416 Crankshaft hitting piston #8 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

FerkLS3 · 02-07-2023, 04:39 PM

Hello, hoping someone can chime in and give some advice on this issue. Ill cut right to the chase, assembling the short block of my ls3 out of my 2010 Camaro and ran into a big issue. Rotating assembly was purchased as package through Texas Speed for the ls3 it included - Lunati 4.00" stroke crank, compstar 6.125" rods, and diamond -2 pistons (wrist pin offset for stroker), and was also balanced by Texas speed. This is the 5th LS engine I have done (first stroker) and I've never ran into this issue before. the bottom of the piston where wrist pin goes through hits the counterweight on cylinder 8 not even at the "tallest point" or "crest" of the radius on the counter weight. All others cylinders (except #7 hasn't been installed due to this issue). piston is not popping out of bore and the rod length is correct all pistons are identical - none notched. Called Lunati and they said they can't tell by picture or videos I sent them and need to see the crank in person to determine if it is defective or not, so they advised me to ship it to them under a possible warranty claim if they determine its defective but assured me they've never had this issue before. Has anyone ran into this before? I attached the best photos I could - they are at the point of contact. Any input at all would be greatly appreciated!

gtstorey · 02-07-2023, 05:34 PM

I would contact TSP. If they put a package together that hits, then they should deal with it. They should deal with Lunati if that is where the problem lies. Since I don't see anyway you could misassemble the parts in such a way to cause the problem it has to be a problem with the parts. I would pull the parts from the engine and show it hitting since it should hit anyway.

FerkLS3 · 02-07-2023, 06:24 PM

Quote:

Originally Posted by gtstorey

I would contact TSP. If they put a package together that hits, then they should deal with it. They should deal with Lunati if that is where the problem lies. Since I don't see anyway you could misassemble the parts in such a way to cause the problem it has to be a problem with the parts. I would pull the parts from the engine and show it hitting since it should hit anyway.

Thanks for the reply, upon further inspection I had the incorrect piston in cylinder 8 because its a stroker its supposed to have a notch, I swapped the notch piston in and its still hitting slightly. my Machinest has advised me to shave down that notch till it clears with a zip tie inbetween to check clearance and it is perfectly safe. Cant believe this is required, Texas speed didn't have much insight or help

HDRDTD · 02-08-2023, 12:09 AM

If you machine the notch on one piston, won't that alter it's weight and cause you to modify all the other pistons till they all weigh the same ??

ZL1_Chris · 02-08-2023, 03:10 PM

Hmm maybe the piston is 180 deg out... is it possible to turn it the other way then it would clear with the offset.

FasNuf · 02-08-2023, 04:10 PM

It almost looks like the rod is hitting the block, but it's actually the piston? Some strokers need the block notched for clearance, but this is the first time I heard the piston hits. Time to verify part numbers with TSP

ZL1_Chris · 02-08-2023, 04:16 PM

Quote:

Originally Posted by FasNuf

It almost looks like the rod is hitting the block, but it's actually the piston? Some strokers need the block notched for clearance, but this is the first time I heard the piston hits. Time to verify part numbers with TSP

It's offset for a reason, wonder what that reason could be? Maybe it's as simple as turning the piston and rod assembly 180 degrees so that the offset is facing the correct direction and then it will clear and work as designed 🤔

FasNuf · 02-08-2023, 10:03 PM

I think he's saying the larger chamfer should be on the crank side radius of the journal. Smaller chamfer meet together when both rods are installed. The bearings fit is specific to the rod and cap respectively.

02-07-2023, 04:39 PM	#1
FerkLS3 Drives: 2010 2ss Cyber Gray Join Date: Feb 2022 Location: Ohio Posts: 8	416 Crankshaft hitting piston #8 Hello, hoping someone can chime in and give some advice on this issue. Ill cut right to the chase, assembling the short block of my ls3 out of my 2010 Camaro and ran into a big issue. Rotating assembly was purchased as package through Texas Speed for the ls3 it included - Lunati 4.00" stroke crank, compstar 6.125" rods, and diamond -2 pistons (wrist pin offset for stroker), and was also balanced by Texas speed. This is the 5th LS engine I have done (first stroker) and I've never ran into this issue before. the bottom of the piston where wrist pin goes through hits the counterweight on cylinder 8 not even at the "tallest point" or "crest" of the radius on the counter weight. All others cylinders (except #7 hasn't been installed due to this issue). piston is not popping out of bore and the rod length is correct all pistons are identical - none notched. Called Lunati and they said they can't tell by picture or videos I sent them and need to see the crank in person to determine if it is defective or not, so they advised me to ship it to them under a possible warranty claim if they determine its defective but assured me they've never had this issue before. Has anyone ran into this before? I attached the best photos I could - they are at the point of contact. Any input at all would be greatly appreciated! Attached Images

02-08-2023, 03:10 PM	#5
ZL1_Chris ZL1_Chris Drives: 2015 ZL1 Camaro Join Date: Oct 2022 Location: Largo,FL Posts: 100 View My Garage	Just a thought Hmm maybe the piston is 180 deg out... is it possible to turn it the other way then it would clear with the offset.

02-07-2023, 05:34 PM	#2
gtstorey Drives: 2010 Camaro SS2,L99, LSA SC Join Date: Aug 2017 Location: Huntsville, AL Posts: 2,155	I would contact TSP. If they put a package together that hits, then they should deal with it. They should deal with Lunati if that is where the problem lies. Since I don't see anyway you could misassemble the parts in such a way to cause the problem it has to be a problem with the parts. I would pull the parts from the engine and show it hitting since it should hit anyway.

02-08-2023, 12:09 AM	#4
HDRDTD Drives: 2013 Triple Black ZL1 Vert M6 ECF Join Date: Mar 2011 Location: Trenton, Michigan Posts: 7,047	If you machine the notch on one piston, won't that alter it's weight and cause you to modify all the other pistons till they all weigh the same ??

02-08-2023, 04:10 PM	#6
FasNuf Drives: 2014 Camaro ZL1 Join Date: Jul 2019 Location: Oregon Posts: 1,617 View My Garage	It almost looks like the rod is hitting the block, but it's actually the piston? Some strokers need the block notched for clearance, but this is the first time I heard the piston hits. Time to verify part numbers with TSP

02-08-2023, 10:03 PM	#8
FasNuf Drives: 2014 Camaro ZL1 Join Date: Jul 2019 Location: Oregon Posts: 1,617 View My Garage	I think he's saying the larger chamfer should be on the crank side radius of the journal. Smaller chamfer meet together when both rods are installed. The bearings fit is specific to the rod and cap respectively.