Thread: 460 internal/external balance?

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Can you help,as i am going to buy a 521ci eagle conversion kit but,the one i am being supplied is externally balanced,my engine is 1976 460ci internally balanced,being told that all i need to get is a externally balanced spacer behind the harmonic balancer?Can i still use the same balancer,ie, not neutral,internally balanced? Are there any differences with the later crank,ie,rear seal locations?
What is the differnce between 1968-1987,460's,to later engines?

i have a 90 460 and all the 460s that i know of are external 429 are internal

the last 512 was internal and the last 554 was external . i spin the mass with the real damper and spacer so every thing is dead on

For sure spin it before you assemble--Never have got a stroker kit yet that was even close on balance, especially the external balanced one's.......

Just out of curosity, which is best, external or internal balanced....

Originally Posted by rdobbs

Just out of curosity, which is best, external or internal balanced....

i have had engines that have seen 8000rpm both ways but it is always nice if the weight can stay on the crank counter weight .some engines it just can not happen less many plugs of heavy metal are put in the crank counter weight that were a fully counter weight crank like a 8 plate help load the crank right thru the RPM range boils down to the use and RPM of the engine and whats not a fast rule just had one that customer took to 10000

Guess I prefer internal balance...Just not sure why!!!!but as Pat mentioned, sometimes the price of heavy metal is just a bit too much and I go external....

thas is were the 1600 and up dollar crank with the counter weights in the right spots help but this is no guarantee still have had to plug them .mass can come in to play. well how much counter weigh you can put inside of the block?? before they hit in the block .oil pump . pistons . very short rods make counter weights diameter smaller to clear pistons adding a heavy pistons /short heavy rods adds to adding weight and may have to be on the outside ends of the crank crank pins can be drill to help the counter weight be more as the pin side weight will not help . more counter weights on crank adds to the need for better oil control there more to this a paper could be written

I prefer internal so I can use any neutral clutch combo--if you are going to race you will play a lot with clutches---flywheel weight, multiple discs, etc, etc

I prefer external so the crank can more economical balanced for a customer and it won't take so much heavy metal

I prefer internal if the rods are a reasonable length(bottom of piston clears conterweigth)

I prefer external for some spec racers so that I can cut down the counterweights of there cranks for an ultra light rotating mass

and on and on and on

i really prefer not plugging a new crank past 4 1nch plugs of heavy metal any way i go HAPPY NEW YEAR JERRY a new year and some new skin for me still can not do much but can run the boring bar any thing gets close to the bar is getting bored. i am in a hole boring mood lately

Happy New Year to you and your skin Pat

I moved our boring fixture over near the surface grinder so I can be boring one block while the next one is getting surfaced---then to the main caps--can drill and tap while the boring bar and grinder run---from there its into the Ck10 either way up for honing with torque plates or line boring the caps--usually do 3 or 4 each way before turning machine around

yep my storm vulcan is by the rottler so i can run both when i am in that work space .the bad deal as the hone is stuck between them so it get dusty but works . i can bore . mill .and hone at the same time .but i not up to that speed. i hope very soon .still get blown way as to how far off and how bad the decks are on the after market blocks???? my stuff is dead nuts on to the deck s and for them to be at 90 thru the crank and cam center line. i can not say that with the last ones i did re did . the owner of the block did the bull work moving and help setting stuff on the machines he just could not understand it ?? .well its nice to know with low tech stuff i still can be better then them on size and finsh any day

comes down to do you want a CNC (same as factories) block job or do you want a blue printed block???One thing at a time, starting at crank/cam centerlines-----

Originally Posted by jerry clayton

comes down to do you want a CNC (same as factories) block job or do you want a blue printed block???One thing at a time, starting at crank/cam centerlines-----

yep i under stand but you would think some of the big Ms and older Pro blocks would be better on size ?? and finsh? but there not

Originally Posted by 460motorvator

Can you help,as i am going to buy a 521ci eagle conversion kit but,the one i am being supplied is externally balanced,my engine is 1976 460ci internally balanced,being told that all i need to get is a externally balanced spacer behind the harmonic balancer?Can i still use the same balancer,ie, not neutral,internally balanced? Are there any differences with the later crank,ie,rear seal locations?
What is the differnce between 1968-1987,460's,to later engines?

The external balnace rotating assembly will fit the 1976 internal balance engine block (D1VE). All 429-460 balancers are neutral balanced, however the flex plate and crankshaft spacer (between the balancer and timing cover) are different between itnernal and external balance engines....so you need an external balance flex plate and an external balance crankshaft spacer, also known as a hatchet weight.

Paul