4.3 brain picking time........

[wncrjb]

Hi All,
I recently purchased my next project, a 1994 chaparral 1830 SS sport.
It has a 4.3 mercruiser and A1 G2 drive.

The original engine is gone ( removed by previous owner )

The carb cover is there with the serial number of : OF360077
and says it's a 4.3 LX

what is the HP of this version?

OK, now is where the fun begins.......
I've built plenty of GM marine engines but never a v-6 so my knowledge of them is limited as far as what is good or bad as far as replacements or inter-changeability between them.

Question #1. is the LX model a 4 bbl version?

#2 when did the balance shaft 4.3 come into use?

#3 what year did the VORTEC begin?

#4 is it true that 93-02 4.3's will inter change?

#5 what year thunderbolt ignition systems will work for my application?

I know I should just buy a new 4.3 crate engine but like I said, I like projects and am looking forward to building a 4.3.

I'm sure I'll be asking many more questions along the way, but this is a good starting point for me.

thanks in advance,
wncrjb

 

[MikDee]

Re: 4.3 brain picking time........

Here's the so called "Holy Grail of the 4.3 V6" from the S-10 truck forum:
"http://www.s10forum.com/forum/f107/the-holy-grail-of-4-3-info-131868/

 

[BAYLINER185]

Re: 4.3 brain picking time........

The 4.3 is basicly the chevy 350 w/ 2 cylinder cut away. I think a lot of the 350 parts can interchange of course except for cams and crank shafts.

I would say alo of your engine building experiance will still come into play as this engine is just like a V8 just missing 2 cylinders.

The VORTEC's I think started in 1993-1994.My father bought a brand new chevy and it actually said VORTEC on the PLASTIC valve covers but on my 1990 and 92 chevy although the engines looked the same they didnt say vortec on them and they had metal valve covers. Not sure if that helps or not.

My 07 bayliner has the plastic valve covers that say vortec.

 

[Bondo]

Re: 4.3 brain picking time........

#1,..... Ayuh,....... 4bbl. Carb. rated at 205hp......

#2,..... I Donno,... Look in MikDee's link for that 1.......

#3,..... The Vortec name was intro'ed Before the Vortec Heads were intro'ed....
The Heads were 1st used in 1996.......

#4,..... All 4.3s will Interchange.....
While there are slight Differences,..... The 1987 to present are reasonably easy to over come......

#5,..... Any of the T-Bolt Igntions systems will work,...... Differences are,...
The T-Bolt IV is the earlier system,+ T-Bolt V has the Anti-Knock sensor added,+ will retard the timing automatically..............

 

[wncrjb]

Re: 4.3 brain picking time........

Thanks for the great information. I now know where to start looking and what to look for when I find it.
wncrjb

 

[Silvertip]

Re: 4.3 brain picking time........

The balance shaft motors appeared in the 1992 Model year but were an optional engine with an engine code "W". They were used in Astro/Safari AWD vans and probably available throughout the GM line of trucks. They were FI motors with a what has become known as the "spider" central port fuel injector system using poppet valves rather than separate electric injectors. I had an AWD Astro that was probably the most versatile and shure footed vehicle I ever owned. The balance shaft motor has an "issue" with the balance shaft bearing clearance but did not cause any reliability issues. Under light acceleration the engine would make a sound very much like light pre-ignition. My current 2002 S-10 has the same characteristic. Unless you have a keen ear, you will never notice it however.