LS7 rebuilt - looking for information
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LS7 rebuilt - looking for information
I am looking for feedback from anyone having experience with rebuilding the LS7 in their Z06. There are many options out there it seems like.
I see a lot of rebuilds with forged internals, typically, along with a few other upgrades. Because I'm living in California, everything needs to pass the SMOG meaning visual inspection, ECU & emissions. I don't have enough knowledge to fully grasp the impact of forged internals on all other aspects of the engine, but I assume that it increases the power output of the engine even by keeping the same displacement, and it would have some consequences on the emissions & else, right?
If someone was looking at refreshing/rebuilding a stock LS7 to fit the original specs and address the two known issues (valve train & rod coating/bearing), what would we be looking at in terms of costs & feasibility? And SMOG compliance?
I see a lot of rebuilds with forged internals, typically, along with a few other upgrades. Because I'm living in California, everything needs to pass the SMOG meaning visual inspection, ECU & emissions. I don't have enough knowledge to fully grasp the impact of forged internals on all other aspects of the engine, but I assume that it increases the power output of the engine even by keeping the same displacement, and it would have some consequences on the emissions & else, right?
If someone was looking at refreshing/rebuilding a stock LS7 to fit the original specs and address the two known issues (valve train & rod coating/bearing), what would we be looking at in terms of costs & feasibility? And SMOG compliance?
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Joined: Dec 2005
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From: God's Country, ID
I am looking for feedback from anyone having experience with rebuilding the LS7 in their Z06. There are many options out there it seems like.
I see a lot of rebuilds with forged internals, typically, along with a few other upgrades. Because I'm living in California, everything needs to pass the SMOG meaning visual inspection, ECU & emissions. I don't have enough knowledge to fully grasp the impact of forged internals on all other aspects of the engine, but I assume that it increases the power output of the engine even by keeping the same displacement, and it would have some consequences on the emissions & else, right?
If someone was looking at refreshing/rebuilding a stock LS7 to fit the original specs and address the two known issues (valve train & rod coating/bearing), what would we be looking at in terms of costs & feasibility? And SMOG compliance?
I see a lot of rebuilds with forged internals, typically, along with a few other upgrades. Because I'm living in California, everything needs to pass the SMOG meaning visual inspection, ECU & emissions. I don't have enough knowledge to fully grasp the impact of forged internals on all other aspects of the engine, but I assume that it increases the power output of the engine even by keeping the same displacement, and it would have some consequences on the emissions & else, right?
If someone was looking at refreshing/rebuilding a stock LS7 to fit the original specs and address the two known issues (valve train & rod coating/bearing), what would we be looking at in terms of costs & feasibility? And SMOG compliance?
There are several ways to legally avoid smog in CA.. ..do the research or better yet GTFO.
Last edited by DSOMC6; Sep 11, 2021 at 09:39 PM.
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Yeah, laws change though and I don’t want to deal with that. The workarounds work until they don’t haha. 500ish HP is plenty already anyways, I don’t need more power - I want reliability.
Cost seems expensive indeed, and the part situation definitely isn’t making it any easier.
I guess once the engine is out, there’s no reason to halfass it anyways and probably best to go with the strongest options… depending obviously on the budget.
I mean this engine has been out there for 15 years, don’t we know by now how to fix properly the bottom end issues without having to rebuild the engine completely?
Cost seems expensive indeed, and the part situation definitely isn’t making it any easier.
I guess once the engine is out, there’s no reason to halfass it anyways and probably best to go with the strongest options… depending obviously on the budget.
I mean this engine has been out there for 15 years, don’t we know by now how to fix properly the bottom end issues without having to rebuild the engine completely?
Melting Slicks
Joined: Apr 2019
Posts: 2,515
Likes: 1,167
From: Northern Wisconsin
Yeah, laws change though and I don’t want to deal with that. The workarounds work until they don’t haha. 500ish HP is plenty already anyways, I don’t need more power - I want reliability.
Cost seems expensive indeed, and the part situation definitely isn’t making it any easier.
I guess once the engine is out, there’s no reason to halfass it anyways and probably best to go with the strongest options… depending obviously on the budget.
I mean this engine has been out there for 15 years, don’t we know by now how to fix properly the bottom end issues without having to rebuild the engine completely?
Cost seems expensive indeed, and the part situation definitely isn’t making it any easier.
I guess once the engine is out, there’s no reason to halfass it anyways and probably best to go with the strongest options… depending obviously on the budget.
I mean this engine has been out there for 15 years, don’t we know by now how to fix properly the bottom end issues without having to rebuild the engine completely?
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If you are going to stay around 500 hp, the bottom end is plenty strong. The only issue is the possibility of having a connecting rod failure due to titanium construction of the stock connecting rods. This seems to be quite rare. I may be wrong, but I get the feeling that those with connecting rod failures are those who run their cars hard. If you limit your use to occasional spirited driving on the street, I think you will be fine with your bottom end the way it is. If you decide that you want to eliminate the titanium rod issue, then you have to get a balanced rotating assembly (forged steel crankshaft, forged steel connecting rods, and forged aluminum pistons). Rotating assemblies are readily available, as are short blocks that are equipped with forged steel rotating assemblies. Nothing wrong with going that way, but it's kind of a shame when the stock crankshaft is a good forged steel piece, and the stock pistons are fine too. The only (possible) shortcoming is the connecting rods. I just finished installing AHP heads at 75,000 miles, and I intend to leave my bottom end alone for as long as I own it.
Melting Slicks
Joined: Apr 2019
Posts: 2,515
Likes: 1,167
From: Northern Wisconsin
I believe the connecting rods can be re-coated, but it has to be done right. I am not an authority on that. There is lots of information on that topic if you search. If I were faced with a situation where the rods needed to be re-coated, that is where I would give up on the titanium rods and change to a forged steel rotating assembly.
Yes, the connecting rod bearings can be replaced, just like on all engines.
Yes, the connecting rod bearings can be replaced, just like on all engines.
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I just paid $13k for a forged stroker utilizing the original LS2 heads (ported/polished/upgraded valves etc) and original block, BTR stage 1 TT cam, assembled etc. The roatating assembly alone was $4500. Pricing and lack of parts availability is just insane right now. I cannot imagine an LS7 would be any cheaper.
There are several ways to legally avoid smog in CA.. ..do the research or better yet GTFO.
There are several ways to legally avoid smog in CA.. ..do the research or better yet GTFO.
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Thanks, guys, this all makes more sense to me now.
It kind of makes me want to just drive and enjoy my car until something happens, top or bottom, and then just buy a new engine with forged internals if/when something happens. Doing the heads won't save the rods, the rod coating's shavings will damage the heads, and doing the rods involves pulling the whole engine. It's not like there's a perfect "preventive" situation in all of that.
The joy of these engines, man. I thought I had enough with my e46 M3 eating rod bearings (although this was a much easier and permanent fix), seems like I'm back for some more fun with this LS7 lol
It kind of makes me want to just drive and enjoy my car until something happens, top or bottom, and then just buy a new engine with forged internals if/when something happens. Doing the heads won't save the rods, the rod coating's shavings will damage the heads, and doing the rods involves pulling the whole engine. It's not like there's a perfect "preventive" situation in all of that.
The joy of these engines, man. I thought I had enough with my e46 M3 eating rod bearings (although this was a much easier and permanent fix), seems like I'm back for some more fun with this LS7 lol