Re: GM Dealer Challenges the Toyota Tundra's Ads... AS BULL

4 valve design has been arround for too long not to use. That is > unless you

> don't think the consumer deserves it. > Also, is the 4.2 L ford engine a 90 degree V6, Is that an indication > of a > lower red line ? > > The 4.6 for the Ford truck is the same pushrod 2-valve.

No it is not. The 4.6L V-8 in the trucks is a 2 valve SOHC design.

The mustang engines are still pushrod design.

No, the 4.0L V-6 in a Mustang is an SOHC design, The 4.6L is the three valve SOHC design.

Is there a Ford V8 with 4 valve design ? How about variable valve > timing ?

Currently none of the Ford V-8s have 4 valves. In the recent past certain models got the DOHC 3.9L, 4.6L, and 5.4L V-8s, but Ford is getting essentially the same horsepower from the 3 valve SOHC design, so they aren't offering a 4 valve V-8 at the moment. Ford does offer several 4 valve DOHC I-4s and V-6s. All the 3 valve engines have variable valve timing, as do the DOHC engines.

> > There is no place in my garage for pushrod based engines. >> >> There is in mine if a Corvette is wrapped around it. I think it >> foolish to >> say you won't consider a pushrod engine. Most current Ford engines >> are >> overhead cam. The only exceptions are the 4.2L and the 3.0L V-6 >> truck >> engines. I think GM has done great things with push rod engines. It >> is > hard >> to beat the Corvette engine in terms of horsepower per lb and >> horsepoer > per >> cubic inch of space occupied under the hood. > > OH ? > Corvette V8 6.0 L 16 valve OHV 400hp-6000rpm 400ft-lbs-4400rpm > Tundra V8 5.7 L 32 valve DOHC 381hp-5600rpm 401ft-lbs-3600rpm > Lexus V8 4.6 L 32 valve DOHC 380hp-6400rpm 367ft-lbs-4100rpm

Look under the hood of a Tundra, and then look under the hood of a Corvette. Which engine takes up more space (the Tundra). Which engine weighs more (the Tundra).

Similar numbers out of less displacement. This would suggest the > Corvette > would benefit greatly from an updated valvetrain design. > > According to the mustang engine specs .. all 3 engines have > hydraulic > lifters hence not DOHC. > So add the 5.4 L to the list of the pushrod engines.

No true. You don't have to have push rods to have hydraulic lash adjusters.

> > I also know the differences in a 4 piston caliper on the front >> > brake >> > rotors. >> >> And what does this mean? Do you think that four piston calipers >> work >> significantly better than 2 piston sliding caliper brakes? I've had >> cars >> with four piston brakes and not seen any advantage. Despite >> Toyota's hype, >> their truck doesn't stop any better than the competitor's trucks. >> So what > is >> the advantage? > > That's easy with pistons on both side of the rotor, more even, and > responsive pressure can be applied on more braking surface area > without > having to float the caliper.

Spoken like a techno geek who thinks if race car has something it is the best thing for a street car. The "pressure" applied is no different if everything is working properly. With sliding calipers the biggest problem is sticky sliders. With modern sliding calipers that are properly maintained this isn't much of a problem. 4 piston caliper don't suffer from sticky sliders (there are none), but they do suffer from sticky pistons (been there) and you have twice as many seals to leak. As far as I am concerned there is only one advantage to 4 piston calipers - you can plumb the pistons in pairs to achieve true dual circuit braking. I am not sure it Toyota is doing this - do you know? I doubt it since they would have to have twice as many brake lines running to the front of the truck.

It also contributes to capacity for greater braking surface area.

No, this wrong.

I'd say there is NO hype in prefering 4 piston over 2.

The Tundra doesn't stop any better than competitive vehicles. If there is no performance advantage, then it is hype.

> > Is the 4.2 liter v6 used on the new F150 the same as this 4.2 ? >> > >> >
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> >> Same basic engine. But if you notice, all the "problem vehicles" >> were 97 > and >> 98 models. If you think Ford is unique in having head gasket >> problems do >> some research on Toyota v6 head gasket failure - >> >>
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> >> Ed > > Yep I'm well aware all manufacturers have had issues with gasket > recalls. > What about cruise control systems that burn your car and house down > ?

Or sludged up engines that burn up your car? You should look at the history of the cruise control deactivation switch recall. Initially there were a very few vehicles from a clearly designed production range that appeared to have a problem. Ford announced a recall for those specific vehicles. Suddenly every sort of Ford truck built in the last 15 years was accused of catching on fire. Fords were accused of burring up that didn't even have the same style circuit. Sort of like the Toyota sludge case don't you think?

Ed

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C. E. White
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