LM7 cam choice 4wheeler article

[Winchested]

Factory LS Camshaft Comparison

LM7 vs. LS1 vs LS2 vs. LQ9 vs. L33 vs. LS7 vs. LS9 vs. LSA dyno test on 5.3L V-8 engine.

www.motortrend.com

So just read this article from last year.

It gives great specs on the various cams

But it basically doesn't spell out any real world experience for type of vehicle. Or purpose.

Throwing an LM7 into a rock Crawler. (not a race ultra 4 car)

In my opinion after reading this article of all the stock cams tested the best real world high torque at low rpm cam is the stocker.

When you're going to spend the majority of your wheeling time between 1000 and 2500 rpm is there really a need for these high horsepower cams that require a valve train upgrade?

 

[TrikeKid]

When you're going to spend the majority of your wheeling time between 1000 and 2500 rpm is there really a need for these high horsepower cams that require a valve train upgrade?

It's fairly universal that the higher torque/rpm you get with a performance cam is moved up the RPM range away from where you use it most while crawling. In a case where the stock setup isn't really optimized from the get go there may be something to gain but those instances aren't very common and I don't think the LS engines are in that category.

 

[Bebop]

Factory LS Camshaft Comparison

LM7 vs. LS1 vs LS2 vs. LQ9 vs. L33 vs. LS7 vs. LS9 vs. LSA dyno test on 5.3L V-8 engine.

www.motortrend.com

So just read this article from last year.

It gives great specs on the various cams

But it basically doesn't spell out any real world experience for type of vehicle. Or purpose.

Throwing an LM7 into a rock Crawler. (not a race ultra 4 car)

In my opinion after reading this article of all the stock cams tested the best real world high torque at low rpm cam is the stocker.

When you're going to spend the majority of your wheeling time between 1000 and 2500 rpm is there really a need for these high horsepower cams that require a valve train upgrade?

There is a stock LM7 in my buggy. Mid range and tip in is excellent. You couldn't pay me to swap a cam in it.

 

[arse_sidewards]

If you're coming from some 4cyl powered pile of garbage just swap the high powa race cam in. It'll still have better off-idle torque than you're used to.

 

[mjlogan88]

There are many truck cams out there that will help up top and not really give anything up off idle. The stock cam in an LM7 is just pitiful

I put this cam in a bone stock LM7 powered truck that ate a lifter and wiped out the stock cam. Did not notice any difference at all idle-2500 but after 3000 it pulled quite a bit harder even with no tuning. Plenty of no springs required cams to chose from as well.

Summit Racing SUM-8727R1 Summit Racing™ Pro LS Vortec Truck Swap Camshafts | Summit Racing

Free Shipping - Summit Racing™ Pro LS Vortec Truck Swap Camshafts with qualifying orders of $109. Shop Camshafts at Summit Racing.

www.summitracing.com

 

[pvkj454]

I had a junkyard LQ4 in my buggy with a mail order tune until I hydro locked it and bent a rod. I installed a Texas Speed stage 1 cam in the new engine. It required a dyno tune, a stall converter, and increased transmission cooling. It wasn't worth the trouble since I rarely use the extra power.

 

[Winchested]

If you're coming from some 4cyl powered pile of garbage just swap the high powa race cam in. It'll still have better off-idle torque than you're used to.

Coming from a worn out IH 345 that still had tons of bottom end torque.

 

[Bebop]

I feel like the throttle response is pretty good. Again, stock 5.3

 

[Winchested]

There are many truck cams out there that will help up top and not really give anything up off idle. The stock cam in an LM7 is just pitiful

I put this cam in a bone stock LM7 powered truck that ate a lifter and wiped out the stock cam. Did not notice any difference at all idle-2500 but after 3000 it pulled quite a bit harder even with no tuning. Plenty of no springs required cams to chose from as well.

Summit Racing SUM-8727R1 Summit Racing™ Pro LS Vortec Truck Swap Camshafts | Summit Racing

Free Shipping - Summit Racing™ Pro LS Vortec Truck Swap Camshafts with qualifying orders of $109. Shop Camshafts at Summit Racing.

www.summitracing.com

Details suggest it needs a valve train upgrade * LS6 springs are required and tuning recommended.

 

[Winchested]

I feel like the throttle response is pretty good. Again, stock 5.3

That's encouraging! What gears are in that?

 

[Bebop]

That's encouraging! What gears are in that?

3.0 TCase and 5.13 in the axles
43" SXs

 

[mjlogan88]

Details suggest it needs a valve train upgrade * LS6 springs are required and tuning recommended.

I put springs in it, had the heads off already so it wasn't much work. Im sure tuning would have helped but it wasn't necessary. There are plenty of other good cam options that don't require spring upgrades too.

In my opinion if you have an LS engine sitting on a stand there is no reason leave the stock cam in there. There is so much potential in the cylinder heads muted by a mild stock cam.

As far as V8's are concerned, if all you care about is low end torque a 5.3 is not a great place to start anyway.

 

[Winchested]

I put springs in it, had the heads off already so it wasn't much work. Im sure tuning would have helped but it wasn't necessary. There are plenty of other good cam options that don't require spring upgrades too.

In my opinion if you have an LS engine sitting on a stand there is no reason leave the stock cam in there. There is so much potential in the cylinder heads muted by a mild stock cam.

As far as V8's are concerned, if all you care about is low end torque a 5.3 is not a great place to start anyway.

It was cheap price was right and didn't have to pay the 6.0 tax and it's better on fuel as I plan on driving it on the road lots. I was more than satisfied with the IH engine it just wasn't worth rebuilding.

 

[mjlogan88]

It was cheap price was right and didn't have to pay the 6.0 tax and it's better on fuel as I plan on driving it on the road lots. I was more than satisfied with the IH engine it just wasn't worth rebuilding.

Having owned 2 IH trucks with 345's and a few GM trucks with 5.3's just be prepared for a polar opposite powerband. I don't think you'll be disappointed though

 

[Winchested]

Having owned 2 IH trucks with 345's and a few GM trucks with 5.3's just be prepared for a polar opposite powerband. I don't think you'll be disappointed though

Interesting. Never driven a GM engine lol. Always Fords. 5.4s or 6.2s or 3.5 Ecobust.

 

[JohnnyJ]

The LM7 cam is 191/190 with 0.457/0.460 lift, and 114* LSA. The LQ4 cam is 196/207, 0.467/0.479, 116*. The Summit cam is 200/205, 0.550/0.550, 113*. So that summit cam isn't much more than a higher lift LQ4 cam.

I was surprised the LQ4 cam has such a split duration.

There's a part of me that think the Truck Norris is cool at 212/22X, .552"/.552", 107 LSA. But reality is, that's it's likely not worth it in a crawler.

 

[Bebop]

According to the webz

Trucks and SUV with Vortec engine
LR4 and LM7
99 12560966 191/190 .457/.466 115.5
00-04 12560967 191/190 .457/.466 114

LQ4
99-00 12560967 191/190 .457/.466 114
01-04 12561721 196/207 .467/.479 116
01-04 LQ4 cam is same as Camaro, Corvette LS1 and LQ9 cam

LQ9
02-03 12561721 196/207 .467/.470 116

 

[mjlogan88]

That summit cam was just a data point I threw out there from personal experience. Bone stock truck that had to pass emissions, hence the conservative duration

Regardless, from the engines you are used to a 5.3 is going to feel pretty soft until you hit 3000 rpm where they really start to shine.

 

[RustyC]

I used a Summit Racing SUM-8719 w/ springs. I habitually can't leave things alone.
Stock bore and compression LM4, I cleaned up the ports in the heads, polished chambers, short block hugging headers, truck intake manifold.
Used HPTuners to touch up the factory tune.
Engine is backed by a TH350/low stall, 2.72 Tcase, 5.13s, 42s.
I'm happy with it as a trail rig. Crawls well and wakes ups quickly from (crawling 2000 rpm) and (I NEED ALL THE WHEEL SPEED NOW!!)

Needed? Maybe Not. But I am happy with the results.