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Chevy 4.3l V6 in a Z


Guest Anonymous

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Originally posted by Mr. Lurid:

Nice to know it can be done. Wanna sell me your mounts? Out of curiosity, how much power were you making?

My best guess and using G-tech 113 mph, 14 psi, 2720lb was around 375 flywheel. Stock 85 vortec heads were a major choking point. I live at near 5000 ft, so we get a big deduction for hp here, maybe around 18% less than sea level. I'd be glad to give you the mounts for cost of shipping. It will place the motor as close as JTR V8 to firewall, and maybe a touch lower. You might want to refine the system, though it worked for me for 5 years. If you'd like, Email me @ Zzealot240@aol.com

John

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Your heads would have been a welcome addition. I really needed to do the 4 bolt conversion as I was flexing the mains pretty badly once I got greedy with the boost. The 85 heads had manly proflows, 195/150s and what little I could do porting. Timing was limited to 22 degrees. A 4 bolt, forged crank, and big heads would have made one bad @$$ ride. I shyed away from the costs.. so, I blew my allowence on what started to be a budget cheep-o 383 hahahaha! What's left of my wallet is still smoking in the corner.

John

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Guest Anonymous

Thanks for all the feedback you guys have provided. You all got me thinking and I have to ask more questions. Is the weight savings from the 4.3 worth the hassle, compared to the sbc? My goal is to build a streetable ride with 350-400hp, that has rocking handling. I don't believe in shortcuts when it comes to install but I'm not made of money either. If I had a Bijillion dollars I'd go rotary from 3gen rx7 and dump my cash into improving the reliability factor.

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A final point, with the 4.3, my weight bias was front/rear 49/51. This was with iron heads and waterpump. From my experience, I would say the V8 is less hassle to install. You mention streetable so I'd think any powertrain you choose, with proper suspension tuning, can be had with rocking handling.

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Guest Zcarsmakemyheadhurt

We build 300hp 4.3 for air boats here,that is with steel heads and a compression ratio of around 10.5:1, streetable. Add a simple NOS system and you are FAST. Or stepp up on the heads and maybe you could make more power.

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Guest Zcarsmakemyheadhurt

We build 300hp 4.3 for air boats here,that is with steel heads and a compression ratio of around 10.5:1, streetable. Add a simple NOS system and you are FAST. Or stepp up on the heads and maybe you could make more power.

 

Alex Costa

Precision Machined Engies

1-800-665-0405

boostit@pmei.net

 

P.S. I have pics of the brodex headed engine we are putting together now if anyone is interested in seeing what they look like.

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Mr. L

 

Weight savings wouldn't be the reason to go to a 4.3. The total savings would probably be in the neighborhood of 75-100lbs. The block is 25 lbs lighter that the sbc, add into that a shorter crank, shorter heads, manifold, etc and two fewer connecting rods and pistons.

 

As John Scott mentioned above, his weight dist was 49/51 with the 4.3, a sbc would be very easy to get to a 50/50 weight distribution. Either way handling would be great for both cars.

 

300 to 350 hp out of a small block is easier and cheaper to come by than with a 4.3. Not that it would be all that difficult with a 4.3, but performance parts are much more plentiful and cheaper for the sbc. If you are patient you can get good used performance parts, such as heads and intake manifolds for the 4.3. New stuff is really expensive and stock 4.3 heads don't have a lot of porting potential.

 

It will be easier to do the v-8 conversion over the v-6. If you go the JTR route the parts are available, or if you want to make your own the design work has been done. If you go the 6 route you will need to design and fab your own motor mounts.

 

I decided to go the 4.3 route just to be a little different. Since I'm not in a big hurry I've been able to accumulate performance parts for the 4.3 at a reasonable price.

 

It just depends on what you are after.

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Alex,

 

I'm interested in the brodix pics, I'll email you. Also, do you know if you can notch the top of the cylinder bores to clear the big valves in the 18 degree heads, obviously staying above the piston rings. Or is the only way to run these heads to use a bowtie block bored to 4.125. Also what is the max bore for the stock production block. Is it 4.040 or can you go to 4.060.

 

Thanks

 

S

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  • 1 month later...

kenshin - Do you already have a 4.3 GM motor? If not, consider the Turbo buick 3.8L V6. The stock block will tolerate at least 550 hp, and it's not that hard to do with all the aftermarket parts available. A bone stock TR motor produced about 300 hp (the official 245 hp was purposely underrated by GM) and 355 ft. lbs torque. Less than $500 in mods can get you to 400 ft. lbs torque.

 

TK

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