Who knows what these engine designs are based on ,if they related at all,when they were each introduced ,what their reputations are and is either one any good ? and how they each compare with their Ford equivilants.

 

The 6.0 is the source of a lot of confusion. There are actually three 6.0's- the passenger car version, the LD truck version, and the HD truck version. They all share the architecture of the LS engine family, but have significant technical differences. By the time you get to the HD truck version, you're looking at cast iron block and heads, with a cam profiled for a very broad powerband that reaches from 1800 rpm to redline. The motors were introduced in late '99 (2000 model year), and power a variety of GM truck products. Caveat- it's a gas hog, but a puller, and will easily outperform a 5.4. In the '06 variation, it sports more HP and torque than Chryslers vaunted Hemi.

The 8.1 is a completely different block. Although GM claimed it was a new engine, it really has it's roots in the old Chevy big block. Big power, big torque, big fuel (and sometimes oil) consumption. The Ford V10 outpowers it, and does it in a more fuel-efficient manner. The newer 3-valve version of the V10 seems to have improved both the efficiency and durability of the prior version.

anyone else?

 

A very fair asessement I agree.

 

I read somewhere that the 8.1 has many of the same internals as the old 454, which was a great motor. I guess I'm old fashioned, but I can't get on board with the V-10 motors yet. Still like the big block V-8!

 

Once you have a V-10 you wont go back to a big block.

 

I'm also old fashioned and feel that GM's small blocks are their best engines and the big blocks have never been developed to their fullest. Even though the 6.0 comes in different variations, there will always be more aftermarket enhancements and accessories available for it as compared to the 8.1 (due to the more widespread use and the close relationship it has with other GM engines). I think big blocks (regardless of manufacturer) have more problems (overheating, oil consumption) because of the size of the pistons and the difficulties inherent in metals expanding and contracting at different rates. This is less of a problem on large commercial vehicles because don't have many cold starts as they are almost always in use. I think that is why Ford and MOPAR has gone the V10 direction.

 

Gosh- we agree on something! I need to qualify, though- the Ford 429/460 was one of the best big-blocks ever made, IMO, and Mopars 440 came in close behind it. Chevy's 396/402/427's were fine, but somewhere the train derailed with the 454. Valve Guide seals were a persistent problem, and they didn't rebuild well. The real story comes out in durability- SBC's making 200 or 300K miles aren't even news, but it's rare to see a 454 go past 150K miles.

The move to V10's is driven by EPA requirements- it's easier to control the burn in a smaller combustion chamber. The problem is they're naturally unbalanced, and require a lot of work to get them smoothed out. The V10 is surprisingly efficient in the SD, and seems to be quite trouble-free as well. I'd like to see Ford do some more work on the 5.4- for all the high-tech specs, it's not competitive with a pushrod GM smallblock (or a Hemi), and there doesn't seem to be a good reason why.

 

i agree with most all of the prior posts. except that i think the 8.1 did better than the older style v10's before they upped the hp. my reasoning being that even though the 8.1 is less hp, it is also pushing less weight then it's ford counterpart that has more hp.

a 5.4 won't do as good as GM's 5.3 or 6.0 you want to talk about a slow motor, that is a dog.

 

I'm an apprentice at Bud kouts chevrolet and i work on them all the time and i happen to like the 5.3L better than the 6.0. the 6.0 is noisy the always sound like they have an ehxuast leak and they are having a problem with the exhaust manifold studs working loose and coming out, and the ones that won't come loose break off. It seems to me the 5.3 gets down the roads better than a 6.0 that might be the fact that its in a half ton vs. a 3/4 ton but the 6.0 seems to be more of a low end grunt motor than the 5.3. i don't see that many 8.1s but i did drive on in a avalanche and i was not impressed, You can feel the torque but it has nothing on highway in higher rpms.

 

I'm dating myself but my first "big block" Chevrolet engine exposure was the 348 and it was a pig. When the 396 was introduced, it was up against the 271 HP high performance Ford 289 and the 300 HP 327 Chevrolet as well as the 389 GTO with 3 deuces and the 442 Olds. It didn't compete well and most of them dropped valves early and used oil often. The two hottest cars in my senior year of High School (1966) were a red Mustang 289 with a 4 speed and a red Chevy II SS Nova with a 327 with a 4 speed with the clear edge to the Nova. The SS396 Chevelle and GTO (both with 4 speeds) were not as good (I think because the large engines and lousy suspensions made them dangerous with any kind of curves. They also wouldn't stop.)

 

454's don't rebuild well? They rebuild as well as anything else, if you use quality parts and know what you are doing. A 454 is just a 427 with a .250 longer stroke. They will last, too. A friend of mine has a 1993 454 Suburban with over 300k. on it. No engine repairs (though it did eat a transfer case, of all things). Valve guide seals are far more of a problem on early 1st. Gen. small blocks and 4.3L, not big blocks. As stated above, the 6.0L is an LS-1 based small block, and the 8.1L is the 'Mark 7' version of the big block. Not too much intercanges with the Mark 4 throgh 6, though. Mark 8's have 2 more head bolts than the earlier versions. I still wouldn't call it an all new engine, though. I think the 8.1L's had more power than the 2 valve Triton V-10's, but the 3 valves are another matter. G.M. still offers the 8.1L in heavy trucks up to 42,000# GVW, but the Trition V-10 stops with the 20,000# GVW F-550. I have been told the reason for this is that Ford is concerned with V-10 durability in high GVW applications

 

Good points all the way around.

duramaximizer- that 1100 lb weight differential between a GM and Ford PU is substantial, and probably explains why the 5.4 is hard pressed to get any better fuel mileage than the V10 in the SD. In the 1/2T it fights both the same weight differential, and the fact that it's just outgunned by the 5.3.

teenagegearhead06- we're both fans of the 5.3. It's a really strong engine, both powerful and fuel efficient in 1/2T applications. The 8.1's in the Avalanche (and the Suburban) are "managed" by the engine computer so they don't rip the transmission out of the truck, so they're not operating at full potential (no Allison). The 5.3 is a "winder," though, where the 6.0 is set up for more low end grunt.

Louisville Joe- I think the reason I said it doesn't rebuild well is a crate motor is cheaper than trying to go through an existing engine, so it rarely gets done. I can't comment intelligently on the 8.1's durability since we see so few of them come through- that market shifted to 6.0's and D-Maxes for the most part.

orbork- gosh, you're older than dirt. My senior year was '72, but you're right. The older muscle cars were all engine with very little in suspension, brakes, and tires to back the engines up. The car to beat at our school was a Pontiac Trans Am with a SD455 (there's always one kid, ya know?). Fortunately he got the car after we sold the 442- I probably would've killed myself trying to prove a point.

 

The 8.1 has its roots with the MKIv and as such shares parts with the MKVI. For the average guy - it is beyond his capabilities, but all those guys running 6's or better and 220 and better are running MK-somethings....the parts available for them tend to be extrememly hard core.

 

Isn't the 8.1 a 502 c.i. big block?

The kid to beat at my high school had a 98 z/28 6speed, a few years before that was my brothers 84 camaro w/ 383. Truck wise it was my buddy with his 96 f250 7.3 w/ 6" lift 35's, intake, edge box, and a banks exhaust.

Highschool...those were the days!

 

No, the 8.1L (496 cu. in.)is a stroked 454, the 502 is a bored out 454.