This engine i would think should have some relative power being a decent sized v6.

I am wondering what did Chevy do to make this motor so under powered?

Iv seen some stock v6 motors burn the rubber off before.

Looking forward to all the replies!

 

It's no secret. The engine was designed 25 years ago to be a truck engine in a heavy vehicle to produce torque at low rpm for towing and pulling and yet try to get decent mileage for the times. No use trying to compare it to a modern designed V6 meant to be put in a lightweight car. Can you think of another truck V6 designed that far back that did it's job better?

 

I didnt know it was that old.

I was really looking to find out what internally makes it so weak.

I figured it was a 2004 so it would live up to the standards of 2004 but i guess i was wrong hehe.

I forget the year model but there is a camaro v8 that is supposed to bolt right up to our mounts.

I was thinking about looking into that swap.

 

I often wondered the same thing but these 4.3 do go back quite far and then the design worked and stayed for the newer models. I am sure if you built it with the right crank and cam selection that it could be a quick motor. Where would someone look to buy one of these new?

 

To answer the question....it's a 350 with two cylinders hacked off. So I'd assume it'd be the 350 that would work with the mounts (could be wrong). But it does do it's job well for the age in which it was created.

 

i think the 4.3 is great, had a 87 astro with the 175hp throttle body injection & 3.73 gears, the '97 S-blazer of the wife's is the spider fuel injection, 200 hp with 3.42 gears. both pull trailrs great, get reanable milge for such a heavy vehicle (the '97 will get 23 hwy!) no its not a stoplight drag race winner, but it aint supposed to be. im mostly a ford fan and admit id rather have the 4.3 over fords 4.0 any day. i think the 4.3 was originally designed for the astro chassis, found its way into S-trucks/S-blazers and became the base motor for the 1/2 ton pickup. sometimes the performance is all about final drive ratio. the astro with 3.73's would squeak the tires on the 1-2 shift just driving normally. the blazer with 3.42's wont, but at 5,000 pounds it would take quite alot to do that anyhow. i think the best the astro did on fuel was 21 highway, we havent had that vehicle in over 10 years. problly any sbc V8 would interchange, most common being the 305 or 350. i wouldnt bother with a 305 though, you would lose more than youd gain with the extra weight.

 

the weak points to the earlier engines were the Heads. They were great for low end torque but after 4500ish they couldnt flow for ****. Plus the 4.3 has a very small grind camshaft. If you have the vortec heads,and you wanna throw some money into it give it a good porting,nice cam and some 3.73 gears in the difs and it'll scooot!


You can learn about the cam,heads etc here :
TBI CHIPS TRUCK MODS

 

Drive any small truck/SUV from the same era with a V6. The 4.3 puts them to shame.

And, yes, I have driven more than a few of them over the years.

 

Thanks chris, this is what i was looking for. ideas on how to make it better

i wanna fix the short comings haha.

still interested in others thoughts!

 

I see no indications on this site, that the 4.3L engine is 'weak'. We have ONE guy - recently - whose block grenaded; most likely due to blown head gasket.

Once you get south of the lower intake manifold gaskets it's a great engine. If you want more beef in the block go to the marine long block like CaptainK did:
https://blazerforum.com/forum/engine...r-61963/page2/
Could start by putting real Fuel injection on it. And it isnt that hard.
4.3L Vortec Marine Intake Conversion Helpfull Hints:
Once you do that.. sky's the limit. Check out his results just bolting a turbo to the stock long block.

If I had the money to do the marine intake, I would ..just for drill

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As to going to the 350, it depends on what you want out of the effort. If you think it would be more reliable for a daily driver, for example, think again. The reliability would come from the upper bolt-ons.

But you'd lose fuel economy, all else equal. In other words what ever you would do to a SB v8 to increase MPG would work just as well for the 4.3 and the MPG would be higher.

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I love the 'conventional wisdom' that goes around about various engines. I've actually heard and read guys who DO wrench on their stuff say the Ford 3.8L is a crap engine. Ask them why.. they just look confused for a minute (because it's obvious the 3.8L is a 5.0 with two cylinders lopped off) and then say "Well... they have a head gasket problem. You cant keep head gaskets on em."
Well, that's true.. every aluminum head 3.8L made in the era of 92-95 is gonna lose head gaskets..
-BUT-
WRONG! The head gasket problem was a head gasket design problem. Exact same thing would have happened if the Windsor 5.0 had been produced with aluminum heads.
And it was fixed.. just like the 4.3 LIM gasket problem has been fixed and the name of the fix is "FelPro"