Camshaft choice for 4.3l Vortec

[Struc]

Over the winter I'm going to rebuild and build up a 1997 4.3l Vortec motor to replace my existing older non-vortec engine that I put in last year. It ran great all year, but lacks the oomph of the original motor, which was cracked. For the $500 I spent putting it together, I can sell it and make money still after it's pulled.

So, I have a 1997 4.3l Vortec out of a Astro Van sitting in storage that I'm going to turn into a marine motor for next season. I'm planning on rebuilding with new rings/bearings at a minimum, and will bore out / deck surface if necessary.

Planning on having the heads surfaced / valve job / etc.

Going to be putting an Edelbrock 2114 intake manifold with Edelbrock 1409 carb on it.

Looking for recommendations on what camshaft would help it breathe a little better without causing issues with it being a marine motor.

Thanks for any recommendations!

 

[wca_tim]

Re: Camshaft choice for 4.3l Vortec

I don't remember if your van has a balance shaft in the engine or not, but if you're rebuilding the bottom end, it might be best to find just a little older non-balance shaft roller short block. The small amount of extra vibration isn't an issue in a boat and it's worth at least 15-20 horsepower. Vortec heads will fit fine on it as will a marine roller cam. do a search for threads Tail_Gunner contributed to (or his original 4.3 build thread). You'll find everything you need to know and more. Sharp guy who's covered the ground you're heading for. I believe the comp cams v6 version of the extreme marine xm-270 grind is the cam you want... Enjoy!

ps. I had a non-balance shaft 4.3 with vortec heads, the same intake and carb you're planning on with about a 10:1 compression ratio and the stock merc roller cam. it ran great, but it was still a v6... if you want a lot more, or are one of those guys that always wants more, it might be worth while to just go to a small block right off the bat.

 

[Struc]

Re: Camshaft choice for 4.3l Vortec

Thank you for the advice, and for the username to search for. I've tried search over and over, and really don't like the capabilities of it - always get 0 results or 10,000 - neither of which is useful.

Does the balance shaft really rob that much power? I guess that is a new concept for me. I knew it robbed *some* power, but didn't realize it could suck that much.

As far as V6 vs V8 power goes... I'm dedicated to the 4.3l motor. I love the fuel consumption, and am not really interested in top speed - the boat already hits around 40mph as-is, and that's fine with me. Just looking for a little more oomph out of the hole more than anything I guess. That, and I built the motor that is in there pretty much just to make it through the 2012 season. It was used and had been rebuilt previously, and had 100,000 miles on the rebuild already. On top of that, it's a non-vortec block & heads, and has a 2bbl carb setup. It has served its purpose and I'm looking for a fresh motor with a little more power that I can keep in there and will run strong for the life of the boat.

I don't have any particular goal in mind as far as HP goes, but just figure that if I'm going through the trouble and expense of putting on a aftermarket intake manifold and 4bbl carb, I might as well put in a nice cam so the engine can breathe properly and put them to use.

I'm thinking it could hit up to 240hp at the crank, though, which will be a nice boost from the current setup.

 

[Tail_Gunner]

Re: Camshaft choice for 4.3l Vortec

The 270 ground on 112 lsa is good all around cam some will think reversion will occur but after two yrs still none. It is a grind for v8's so you have to call compcam tell them you want a xm270 cam ground with 112 lsa for a 4.3 v6. No extra cost and it is different than there cam's they have in there v6 lineup....Dont let them switch you to the v6 lineup..the xm cam help the vortec heads breathe. Have fun..start a thread you will get lots of input.

 

[Struc]

Re: Camshaft choice for 4.3l Vortec

So, I was looking at your original build thread from a couple years ago Tail_Gunner, but it kinda ended abruptly.

Tell me about what you decided on for everything, and what your expirence has been since finishing it - or am I missing the end of your build up thread someplace else? What pieces did you end up with?

 

[Tail_Gunner]

Re: Camshaft choice for 4.3l Vortec

Yes the engine is done it was new so not much was needed the 270 is a great cam. High lift dual pattern and just a little bit of overlap. The motor was a TBI motor and i almost tossed it out of ignorance the tbi that is. Glad i did not do that...Volvo had set up that Little v6 to be a hot rod 454 tbi vortec heads mefi programming all it needed was a good cam and a more aggressive tune for the engine and that's where i quit the thread. From that point on it was all about efi and learning how the program worked and how to reprogram it.

What ever is done to 5.7 can be done with a 4.3 cranks are different and some oil gallery's but if you want to stroke it yes you can....bore yep..supercharge it yep even interchange parts. Id leave the counter shaft in the engine was designed for that... which i consider a hard part not to be tinkered with.

It was fun and very interesting i wished i had dynoed the motor but that is a real pain in the neck at $100 a hour...and kind of kills the wisho meter.. Who know's the hp over 270 maybe 300.....

stick with a roller block..dished piston's..EST dist...eldo intake and carb. The one hold up with the 4.3 is the intake manifold not much out there at all..if you go with that cam you will need springs and retainers....pretty cheap though if you use ls6 springs

How much of rebuild are you planning..a complete build block pistons headwork??? Whate ever it is there are quite a few in here who have a wealth of knowledge and there not just back yard hacks such as myself...