[95 imp]

Any difference(s) between the L87 truck short block and the LT1 short block?

(I'd think the cam is different at minimum)

What about the heads?

[Jeb114]

There are no spec's for the heads yet. But its an iron block motor not aluminium with lower compression designed for towing applications. Its rated and 401hp and 464tq.

[Rayvan]

I think you mean L86. Same block as LT engines, but with lower compression and 420HP

[95 imp]

Originally Posted by Rayvan

I think you mean L86. Same block as LT engines, but with lower compression and 420HP

Same forged crank too?

[Bobkd]

I believe the lt1 and l86 share everything except intake manifold, exhaust manifold and tune. All internals are the same.

[Hyperion]

Originally Posted by Bobkd

I believe the lt1 and l86 share everything except intake manifold, exhaust manifold and tune. All internals are the same.

Parts sharing FTW!


L86 specs
https://help.summitracing.com/app/an...6-engine-specs

LT1 specs
https://help.summitracing.com/app/an...1-engine-specs

[95 imp]

Originally Posted by Hyperion

Parts sharing FTW!


L86 specs
https://help.summitracing.com/app/an...6-engine-specs

LT1 specs
https://help.summitracing.com/app/an...1-engine-specs

According to Summit, they are the EXACT same motors. Heads, cam, and pistons are all the same specs and PN's. I wonder if GM is giving the truck the full on LT1 motor with the same hp as the Camaro to streamline manufacturing and just lowering the advertised hp or the Summit page has errors.

The plot thickens....

[iPODFAN11]

Originally Posted by Jeb114

There are no spec's for the heads yet. But its an iron block motor not aluminium with lower compression designed for towing applications. Its rated and 401hp and 464tq.

Nope. That would be the L8T in the 2020 HD trucks. L8T is a 6.6 liter iron block/aluminum head. 401hp 464 torque.

Originally Posted by Rayvan

I think you mean L86. Same block as LT engines, but with lower compression and 420HP

Yes and no at the same time. See below.

Originally Posted by 95 imp

Any difference(s) between the L87 truck short block and the LT1 short block?

(I'd think the cam is different at minimum)

What about the heads?

L87 is the 2019 new body updated Silverado 6.2. I "think" the blocks are the same, but I can't verify (no p/n for the L87 block). The AFM oil feed bosses are still there, but the AFM system is different.

The 6.2 L87 uses DFM (Dynamic Fuel Management) so all 8 cylinders can be "active" in terms of shutting down. 17 different patterns are possible with this, running on as low as 1 cylinder. DFM doesn't use a VLOM in the valley of the engine anymore like LT1 still uses. L87 has a flat traditional valley cover. There are now 8 individual oil control solenoids, one per cylinder to control DFM operation.

Cylinder heads are the same part # LT1 to L87. L87 now uses an LS style water pump/water pump housing. LT1 has the L86 style water pump housing still.

L87 and LT1 use different cams. Both are 11.5:1 compression ratio, 93 octane recommended/required, can run on 91 with reduced performance.