[Kerry]

Will it work? Seems everyone is out of rods for 4 to 8 weeks

quote From an article I found
Components differ among the parts attached to the crankshaft as well. Like the LT1, the LT4 uses 6.125-inch-long forged, powdered-metal connecting rods, but they’re highly machined for greater strength and reduced reciprocating mass. They have the same balance mass as the LT1 rod but a higher load capability, with exclusive features including machined lightening slots and a “stepped” pin end with a premium bushing.


What is a stepped pin end?

[laynlo15]

The crank is turned differently on the Lt4 with fillets on the journals.v the Lt1 thats not. Don't know if they are interchangeable
https://th.bing.com/th/id/R6ae2fc6cb...sl=&pid=ImgRaw
https://th.bing.com/th/id/Re3b474f86...OIw&pid=ImgRaw
https://www.corvette-web-central.com...Crankshaft.jpg
https://www.onallcylinders.com/2018/...ads-cam-specs/
https://www.onallcylinders.com/2018/...am-specs-more/
I've posted some info for you to take a look at. Hope it helps

[Kerry]

Thank you laynlo very helpful. So maybe I order 1 and see?

So I blew out the front seal and did a blow down test. All cylinders were at 5% except 2 is at 22% and I hear feel it blowing air up through the oil air separator, so that means its going by the rings into the crankcase. Im guessing got a broke ring land. Got the head off that side. Bore and even top of piston looks good. Should have piston out tomorrow.

If it is I will post up pics. So Im gonna forge it while its down.

Question should I go 10 to one like the lt4? It should be more forgiving an easier to tune I suppose but at what power cost with 12 pds of boost

this is at 660 rw

[Joshinator99]

Originally Posted by Kerry

Thank you laynlo very helpful. So maybe I order 1 and see?

So I blew out the front seal and did a blow down test. All cylinders were at 5% except 2 is at 22% and I hear feel it blowing air up through the oil air separator, so that means its going by the rings into the crankcase. Im guessing got a broke ring land. Got the head off that side. Bore and even top of piston looks good. Should have piston out tomorrow.

If it is I will post up pics. So Im gonna forge it while its down.

Question should I go 10 to one like the lt4? It should be more forgiving an easier to tune I suppose but at what power cost with 12 pds of boost

this is at 660 rw

If you’re planning on upping the boost, definitely drop the CR to 10:1. If you are always going to run E85 or are staying at that power level, the motor is technically more efficient at 11:1 and you could stay there. Just my 2 cents.

[Kerry]

see other post for inspection tare down pics

[radz28]

I've seen the rod length stated at 6.125 but I thought I read GM state it was like Gen III/IV 6.098. I think LT1/LT4 are the same, regardless, though. If you stay with consistent ring land height, you shouldn't have a problem, I'd imagine.