Dan87IROC-Z

How come there are so many posts about them and TPI compatible intake, why does everyone want them so bad? From what I see, they aren't the best flowing heads, compared the the AFRs, Brodix, Trick Flows and such. Is it just because they only cost like $400? I am just curious, am I missing something?

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission
Borg Warner 7.75" 9 Bolt Rear End with 2.77:1 Gears.

Current Mods: LT4 HOT Cam, Comp Cams 1.52:1 Roller Rocker Arms, LPE High Flow TPI Baseplate, Edelbrock TES 1 5/8" Headers, Catco 3" High-Flow Catalytic Converter, Hooker 3" Aerochamber Cat-Back System, Transgo Shift Kit, Performance Resource Chip, Accel Ignition, K&N Filters, JET TPI Air Foil, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET: 14.32 @ 97.7mph
(corrected for elevation)

88IROCs

Silly Wabbit, cylinder heads aren't just about big flow numbers anymore. It's not only about how much air you can stuff in the cylinder, it's also about what you do with it - once it's in there. Stuff like mixture motion, quench area and plug placement all play a part in producing the most power.

The Vortec's are easily the best cast-iron heads the General has ever sold. And it doesn't hurt anything that they're cheap like borscht. And a good indication of their goodness is that: GMPP's FastBurn head(made famous by the "ZZ430" crate engine) owes a lot of it's design to the Vortec head. And in a fit of flattery, Edelbrock copied the Fastburn head for it's "E-Tec" line(and the rest of the aftermarket cylinder head maker's seem to be calling anything designed in the last 25 years "Fast Burn"). The fact is the Vortec's have sparked a lot of interest in cylinder heads, and hopefully the spirit of competition will spur other manufacturer's to develop useful innovations of their own.

The reason us TPI guys want a Vortec compatible base, is because we don't want the carb and TBI guys to have these heads all to themselves.

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"The reasonable man adapts himself to the world.
The unreasonable one persists in trying to adapt the world to himself.
Therefore all progress depends on the unreasonable man"
--George Bernard Shaw.

[This message has been edited by 88IROCs (edited July 31, 2001).]

Mista

Fats burn idea..........
goes back to Larry Wilmer (TOO/ENDYN) and about 1986 when it hit big time.

Million dollar Bill is a big tip off.

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86 T/A 5.0 A4 & 2.77 gear
15.62 @ 86 mph
93 Civic 1.6L
13.5 @ 100 mph

88IROCs

Actually, I think the factories were playing with Fast Burn chambers back in the late 60's/early 70's. However, lower octane gases and new emissions laws put the research on the back-burner for quite a few years.

The first production 'street' head I saw that used 'fast burn' principles came from Fueling Research. It was designed for Chevy big-blocks, and it's developer Jim Fueling claimed it could run run at 11:1 CR on 87 octane without detonation. Jim Fueling has been working on cylinder head design for over 20 years, and that was one of his many innovations in this area. Unfortunately, the asking price of $5000/pr made sure these heads never came into widespread use. This was all in the early 90's, and I don't know if Fueling Research is still in existence.

afgun

Fueling is still around... I believe an article about fueling heads was featured in GMHTP a couple years back.

They're around at <A HREF="http://www.feuling.com/">http://www.feuling.com/</A> but the website leaves a lot to be desired...

Cntrvrsy

I'm curious as 2 why there haven't been any independant tests on GMs ZZ430, specificly the Fast Burn heads. Chevy High Performance magazine has conducted a series of tests with the 350 chevy using Vortecs, TFS, and dozens of CompCam camshafts but they didn't try out the FastBurns. All they basically mentioned was that it is a ported aluminum version of the Vortecs. Has there been any independant tests that I missed?

88IROCs

There was a build-up a while back that compared GMPP's top three street heads for traditional small-blocks(LT1 and LT4 need not apply). The aluminum L98 made the least power, then the Vortec and finally(no surprise) the FastBurn's were top dog. All internal engine components were kept the same(which put's the L98 at an advantage) and all used the Edel 'RPM' manifolds(another disadvantage to the L98's).

I suspect part of the reason not a lot of the magazine's are testing them is the lack of aftermarket support for these heads. That and most magazines nowadays seem to focus on making the most hp with the least moolah.

vortecfcar

Bought mine for 125 off a wrecked truck and bolted them on....then proceeded to run a 13.0 @ 107 in the heat and humidity. Given Ive done other things to the car, but you'd have a hard time arguing with that MPH on an automatic car.

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91 RS W/carbed 350, Vortec heads, performer rpm, Comp cams Xtreme energy 224/230 duration and .477/.480 lift. BFG Drag radials. 3.42 posi,Corvette servoed 700r4, 3000 stallconverter. Edelbrock TES, 3inch cat, flowmaster with single 2.5 inch exit.
Best time yet to come
12's?? :crossthumbs:

This is a Pic of my car in race trim www.tbns.net/billyjay/camero.jpg

Yes I know how to spell camaro- so dont ask. I didnt make the link

IROCZTWENTYGR8

iTrader: (1)

vortec, what did u run before them??

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89 RS

STILL Looking For:
87 IROC-Z28 350 TPI

FastBroker

Vortec heads come with springs that are only good to about .450" lift and should be changed to higher lift springs for cam lifts above .460" (or high ramp speeds) or there is a VERY good chance that the associated spring binding will ruin your camshaft prematurely. New springs are pretty cheap, too. I use the springs/retainers/locks from the Hot Cam kit. Entire stuff about $60 from GM and lighweight/strong too.

To let you know how good the Vortec heads are, bolting them onto a ZZ4 engine (removeing the ZZ4's Al Corvette small-chamber heads) gives the ZZ4 a boost of 10hp. That may not sound like much but the Vortec heads ALSO reduce the compression of the motor from 10:1 to 9.4:1. ie, less compression w/more HP... Good heads and great price.

johnsjj2

Vortec heads are good to a point. After that, it is no longer cost effective to use them. I bought 2 350 engines from a friend who has a connection at a GM dealer. These were warrany engines. 1-out of a 98 truck, 1-from 91 model year. $500 for both. The 98 had the Vortecs on it. I took them apart, and began pocket porting them. I had/wanted to buy SS swirl polished, undercut valves-$100, .580 lift springs-$30, studs-$36, cut for studs-$85, +.050 locks-$32. Add to this the difference of the dedicated intake, and self aligning RR, plus the $450-500 for the heads, and you could almost get some AFR's. I am running a setup very close to the 520hp 350 that CHP(?) built. If I would have sprung for the extra $200-300, I could have had the 500-520hp. If you want 350-400hp, the Vortecs are good with a small cam-(lift). If you want anymore, you would spend more on the Vortecs, and your options down the road are still limited, with TFS, AFR, Edelbrock, or Holley, you have other avenues to chose later. Just my .02.



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Joshua Johnston
1991 Z-28
Flowmaster
K&N
305 / 5spd. (Temporary)

vortecfcar

I went straight from a TBI 305 to the vortec 350 so I have no before and after times- sorry

Ray87Z

FastBroker, are you using the HOT Cam springs/retainers on the Vortecs with no modding to the heads? What cam are you running, did you clearance the guide bosses to accept over .480 lift or do the retainers from the HOT cam kit help with that problem?

I'm still running the stock setup on my Vortecs with a Comp 262 cam (.469 lift on exhaust side). I want to step up some but don't want to spend much money on the spring set and would like to avoid any modding to the heads (clearancing)...

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Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

unknown_host

iTrader: (1)

i have looked into both vortec and non vortec sub $800 heads and here is my view:
Pro: Vortec heads are way cheap
Con: 1.92 and 1.5 valves (not many sub 800's arent tho)
Pro: Many magazines like CHP have done buildups and have gotten respectable #'s from them
Con: must buy a vortec intake manifold.

hope this helps.

johnsjj2

Ray87Z-I may be able to answer your question-To get the proper installed height for the springs, I needed +.050 inches. This was accomplished by using offset locks. I have .580 clearance between the bottom of the retainer, and the top of the valve seal. All springs are within .007" of the 1.79" installed height. I am running a .510/.520 lift cam, so I have enough room, but it is close.

Hope this helps some....



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Joshua Johnston
1991 Z-28
Flowmaster
K&N
305 / 5spd. (Temporary)

Ray87Z

Hmm, that's good to hear. Did the springs you chose also fit in place of the stockers without messing with seat area? If so what are they and where did you get them? What about these offset locks? I don't know alot about the valvetrain (never had to mess with it before), so forgive if any of this is a stupid question.

Sounds perfect if the whole package didn't require jack in the way of modifications to the heads, I would only want to go as high as .510/.520ish max anyway... I'd be doing the swap of everything without taking the heads off the engine so that's why I need to avoid any kind of machining to the heads, even minor crap to run larger diameter springs and what not. Should have had all this done by a shop before I put the heads on the engine, could have done it right then and had no worries with this crap now...


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Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray


[This message has been edited by Ray87Z (edited August 02, 2001).]

johnsjj2

The springs were stock diameter, 1.25"(?). I think Crane sells them under H-11 tool steel springs. If you go to www.fastvalves.com , they have them too for like $35.00. The locks are Crane also, part# 270-99095-1 in Jegs, $32.00. I would make sure that +.050 is all you need. You can do this with a valve spring micrometer, or in a pinch, you can use a set of calipers.



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Joshua Johnston
1991 Z-28
Flowmaster
K&N
305 / 5spd. (Temporary)