweights to keep more weight there for the heavier rods.

[trotrof1]

Great thread. I recall seeing a 427 short block that had the cylinders honed and the walls were almost chrome like. Clearly a visible metallurgical difference.

[mygt350]

Since every engine was run and finish balanced before it was released for installation, would seem all 289 HiPo engines would receive the large nose balancer. And, engines destined for a 4-speed, would have a flywheel installed prior final run. Likewise, engines destined for automatic use would have a flexplate installed. Both flexplate and flywheel installed prior final balance so metal on flexplate/flywheel could be added/drilled as needed. That would imply the "completed assembly" would include the entire rotating assembly from balancer  to either flexplate or flywheel before it was shipped off for installation??

[Bob Gaines]

Since every engine was run and finish balanced before it was released for installation, would seem all 289 HiPo engines would receive the large nose balancer. And, engines destined for a 4-speed, would have a flywheel installed prior final run. Likewise, engines destined for automatic use would have a flexplate installed. Both flexplate and flywheel installed prior final balance so metal on flexplate/flywheel could be added/drilled as needed. That would imply the "completed assembly" would include the entire rotating assembly from balancer  to either flexplate or flywheel before it was shipped off for installation??

I always figured it also included in the case of a manual the block plate ,clutch,pressure plate,clutch fork,throw bearing ,bell housing,starter and of course hardware.