hey guys ive got a 86 monte carlo with a 4.3L v6 with throttle body injection, are there any good mods out there for these engines? can i take vortec heads from the newer v6's and put them on my motor? i would like to make around 300hp with this engine, is it resonable without spending too much money? thanks in advance on any imput!
262 4.3L v6
- Thread starter Regulator
- Start date
I'm not sure that I could use the words "reasonable" and "inexpensive" to describe any attempt to build up a 300hp V6. Hot Rod Magazine did manage to get 301hp out of a 4.3 bored out to 270cuin but between the fairly large roller cam (224/224 [email protected]; .525/.525 lift@valves; 110 sep) and heavily ported heads, I'm not sure how this engine would be that desirable on a relatively heavy Monte Carlo.
http://www.hotrod.com/techarticles/engine/113_0208_chevy_43l_262ci_v6_engine_build/index.html
Its possible that you could fit a centrifugal blower to your V6 and make it produce 300hp for less than the cost of swapping in a 330hp Chevy 350 HO, but you would probably have to figure out everything on your own which can be costly and frustrating.
If you were willing to live with 200-250 hp, you could do a fairly streetable buildup on your 4.3. I believe that the 96 & later Vortec heads can be swapped on your early 4.3. It will require you to change to a Vortec compatible intake manifold (I think Edelbrock has one for TBI intakes) . There are also a variety of camshafts available from Comp and other manufacturers, headers and exhaust systems. 80ECLT could also offer a few suggestions regarding the TBI system.
The motor has potential, it just depends on how much of a science project you're looking for.
http://www.hotrod.com/techarticles/engine/113_0208_chevy_43l_262ci_v6_engine_build/index.html
Its possible that you could fit a centrifugal blower to your V6 and make it produce 300hp for less than the cost of swapping in a 330hp Chevy 350 HO, but you would probably have to figure out everything on your own which can be costly and frustrating.
If you were willing to live with 200-250 hp, you could do a fairly streetable buildup on your 4.3. I believe that the 96 & later Vortec heads can be swapped on your early 4.3. It will require you to change to a Vortec compatible intake manifold (I think Edelbrock has one for TBI intakes) . There are also a variety of camshafts available from Comp and other manufacturers, headers and exhaust systems. 80ECLT could also offer a few suggestions regarding the TBI system.
The motor has potential, it just depends on how much of a science project you're looking for.
^^ yeah, the later stock 4.3s were just under 200 hp from the factory. I'd imagine some mild mods would get you 250 hp, maybe more. Most people will tell you it would be cheaper to build a 350 for the same money, and get more power. Not sure you'd be making any better economy with a blown 4.3 verses a NA V8.
Hopefully 80ECLT will give you more specifics. He posted pictures of his 4.3 build a while back.
Hopefully 80ECLT will give you more specifics. He posted pictures of his 4.3 build a while back.
thanks for the info guys! im still trying to figure out what i want to do, Im planing on getting the level 2 2004R from bowtie overdrives, and either rebuild the 4.3 and add Heads, cam, intake, and headers or swap in a 4.8 or 5.3 LS. do you think i would get better gas mileage with the 4.3 or a 4.8? 5.3? what about cost wise? Sorry for all the questions, just trying to get all the info I can before i decide. TIA
Regulator,
No problems with all the questions, hopefully you will know a little more and make better decisions than I did. ](*,)
I'm not able to speak for fuel injected motors, but my experience with Darwin's carburated (Holley 4160) 4.3 V6 suggests that good mileage can be somewhat elusive with the smaller mill. After having the carb rejetted with a wide band O2 sensor and changing the power valve I was able to see 23.92 at 65mpg during a road trip, but combined city/highway mileage has been less than 20mpg. Attempts to fix this with a milder Crower cam were less than satisfactory. With the original Comp 252H cam I was seeing about 200hp gross, probably 150-180hp with the new stick.
Working with V6s has 3 drawbacks. Less displacement means that you have to push the engine harder and suffer the drivability consequences to get a certain level of hp. There are fewer aftermarket parts available than for the small block Chevy and there are fewer people who have much experience with the sixes, so you are more on your own than with the V8s.
I have heard of carburated 305s and 350s getting more power and better fuel economy than I've netted with my carbed 4.3, but I don't know much about fuel injected engines or the LS V8s so I'll leave those topics for others.
No problems with all the questions, hopefully you will know a little more and make better decisions than I did. ](*,)
I'm not able to speak for fuel injected motors, but my experience with Darwin's carburated (Holley 4160) 4.3 V6 suggests that good mileage can be somewhat elusive with the smaller mill. After having the carb rejetted with a wide band O2 sensor and changing the power valve I was able to see 23.92 at 65mpg during a road trip, but combined city/highway mileage has been less than 20mpg. Attempts to fix this with a milder Crower cam were less than satisfactory. With the original Comp 252H cam I was seeing about 200hp gross, probably 150-180hp with the new stick.
Working with V6s has 3 drawbacks. Less displacement means that you have to push the engine harder and suffer the drivability consequences to get a certain level of hp. There are fewer aftermarket parts available than for the small block Chevy and there are fewer people who have much experience with the sixes, so you are more on your own than with the V8s.
I have heard of carburated 305s and 350s getting more power and better fuel economy than I've netted with my carbed 4.3, but I don't know much about fuel injected engines or the LS V8s so I'll leave those topics for others.
It would be a challenge to build a 300 hp 4.3 for little coin. I have a ton into mine and i would guess its about 250 hp. But mine is limited by the EFI systems capability. You can swap vortec heads but you will need an aftermarket 4.3 vortec intake manifold, the vortec heads will not work with your stock tbi manifold. PM me for more info.
Do a 4.8 LS or really the 5.3.
I know its been ingrained into our heads that less cubes = more MPG, but that is something that just becomes less true every day. Id bet a lot that a stock 5.3 would get considerably better MPG than a 250+ HP modded V6. LS motor hands down. Keeping it EFI will be of comparable cost or maybe even cheaper to carb'ing it assuming you are smart in choosing parts.
Complete junkyard 5.3: $1000 max
Re-work harness/ECM: $350
Plumb fuel system: $200'ish depending on what you wanna do
Headers: $50-$800 depending on stock manifolds vs nice LT's
Other Misc, flexplate, fittings, etc: $500
If you were pretty careful and used stock manifolds I bet you could pull off the motor swap for $2000 or less.
I know its been ingrained into our heads that less cubes = more MPG, but that is something that just becomes less true every day. Id bet a lot that a stock 5.3 would get considerably better MPG than a 250+ HP modded V6. LS motor hands down. Keeping it EFI will be of comparable cost or maybe even cheaper to carb'ing it assuming you are smart in choosing parts.
Complete junkyard 5.3: $1000 max
Re-work harness/ECM: $350
Plumb fuel system: $200'ish depending on what you wanna do
Headers: $50-$800 depending on stock manifolds vs nice LT's
Other Misc, flexplate, fittings, etc: $500
If you were pretty careful and used stock manifolds I bet you could pull off the motor swap for $2000 or less.
It sounds like he wants to build what he allready has. But very true about the less isnt always more for MPG.
