My Vortec engine build.

Jun 21, 2021
87
I figured I would start a thread to track my progress and just put some information out there for anyone who is looking for vortec info and also for me who may have some questions. My initial plan was to do a vintage looking small block that was period correct, but life happened and so I went ahead and put that on the back burner for now, and do a simple heads, cam and intake package so the car would at least make decent HP for the time being. As anyone knows, as nice is my 77 Z28 is, 185hp is ridiculous.
RobsCamaro.jpg

I went ahead and bought NEW GM 062 Mexican casting Vortec heads assembled as part of a top end package that Chevrolet Performance sells, p/n 12558060K1 which comes with the heads, head gaskets, head bolts and intake bolts. I believe the head gaskets are .028" compressed but I am not sure if I will need them or not yet.
vortec3.jpg

vortecchamber.jpg

vortec4.jpg


Now, knowing that the springs are not going to work with the cam and retainer to seal clearance is an issue, I went ahead and purchased Alex's Spring kit p/n VSK4H50 for use with the cam I need (more on that later) and also remedy the clearance issue.
alexs.jpg


For the intake I chose to stay GM (I work for GM) and went with the Chevrolet Performance 12366573. This is the same high rise dual plane GM uses on a lot of its crate engines which should be perfect for what this car needs. These intakes have a good reputation with the circle track crowd and is said to be very similar to the Edelbrock RPM.
CPintake.jpg


For the camshaft I am going to run a hydraulic flat tappet this go round. After talking to a few well known builders, the flat tappet below 220-ish or so lift really does not give up much to the roller. For the price difference I am willing to take that chance and find out. The only problem is Im not sure which one, so I bought both cams I liked as well as the lifter kit, 3100 roller timing chain, Magnum 1.5:1 rocker arms and pushrods, which is still waiting to be filled due to a lifter shortage.
Cam #1 choice is an XE262H-10, 218/224 .462"/.469" ground on a 110 with a 106 ICL.
This cam I think would be the better of the 2 for drivability and cruising. I have found numerous people who run this cam with Vortec heads and reported they are very happy with the results. I have seen anywhere from 260rwhp to 340rwhp with this build. There have also been a few magazine builds with this cam, making over 415hp.
Project Danger Mouse -
https://www.motortrend.com/how-to/s...est-engine-results-danger-mouse-part-fifteen/
- and -
Project Clone - a copy engine made after Danger Mouse that also put up about the same numbers
https://www.motortrend.com/how-to/sucp-0401-chevy-350-small-block-clone/

Cam option #2 is the Comp XE274H-10. This cam is more aggressive with 230/236 .487"/.490" also ground on a 110 with a 106 ICL. I have heard idle videos of this cam and also researched a ton of info where this was used with Vortec heads with great results. There are also a few builds I could highlight but I will just tell you what you already know, it made more power but sacrificed some low end tq and driveability. The reason I am hanging on to this cam is for the simple truth, I might need it!

This past weekend I drove to Houston to go see the in-laws and dropped my new heads off to Mark at MK Racing Heads, a local respected porter who does a lot of Super Stock Class heads for a little clean up and to set up the valve springs. We talked and BS'd for literally a couple hours and I have to say that I was really impressed. He works out of his house and believe me, he DOESN'T need to BS for money. He even showed me exactly what he was going to do to the heads, and how he focuses on port shape more than anything. It was really cool to see his work and how the ports had a really trick twist to them. Were going to stay with a 1.94 intake valve and try to get the velocity up as much as possible all the way up to .500-.550" lift and keep them flowing where the flow will not drop off like stock vortec heads do. This, I believe will be my ace in the hole. He basically gave me a wink and said, expect 30 more hp.

http://www.mkracingheads.com/

I am also going to mill the heads a little, but I need to get some measurements first so its back to the garage for tear down. Not wanting to scuff the paint, I ordered a full face fender cover from Bob's fender covers. It fits like a charm and it works!
bobsfc.jpg

RobsZ28.jpg


As you can see I got the intake and valve covers off and all the coolant drained. I also ordered a few more parts.

The clutch was no doubt going to have to be upgraded, so for this I leaned on my own experience and bought a McCleod Super Street Pro Clutch kit. p/n 75224. I also need to see if I can resurface the flywheel I have or just replace it. I will know once I remove it and check for damage which should be any weekend now.
fewparts.jpg


The factory exhaust on the car is also a y-pipe into a dual outlet type exhaust. This will not work. I ended up ordering the Flowmaster 17149 2 1/2" exhaust system but it is also on back order. They are saying mid August due to covid, but we'll see.
https://www.holley.com/products/exhaust/exhaust_systems/flowmaster/american_thunder/parts/17149

Alright. Enough for tonight. I need to go check on some of my orders and hit the sack.
 

1980RS

Veteran Member
Jun 17, 2006
6,399
MN
I for one know that intake works very very well. As for the heads after I did my mild porting like you porter will be doing I replaced the valves with some aftermarket ones and added a 30° back cut. My times were super good at the track, around 32° timing is the sweet spot for those heads. I have the same thing in my street car now an L-31 right down to the stock truck cam and it will still light the tires up in the first 2 gears. When I had my LT4 Hot Cam in it the car would pull to 6500 effortlessly and not miss a beat. I sure would like to put that cam back in with one of my better carb I have redone over the Edeljunk one I had on there with the off idle issues. As for the heads, I just switched out some old 70's heads on my junky 400 with a set of 906's and picked up 6 tenths and 4.5 mph a couple of weeks ago, now 3 people want to buy the 400. I could not give it away last year and looks like I will be getting close to 2K for it now. You will think you put a nitrous plate on that car when you get the engine done.
 

biker

Veteran Member
Gold Member
Dec 7, 2014
5,078
Canada
Wow. Looks like you made some good choices. Nice clean safe work area too. Best choice you made is including a good experienced builder. He will save you from making ill-informed choices and give you the most important assembly and tuning tips.
I'm excited for you, this should be a really good, strong engine. For what it's worth, I'd go with the bigger cam. I cant remember what your gearing is, but with a standard trans and 3.42-3.73 gears, it will be pretty quick.
With proper timing and carb tuning, you wont have any driveability issues.
 
Jun 21, 2021
87
I for one know that intake works very very well. As for the heads after I did my mild porting like you porter will be doing I replaced the valves with some aftermarket ones and added a 30° back cut. My times were super good at the track, around 32° timing is the sweet spot for those heads. I have the same thing in my street car now an L-31 right down to the stock truck cam and it will still light the tires up in the first 2 gears. When I had my LT4 Hot Cam in it the car would pull to 6500 effortlessly and not miss a beat. I sure would like to put that cam back in with one of my better carb I have redone over the Edeljunk one I had on there with the off idle issues. As for the heads, I just switched out some old 70's heads on my junky 400 with a set of 906's and picked up 6 tenths and 4.5 mph a couple of weeks ago, now 3 people want to buy the 400. I could not give it away last year and looks like I will be getting close to 2K for it now. You will think you put a nitrous plate on that car when you get the engine done.

We'll see what he comes up with on the porting, bowl work, etc. If he calls me and says, hey I think we need to put some valves in it, I will pull the trigger. What you're describing is pretty much what I'm after. A car that will run some good times and boil the tires at will. The only thing that concerns me is how the bottom end is going to hold up.

Wow. Looks like you made some good choices. Nice clean safe work area too. Best choice you made is including a good experienced builder. He will save you from making ill-informed choices and give you the most important assembly and tuning tips.
I'm excited for you, this should be a really good, strong engine. For what it's worth, I'd go with the bigger cam. I cant remember what your gearing is, but with a standard trans and 3.42-3.73 gears, it will be pretty quick.
With proper timing and carb tuning, you wont have any driveability issues.

Yeah its nice and clean for now, lol. I bet when its all said and done it wont look like that. I'll probably have to power wash everything and repaint the walls.... No big deal.

Like I said above, Im not scared of the bigger 274, Im just curious as to what the bottom end might think about it. I am looking into the idea of a good balancer. The rear gears are the factory 3.73's in the 8.5 10 bolt. I'm pretty sure its worn out too. Thats another expense I see coming soon. I've actually been debating going to 3.42's or even 3.23's so I can at least cruise at 70. Right now cruise speed is 55-60mph and Im already at 3 grand! Not real fun considering the highways around my house are 75-85mph POSTED but the 373's makes a 185hp car feel like its got more than it does, thats for sure.
 
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1980RS

Veteran Member
Jun 17, 2006
6,399
MN
We'll see what he comes up with on the porting, bowl work, etc. If he calls me and says, hey I think we need to put some valves in it, I will pull the trigger. What you're describing is pretty much what I'm after. A car that will run some good times and boil the tires at will. The only thing that concerns me is how the bottom end is going to hold up.

Here is why I put the aftermarket valves in the heads over the good stock GM ones, the heads flowed better for a grand total of $72 at the time, cheap air flow for sure. As for the bottom end I just ran the carp out of a 400 that was put together 30 years ago and ran it twice at the track to see what it would do and all is good, Just don't spin it to the moon and float the valves and you will be fine.
 
Jun 21, 2021
87
We'll see. I really like the idea of using the 262 and not spinning the bottom end much past 6,000 while seeing a possible 400+hp. Seems to me it would be a good driving car that wouldn't give me much trouble. I think the 650 carb I bought would also work well with that cam. Lots of throttle response, great torque and if Mark does a great job with the porting, it should carry that 5600-5700 peak hp rpm for a while without falling flat on its face. Our goal is to literally have the car jump forward at the gear change. Rockin!
 
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Jun 21, 2021
87
Great detailed build with helpful links. I have the smaller cam in my 350 w/ Dart Iron Eagle Vortec heads, auto trans and OE 3.42 ratio gears. Very happy with bottom end torque, drivability and excellent vacuum for pb.
I noticed your flat hood, have you researched hood clearance ?
https://nastyz28.com/threads/vortec-compatible-intake-manifold-under-stock-78-z28-hood.290223/

I wouldn't think this intake would be an issue since I have an original Z28 Winters intake that I know fits, and the 573 doesn't seem any taller. I think you're right and its a good idea to measure, so tonight, I will post some pics of both and measure them.

As for the air cleaner problem, I bought a 70-72 dual snorkel LT1 air cleaner assembly from Rick's Camaros (p/n 33-146451-1) a couple weeks ago, but like everything else, its backordered. SMH

https://www.rickscamaros.com/camaro...ly-with-chrome-lid-1970-1972-33-146451-1.html
 

G72Zed

Veteran Member
Sep 8, 2015
4,084
Canada
We'll see. I really like the idea of using the 262 and not spinning the bottom end much past 6,000 while seeing a possible 400+hp. Seems to me it would be a good driving car that wouldn't give me much trouble. I think the 650 carb I bought would also work well with that cam. Lots of throttle response, great torque and if Mark does a great job with the porting, it should carry that 5600-5700 peak hp rpm for a while without falling flat on its face. Our goal is to literally have the car jump forward at the gear change. Rockin!

The 650 cfm holley carb and that intake with properly massaged Vortec heads you are getting breathed on/ported will fly past the 5,600- 5,700rpm mark with ease. The GM punny cam in the 602 crate with stock Vortec with my 650HP/spacer combo makes peak TQ @ 4,200 and peak HP @ 5,500 through 1-5/8 headers and a complete air cleaner assembly and still makes 388hp @ 5,800 and only a few points down at 6K.

And that's good for a cam with only 212/222 @ .050 and only .435-.460 lift on a nice 112.5 LSA. If your looking at the XE262H, it's going to pass that upper rpm range of 5,600 in a blink of an eye. And ported Vortec heads, yep.....

NB: That GM intake works well, in places that most don't pay attention to because it does not have the big aftermarket name on it....but it works beyond well, and well worth the money. JMO

Now off to tune and watch some 900+HP BBC's turn 8,200 rpm for a few hours...surprised I'm only half deaf LOL

Inked 602 94 octane 2_LI.jpg
 




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