'96 4.3 vortec build

[overS-10ded]

I'm buying parts for my rebuild and am needing to verify a few items and open to any and all help. Im running a intercooled ProCharger P1sc and have for over 30,000 trouble free miles using a marine manifold conversion and '0411 pcm in my '91 Blazer. This site and you people have some of the best information and experience and my build is very similar to the outline of that of a turbo Typhoon or Syclone boost build. My idea of my Blazer has been to create a semi-Pro Touring DD. My wife and I do 5,000 miles over 4 months at a time cruising accross US and Canada-camping, seeing family and friends, and enjoying the sights. We live in Costa Rica and do our vacations in this vehicle but otherwise it is stored for up to a year at a time between heavy use. I put the engine in that had 28K on it in '06 - out of a '96 Jimmy and now has 88K-still running GREAT! However this last visit I was prepping to drive her for a month while in St Petersburg FL where it's stored and while changing to larger injectors I dropped a plastic shafted q-tip down the injector hole while cleaning some dirt off the injector seat. I didn't really realize it wasn't the nice hard paper shaft and the plastic shaft just twisted with my first spin between my finger and thumb and it spit out of from between my fingers and disappeared! After failing to retrieve it after 4 hours of fishing (never even saw it) I weighed pulling the intake. $75 gasket! And I have accumulated everything to put my new cam in...but I want to pull the heads and relieve the pushrod hole for 1.6 UltraProMag roller rockers. So, I decided to overhaul at this time! I'm hoping to have a good crank and don't know yet but suspect so as oil pressure is very good however is has come down 5 psi over the last 10k miles. Machine work as needed and to include square deck and bore and hone .030. Current boost is 11-12psi at 5.5K and 2500 stall on my 700r4. 44# Dekas - Here is the list of what I have:

Pistons- Sealed Power LW2603F +030
Rings- Total Seal MS 3690 +035 AP (total seal top ring)
Cam- Mellings MC1275 (92-95 CPI grind)
Valve spgs- Comp 26928 (26918 spec equivalent) - Comp 787 retainers - Comp 648 locks
Lifters- Comp 875
Rockers- Comp Ultra Pro Mag 3/8's 1.6 ratio
Timing Chain- stock single roller timing chain, tensioner, new plastic front cover
Pushrods- 3/8" Trend .080 wall 7.150"
Steel center bolt valve covers to clear rockers

Going to buy;
Eagle CRS570063D H-beam rods (I just love them for a lil' over $400!)

I have questions about:

Head studs- ARP 233-4001 or ??

Question about the mains also- at the least using ARP studs?? I'm planning on using the stock crank. Probably not seeing more than 6,300. I'd really like to hear about experiences in this area most!! Can sbc 2 bolt large journal stud kits be used for 4.3?

'96 Vortec heads;
using the conversion studs ARP 100-7201 for the roller rockers. Expecting to have the exhaust lightly ported and a GOOD valve job. I will port match my intake (cast iron). Match the exhaust as best as poss with a rectangle vortec port into a round header pipe!

Valves- staying with stock size 1.94, 1.50, but how are the stock valve quality for '96? Maybe just replace the exhaust with a quality piece? I usually do that on a rebuild anyway but how about the intake valve? Looking for suggestions on valves.

Last question-sorry, I didn't google first but what is done when "filling" a 4.3 block? I see half filled, and filled??

Side note- I'm removing the balance shaft from the motor as well. The original '91 tbi motor did not have a balance shaft and to me there really isn't that much difference-however there is a subtle one that I don't mind. But I'd rather remove the excess 11# static weight plus what ever drag it has to create on the spinning assembly.

I am looking for a machine shop in St Petersburg-Tampa area that has a 4.3 v6 torque plate (seems to be rare) and a cylinder head shop that KNOWS 4.3 vortec head porting.


Thanks and good times!
Bruce

 

[Quickstop [UK]]

Re: '96 4.3 vortec build

I think you can save yourself a lot of work and money.

The 1.6 RR are not worth pulling your heads and doing all that work. I have roller rockers and am looking at getting rid of my 1.52 RR (Comp Cams) because they sound like a sewing machine.

The 1.6 vs 1.52 ratio has been calculated to offer a negligible advantage and if doing so means you have to pull your heads and do a "refresh", I'd not even go there.

Instead, maybe get another junkyard motor and build a fresh motor. If you need to.

The Q tip will likely be incinerated and turn to ash very quickly and be expelled from the cylinder. It won't go through a turbine so I doubt you'll see any ill effects.

:2cents:

 

[dgoodhue]

Re: '96 4.3 vortec build

The cam that you spec'd is decent for a stock cam, it much more aggressive than your stock one. Normally I would agree with Quickstop assessment of 1.6RR being a waste on cam swaps and vortec's, because stock Vortec peak at .450 lift and even ported Vortec don't flow much better past .500 lift. The cam you spec'd has .432/.439 lift.

You should figure out and calculate and research what is needed for springs. I know Vortec run into issue with higher lifts and standard SBC springs. Most of us have cams over .500 lift and use Beehive Springs for that reason (myself included)

I wouldn't do head studs, you will have to pull the motor to remove the heads and clamping force isn't an issue with design of the block and heads anyways.

I have bigger valves 2.00/1.56 and fully ported Vortecs. I had thought about just using stock vortices with home porting job, valve job and stock sized comp cam valves for peace of mind. I ended up getting an unexpected bonus that paid for my Vortec, (I actually already had bought the valves and returned them to summit) My thought process of using better valves was that I was more worried about a valve damaging my turbo. Our stock heads use nothing special for valves, I can't remember anyone burning stock valves.

I have a 03 balance shaft motor, I just left the balance shaft in. These motors aren't high reving.

Usually most recommend 4 bolt mains for over 500hp.

I wouldn't fill my block for a 11-12psi supercharger build. Those filling the block are pushing the limits of the block (which is the weakest link once good a set rods, pistons and 4 bolt wins are added). I wouldn't start thinking about filling a block until I was going for 600+ hp builds. I usually run about 15psi on my junkyard 4.3 Vortec motors, I have run it up to 18psi.

 

[overS-10ded]

Re: '96 4.3 vortec build

I think you can save yourself a lot of work and money.

The 1.6 RR are not worth pulling your heads and doing all that work. I have roller rockers and am looking at getting rid of my 1.52 RR (Comp Cams) because they sound like a sewing machine.

The 1.6 vs 1.52 ratio has been calculated to offer a negligible advantage and if doing so means you have to pull your heads and do a "refresh", I'd not even go there.

Instead, maybe get another junkyard motor and build a fresh motor. If you need to.

The Q tip will likely be incinerated and turn to ash very quickly and be expelled from the cylinder. It won't go through a turbine so I doubt you'll see any ill effects.

:2cents:

Hey thanks for your opinion. I felt the same about incinerating the qtip but have been inching toward this build for a while now, collecting parts here and there. Mostly using the q-tip as an excuse!
The 1.6 full roller rocker arms with my cam will give me .461 intake lift and .469 exhaust. Perfect for the Vortec heads and I have the UltraProMag rockers already ! I know and have driven this engine for a long time. If it checks out good, which I think it just might, it will be a well seasoned block to do my build with!

Good times!
Bruce

 

[overS-10ded]

Re: '96 4.3 vortec build

The cam that you spec'd is decent for a stock cam, it much more aggressive than your stock one. Normally I would agree with Quickstop assessment of 1.6RR being a waste on cam swaps and vortec's, because stock Vortec peak at .450 lift and even ported Vortec don't flow much better past .500 lift. The cam you spec'd has .432/.439 lift.

You should figure out and calculate and research what is needed for springs. I know Vortec run into issue with higher lifts and standard SBC springs. Most of us have cams over .500 lift and use Beehive Springs for that reason (myself included)

I wouldn't do head studs, you will have to pull the motor to remove the heads and clamping force isn't an issue with design of the block and heads anyways.

I have bigger valves 2.00/1.56 and fully ported Vortecs. I had thought about just using stock vortices with home porting job, valve job and stock sized comp cam valves for peace of mind. I ended up getting an unexpected bonus that paid for my Vortec, (I actually already had bought the valves and returned them to summit) My thought process of using better valves was that I was more worried about a valve damaging my turbo. Our stock heads use nothing special for valves, I can't remember anyone burning stock valves.

I have a 03 balance shaft motor, I just left the balance shaft in. These motors aren't high reving.

Usually most recommend 4 bolt mains for over 500hp.

I wouldn't fill my block for a 11-12psi supercharger build. Those filling the block are pushing the limits of the block (which is the weakest link once good a set rods, pistons and 4 bolt wins are added). I wouldn't start thinking about filling a block until I was going for 600+ hp builds. I usually run about 15psi on my junkyard 4.3 Vortec motors, I have run it up to 18psi.

Hey dgoodhue thanks for your time and info! I have done research for a very long time and I think I have a sane plan for a solid 350-375 horse 10psi motor. The head studs I'm looking at have an allen head socket on the end of the stud to install/uninstall the stud which others have said they can remove their heads by removing the studs while in the car. I haven't bought them yet. What head bolts did you use in your build?
I'm removing the balance shaft because I'll be doing all the work anyway and why not lose 11 lbs? I understand it doesn't make much difference either way-in or out!
I'll have to wait to look at the whole thing at tear down and see what the valves look like and see if I can find a "bonus" to get some new valves. The Beehives I have will be perfect for my setup which I plan on turning lil over 6. My valve train I'm trying to keep light as poss so this low revving engine might rev faster anyway. Going to use studs on the 2 bolt main, don't think I need the 4 bolt mains. And thanks for your input on the "filling".

Good times!
Bruce

 

[dgoodhue]

Re: '96 4.3 vortec build

I had done a lot research and calculations as well, but I did all that over 10 years ago, so it isn't all fresh in my mind. Some parts have probably changed since I was last buying/build my engine.

I used ARP 233-3701 12 point cylinder head bolts. My engine is up around 450-475hp at 15psi.

I have 214/214 .535/.535 115lobe separation cam and I shift my engine @ 5500rpm. 6000 rpm is pretty high for the cam you have selected; I don't have a marine intake, so I am not sure if that shifts the rpm band upward. Spinning the engine to higher rpms does put more stress on the lower end of the motor, but you should be fine at your power levels. In some ways, I would rather throw more boost at my engine than rpms, but I am already up around 5500 rpm through the 1/4 mile traps as it is.

Also I forgot to mention in my first response, I would not use the comp cam 875 lifters, I use the 850's. The 875-16 require only 0.002-0.004 of preload (compare to 0.050-0.100 850 lifter) and its really important to get that correct or it can damage the lifters. If you search on them, you find lots of users on forums with damaged lifters. Personally, I would leave the 875's for race engines.

 

[overS-10ded]

Re: '96 4.3 vortec build

I had done a lot research and calculations as well, but I did all that over 10 years ago, so it isn't all fresh in my mind. Some parts have probably changed since I was last buying/build my engine.

I used ARP 233-3701 12 point cylinder head bolts. My engine is up around 450-475hp at 15psi.

I have 214/214 .535/.535 115lobe separation cam and I shift my engine @ 5500rpm. 6000 rpm is pretty high for the cam you have selected; I don't have a marine intake, so I am not sure if that shifts the rpm band upward. Spinning the engine to higher rpms does put more stress on the lower end of the motor, but you should be fine at your power levels. In some ways, I would rather throw more boost at my engine than rpms, but I am already up around 5500 rpm through the 1/4 mile traps as it is.

Also I forgot to mention in my first response, I would not use the comp cam 875 lifters, I use the 850's. The 875-16 require only 0.002-0.004 of preload (compare to 0.050-0.100 850 lifter) and its really important to get that correct or it can damage the lifters. If you search on them, you find lots of users on forums with damaged lifters. Personally, I would leave the 875's for race engines.

Hey Dave, thanks for your added information! My engine would shift at 4,900 before the s/c install. The ProCharger pulled (or pushed) the extra rpm's out of the cam! The shift point I am referring to is my 700r4 auto shift point and not a manual shift point-just for clarification of the higher rpm not being me holding it in gear longer, I have a corvette governor but the only difference was the s/c install and the shift point moved up 800rpm! After I built the 700r4, this did not change. So I'm thinking with the CPI cam it should be worth at least another 200 rpm over the anemic '96 cam. I got the CPI cam in the box for $100. I am also aware of the Comp 875 complaints and the requirements for (the lack of) preload. The main problem is guys trying to adjust them to "normal" preloads and this will break the retainer and then the lifter can come apart. Also, for consideration of consistency, all my numbers here are from the PCM and logging with EFILive tuning software.

I have a lot of wrenching experience. I am a retired pilot and aircraft mechanic and have built and worked on cars since I was 15 with my first '57 chevy in 1974 which I swapped out the 292 6 for a lg journal 2 bolt 327 that eventually I built and ran a EA Whithers prepped 471 blower set up @ 16% OD = 750HP when I was 18 - I ended up selling the running engine in 1978. Right now in CR I am getting ready to rebuild my wifes Toyota 4a engine in her '86 Tercel (which I upgraded from a 3a). Here my vehicle is an '88 Cherokee with a Mitsubishi 2.5liter 4cyl turbo diesel conversion. I'm a gearhead!

What did you use for your bottom end, did you go 4 bolt? Thanks again Dave for sharing your information and experience.

Good times!
Bruce

 

[Don W.]

Re: '96 4.3 vortec build

Bruce, From what kind of flying did you retire from? I don't fly anymore but did a bunch of charter flying years ago. Virtually all in a 182 up and down Calif. Didn't make much money but had a lot of fun.

I'm making about 450 hp (calculated using the internet based on 11.605 ET and 118 trap speed.) Specs: 4 bolt mains, Eagle rods, .030 over, 9.0/1 CP pistons which I would highly recommend BTW, "custom" Comp cam which is not all that custom (others have used it here), 275/285 dur, .502/.484 lift, 114 lobe separation.

1.5/1 rockers. stock valve size, Vortec heads with mild porting on the intake, just a cleanup on the ex., 60# injs, "built" trans. 1-2 shift at 5100, 2-3 at 5675, TC lock at 5250. 2800 stall converter. Interestingly for a motor like this my machinist said stock GM lifters would work and they seem to be doing fine. I use 3/4 turn on the rockers for pre-load. Hybred turbo, 3" end to end exhaust, 20# boost. Meth inj. 20* advance with -0- knock.

Only recommendation I might make is King bearings, the CP pistons, and a double roller chain. If I was starting from scratch I would probably use I-beam rods. My other thought is Magnacor wires. They made a huge difference in the way this thing runs. Plus my usual rant to make sure you degree the cam and have it balanced.

HTH a bit. Are you still wrenching on planes or flying?

Enjoy.

 

[overS-10ded]

Re: '96 4.3 vortec build

Bruce, From what kind of flying did you retire from? I don't fly anymore but did a bunch of charter flying years ago. Virtually all in a 182 up and down Calif. Didn't make much money but had a lot of fun.

I'm making about 450 hp (calculated using the internet based on 11.605 ET and 118 trap speed.) Specs: 4 bolt mains, Eagle rods, .030 over, 9.0/1 CP pistons which I would highly recommend BTW, "custom" Comp cam which is not all that custom (others have used it here), 275/285 dur, .502/.484 lift, 114 lobe separation.

1.5/1 rockers. stock valve size, Vortec heads with mild porting on the intake, just a cleanup on the ex., 60# injs, "built" trans. 1-2 shift at 5100, 2-3 at 5675, TC lock at 5250. 2800 stall converter. Interestingly for a motor like this my machinist said stock GM lifters would work and they seem to be doing fine. I use 3/4 turn on the rockers for pre-load. Hybred turbo, 3" end to end exhaust, 20# boost. Meth inj. 20* advance with -0- knock.

Only recommendation I might make is King bearings, the CP pistons, and a double roller chain. If I was starting from scratch I would probably use I-beam rods. My other thought is Magnacor wires. They made a huge difference in the way this thing runs. Plus my usual rant to make sure you degree the cam and have it balanced.

HTH a bit. Are you still wrenching on planes or flying?

Enjoy.

Hello Don! I was Pt135 scheduled from PHX to SEZ (Phoenix to Sedona) and also SFAR50 (Grand Canyon) from '85 to 89-then on my own. I use to fly our company route 3,000' below the rim of the canyon on our FAA deemed senic route. When I quit that company-Air Sedona, we were at 7,000' above the North Rim! I'm glad I had that extreme opportunity and experience before the tight regulations. That was all fix wing single Cessna time in 172, 182, 206, 207 aircraft which I also maintained. At the same time I owned a 1950 Navion B model with a Continental IO520 conversion which I owned for 17 years. That airplane is the '57 chevy of the sky with all the different mods available. I was 26yrs old (1985)---for 11,500$! I worked on it about 10hrs for every hour I flew my Navion but I did soooo much work to that beauty-to me a labor of love! I was a AZ charter pilot for the most part. I built my house at P52 - a private hard surface airpark in Camp Verde, AZ-15 miles outside Sedona AZ where I created my dream of my airplane in my garage! I also worked for a few different aviation maintenance facilities in Sedona.

Life happens and a divorce dissolved my toys and life and I was given the opportunity to be a single dad raising my two kids. Moved to Colorado and it took a few years to get over and accept the past but as soon as I could I bought a 1958 C-175 with lots of plans to do a O-470 and tail wheel conversion. I had an accident that wrecked my back for a few years and I couldn't fly for a year post surgery-finally after getting back into the cockpit, I didn't get around to doing what I wanted for the C-175 and sold it for now teenaged needs of my two growing kids. I had my Blazer when I got rid of my Navion in AZ, and promised myself to make the Blazer my center of attention for my need to modify and engineer-and figured it would be something I could afford-lol. I sold my C175 in 2006 and got my kids through HS and met a woman in Costa Rica -(eHarmony.com) and I moved there in 2009. I got my last bi-annual in 2007 and didn't log any time after that. I have just under 2,500 hrs. All my friends I started with are now with major carriers with over 10,000 hrs- that was never what I wanted.

I greatly appreciate your input about the lifters. I haven't heard a thing bad about stock lifters. I might be sliding the 875's over to ebay! What PCM are you using? I'm planning on using the KING bearings. I'm sticking with the forged pistons I have which should work out to be around 9-1 depending on head gasket thickness- With a .045 quench.

The single row roller-stock oem fare, was to replace the stock link chain and I thought it to be an upgrade as they went to those in '98. For me, more of an experiment in weight reduction. And then GM added a tensioner to stop the chain slap that sets off the knock sensor when it streches! So with the OBDII engine and subsequent plastic front cover and crank sensor on the nose of the crank requires a special set, that I haven't quite nailed down yet. But I agree that is a pretty standard approach in any hi-po build to upgrade to double roller chain. And yes-degree the cam! Balance assembly. For the money of reconditioning my I beam rods with ARP bolts and then having them installed with pistons, or bushed so I can install the pistons, will cost less than the H beam rods, but not that much less, about $120-price of a double roller? And the Eagle H-beams are supposedly lighter than a stock 4.3 rod. Anyway dam sexy for $429 Jegs price. However, I am on a budget and appreciate viable information that I can use to re-asses my own ideas and to spend the money where it is needed and not for something that really isn't required.
Your combo seems to work very nicely! Thanks for indulging me in my aviation memories. Life is one grand adventure!!

Good times!
Bruce

 

[ItsMyTy]

Re: '96 4.3 vortec build

I would not use the comp cam 875 lifters, I use the 850's. The 875-16 require only 0.002-0.004 of preload (compare to 0.050-0.100 850 lifter) and its really important to get that correct or it can damage the lifters. If you search on them, you find lots of users on forums with damaged lifters. Personally, I would leave the 875's for race engines.

THIS

Go with the 850s

 

[Don W.]

Re: '96 4.3 vortec build

How I miss flying. Learned to fly in 1968. In a Cherokee 140 then promptly bought a 1947 PA-12 Super Cruiser (tail dragger) and had to learn to fly all over again.:rotf: Then to a Cherokee "C", (older 180 hp Cherokee). The a straight wing 180 hp Cherokee Arrow. That was fun airplane. Fairly fast on not much gas. Then, like you, I had to quit for a number of years. Things change again and I get a 1982 C-182. Best of the bunch. Fairly fast and carried whatever you could cram into it. Ended up leasing it back to the FBO and flying it as a charter pilot. Also flew backup "Air Attack" for Calif Div of Forestry. Air Attack is what most people refer to as the "spotter plane." Didn't do many fires but once certified by them I did a lot of charter work. Finally quit back in the late 90s with 2600 hrs. Great memories.

I have a friend who's a corporate pilot flying a King Air. Sweet...

Good luck with your build. Keep us posted.

Don

 

[Don W.]

Re: '96 4.3 vortec build

Couple of pics:

Formation with a PBY

https://www.dropbox.com/s/fb2nxtmmjonlr3n/PBY.jpg?dl=0

And we used to fly over to Lake Berressa (about 60 miles N of SFO) and land on the island. Can't do that anymore...

https://www.dropbox.com/s/azxkk5oo71vwb4t/3483M Berressa Island-1.jpg?dl=0

Fun times.

 

[dgoodhue]

Re: '96 4.3 vortec build

What did you use for your bottom end, did you go 4 bolt?

I have a junkyard balance shaft short block in my truck, so its a 2 bolt motor. It was my 1st blank sheet tuning project I had done, so I didn't want to risk damage a built short block. Some day I will build another motor. The junkyard motor has lasted longer than I expected even despite a couple tuning faux pas.

 

[overS-10ded]

Re: '96 4.3 vortec build

Dave I hear ya there! I have had a few learning burps in my tuning with this motor too. I will just have to wait until tear down to tell for sure. Thanks!

Good times!
Bruce

 

[overS-10ded]

Re: '96 4.3 vortec build

Couple of pics:

Formation with a PBY

https://www.dropbox.com/s/fb2nxtmmjonlr3n/PBY.jpg?dl=0

And we used to fly over to Lake Berressa (about 60 miles N of SFO) and land on the island. Can't do that anymore...

https://www.dropbox.com/s/azxkk5oo71vwb4t/3483M Berressa Island-1.jpg?dl=0

Fun times.

Thanks for the photos Don! I have a box of pictures at my son's in St Petersburg but not much on my laptop. You speak my language my friend! I got my ticket in 1982 learning to fly in the mountains of Colorado. I have worked on a Piper Arrow installing speed mods that are from the outfit Knots2U I think. I spent a week installing flap gaps, aileron gaps, and I think the biggest gain was from a elevator gap seal. As the mechanic I test flew the mods, as was standard practice. I liked the Arrow very much and the owner was very happy with how the mods worked! And you are right, the C-182 is fabulous. I have around 800 hrs in a 182. If you have any more pictures you would like to send, use this email; bruces416@yahoo.com

Good times!
Bruce

 

[overS-10ded]

Re: '96 4.3 vortec build

What timing sets are being used on '96up Vortec obd2 builds? And does the balance shaft affect the use of double roller timing set?

Good times!
Bruce

 

[dgoodhue]

Re: '96 4.3 vortec build

What timing sets are being used on '96up Vortec obd2 builds? And does the balance shaft affect the use of double roller timing set?

You need to use a balance shaft timing chain set because of how the balance shaft spaces the cam gear. I don't think the traditional SBC timing gear set can be used. I used GM parts. GM had a TSB for timing chain for rattling, so that is what I used based on another persons experience.

12458911 Chain Kit and new gears
89017257 Tensioner
89017259 Cover Kit.

Comp Cams also makes a balance shaft timing chain.

 

[overS-10ded]

Re: '96 4.3 vortec build

Yea those are the exact parts I have - and figured on using based on the point that the balance shaft and gears take up a lot of space. But then balance shaft/gears delete still has an issue with the reluctor ring and crank sensor, and the plastic front cover from what I have read on different threads here and there. I'd like something a bit more substantial I think. The cloyes c-3211 single roller looks like the chain is quite a bit beefier than the oem one!

Good times!
Bruce

 

[Don W.]

Re: '96 4.3 vortec build

I knew the balance shaft motor took a different chain just not if you could get it as a double roller.

 

[overS-10ded]

Re: '96 4.3 vortec build

I knew the balance shaft motor took a different chain just not if you could get it as a double roller.

I think I'm going with the Cloyes C-3211 or 9-3654x3 vs the oem roller chain.

http://www.cloyes.com/Images/CloyesHP_Catalog.pdf

Now about the bottom end and using the stock crank; I read that "500HP" is the number many use to include 4 bolt mains. What is the best options for the 2 bolt if I stay with that route?

Good times!
Bruce