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Old 12-03-2010, 06:47 PM   #1
chev-obsession
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Bowtie heads vs. Vortec heads

What is the difference between the bowtie heads and vortec heads?
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Old 12-03-2010, 08:50 PM   #2
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Re: Bowtie heads vs. Vortec heads

Bowtie heads are racing heads. Most of the bowtie castings have large ports and are along the same lines as a set of dart iron eagles. The vortec heads are a stock head that came factory. They are the best flowing productions head from Gm but its not fair to compare vortecs to bowties its apples to oranges.
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Old 12-03-2010, 09:05 PM   #3
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Re: Bowtie heads vs. Vortec heads

the vortecs out flow most bowtie heads,
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Old 12-03-2010, 11:20 PM   #4
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Re: Bowtie heads vs. Vortec heads

There are also Bowtie Vortec heads. They are over the counter heads with larger intake ports, valves, etc. than the production heads.
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Old 12-04-2010, 10:57 AM   #5
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Re: Bowtie heads vs. Vortec heads

vortecs might outflow bowties under .500 lift but anything over that and vortecs are done. They simply wont flow anymore.
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Old 12-04-2010, 11:20 AM   #6
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Re: Bowtie heads vs. Vortec heads

These conversations are best had with specific part numbers in front of everyone
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Old 12-04-2010, 11:23 AM   #7
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Re: Bowtie heads vs. Vortec heads

Utt ohh here comes tickers with facts again .... Very good point.
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Old 12-04-2010, 12:06 PM   #8
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Re: Bowtie heads vs. Vortec heads

ok lets say the 906 casting to the 034 bowtie
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Old 12-04-2010, 12:32 PM   #9
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Re: Bowtie heads vs. Vortec heads

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ok lets say the 906 casting to the 034 bowtie
This is a question that has an answer

The Vortec is a far better head. The 12480034 head is intended for racing classes that require a "Stock/Replacement" type head and they're based on the '462 (camel back) type casting...but with a ton of extra room in the casting for decking or angle milling and porting. They have a bit better chamber and runner configuration than the old heads, but not by much. They're only available bare for around $750/pair...so they're pretty pricey for mild street head!

This is the same type of head offered by Dart, World, etc. that has been certified for those "old skool" racing classes.

Racers add in 40 hours or so of porting and maybe a little angle milling and get a pretty decent tier 1 head out of them...but for most folks either the Vortec or another tier 1 head is going to be a better deal.

Last edited by Ticker; 12-04-2010 at 05:13 PM.
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Old 12-05-2010, 11:09 AM   #10
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Re: Bowtie heads vs. Vortec heads

ok sweet thats some good info!

I was mainly asking what the difference between the two was. not really trying to compare. my bad!

So these "vortec bowtie" heads, are they good for the street or more for race?
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Old 12-05-2010, 01:40 PM   #11
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Re: Bowtie heads vs. Vortec heads

No bad - just Chevy puts "bowtie" on a lot of stuff

GMPP sells Bowtie Vortecs in two sizes - "small port" 185cc under P/N 25534421 and "large port" 225cc under P/N 25534446. Both heads have 2.00/1.550 valves. It takes either a fair bit of RPM or a fair bit of CID to use these heads, so they'd be targeted at a 450+ HP 355 for the small ports, and a 500+ HP 400+ for the 225s.
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Old 12-05-2010, 03:11 PM   #12
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Re: Bowtie heads vs. Vortec heads

so the small ports would'nt really go well with my 327?

it was just an idea more or less, i know that people have showed me some other heads but thought i might ask since i didnt know anything about them.
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Old 12-05-2010, 03:27 PM   #13
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Re: Bowtie heads vs. Vortec heads

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so the small ports would'nt really go well with my 327?

it was just an idea more or less, i know that people have showed me some other heads but thought i might ask since i didnt know anything about them.
Well, this is a completely different question, i.e. what head to use for a specific application .

Specs on the 327 would help - CR, cam, intake, exhaust, gears, budget, etc.

Last edited by Ticker; 12-05-2010 at 03:27 PM.
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Old 12-05-2010, 06:01 PM   #14
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Re: Bowtie heads vs. Vortec heads

well only i can't answer all of those questions.

im shooting for 9.5 to 10.5 cr, cam idk yet most likely a Crane around a .470 lift with a 110 lsa, exhaust not sure, gears 3.73, intake eldelbrock rpm air gap most likely, no more than 2500 stall , manual brakes. budget... lol probably $2500 but who knows
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Old 12-05-2010, 07:31 PM   #15
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Re: Bowtie heads vs. Vortec heads

Small port vortecs will be fine with that cam.
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Old 12-05-2010, 08:37 PM   #16
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Re: Bowtie heads vs. Vortec heads

In that case you're looking at the standard GMPP Vortecs - not the Bowtie versions.
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Old 12-05-2010, 09:57 PM   #17
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Re: Bowtie heads vs. Vortec heads

I agree

The standard Vortecs will work just fine on a mild to moderate 327.

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In that case you're looking at the standard GMPP Vortecs - not the Bowtie versions.
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Old 12-05-2010, 10:25 PM   #18
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Re: Bowtie heads vs. Vortec heads

Fair enough. Thought i might ask though! Thanks guys!
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Old 12-06-2010, 02:43 PM   #19
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Re: Bowtie heads vs. Vortec heads

Does anyone have some flow numbers any of these heads Also what is the best vortec head out there for street 400ci plus?
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Old 12-06-2010, 10:32 PM   #20
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Re: Bowtie heads vs. Vortec heads

Most every aftermarket head manufacturer will have flow numbers on their website. Here are a couple private sites with some flow numbers also.....

http://users.erols.com/srweiss/tablehdc.htm

http://purplesagetradingpost.com/sum...fo/heads1.html

As for what head to use on a SB400, that depends on a lot of things. A couple being, how the rest of the engine is built and what is the intended useage of this engine.

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Does anyone have some flow numbers any of these heads Also what is the best vortec head out there for street 400ci plus?
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Last edited by Captainfab; 12-06-2010 at 10:34 PM.
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Old 12-06-2010, 11:21 PM   #21
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Re: Bowtie heads vs. Vortec heads

Quote:
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That's a great site and the reference I use often

Vortecs: 230/148 @ ~.475
Bowtie/Small: 245/160 @ ~.500
Bowtie/Large: 260/165 @ ~.500

Note that although the flow isn't all that much higher on the small-port bowties, the intake/exhaust ratio is FAR better. You can also see that lifting these heads to the moon doesn't buy much.

Also note that all Vortec designs have far better low- and mid-range flow than even most tier II heads.

There are two aspects to head selection: flow and intake runner size.

First selection is flow, and that's based on the HP you want to achieve. The very general rule of thumb is HP = .257 * (intake flow) * 8 It's important to match the intake flow to the intake...a dual-plane manifold takes up about 25% of the intake flow, a tall single-plane maybe 10%.

Second is runner size, and the general rule of thumb is to use the smallest runner size that will deliver the required flow.

As you work these numbers you find out pretty quickly why the big dollar heads are worth every penny.

Last edited by Ticker; 12-06-2010 at 11:25 PM.
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