Chevy 4.3 Vs. Ford 4.9

ignorant1

I´´m planning to buy a 1990 6 cyl ex-cab truck for
everyday use in a city with lots of traffic jams.
Gas mileage is a main concern.

swobig

...maybe the 4.3L gets a little better mileage?? But, the Ford 4.9L was a very good engine - damn near bulletproof. I know of some problems with the 4.3L, but it too is a good engine. If I had a choice I'd pick the 4.9L, but mileage may be a little worse...

arkie6

I owned a truck, S-10 with a 4.3 V6 and here are some of my observations:

1. The 4.3 is a 90 degree V6. The optimum configuration for a V6, with regard to vibration and balancing, is 60 degrees (6 cyl X 60 degrees = 360 degrees or 1 revolution). The reason the 4.3 V6 is 90 degrees is because it is derived from the Chevy 350 90 degree V8. A 90 degree block is optimum for a V8 (8 cyl X 90 degrees = 720 degrees or 2 revolutions). Anyway, what this translates to is the fact that the 4.3 V6 is not very smooth and early 90s models had a rough or uneven idle and a fairly low redline. I believe later (>94 models) and current models have a counter rotating balance shaft to help tame this vibration somewhat. The 1990 model engine does develop good torque down low in the RPM band, about 235 ft-lbs, but only about 160 HP.

2. The Chevy 4.3 V6 inherited the valve guide seal problems of the Chevy 350 V8. It is fairly common to see blue smoke at startup on these engines once they get about 80,000+ miles on them due to oil leaking past the valve guide seals.

cdean

that was absolutely bulletproof. Good mileage, ran the hell out of the engine, never ran rough, never burned a drop of oil.

there are practically as many 4.3's out there as there are 350s. VERY popular engine in the Blazers. Also, a highly popular engine in mid size marine craft. thousands of 15-17 ft ski boats out there with Vortec 4.3.

4.9 is bulletproof, but 4.3 outperforms.

swobig

should dump the 4.3L in favor of the 3.8L. Probably just as many if not more of them around than the 4.3L. More horsepower, better mileage, good torque, but what do I know...

nrd525

I had an 88 S10 Blazer with the mighty 4.3,ran good,had it four years,and sold it to a friend who is approaching 200,000 on it.It was stolen twice,had the oil pan punctured on one of the off road joyrides,and has had no engine problems whatsoever.
I know of a couple of others,one in a Monte Carlo that are close to 300,000.It looks like the motor will outlive the car.

Rocles

swo,
The 3.8 is a nice one. Lopped off 305, right?

superjim2000

Roc the 305 was a small bore 350 and not a very good engine. The 3.8 dates back to the 60's, however you'll notice its called the Series II now because of two major revisions to improve mileage, emmisions and performance.

My brother in law owns his own shop and has seen quite a few 4.3's go over 200,000 miles in full size trucks without ever having the valve covers off. I have a 4.3 S10 and it has been great.

swobig

no relation as I know it. I've seen a lot of warped pistons in 4.3L engines - mid 90's models. Don't know that the 350 had this problem, but lot of buddies of mine had problems with em. Some were ok though, maybe it was the driver? 3.8L just make sense to me instead of the 4.3L - been around a long time and it consistantly gets good reviews...

superjim2000

The 3.8 Buick wins and I'd like to see it in Chevy trucks. More power better mileage, less weight. Buick was able to make two major revisions to this trusty engine, maybe because its used in fwd cars but it is offered in RWD Camaros with a 5 speed if desired. The 4.3 is great, the 3.8, that's even better. )

powerisfun

...are great! The 3.8 may have more horsepower, but the 4.3 has more torque which is needed in a truck. Now if they put the supercharged 3.8 in the truck that would be the perfect combination of torque and horsepower. When it comes to torque, the only replacement for displacement is forced induction (supercharging, turbo charging).

ignorant1

I'm the one that started this stuff, and I just want to tell everybody down there that all your contributions have been great. I already made up my mind and I'll go for the chevy 4.3 rather than the ford 4.9. Thanks you all.

Rocles

Thanks for setting me straight on the 305-3.8 question.

swobig

yeah, the 4.3L has about 20 ft. lbs. on the 3.8L, but a V-6 truck is usually not a towing monster anyway. Anyway, I hear of two new inline 6's from GM, but can't understand it. Why not just drop 2 cylinders off the 5.3L or 4.8L instead of developing a new engine? I would think parts interchangability, reliability would already be there. I just don't understand some of the moves they make...

cdean

the new inline 6 series from GM is interesting. why didn't they lop of cylinders from the v8s? supposedly the new I-6's are supposed to have great torque and great fuel economy. i'll wonder if the engines are more 'driveable' than the v-8 series. especially going into the blazers.

swobig

...anybody have a clue???

Rocles

cdean,

That was a near-miss! You were about to praise a Ford motor! Heavens forbid! (GM's Heaven, that is)

arkie6

A V6 derived from a 4.8 or 5.3L V8 is not a good thing from a balance standpoint - like the 4.3L V6 derived from the 350 V8. A properly designed V8 has a 90 degree angle between the cylinder banks (8 cyl x 90 degrees = 720 degrees or a multiple of 1 revolution, 360 degrees). A properly designed V6, like the 3.8L, has a 60 degree angle between the cylinder banks (6 cyl x 60 degrees = 360 degrees). This is the problem with the 4.3L V6 (90 degree block) that Chevy has tried to compensate for by adding a balance shaft.

cdean

Not uncommon these days. Hell, its been around since '88. Ford and Dodge both had some early balance problems in their v10s. don't know much about their 6's.

superjim2000

The 3.8 and 4.3 have balance shafts, are both 90 degree and both are V8 decendants. The Buick 3.8 is superior, no question. But don't kid yourself its a 90 degree V6.

The 2.8/3.1/3.4 GM family are 60 degree V6's.

The reason for the new engines is ease of manufacture, the inline 4,5 and 6 will come from the same assembly line. All cylinders in a row, no second bank to machine. One head not two.

And since they're all inline its much easier to use DOHC on them, (all versions are to be DOHC)
vs a "V" engine.

superjim2000

Straight means good for the 6. The 4 and 5 will have balance shafts.

meredith

After 30 or more days of inactivity....

this topic is being "frozen." It will be archived or deleted in the next 10 days or so.

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