buckhunter

I was woundering if any one has ever put a 4.3L v6 in a 87 camaro RS and if so can i have some tips on what i all need to do? thanks! o ya i have another question to. will i have a problem with the oil pan fitting?

Apeiron

It's exactly the same as putting in an SBC, only with 2 less cylinders.

KrisW

iTrader: (5)

I'm afraid he's right... You need a V8 transmission and V8 motor mounts.

Then there is the question of fuel. If you run a carburetor or fuel injection neither will just match up to what you have. To my knowledge there has never been a multiport fuel injection manifold made for the 4.3. If I could find one I might put one in my '88!!

Jay

iTrader: (2)

The early style Vortec 4.3 in the S series trucks and Astro vans is sort of multi port. It has large runners.. looks like a TPI oversized. It's a Central port injection with 6 lines from one unit going to the cylinders. It could be hooked up to a multiport F bodys fuel system with a little work, but nothing too difficult. They both use high pressure systems with a return. I thought about doing it since I had one and a spare Firebird but never got around to it and ended up putting it into another S10. Decent engine.. something like 200 HP and @ 270 TQ
As I remember the motor mounts may have to be custom, I think I had found an alignment issue.

KrisW

iTrader: (5)

So... regular mpfi injectors will press down into the holes for the cpi nozzles?

I am definitely willing to try that if they are just a drop in. Otherwise I am thinking of tig welding 6 of the aftermarket injector tubes from Holley to one of my aluminum TBI 4.3 manifolds. I have seen guys do this to carburetor manifolds in order to convert them to mpfi.

As for the mounts I guess you might have to drill or slot a few of the frame holes to get the chevy lowers to line up in the original position. It's not that bad of a job; I have done it for Buick/Olds engines before.

2_point8_boy

Please BEFORE you post something like this next time...it's been answered a hundred times.

wesilva

iTrader: (35)

Anyone know if the computer from a 2.8 can be reprogrammed to run a 4.3...provided you used the correct injectors and sensors?

nelapse

iTrader: (17)

No. The system is completely different.

KrisW

iTrader: (5)

I have to disagree; I think with all of the DIY PROM stuff on this site you can just about reprogram anything.

I am going to be doing the same thing with a Buick V6 in the near future, as soon as my garage situation is squared away!

My brother in law has done similar things with S-10 pickups. He has gone from 2.8 to 4.3 in the same year truck (1988?) by changing prom chips. He had both trucks and it seemed to run okay. They were both TBI from the factory so it was a matter of hooking everything up properly.

nelapse

iTrader: (17)

The 2.8 ECM has a completely different MEMCAL than the 4.3.

You can upgrade the MEMCAL/PROM till you are blue in the face, I do not think it would make a difference.

2_point8_boy

The CPI style injection only uses one actual injector, it just has 6 little hoses running you to the ports. I don't see how you can make a 2.8 compouter/harness work without MAJOR work, and then it'll be just easier to swap the stuff out for the right stuff to begin with.

KrisW

iTrader: (5)

LOTS of 4.3s use TBI in S-trucks, not CPI. The TBI 4.3 engines are third gen era engines and use all of the same parts in the harness that 2.8s use.

I don't know about the CALPAK; I do know that if you replace the replaceable chip in the 2.8 computer (does the CALPAK swap out? It looked like a pretty long chip, but anyways...) the engine runs fine and took my brother in law to work everyday for a year until the rest of the truck gave up the ghost...

I have seen guys switch from TBI to TPI and vice versa on this site. It CAN be done with tuning. And if you had to use a 4.3 TBI computer from an 87-93 S truck then so what? How is that different than putting Speed density where Mass air flow once was while swapping from 5.0 to 5.7... You re-pin your harness to fit the computer that you are using, right?

nelapse

iTrader: (17)

No offense, but what the heck are you talking about?

The MEMCAL the "long chip" thing you described is the socket that holds the PROM. The V8 computers have long ones, the V6 ones have like small square looking ones. Sure you saw TBI to TPI's all day long. They also got new ECMs. Your argument is that you can use the same ECM with a new PROM.

wesilva

iTrader: (35)

I get ya...nelapse. I was actually considering converting my Edelbrock manifold to accept injectors and used a Wilson adapter to bolt on a throttle body. If I did that, what are my options for a CPU? Aftermarket only?

nelapse

iTrader: (17)

Well you can use the ECM 7302 and convert your car to speed density. This is one of many posibilities.

Here is a thread that may help, https://www.thirdgen.org/forums/alte...-manifold.html