4.3l Vortec head,intake,4bbl Upgrade!

[Bergerson]

1990 chaparral 1900 4.3l

Going to the lake today to test out the new heads,Elderbrock Performer intake and 4bbl carb, hit a few snags along the way with the swap from the old heads intake and 2bbl, had to make a custom throttle linkage bracket, custom fuel line, and had a hell of a time getting the rocker arms/valves adjusted right. turns out these heads/valves require just a torque of 22 ft,lbs. not 0 lash + 3/4 of a turn.. had to do it three times before i got it right. but all is back together with a new cam of about the same specs of the factory, just a tad hotter. didnt want any water inversion. sure has a lumpy idle now.. sounds like a big block. cam is dialed in for 1000- 5500 rpm band. as wall as the Performer intake. I cant wait to feel the seat of the pants of the 4bbl on take off. the 2bbl was always quite a dog out of the hole. barley able to pull a 200lb slolmon skier out, wake boards no prob, and 2 ski's are barley okay. I am so excited to try this out. leaving for the lake in about an hour. thanks for all the help i received on the boards and all the ?'s you guys answered for me. WIsh me luck! not so sure i have the timing dialed in perfect but i will mess with it on the lake if i need to today.

 

[jkust]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

I am excited for you. Post an update when you get top speed and wot numbers on gps.

 

[Bergerson]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

WOW!!!! It feels like I droped a 350 in this boat!!! WOOOOHHAAAA! dam this thing hauls ***!! with power to spare... I used to only be able to hit 4100-4200 rpm WOT with a two speed 17-23 Pitch prop before. Now I can wrap it out easily hit 5000 rpm in the second pitch 23. top speed Before 46.5 mph, WOT 5200 rpm now 60.2 MPH. This thing is unbelievable! Now granted I only took it up to the 5200 RPM for about 20 seconds just to see what it could do. and at that time I had 4 people in the boat. Overall performance of the boat now is SO SO much nicer. I had 5 people on the boat yesterday and had absloulty no problem pulling up a skier with 4 people in the boat. I LOVE this new power! dosent struggle to jump out of the hole and can cruise at half throttle 4000 rpm all day long without bogging down and feeling like the engine is struggling to keep up to my demands. now I hammer the throttle and the 4bbl kicks in and it is a seat of the pants feel. litterly sets you back in the seat. and is on plane in about 3-4 seconds. used to be 6-8 seconds before. I am going out again today in about an hour to play some more! I am so thrilled with the results!!!

 

[porter09]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

Hello,

I just posted a question this morning about doing this conversion myself. My old 4.3L (1993 19.5" boat) blew up and I?ve got a 2001 vortec to put in. I'm considering losing the stock 2bbl, since I have top replace the intake anyway. Was thinking about going to a 4bbl and maybe getting an Edelbrock intake since it's not that much more than a merc 4bbl intake.

What carb and cam did you go with? I mostly use the boat for pulling skiers and tubing. I?m very encouraged by your post. Any other advice you can offer if I decide to go this route?? Thanks a lot. Skeeter

 

[Bergerson]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

I got a used 4bbl off of a 99 stingray, it looks just like a elderbrock 600cfm 4bbl. you will need to rig up or buy a throttle cable bracket, and repalce the fuel line from the pump to the carb, its a little different than the 2bbl line. other than that it was pretty straight forward and only took about 4 hours start to finish. yours should be just as easy or easier, all you need to do is change intake on your new motor and pull and drop the whole motor. a little easier than tearing everthing down to the block while its still in the boat. Good luck! It has made a night and day difference in my boat. this motor just flat out screams now!

 

[mylesm260]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

I did the same swap (except I'm EFI) and noticed the same thing..

The vortec 4.3's are far superior to the older non-vortecs.

And it's not just top end power either, from idle to redline, the vortec engines make more torque.

Glad you're upgrade worked out for ya!

 

[porter09]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

Thanks...

Two more questions, 1) What cam? Should I just leave the stock GM truck cam or look for something else? You mentioned changing the cam on yours. 2) The old 4.3 had a steel oil pan. This new vortec has the cast aluminum. No problems with the new pan and the fly wheel cover or starter. I read somewhere that the old steel pan won't fit the late model (mines 2001) blocks. I REALLY appreciate your help. Thanks, Skeeter

 

[mylesm260]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

I myself am running the stock vortec cam, it works flawlessly in my setup.


The trucks with the vortec 4.3's all got peak power in the 4400-4800 range, bang on for marine. I can't imagine going much hotter than that without water ingestion issues.

 

[winner228]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

what cam and springs did u go with.

 

[winner228]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

and is a astro van cam the same as the trucks cam.

 

[Bergerson]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

I used the beehive springs to be certain there would not be any issues with the lift of the cam. this is the cam I used from comp.

http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=99&sb=2

All I can say is WOW! I am not quite sure how much HP and Torque this setup gave me over what i had but it is alot! a whole lot more! for sure worth the time and $$ for the upgrade!

 

[mylesm260]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

After some research, I think I rated my setup for 228HP (the same as an 09' GM 4.3 marine engine)

If you're running a hotter cam with some valve-train work, I could easily see you running 250+.

It totally explains you're increase in performance... the old 2bbl non vortec 4.3's were 160-175 HP, depending on year and configuration.


And yes, the astrovan cams are the same as the truck cams. (both 200 HP in 4x4 / AWD versions)

 

[MikDee]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

Here's a real good factory roller cam! and, It can be used with the stock valvetrain & limited lift Vortec heads,,, But, it's not for a balance shaft engine

http://www.gmpartsdirect.com/performance_parts/store/catalog/Product.jhtmlPRODID=2628&CATID=304.html

If you have a Vortec balance shaft engine, this is the hottest factory offering, using the stock valvetrain, & Vortec heads as used on the Chevy trucks, from www.S10Planet.com -


* '92-'95, Vin W, w/ balance shaft
- Lift (I/E) - .432/.440
- Dur @ .050 (I/E) - .208/.208

 

[mylesm260]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

Thanks...

Two more questions, 1) What cam? Should I just leave the stock GM truck cam or look for something else? You mentioned changing the cam on yours. 2) The old 4.3 had a steel oil pan. This new vortec has the cast aluminum. No problems with the new pan and the fly wheel cover or starter. I read somewhere that the old steel pan won't fit the late model (mines 2001) blocks. I REALLY appreciate your help. Thanks, Skeeter

In my experience, yes, my steel pan did not bolt up to my vortec block, completely different offset on the bolt hole locations.

I ended up going with the aluminum pan from the vortec. It basically works out to extra oil-cooling, as the vortec pans act as gigantic heat-sinks to pull heat out of you're oil.

I would suggest coming up with a game plan before you un-bolt the factory oil pan from you're vortec engine. The gasket from the factory cannot be re-used (in my experience) or it will leak.

Also keep in mind if you're vortec engine was 4x4 or AWD, you will have a deep sump oil-pan and a deep pickup on you're oil pump. This will mean you will have to get creative with you're dip-stick setup.


On a side note:

2WD 4.3 vortecs (trucks and vans) were rated for 180 HP
4WD/AWD 4.3's were rated for 200HP

They both have the same cam, the difference is a restrictor plate on the throttle body and ECU tuning.

 

[MikDee]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

On a side note:
2WD 4.3 vortecs (trucks and vans) were rated for 180 HP
4WD/AWD 4.3's were rated for 200HP
They both have the same cam, the difference is a restrictor plate on the throttle body and ECU tuning.

Actually No, the camshafts are different, as well as the fuel injection system, that's where they get the 20hp difference:

(1996-?98 VIN "X" WITH BALANCE SHAFT: The VIN "X" engine replaced the VIN "Z" in ?95. It is identical to the ?96 VIN "W" engine except for a milder cam and 10 less horsepower. The cam is a p/n 10241692.)

(1996-?98 VIN "W" WITH BALANCE SHAFT: The VIN "W" engine has a 10541691 camshaft and makes 10 more horsepower than the VIN "X" engine. There is also a special roller cam for the VIN "Z" turbocharged engines (p/n 10214714) along with a couple more with a fuel pump lobe for marine and industrial applications, but these are the common ones that were used in most of the cars and trucks. All of these cams can be identified by the last three digits of the part number that is stamped on the barrel of the cam, just behind the last lobe and in front of the distributor gear.)

AND, The cam I recommended previously, is the best of them all, it's from the:

(1992-?95 VIN "W" WITH BALANCE SHAFT: The premium high output engine came with central fuel injection, a balance shaft and a better cam starting in ?92. The original cam, p/n 10144047, was used from ?92 to ?94. It was replaced by p/n 10241693 in ?95. They are comparable grinds so most rebuilders are interchanging them.)

Source: www.S10forum.com

 

[winner228]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

OK good info. but i still dont know what cam i have the numbers are .CPC.BC.19...324.CPC and on the vary top of the cam it's 7324
19
6253 thanks for any help.

 

[winner228]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

and that comp cam is for a v8 not v6.

 

[n2ostroker]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

and that comp cam is for a v8 not v6.

It is for a V8 ut Comp will grind it for a V6. You just need to call them.

 

[mylesm260]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

Actually No, the camshafts are different, as well as the fuel injection system, that's where they get the 20hp difference:

(1996-?98 VIN "X" WITH BALANCE SHAFT: The VIN "X" engine replaced the VIN "Z" in ?95. It is identical to the ?96 VIN "W" engine except for a milder cam and 10 less horsepower. The cam is a p/n 10241692.)

(1996-?98 VIN "W" WITH BALANCE SHAFT: The VIN "W" engine has a 10541691 camshaft and makes 10 more horsepower than the VIN "X" engine. There is also a special roller cam for the VIN "Z" turbocharged engines (p/n 10214714) along with a couple more with a fuel pump lobe for marine and industrial applications, but these are the common ones that were used in most of the cars and trucks. All of these cams can be identified by the last three digits of the part number that is stamped on the barrel of the cam, just behind the last lobe and in front of the distributor gear.)

AND, The cam I recommended previously, is the best of them all, it's from the:

(1992-?95 VIN "W" WITH BALANCE SHAFT: The premium high output engine came with central fuel injection, a balance shaft and a better cam starting in ?92. The original cam, p/n 10144047, was used from ?92 to ?94. It was replaced by p/n 10241693 in ?95. They are comparable grinds so most rebuilders are interchanging them.)

Source: www.S10forums.com

Wow, that's great info, thanks for correcting me.

So for all of you considering this swap, make sure you're doner vehicle is a 4x4 or AWD, as they have the more desirable cams.

 

[porter09]

Re: 4.3l Vortec head,intake,4bbl Upgrade!

Wow...Thanks for all the great info!! I think at this point given the cost outlay for the engine and the upcoming cost of getting a new manifold and carb, I'm going to stick with the stock cam for now and see how I like it. The little misses is already on my ***** about the basic costs of switching from the non-vortec to the vortec. I'm sure you guys know the story, "....our boat has been fine all these years...why do you need more power now..." A custom cam and additional valvetrain components will just add fuel to that fire! Thanks again for all the great help. Skeeter