Ok thanks good to know. Out of curiosity how can you tell is it the 7373? Why don’t they just stamp the full part number?
Life is like a box of chocolates....L9h engine
- Thread starter ckeister
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
It looks good to me. Lifters look good only one has a slight suspicious wear mark on the very outside of the roller. I’ll see what the machine shop says. As far as I know the only way to know for sure is to assemble and put a degree wheel on it?
So I have it completely torn down to bare block. Three or four pistons have scoring you can catch with a fingernail with number one being the worst. The one/two rod journals have a small line you can catch and same with number one main. Visible cross hatches in all cylinders but number one is a little cloudy at the top 1/4 or so of the bore.
Cleaned the deck and checked it with a machinist block and feeler gauge it’s flat. So I think a mild hone and light crank polish is all it needs.
My finale opinion is this thing got run low on oil at some point and it got new rods and mains put in it. I probably could have just run it and it would have been fine for 50K but now that’s it’s torn down……found a set of engine tech pistons for $250, rings, bearings, and back together it goes is where I’m at right now. Going to the machine shop next week.
Cleaned the deck and checked it with a machinist block and feeler gauge it’s flat. So I think a mild hone and light crank polish is all it needs.
My finale opinion is this thing got run low on oil at some point and it got new rods and mains put in it. I probably could have just run it and it would have been fine for 50K but now that’s it’s torn down……found a set of engine tech pistons for $250, rings, bearings, and back together it goes is where I’m at right now. Going to the machine shop next week.
01FormulaTA
Full Access Member
- Joined
- Mar 23, 2017
- Posts
- 536
- Reaction score
- 567
Yes, the 7373 and google. It definitely would make more sense to just stamp the full number but then again we're talking about GM here lol....
My 2 Cents....Machine shops are expensive...pistons look fine to me, rod bearings looked good...I would clean everything up real nice, hit the cylinders with a ball hone, put it all back together and send it....only things I would replace would be new head gaskets, new head bolts and new lifters and trays....Good Luck!
Head Gaskets Part Number X2 - 12610046
Head Bolts X2 - 17800568
LS7 Lifters - 12499225
Lifter Trays X4 - 12595365
I would do that if I was doing the install. But I’m paying a shop to do it.
It’s going to the machine shop because I have never installed cam bearings let alone in an aluminum block. I have heard these can be difficult so not gonna make this my first attempt. I may home the block cuz I’ve done that but the crank and cam bearing I want the shop to do.
I’m not ok with a couple of the piston skirts so for $250 I’ll just get them and I’m a parts hoarder so I’ll just keep the others as spares.
I’m already buried in this rig financially so I’m gonna make sure everything is right and we are gonna keep it til the wheels fall off……lol
Thanks and keep an eye out. This will be the first engine build I’ve done in about 20 years so I’m gonna start another thread so hopefully you guys can help me out through the build.
Thanks
petethepug
Michael
The motor looks like it was rebuilt by an engine rebuild business like Jasper you’d source through AutoZone or similar. They make their own L9H long blocks mixing and matching parts from other motors within their own specs.
Finding an extremely low volume L9H at that price is uncommon. Getting into it for prudence pays forward. Shifting the rebuild responsibility to a shop when you’re running in overdrive is a smart move.
You made all the right moves and did diligence. It’s just that times are more tricky and the secret of the L9H is out. You still won this arm wrestle by playing the long game and expecting the unexpected.
Try and find a solution to relocate the oil pressure sensor to somewhere more accessible and slap those arp exh mani bolts in. You’re still reaching your goal, the stakes were stacked higher due to the L9H’s scarcity.
Finding an extremely low volume L9H at that price is uncommon. Getting into it for prudence pays forward. Shifting the rebuild responsibility to a shop when you’re running in overdrive is a smart move.
You made all the right moves and did diligence. It’s just that times are more tricky and the secret of the L9H is out. You still won this arm wrestle by playing the long game and expecting the unexpected.
Try and find a solution to relocate the oil pressure sensor to somewhere more accessible and slap those arp exh mani bolts in. You’re still reaching your goal, the stakes were stacked higher due to the L9H’s scarcity.
The block has the Vin stamped in it so its the original block......
Went to the machine shop Friday. Never used them before but my machinist retired and only does head porting for racing guys now. Young guy spent about 45 minutes listening to the history of the motor from CARFAX what I intended to do with it and budget concerns.
He did say the dots and paint lines on the rod caps could be factory but the orange numbers painted on the rods definately were not. Seemed pretty knowlegeable about the LS platform.
So we left with he is going to clean and hone block, install Durabond cam bearings, and polish the crank. He said the skirt scoring was no bueno so he's going to check the pistons to see if we want to just relpace 2-3 or get a full set. He's also going to inspect the rods and make sure they are ok and not too much weight variounce between them but im not really worried about the rods.
My final theory on this motor......I immediately noticed the this one did not have a low oil indicator switch in the pan like mine does. At 46K the dealership noted in CARFAX that the "oil pan repaired/resealed" then a "no crank/no start" and the vehicle was traded in. So I think it got ran low on oil the dealer told the owner it's going to cost 15K to fix it "but well give X amount in trade and get you into a brand new one." Then slapped new bearings in it and put it back out on the lot. Still cant explain the numbers on the rods so maybe they actually seized it up. But that's my theory and im sticking with it.
Machine shop says it will be a week or two. In the mean time i'm gonna lap the valves and put in new seals. Then the rebuild begins.
FYI, they did away with the oil level sensor in the oil pan at some point. My 03 has it, the 2014 does not.
It's actually pretty common for the L92, L9H and L94 to consume no oil between oil changes, even approaching 200,000 miles. With hone marks clearly visible in the cylinders. I'd be more inclined to think they had a catastrophic loss of coolant and didn't shut it off till it was too late. That can happen very quickly if that tee connector breaks at the firewall. By the time the gauge says it's overheated it's way too late.
OEM GM oil pan gaskets have known issues with leaking oil, not surprising they had to replace it. It's the one gasket on the engine you definitely want to go with the Felpro. (I use Felpro exclusively on all my builds, including their head gasket. ARP head bolts as well. Not the studs.)
It's actually pretty common for the L92, L9H and L94 to consume no oil between oil changes, even approaching 200,000 miles. With hone marks clearly visible in the cylinders. I'd be more inclined to think they had a catastrophic loss of coolant and didn't shut it off till it was too late. That can happen very quickly if that tee connector breaks at the firewall. By the time the gauge says it's overheated it's way too late.
OEM GM oil pan gaskets have known issues with leaking oil, not surprising they had to replace it. It's the one gasket on the engine you definitely want to go with the Felpro. (I use Felpro exclusively on all my builds, including their head gasket. ARP head bolts as well. Not the studs.)
Similar threads
