Diamond Piston Questions on weight

[84BuickGNYorkPA]

I got a stroker crank by accident, even thought the part number on the box is a verified stock stroke crank. So machinist discovered this after the crank was balanced with the existing 3.840 diamond pistons. Ok so the solution is to just go with the stroker at this point by getting the stroker diamond pistons. Here is the question, do they weigh the same? If not and I'm guessing not the crank will have to come back out of the block and get rebalanced.

Chuck

 

[turbodave231]

The piston won't be the same, but maybe close. The only way to know for sure is weight the new/correct pistons.

Funny, I ran into the opposite situation recently, stroker crank with stock stroke pistons. Mine were .030 not .040

 

[pacecarta]

if you installed a stroker crank ...the crank has to come out anyway because you need to clearance the block at the oil galley so the rods dosn't hit the block and the rods need to be clearanced and double checked for interference with the cam
another is most stroker pistons are setup for longer 6.0 connecting rods , trying to stick with the 5.960 rods youll be looking at a custom stroker piston . not really a big deal since youll be waiting for them anyway because i doubt you'll find .040 stroker pistons sitting on a shelf
either way you'll need a rebalance


easier (on your wallet) and quicker solution is contact the seller , have them make good on their mistake and get a stock stroke ,. you're already looking at removing the crank and a rebalance ....so getting a new stock stroke crank balanced will be the cheapest in the end and you wont need to notch the block or have the rods clearanced or wait for custom pistons

 

[84BuickGNYorkPA]

Good point Paul, I need to talk to the vendor, when I called Friday there was no answer. Part of me wants to go stroker for the extra displacement... I must admit.
The rods are brand new and not altered, on the website they are using the same rods on the stock stroke as the stroker kit rotating assembly. The car has been down for a year next month, at this point I can wait for custom pistons.
As far as clearing the block, (2) of the connecting rod caps seam fine, I didn't know that there are issues with cam clearance, so thanks for the heads up.

Chuck

 

[SHADOWII]

If you know the weight of the diamond pistons you have now, you might be able to come up w/a ballpark figure based on a set I recently purchased.
3.820" = 375grams

 

[84BuickGNYorkPA]

I have the weight at work, thanks for the reference!
The pistons you mentioned are for a stock length connecting rod with the stroker crankshaft correct?

 

[SHADOWII]

No, these are stroker pistons, 6.50" rod w/o the pin.

 

[TurboBuRick]

Who's the ass hat boxing these cranks? I recently had the same thing happen. What a crock of shit!

Had to order new pistons to work with std rods. Hopefully they get it right...

 

[bison]

Who's the ass hat boxing these cranks? I recently had the same thing happen. What a crock of shit!

Had to order new pistons to work with std rods. Hopefully they get it right...

Sum Yung Boi


Sent from my iPhone using Tapatalk

 

[TurboBuRick]

I don't know, I doubt they are coming from China in a Eagle box.

 

[84BuickGNYorkPA]

This is an Eagle crank, runout is under .0002, sizes are good, my previous issue was the King bearings had taper... the nightmare continues while the season slips away.

Chuck

 

[TurboBuRick]

I know how you feel. I'm having a very similar experience. I've built a few 109's but this recent one has been one thing after another...

 

[WPP-Bill]

Our +.020 Diamond stroker pistons weigh 522G and use a .940D/.155W wrist pin that weighs 134G. We have +.030 and +.040 in stock as well, designed for use with Molnar 5.960 rods, if you need them. Keep in mind with a stroker crank you may need to clearance the block and your existing connecting rods.

 

[TurboBuRick]

Hey Bill, can you snap us a picture of the pistons you have?

TIA

Rick

 

[WPP-Bill]

 

[84BuickGNYorkPA]

Bill,
Thanks for the offer, but Eagle is picking up the crank at the machine shop and replacing it with the intended crank balanced to the current bob weight value. Big thanks to Mike and Maryanne over at FTS for getting me back on track.
Chuck