Any differences in LS7 engines

[try2pas]

I am looking for a LS7 engine. Are there virtually ANY differences in LS7 engines from their inception in I believe '06 through '12? I would like to put this engine in my '80 with an auto tranny (4L70E). Any words of wisdom or general advice on this?

 

[catbert]

What a sleeper that would be. What would you do to the transmission to make it work with the monster 427?

 

[try2pas]

4l70e

I would hook it to the 4L70E in there now as it is supposed to be good to about 495 lbs of torque and the LS7 is 465 lbs or so I believe. On that subject, would it "hurt" anything to not have the separate oil reservoir (there is no room in an '80 that I can see) but to go ahead and put a oil pan on it like the LS3 that I have in there now? I think the rear end might be an issue though (Danna 44).

 

[vetmaniac]

One of the reasons GM didn't offer the C6Z with an automatic - they had none available that could handle the 470 ft. lbs. of torque. Be warned.

 

[6 Shooter]

I've always like the supercharged version!

:cool



​

 

[Tuna]

Why not take a look at LSA engines from the CTS V or ZL1 Camaro.

The LSA is wet sump - no remote oil tank - and has more HP than the LS7.
The LSA can be had with the 6-sp auto (which seems to make the LS7's requirement to have a manual not necessary).
The supercharger might require a raised hood.

 

[try2pas]

Wet sumps

Would the LS7 work as well with a wet sump as my LS3 now works with a wet sump? I am not after total horsepower but I want that 427 cubic inch engine. It's just soooo cool.

 

[TooFast]

One of the reasons GM didn't offer the C6Z with an automatic - they had none available that could handle the 470 ft. lbs. of torque. Be warned.

There are posts on another Forum of some of the 2011 and 2012's dynoing out at 500 ft. lbs. or a little above.

 

[NORTY]

I am looking for a LS7 engine. Are there virtually ANY differences in LS7 engines from their inception in I believe '06 through '12? I would like to put this engine in my '80 with an auto tranny (4L70E). Any words of wisdom or general advice on this?

The stock LS7 is rated @ 470lb.ft.
I would suggest using a 4L80 trans as it has a higher capacity.
They can be built for lots of power.
Now, if money were no object, I'd look at the 6L90 from the blown Caddy. That trans IS rated for a lot more torque than what the LS7 makes.

You'll want to give yourself a hundred lbs. of torque buffer for your trans capacity. You know, just in case you decide you like headers or a tune or other performance enhancements...


EDIT~ Thee are a coupla differences regarding parts suppliers for the LS7.
1. During the MY 2007, there were 1500 chinese made rockers than made it into the inventory stream. This is responsible for the offset rocker bearing cage failures. (Approx. Oct 2006 to Apr/May 2007.)

2. Valve guides of "dubious" quality have made it into the supply stream as well.

Getting back to the LS7 itself, are you sure you want this engine in your car, knowing about the valve guide/geometry/heat issues?

 

[1analguy]

...On that subject, would it "hurt" anything to not have the separate oil reservoir (there is no room in an '80 that I can see) but to go ahead and put a oil pan on it like the LS3 that I have in there now? I think the rear end might be an issue though (Danna 44).

An LS7, in your application and for your type of use, would work just fine with a wet sump pan...as long as the correct oil pickup setup is available.

Are you sure that you have a Dana 44 and not a Dana 30? My understanding has been that the automatic-equipped cars had the much more marginal Dana 30 in them...or was that just later with the C4s? As far as the Dana 44, it has been in use by the off-roaders for decades and they pound hell out of them with little trouble. Additionally, IIRC, C4 stick applications (including my GS) all had aluminum-cased 44s in them...and tons of them were drag raced without too many problems. Manual-equipped dragging has to be much harder on the pumpkin than any kind of street use with an automatic, so you'd probably be good to go there as well if you do, in fact, have a 44...

 

[Hib Halverson]

An LS7, in your application and for your type of use, would work just fine with a wet sump pan...as long as the correct oil pickup setup is available.

Are you sure that you have a Dana 44 and not a Dana 30? My understanding has been that the automatic-equipped cars had the much more marginal Dana 30 in them...or was that just later with the C4s? As far as the Dana 44, it has been in use by the off-roaders for decades and they pound hell out of them with little trouble. Additionally, IIRC, C4 stick applications (including my GS) all had aluminum-cased 44s in them...and tons of them were drag raced without too many problems. Manual-equipped dragging has to be much harder on the pumpkin than any kind of street use with an automatic, so you'd probably be good to go there as well if you do, in fact, have a 44...

All C3s with the aluminum rear axle used an early version of the Dana 44.

C4 was the platform that used two different Dana axles. All 84s and 85-96 automatics used the Dana 36 and 85-96 manuals used the Dana 44.

 

[1analguy]

Dana 36, not Dana 30. Gotcha. I was really digging back through the old cobwebs on that one...

 

[Hib Halverson]

I hate cobwebs and a really hate "old cobwebs".ad

 

[1analguy]

There may be another issue to consider here. Doesn't an LS7 have an eight-bolt crank flange, or is that just the LS9? If it does, is there a flex plate that will fit it? Maybe the aftermarket has already thought of the need for such a thing...

 

[try2pas]

Where to purchase a new or used LS7?

Where should I go to purchase a new or used LS7 and get a good deal? Used preferably but would consider new. Anything to look out for?

 

[Hib Halverson]

There may be another issue to consider here. Doesn't an LS7 have an eight-bolt crank flange, or is that just the LS9? If it does, is there a flex plate that will fit it? Maybe the aftermarket has already thought of the need for such a thing...

LS7 cranks have a six-bolt flange.

Also, cranks, the only major difference amongst LS7s are the crankshafts. Both are forged steel and both have the same strength, but the earlier engines used a 4140 crank but later engines use a forged steel which meets 44MNSIVS6. The reason for the change was the manufacturing process used to make the newer cranks is less complex.

 

[1analguy]

...Also, cranks, the only major difference amongst LS7s are the crankshafts. Both are forged steel but the earlier engines used a 4140 crank but later engines use a forged steel which meets 44MNSIVS6. The reason for the change was the manufacturing process used to make the newer cranks is less complex.

That sounds as though it may have been a cost-cutting move...

 

[Hib Halverson]

That sounds as though it may have been a cost-cutting move...

Precisely!

 

[toppthat]

Would the LS7 work as well with a wet sump as my LS3 now works with a wet sump? I am not after total horsepower but I want that 427 cubic inch engine. It's just soooo cool.

Look up Mast Motorsports.com. Click on sidebar topic-mast 669 hp ls7 outperforms gms ls9 and saves thousands and click on read about it here. It shows an article about a wet sump ls7.