Lower intake swap / Vortec head & cam install on stock bottom end

[Tooky]

The time has finally come, for all 6 years I've owned this truck, I've been running the stock 179*/190* camshaft and the pathetic stock 165cfm heads... After reaching 27 PSI with 0 knock I felt like the limit was (nearly) reached for power production on this combo unless I added nitrous. I wanted to do nitrous with the stock heads and cam and try to go for Phil Long's times but those stock heads/cam suck so bad, I just can't wait any longer, I figure 6 years is enough time already. With 24-25 PSI on 93 octane with alcohol injection and full accessories, I got it to run consistent 11.80-12.0s @ 112mph for the last 4 years, with a best of 11.79 @ 114 MPH (back when I had the stock torque converter).

The plan was to swap lower intakes with a powdercoated spare I purchased, and send my original off to be machined for Vortecs, and then do the install later. RPM said they only need 3-4 days to do the machining so I changed plans and decided to move the schedule up and do this all in 1 shot!

I'll be installing ~2004 brand new unported, stock valved, OEM #113 Vortec heads with stock "shaft mount" 1.5 roller rocker arms, and a custom camshaft of significant duration. I wanted to have the heads ported but head porting seems like a terrible return on the money invested, not to mention a total crap shoot depending on who does the work. I plan to port the injector bungs of the lower intake manifold myself, and some porting to the stock exhaust manifolds. I've never pulled heads off a vehicle before or installed a cam so this will be a chance to really put my wrenching to the test.

I'm hoping to get this combo solidly in the 10s by the time I'm done with it. If I can get even a 10.99 on 93 octane with pump gas with this setup, I'll be happy as a pig in shit, considering stock bottom end with 100% stock accessories and practically stock appearance under hood on this minimum budget build. I'm trying to do this upgrade complete for $1000 total, to (hopefully) go from 11.80's into the 10s. With the PTE51 turbo kit, SMC alcohol, Ultimate chip, tuning software/devices, CBR LS1 brakes, etc. I totalled it up about a year ago and it came in right around $3000 total in mods other than the purchase price of the truck, $6000 if you include the max effort 700R4/custom Yank converter.

I don't know who has the "fastest stock bottom end" SyTy but whoever it is, I'm going to be gunning for them! :1gun:

Monday July 23rd I started disassembly. Here's the "before disassembly photo". If everything goes correctly, it should look identical when it's finished.

Intercooler removed. That's a lot of wires/hoses to deal with!

It only gets worse. TB/Upper intake removed. Took me 6.5 hours from 9 PM Monday night to 4:30 AM in the morning, plus 1 hour of screwing off. I know there are people who claim they can pull an intake in no time at all, but I don't believe it.... You have to drain the coolant from radiator and IC, first find suitable containers.... jack up the truck, find a drain mechanism for the radiator so it doesnt run down the frame rails and all over the garage, etc. etc. etc. Maybe if you had a shop, or had a race truck with no accessories. Although I certainly don't claim to be the fastest wrench out there :lol: I placed all the removed parts on a table in order and tagged with notes/photos to reassemble in the same manner it came apart.

Tuesday spent 1 hour working on lower intake, did not get pulled. (problems with vacuum cleaner, didn't want all the caked-on crud to fall into lifter valley).

Wednesday spent 3 hours, got the lower intake off, stripped of parts, photographed, packaged, sent off to RPM for $250 lower intake machining for Vortecs. I am going for a gloss gray appearance, what I feel it should have been stock.

My first look inside this motor! It doesn't have the lifter "spider" I thought it would. I think this plastic 'rail' type is because the motor was replaced in 1994 (under warranty). Take a look at the heads. I was secretly hoping for L35s :lol: Even though I already knew the casting # was just the lowly LB4.. The coolant ports appear practically packed full of shit, even though I change/flush the coolant almost yearly, and I have ran "prestone SuperFlush radiator cleaner" through it once before.

Here's a look at all the excess metal I intend to remove near the injector bung. What a bottleneck! Wish I would have tried this with the stock motor.

Here's my original intake fresh off the motor, next to my spare stock lower intake that's been powdercoated gray. I want my Vortec-converted intake to look the same way! GM sure did a shitty job overspraying these intakes with black paint! I think the black looks just awful, like it's packed full of grease & dirt.

Here's the brand new Vortecs I'll be installing:

Everyone says it cost $50-$100 (tops) to drill the vortecs for the SyTy manifold. Local shop wants $150 and 2 weeks! Then I called everyone I knew and stumbled across an unbelievable stroke of luck. A friend of mine offered to do it for free at his work next week on his lunch break. Evidently he works at a machine shop and I didn't even realize it.

I'll be having the valve spring seats/guides cut down to fit standard springs, and drilling holes for the factory SyTy dipstick and ignition wire looms. The goal is 100% bolt on, stock functioning. :rock:

Here's the rest of the details on the build. I'll be tuning the Stock ECM with the Moates Ostrich. Of course I'll continue to use the KILLER stock intercooler for the forseeable future. (Plus, without that intercooler it would never look stock.) The PT51 turbo will stay on as well, until I can truly "max it out".

 

[TYPHOOL7]

Re: Lower intake swap / Vortec head & cam install on stock bottom end

hell yeah Took, looking good, although when you go faster than my $$ truck imma kill you.. time to aim for low tens to hide from Tooky

ps upper intake comes off in the shortest amount of time less the factors of cleanliness you mentioned

 

[Flyin Ryan]

Re: Lower intake swap / Vortec head & cam install on stock bottom end

Good luck on the swap man.. always enjoy reading your post they always have tons of detail and reason.. looking forward to whatever else you add to this thread especially the pics

 

[turbodig]

Re: Lower intake swap / Vortec head & cam install on stock bottom end

Here's a look at all the excess metal I intend to remove near the injector bung. What a bottleneck! Wish I would have tried this with the stock motor.

Gotta go carefully with this. The Vortecs have a much higher roof, so you need to leave some material to blend with. It would be considerably better to build the runner up around the injector boss, such that you can get a semi-smooth continuation of the roof of the intake port. Otherwise, you get quite a ski-jump in there.

Here's some pics I took of mine. I probably went a bit farther than I should have... The tips of the injectors are just starting to neek into the port. You don't want that, as the "closed-end pole" it creates is bad for flow. Ideally, the best setup would be to create an airfoil shape around the injector hole, extending as far as possible up the intake and down into the port. We can't add material to the cast heads (unless you like moroso putty), so you're kinda limited with what you can do.

(This is rough state... I cleaned 'em up after this pic, got the surfaces milled too.)

Nolan had some really good pics of modded manifolds, as well.

This picture is really good for visualizing what you want to do with the intake.
(too bad we don't have a fire-wrecked intake to cut up)

http://www.turbotimelounge.us/gallery/myclone/aag

Notice how the roof of the port is starting to turn back towards the intake, just at the end of the port?... you want to effectively continue this turn inside the intake. A sharp turn here isn't a good thing... you want to make a gently swooping bend.

Imagine the whole path as one big chunk of garden hose... kink it, and it won't flow.

The harbor frieght electric long-nose grinder is your friend. Rig up a household dimmer switch to control speed (get the highest watt dimmer you can find). This kicks the crap out of using an air-powered die-grinder.

Get a bunch of cartridge rolls, and maybe an aluminum cutter (carbide). You can use the Harbor frieght metal rasps to do big material removal, also, but they load up quick and don't last long. A set will do you a whole manifold, then you chuck 'em.

I find it handy to use a flex-shaft Dremel to do the finish/detail stuff. You can get some 1/4" sanding drums that let you get into tight places. The dremel is easier to control material removal.

It's a patience exercise. Speed kills. Take your time, make a few grinds, examine your port shape, feel for contour, grind some more, repeat. Making a template like I have in the pics helps to get a repeatable shape on all the ports.

Later,

 

[93 TY 2185]

Re: Lower intake swap / Vortec head & cam install on stock bottom end

The harbor frieght electric long-nose grinder is your friend. Rig up a household dimmer switch to control speed (get the highest watt dimmer you can find). This kicks the crap out of using an air-powered die-grinder.

Good call they also have a 15 Amp "router speed control" on sale.

Links to Grinder and speed control.
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=44141
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=43060

 

[ashman]

Re: Lower intake swap / Vortec head & cam install on stock bottom end

bought one of the HF speed controls last week. works great.

 

[dgoodhue]

Re: Lower intake swap / Vortec head & cam install on stock bottom end

I didn't remove as much material as Dig. I like Dig's, carboard cut out idea for measure port work. I tried to do each on my ports evenly. Initially, I took down the injector bung with a metal file. I did each port a little bit at a time (1 minute) and did them evenly as possible. My air compressor limited how long I could my grinder anywyas, so changing ports every minute just gave it a chance to catch up.

I measure my Vortec ports shape with a gasket and another sheet of paper behind it and place in on my intake ports. First thing you will notice is basically the Vortec port extends to the edge of the stock manifold. I was trying for more of bell mouth output to reduce turbulence. I did remove some materal to open the port up a little. The Bortec will need to be bell mouthed on one edge as well (too narrow and the port isn't rectanglar. The port tranistion is going to be ackward anyways with a bell mouth coming out the intek on the top of th eport and a bell mouth going to the side of the head. Even whats lost in that transition will be more than made an unported Vortec stock air flow of ~50% more than stock LB4 and its far supperior resistance to detonation.

 

[James Thomas]

Re: Lower intake swap / Vortec head & cam install on stock bottom end

Gotta go carefully with this. The Vortecs have a much higher roof, so you need to leave some material to blend with. It would be considerably better to build the runner up around the injector boss, such that you can get a semi-smooth continuation of the roof of the intake port. Otherwise, you get quite a ski-jump in there.

Here's some pics I took of mine. I probably went a bit farther than I should have... The tips of the injectors are just starting to neek into the port. You don't want that, as the "closed-end pole" it creates is bad for flow. Ideally, the best setup would be to create an airfoil shape around the injector hole, extending as far as possible up the intake and down into the port. We can't add material to the cast heads (unless you like moroso putty), so you're kinda limited with what you can do.

(This is rough state... I cleaned 'em up after this pic, got the surfaces milled too.)

Nolan had some really good pics of modded manifolds, as well.

This picture is really good for visualizing what you want to do with the intake.
(too bad we don't have a fire-wrecked intake to cut up)

http://www.turbotimelounge.us/gallery/myclone/aag

Notice how the roof of the port is starting to turn back towards the intake, just at the end of the port?... you want to effectively continue this turn inside the intake. A sharp turn here isn't a good thing... you want to make a gently swooping bend.

Imagine the whole path as one big chunk of garden hose... kink it, and it won't flow.

The harbor frieght electric long-nose grinder is your friend. Rig up a household dimmer switch to control speed (get the highest watt dimmer you can find). This kicks the crap out of using an air-powered die-grinder.

Get a bunch of cartridge rolls, and maybe an aluminum cutter (carbide). You can use the Harbor frieght metal rasps to do big material removal, also, but they load up quick and don't last long. A set will do you a whole manifold, then you chuck 'em.

I find it handy to use a flex-shaft Dremel to do the finish/detail stuff. You can get some 1/4" sanding drums that let you get into tight places. The dremel is easier to control material removal.

It's a patience exercise. Speed kills. Take your time, make a few grinds, examine your port shape, feel for contour, grind some more, repeat. Making a template like I have in the pics helps to get a repeatable shape on all the ports.

Later,

So Dig, how did you come up with this template and how can it be reproduced?

____________
James

 

[E-Rue]

Re: Lower intake swap / Vortec head & cam install on stock bottom end

iv seen a ton of intakes done like that but i usually leave a little more material to cover the injector..... kinda make an air foil.

not sure if its obvious from this pic, but the intake has a piece of plate welded to each side of it, and an obserd amount of material added around the injector bung so that it doesnt get too thin when i get carried away with the carbide cutters. if you smooth down the weld on the outside of the intake before having it powdercoated its impossible to tell its not stock by anyone that doesnt know what they are looking at.

it really helps to get a lot of weld added around the injector on the top of the intake, because you will want to remove a lot of material from the injector side of the port to get a straight shot at the back of the valve. your basically adding material to the outside so you can take it away on the inside. if you look closely at dig's pics, you can see that even tho he has removed the entire protrusion into the port where the injector sits, it still has a strong taper back into the intake..... the less taper you have and the farther you port back into the intake the more air it will flow.

also id love to custom spec you a cam.

e

 

[turbodig]

Re: Lower intake swap / Vortec head & cam install on stock bottom end

So Dig, how did you come up with this template and how can it be reproduced?

____________
James

Trial and error.

Really, though, there's nothing magic about the shape. Once you get one of the ports to your liking, you cut up beer-case cardboard until the curve matches your "good" port.

Same can be done with heads, to get your short-side turns and bowl shape right.

It's a old trick... I picked it of from a book (I think one of the Vizard books), so I can't claim credit for it.

 

[turbodig]

Re: Lower intake swap / Vortec head & cam install on stock bottom end

iv seen a ton of intakes done like that but i usually leave a little more material to cover the injector..... kinda make an air foil.

e

That's nice work.... that's what they should look like.

It's too bad we can't add material to the vortecs; it'd be nice to replicate that shape behind the injector hole (downstream from it) as well. Good excuse for -8 Brodies...

If you really wanna get sneaky with appearance, you can shot-peen the welded/ground area so it looks like a cast finish. Like you say, with the manifold in place 99% of onlookers will never notice.

The socks are cool too.

 

[It's just a six]

Re: Lower intake swap / Vortec head & cam install on stock bottom end

Just a little info to pass,,,,
If you do not want your porting rasps,/carbide cutters plugging up,,,,, spray a little WD-40 every onece in a while,during the porting process. to free up the stuck aluminum,or LPS 1 & so on.

 

[It's just a six]

Re: Lower intake swap / Vortec head & cam install on stock bottom end

Personally,
I would just cut/grind around both sides of the injector boss's(as to raise the intake ports)., & weld extra aluminum on top of your intake manifold,but, after you do that you would need to repowder coat your intake again. :2cents:

 

[Tooky]

Re: Lower intake swap / Vortec head & cam install on stock bottom end

Things moving along slowly. Been humid and hot as hell here the past week so not much got done. I did order a custom cam and removed some more stuff from the motor. The vortecs are at the machine shop getting drilled for the syty pattern, cut for larger springs and clearanced for more lift, dipstick/wire loom holes drilled, and the decks resurfaced. I wasted at least a week trying to find a machine shop who could do the drilling for less than $125 but every lead eventually fell through so I had to bite the bullet.

I took a good look at the shop manual and realized I'm definitely in way over my head at this point! But a friend of mine likes to say, that's when you know you're about to gain some good experience.

I doubt I'll still be able to get this done before Nationals but I'm going to try.

 

[Tooky]

Performance Predictions!

Performance Predictions!

I also spent some time (okay, all of my free time lately ) thinking about what this "should" run after it's finished. I came up with three scenarios. Usually when you get something done, it either works just like you thought, better than you thought, or nowhere near as good as you thought it would. Here's my predictions:

Worst case scenario (assuming the bottom end doesn't let loose which is the ultimate worst case scenario :lol: )
11.40 - 11.50 @ 115-116 MPH. I could see this happening if the unported vortecs are severely overhyped and/or my PT51 turbo is already closer to it's limit than I thought.

What I realistically expect once tuned well at high boost with alcohol
10.95-11.30 @ 117-124 MPH. I'll still be somewhat "surprised" if it really works out this well!

Best case scenario (if it works beyond my expectations)
10.65-10.90 @ 125-127 MPH. I doubt this would happen but I've had a few mods on my truck work out better than I expected in the past..

 

[supersports10]

Re: Lower intake swap / Vortec head & cam install on stock bottom end

i love the tooky thread's......

always informative with pic's.

tooky... what application is your turbo to intercooler hose from??

 

[Tooky]

Re: Lower intake swap / Vortec head & cam install on stock bottom end

Clint, to say "thanks" I searched through my photo archive for you. Autozone radiator hose part "304" is the magic number!! Cut a little to fit but you'll see it's the perfect hose!! I honestly have no idea why anyone would run a hose with a huge hump like some I've seen but I can only imagine it's because they didn't know about the ol' Autozone #304.. :lol:

 

[jwaller]

Re: Lower intake swap / Vortec head & cam install on stock bottom end

there is no need to cut the heads for larger springs. I personally use a comp spring and have never cut a spring seat. it's a waste of time and money.

 

[turbodig]

Re: Performance Predictions!

Re: Performance Predictions!

I also spent some time (okay, all of my free time lately ) thinking about what this "should" run after it's finished. I came up with three scenarios. Usually when you get something done, it either works just like you thought, better than you thought, or nowhere near as good as you thought it would. Here's my predictions:

Worst case scenario (assuming the bottom end doesn't let loose which is the ultimate worst case scenario :lol: )
11.40 - 11.50 @ 115-116 MPH. I could see this happening if the unported vortecs are severely overhyped and/or my PT51 turbo is already closer to it's limit than I thought.

What I realistically expect once tuned well at high boost with alcohol
10.95-11.30 @ 117-124 MPH. I'll still be somewhat "surprised" if it really works out this well!

Best case scenario (if it works beyond my expectations)
10.65-10.90 @ 125-127 MPH. I doubt this would happen but I've had a few mods on my truck work out better than I expected in the past..

Not to rain on your parade, but your first few runs will likely be high 11s. Once you've had some time to sort everything all out, I don't think 11.40 is out of the question. Maybe a .30, with a good hook. Miracle air day, 11.10-11.20.

You're entering territory where .1 costs you a lot more HP than it used to. Also, below 11 seconds, the first 100 feet is critical to your times. People fool themselves into thinking they can "make it up" with more top end, but it takes *lots* of HP to make that happen.

Again, not trying to whizz in your Wheaties, but that's the reality that plays itself out time and time again. It'd be neat to see it run high 10s, but that's not really likely.

 

[dgoodhue]

Re: Performance Predictions!

Re: Performance Predictions!

You're entering territory where .1 costs you a lot more HP than it used to. Also, below 11 seconds, the first 100 feet is critical to your times. People fool themselves into thinking they can "make it up" with more top end, but it takes *lots* of HP to make that happen.

I totally agree. I was doing some calculations for a friend to make his mid 11 sec car run a 14.0 so he could take a passenger. He wanted to do a full 1/8 mile. My inital calulation of run his car upto 100mph and then keeping the speed a constant 100mph was coming back with only .3-.4 penalty :shocked!: I calculated he had to quickly slow down to 60mph, the 1/8 mile make such a hug difference in 1/4 mile times. This is also why when you see a fast car blow up/back out of it half way down the track and coasts; it still runs a great number with just a low mph.