Hi I'm looking for the amount of weight the General uses on a neutral balanced flex plate to make it standard external balance for both older Mark IV (with 2 piece seal) and the new Gen stuff with one piece. It looks like they changed the amount of weight to m graemlins/waving.gif e?

Paul,
The physical size of the weight really does not mean much. I have seen them several sizes, but the amount of "unbalance" was still the same. You cannot tell by looking at them. Also, on the newer, one pc seal, cranks, the "unbalance" amount is different for a cast crank and a steel crank. Different flywheels for cast and steel. The newer ones definitely use more weight because there is no longer an oblong flange on the end of the crank to help with the balancing.
Basically, you have to use the correct flywheel for the combination.

Well it's back to the balance guy for me. Got a new CAT cast 454 crank off ebay and with my incredible luck it was 330 grams out in rear and 73 in front. I should have sent it back but elected to balance it when the machinist said he could. When he got to working it, it became clear it would need a few slugs of heavy metal, but we ended up using a stock GM 502 Flexplate and that made it come in "shift". I called the CAT dudes and told them what happened and they sent me a new SFI 454 late model flex plate good price not not free. The GM one had a weight marked 42.54 in-oz on it. It was not the usual aftermarket weight that is (about 6" long and an 3/4" wide). It was about 2 by 2. The CAT one showed up today and it has that same long weight in the normal spot + 6x 1/2" holes on the opposite side. The 502 plate we used for the balance is the "std for that shop. I called the machinist and he said he could check my CAT one against the std. More $. That's it for me and China BS... serious quality issues for sure. The CAT information said it was balanced to OEM spec. Could you imagine how quick that would have destroyed my TH-400 case... or worse BTW I had to get this engine built so it's together. No more SCAT, CAT or Eagle junk for me... "spitting sounds as I clear my mouth" Worst come to worst, I'll get a GM Flexplate. graemlins/clonk.gif graemlins/clonk.gif graemlins/clonk.gif graemlins/clonk.gif

Paul,
There is a huge difference between the quality of some of the different vendors you mentioned.
I have been using, balancing & selling Scat products for over 12 years without any problems to speak of.
Their quality control is excellent.
I have never had to send a crank back or have it reground to make it work nor have I had any balancing issues that were unexpected for the parts used.
I have had CAT stuff brought into my shop & to keep this polite I will just say I prefer not to deal with it.
I have also balanced a lot of eagle stuff & had no major problems I just don't use their stuff because I am a dealer for Scat & have no reason to change.
I have used Eagle rods customers have brought in & find them very good but I have had a few issues with their cranks regarding sizing in the past.
I have heard they have remedied this problem but I don't know this for a fact.
Sorry you had a problem with your crank but I don't find it completly unexpected :D

Mike, Thanks for the input...