Flow Data

Sorry about the hand written graph. It is really close (I swear). I might do another one later by pulling the numbers off and plotting them in Excel. Just thought this was interesting. Looks like the 6.0L heads are the way to go for most of us. They offer much more flow under the curve. Looks like they cross over at .575.

<small>[ August 28, 2002, 11:04 PM: Message edited by: JP98SS ]</small>

 

You can't really compare different flow benches, but I will say that if you buy MMS heads (especially the stage 2) you get as good or better performance for less cashola. How many 127mph heads/cam cars does MTI have? How many of those run it in 1200' DA? <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Hey Tony what ever happend to that guy that returned my heads so many months ago? How much power does he make now? <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

It might not be a completely fair comparison. But if it helps...the heads weren't flowed by MMS. Looks like the heads are optimized for their 229 cam at .579 lift.

 

Nice numbers on the 6L heads! Nice and fat through the midrange. Intake and exhaust port CC's would help in the comparo too <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Cheers,
Chris

 

Just FYI, but that flowsheet you show has "Coates" listed as the name of the owner of the MTI heads. He posts here as "Poolfanatic", and his car pulled 446 rwhp on motor alone (346ci) and hauls ***. So, would that flowsheet have told you this would happen? Probably not. Also, why is the MTI curve much more smooth across the board? You also have "Stage 3" written next to the MMS heads, but Coates' heads are only stage 2 and are designed for 346ci. Here is how my MTI LS6 Stage 3s flow for another comparison:

http://users.ev1.net/~ynot_dv8/flowLS6.jpg

-Tony

<small>[ August 29, 2002, 09:02 AM: Message edited by: Nine Ball ]</small>

 

Tony,
I think the MTI combo is great too. The cam is obviously very well matched to the heads. Isnt he using a reverse split? 230/227
I am just pleasantly surprised with the FAT midrange numbers of the MMS 6L heads. Makes you wonder if the added cash for Ls6 cores are worth it.
cheers,
Chris

<small>[ August 29, 2002, 08:51 AM: Message edited by: Chris ARE 360 ]</small>

 

Chris, his graphs are comparing MMS Stage 3s vs MTI Stage 2s. Possibly flowed on varying benches with different sized test bores, etc...

Hard to compare any numbers unless they are on the same bench with the same operator, as Terry suggested. You could compare my Stage 3 numbers to Coates' Stage 2 numbers though, since they were both flowed on the same bench by the same operator with the same method.

And yes, 6.0L heads are just as good as LS6 heads when ported by the same person. The sucky thing is that GM does not sell bare 6.0L heads, only fully assembled ones. This makes the 6.0L cores more expensive, unfortunately.

-Tony

 

Damn, I'm famous!

<img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

As Tony said, these are just MTI's Stage II's that I have on my stock CI 346. It pulled 446 rwhp and he wasn't kidding when he said it hauls ***. (No track time yet, stock clutch and 10 bolt are the limiting factors right now).

A fair comparison would be to ask Jayson to sponsor my car and build me an MTI 422 with some Stage III's, flowbench them first and then post the results up here. All at no charge in the interest of science!

Jayson, you listening? <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

To be really scientfic I should get a set of MTI Stage 3 LS6 heads to try out. Too bad I don't have $5k laying around. I just checked the price on those... <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />

 

You don't need $$$ LS6 or 6.0L heads to make 446rwhp on a 346. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Terry Burger:
<strong>You don't need $$$ LS6 or 6.0L heads to make 446rwhp on a 346. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">so Terry, if i buy some LS1 heads and cam (with my LT headers) i will make AT LEAST 456 RWHP (considering i am a MN6 car)? i think my mods are pretty typical of the agressive bolt on car. most people do not have as many mods as i do.

if not, are you willing to pay for the H&C + install price? you seem VERY confident in MMS making this kind of huge power. just wondering if you would be willing to put your money where your mouth is?

-note the lack of uppercases <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">
if not, are you willing to pay for the H&C + install price? you seem VERY confident in MMS making this kind of huge power. just wondering if you would be willing to put your money where your mouth is?
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Let's make it worth my while OK? I'll pay for the heads/cam, if you make less than 446rwhp you get to keep them, if you make 446 or more I get to keep the car. Deal?

 

Terry,

So that's why you're getting rid of the LS6 heads. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> I wondered why you wouldn't use the 6.0L heads if you're throwing in new pistson to up the compression.

FWIW, out of those two heads, I would take the MMS 6.0L's. But then again, I will just port my own. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> I kind of like the 6.0 chamber shape better for a bigger motor.

JP98SS:

Those numbers AREN'T even close, about 30-35 numbers in the midrange isn't close.

 

Jantzer: The close that I was refering to was me transfering the numbers onto the graph by hand.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">
So that's why you're getting rid of the LS6 heads. I wondered why you wouldn't use the 6.0L heads if you're throwing in new pistson to up the compression.
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Who said I was not going to be running LS6 heads? <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Nine Ball:
<strong>You could compare my Stage 3 numbers to Coates' Stage 2 numbers though, since they were both flowed on the same bench by the same operator with the same method.-Tony</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">So why don't you post a nice comparo between yours and Coates heads?

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Nine Ball:
<strong> Here is how my MTI LS6 Stage 3s flow for another comparison:

http://users.ev1.net/~ynot_dv8/flowLS6.jpg

-Tony</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">FWIW, my Stage III LS6 head flow numbers could be layed directly on that graph. Looks about the same.

I don't like that this thread is basically a MMS vs MTI thread, especially since it is not the shops doing it.

 

Are the valve sizes the same between the 2 heads? If not, Its like comparing a 346 to a 370. You really cant.

 

terry dont change the rules to suit your game. A4 vs. MN6 is a different game. you know this.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">
terry dont change the rules to suit your game. A4 vs. MN6 is a different game. you know this.
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Not true, a locked A4 with small converter dynos the same as an M6.