4.3 Vortec build up and traps

[dsmmace]

Re: 4.3 Vortec build up and traps

Well I thank you for pointing out the lift being too high for regular vortec heads. That made me question my engine builder, but he told me to stop worrying, it was all taken care of a when he rebuilds the heads. I'm just glad that I won't have to spend any more money to make things work. I guess that's my I return to the same guy to do my engine work for me.

Did I tell you to try to find a torqueshift prop yet? I have mine preset to go from 13 to 18 pitch.

 

[Tail_Gunner]

Re: 4.3 Vortec build up and traps

No problem actually after searching the 266 i found the xm270 hr..it has the big M word..marine and a better power band with the same lift as the 270 ahr.. So thank you..

The attempt to mod the efi is over, while they can and will reprogram the ecm it will more then probably need added support to tune the thing right requiring me to get additional scan tools ...im not intrested in that.

So the efi is up on ebay and parts are being ordered so i can continue this little project. March is here is have 30 days to get it up and running..and she will be a complete marine "tinkered" mod..

320346336416...

 

[dsmmace]

Re: 4.3 Vortec build up and traps

Hold the phone, I have only found that is a v8 only cam? Share a part number please.

 

[Tail_Gunner]

Re: 4.3 Vortec build up and traps

Call comp cams direct 800-999-0853.give them the that cam number and they will cusom grind you one for the same money. Just tell them you like the profile and the reversion aka no issues they will grind you one..Or wait till tommorow and i will post the numbers, But they will still take you thourgh the steps...Until you say thats the cam i want..

 

[dsmmace]

Re: 4.3 Vortec build up and traps

I was curious about the cam numbers, but I would presume that they would be the same as the v8 cam, just a little shorter.

With a setup like this, what are you planning to do with exhaust manifolds if anything? And what about the prop, since you are making more power, would you not prop it like a v8?

 

[Tail_Gunner]

Re: 4.3 Vortec build up and traps

That cam number is a just a grind type, it can be ground for either a v8 or v6, you simply need to inform them that is the profile and you want one ground for you type of motor.

CS XM 270 HR-12 218@.050 E 224@.050
Not this one
CS XM 270 HR-10 I 226 @.050 and E 236 @ .050

http://store.summitracing.com/partdetail.asp?part=CCA-08-417-8&view=32&N=700+115

That'd be it..only with a v6 grind

I believe the part no is 56-000-8....3313-3314 hr 112+2. As to exhaust i do not intend to do anything at this time, but if reversion comes into play i do have some corsa's i picked up and will mod if needed.

Im lucky in the fact that the sx drive has a 1.66 ratio if it had a 2.0 or 1.98 that could be a problem with prop size vs hole shot. Propping should be as simple as pitching up until the boat reaches 5500 rpm. I know i will be losing some low end launch so i will be adding tabs to assist the lift.

The boat currently does 56@4900 with a 21p 3 blade ss about 8% slip...The future who know's..Id be quite happy if it turned a 24p @ 64....or 25p @ 66. Just all speculation, but if all the stars align and a gentle breeze is blowing..I just might get lucky...Now if that happen's ive stumbled upon a name for the old scow...."TINKERED"......TINKARD..

 

[dsmmace]

Re: 4.3 Vortec build up and traps

Have you fired your motor up yet? I'm dying to get my motor back in May sometime.

 

[Tail_Gunner]

Re: 4.3 Vortec build up and traps

Not yet, i still dont have a clear direction as of yet, iv'e been caught up in this reversion issue. It seems that Volvo has designed a nozzle for the lack of a better description at the end of the riser that shoots or sprays water down 4" exhaust that cools the tubing.

The down side is there is going to be some atomization of the water that could very well be sucked back into the header's due to valve overlap. But just how much overlap does that take 20-40-or 60 degrees seems to be the puzzling question.

Bondo as usual has provided a path as simple as extending the length of the exhaust aka though the transom exhasut...and after a little browseing i believe i have found a simple and cost effective way to do that. There was a term "Dumpster Diving" made and that led me to deisel truck's graveyard..You ever see those long chrome stacks..they sure would make some nice tubing to the transom...

Vovlo has also come up with simple H pipe connection for the 8.1 Don has confrimed as much but you cannot find any of the results on the net, Dont know if that is effective but it would negate back pressure and that's performance robbing.

I just need to answer some of my own concerns on that delima....It maybe as simple as capping the water at the end of the riser and injecting it down stream...Using a 6" ceramic coated extension pipe behind the riser and letting if all dump into the exhasut flare's.

I hate the ideal of going thru the hull but a after a trip to the junk yard we will see.

May i ask did you use the 266 comp cam..Using some dyno program's it seem to yeild higher tourqe..

 

[Silvertip]

Re: 4.3 Vortec build up and traps

I'm a GM guy but I did buy a bunch of Ford stock a couple months ago and it's making me money.

 

[Tail_Gunner]

Re: 4.3 Vortec build up and traps

I'm a GM guy but I did buy a bunch of Ford stock a couple months ago and it's making me money.

2010 will be a great year for Ford, maybe not in sold number's but the new Taurus Fiesta and the hybrid Fushion will complete the line up...Sad new's to hear about GM...and Chrylser....Ford may end up being the dominate market force...Your investment should give you a good yeild...think $12-15 a stock.......

 

[Bondo]

Re: 4.3 Vortec build up and traps

Ayuh,... The Truck Pipes Ain't the way to go TGer,...
It's Chromed Steel,... It'll be a rusted mess in No time...
I've been building mine outa Milkhouse,+ Papermill SSteel pipe....(Ayuh,.. Dumpster Divin')

Take a click over Here,+ have a look around for Ideas...
At the top of the story page, it lists Dry Offshore, Wet Offshore, etc..
The Dry Offshore pictures are the pipes we're putting on Bob's 50' Scarab's center motor....
The Wet Offshore resemble, but aren't the same as the risers I told you about for my project motor,.. Mine are actually Longer,+ drop Down rather than Back like the 1s on the page..
The 1s on that page are Alot like the 1s on my 4.3LX,... Mine aren't quite that long though... Mine are just a sweep back radis dumping a couple inches farther back that stock...(they'd still work with a Y-pipe if I had 1)

You need Water Cooled pipes all the way til they dump,+ mix...
The Gilmarine site should give you some Ideas,+ Insights...
Or google up some of the other Offshore pipe manufacturers...

Btw,....
I still think you'll be Happier with a slightly Smaller cam....
The 1 I last saw listed over at Hotrodders was a 1500rpms to 6500rpm cam...
You're going to need a Kicker motor just to get goin' fast enough to Light the 4.3....

 

[dsmmace]

Re: 4.3 Vortec build up and traps

Yes I already purchased all my parts including the 266 cam. I bought it based on the powerband and the suggestion of my engine builder, I didn't see much of a power increase after going to a bigger cam on the dyno software. My engine builder also removed the balance shaft as well. I'm not worried about this since I had him balance and blueprint the new motor.

I still have the old one piece mercruiser manifold units that are in great shape, I am so far inland I will never see salt. If I had to replace manifolds I would buy the imco marine thumpers. I like power, but not loud.

 

[dsmmace]

Re: 4.3 Vortec build up and traps

I picked up my new motor this weekend, I should have good or bad words in a couple weeks. The block is assembled, heads, intake and oil pan are on. Now to reinstall all the wiring, accessories, sensors and exhaust manifolds.

 

[dsmmace]

Re: 4.3 Vortec build up and traps

My motor is in, I am having difficulty with the idle. My cam choice may have been too big to idle under 1000 rpm, I'll have to make some adjustments on the Edlebrock carb I'm sure.

I have yet to wet test it, hopefully this weekend.

 

[Tail_Gunner]

Re: 4.3 Vortec build up and traps

Congrats...I have purchased all the parts..there just sitting there waiting until i can fully understand or feel comfortable with reprogramming the fuel talbes and timing curves..The 266 is not that big..Have you installed the right metering kit?

Iam sure you have ran it above 2000 rpm for more the 20 minutes to break in that cam...Just a question..no more no less What metering kit have you put in or what cfm carb???

Opps and if you do run into reversion..I have a plan..

 

[dsmmace]

Re: 4.3 Vortec build up and traps

I change my mind on the cam.

After finally getting the boat into the water and not having my fuel pump cut out on due to shoddy wiring. I finally got a chance to ring it out a bit. With my cam choice of the 266 comp cam, the 1409 kit with the 600cfm carb and intake manifold, I finally have dialed in enough to have decent day with it out on the water. I had difficulty setting the base timing, but the mechanics took it for a wet test and set it under load. I do experience a little amount of hesitation (throttle transition) lower rpm speeds, but with time and some more money I will be able to tune it out.

But DAMN does my setup ever move now. I can cruise and troll effortlessly, but my old 21 pitch 3 blade cheapy prop has my boat screaming past 4800rpm VERY easily and I have lots of throttle left, I immediately noticed the difference when cruising at 3000rpm and giving it a little jab of the throttle, there is so much more get up and go it was surprising. I will have to change pitch as right now I am getting 10mph per 1000 rpm with my 20.5ft 2000 Bayliner Capri. I guess I will finally throw on that Torqueshift prop for the next trip to the lake.

 

[MikDee]

Re: 4.3 Vortec build up and traps

Wow! I just stumbled onto this thread, very interesting, and a lot of great info here! I also learned a lot of this from hanging at the Chevy S-10 forum. I'm trying to find the best mods, & cam, for my 95' S-10 4.3 TBI Auto 2WD, at 160hp stock it is a little anemic The Comp cams 270 is a very popular aftermarket cam there. I also found out, I have the same heads as the 95'-CPI 195hp engine, and the TBI system is not much different then the CPI system, but the camshaft is much better, (for a stock unit) maybe 30hp more, it is the same specs as the one that Mkos mentioned - 202*/210* duration, & .404/.410 lift at 112* overlap marine/truck cam
Having the later balance shaft engine, there's not many cams available without going overboard on the whole expensive $ complete valve train renew I may opt for this factory cam, just so I can keep all the rest of my valve train stock., if I ever get around to doing it

Hey TG, & dsmmace, Good Luck, & More power to you guys, keep up the good work!
and by the way, TG you are quite well informed

 

[dsmmace]

Re: 4.3 Vortec build up and traps

So lets talk jet sizing. What is working for you? The 1485 kit works, but seemed lean on the secondaries. I swapped to 0.092 secondary and the motor seems happy, but I think it is down on power. Any hints or suggestions for what worked for you?

 

[dsmmace]

Re: 4.3 Vortec build up and traps

So to follow up, my timing retarded off quite a bit. The shop has now since fixed that, which gave me a huge jump in power. But the bad news is I am back to tuning the carb again.

With the 1485 kit and swapping the secondaries to 0.092 I have a lean surge under constant throttle at 3000-4000 rpm. And when getting up past 4000 rpm it lugs down as if it is flooding and actually bogs/slows down when the secondaries open up.

So the plan of attack is to swap the 0.092 into the primaries and put the 0.089 into the seconaries and leave the metering rods alone.