I am still trying to order my crank and they keep asking me about the freaking bob weight for my setup....

I weighed a rod and piston complete with screws caps pins and all attached to it.. came to the weight of around 1335.8grams and they are still saying its too light... I mean come on callies, shouldn't you have any freaking idea of what the bob weight on an lt1 383 is??????

i have JE -31cc dish pistons 5.7 eagle ESP rods (which should be around 620grams or so) clevite bearings and the such...

Let me know how you can help me out here....

 

i beleive you also have to take in account the rod bearings and a couple grams of oil...

 

Rod bearings where attached and all... so i dont get it...

The thing is that they havea more expensive crank for 1800+ bob weight... so i do not understand what is it they want with the freaking bob weight...

 

Bob weight is composed of all of the reciprocating weight and usually 1/2 of the rotating weight on a crank throw. Remember there are 2 sets of pistons, rod, etc. on each throw in a V8.

Reciprocating weight: piston, pin, retaining clips, rings and a few grams of oil PLUS the small end weight of the rod.

Rotating weight: big end weight of the rod, rod bearings.

So you could use 2 times recip wt. of one cylinder plus the rotating weight of one cylinder for your bob weight.

How about taking your parts to the guy who will balance your rotating assy and have him weigh them and give you a bob weight figure. He's got to do that anyway when the crank comes in.

If you give the crank company a low bob wieght, you'll end up putting lots of expensive heavy metal in the crank.

Good luck.

 

Because its a freaking pain to ask anything, let alone get him to finish a job in time... The thing is its the only guy i trust and he is 50 miles away from where i live...

So everything is a pain... so a bit of help can be appreciated...

Thanks

 

That's too bad.

If you don't have the exact % big end and % little end weight of the rods, it's not too hard to rig up a way to measure it, at least for approximating the bob weight for the crank company.

Ever visit the Arecibo Observatory? It's operated by a college near us here in NY. I also had some pilot friends in the PR ANG back when they were first flying A7-D's. Long time ago...

Good luck.

 

Yes i've been there quite a few times...

PLace is freaking nice and freaking big... And bigger are the stories about aliens there

I've been to every important place in this island... jeje ..

if you ever come here.. let me know

I will walk you thought... and thanks.. I Will head over to the machine shop in the morning.. I hope he has everything ready..

THANKSSSSS

 

 

Try a story like this....

Having a freaking dish on front of you and the electricity goes out entirely... no backup system works.. nothing electrical works.. period... just stare!!! uuu creepy

I got the bob weight calculated...

1834.4

THANKS!!!!