High Flow Heads On Stock Motor

silent mumbler · Feb 9, 2017

So I'm Ben, I'm a new guy with a 92 gt. i have acquired a set of trick flow r series 205 heads from a friends drag car. They supposedly flow 350 cfm on the intake and have 61cc chambers. Would there be any draw back to putting these on my stock 5.0?

CarMichael Angelo · Feb 10, 2017

Potentially poorer performance and loss of current fuel mileage. Port velocity will be slowed because of the larger port.
The end result will be a sluggish, torqueless bottom end.

Now,.....If you add a cam, intake, and exhaust to the mix......Then they'll work.

There are a couple of examples on this forum where somebody else has done it and yielded really good power out of the combo.
here's one:
https://www.stangnet.com/mustang-forums/threads/nikwoacs-commitment-issues-engine-build.833852/

silent mumbler · Feb 10, 2017

Thanks for the reply. Sounds like I'll be better off spending money on the 408 that these heads are meant for.

CarMichael Angelo · Feb 10, 2017

silent mumbler said:
Thanks for the reply. Sounds like I'll be better off spending money on the 408 that these heads are meant for.

Where'd you get that from? If you're going to buy a 408, and go through the expense and labor to swap it in, a cam, intake, and exhaust headers for the current engine are way cheaper than a 408.

The engine build I linked is a perfect example of what you could expect from big head on a stock shortblock, provided you add the supporting mods to make it all work cohesively.
I don't know about you, but I'm sure that there are plenty of guys out there that would be giddy w/a N/A 335 whp / 325 ft/lb rwtq out of a 306.

Noobz347 · Feb 10, 2017

Just add boost and split that thing right down the middle.

tannerc91gt · Feb 10, 2017

What are the rest of the flow numbers? Peak doesn't mean much out of context

tannerc91gt · Feb 10, 2017

I see the 205s are 305cfm but I believe that's at .700. Maybe yours have had some work done?

They'd be better suited on a motor with more cubic inches. Mike summed up why pretty well.

tannerc91gt · Feb 10, 2017

madmike1157 said:
Potentially poorer performance and loss of current fuel mileage. Port velocity will be slowed because of the larger port.
The end result will be a sluggish, torqueless bottom end.

Now,.....If you add a cam, intake, and exhaust to the mix......Then they'll work.

There are a couple of examples on this forum where somebody else has done it and yielded really good power out of the combo.
here's one:
https://www.stangnet.com/mustang-forums/threads/nikwoacs-commitment-issues-engine-build.833852/

Nik is who I was thinking of after reading his post as well. Car ran well for the combo IIRC. But that's not to say it wouldn't have run better with more appropriate heads.

As you said, it's heavily dependent on the rest of the combo. You can do a lot with a 300" motor.
Don't like seeing people get wrapped up in peak flow numbers at .700" and then they run a .512 lift camshaft and drive a lazy car around.

a91what · Feb 10, 2017

+1
average numbers are what to look for, it's best to get a higher mean flow rate rather than a high peak. This creates an engine that make a high mean torque curve. This translates into better drivability and a fun street car.

Noobz347 · Feb 11, 2017

I'll answer the question by saying that there's no reason NOT to put those heads on a 302.

hoopty5.0 · Feb 11, 2017

Noobz347 said:
I'll answer the question by saying that there's no reason NOT to put those heads on a 302.

...Provided he gets the right supporting parts

Noobz347 · Feb 11, 2017

hoopty5.0 said:
...Provided he gets the right supporting parts

That goes for practically ANY bolt-on.

stykthyn · Feb 11, 2017

Meh, use stickers to fill the HP gaps

Noobz347 · Feb 11, 2017

You can use the small Summit stickers to cover the flat spots on the dyno graph.

hoopty5.0 · Feb 11, 2017

Noobz347 said:
That goes for practically ANY bolt-on.

The internet proved that everything must be spelled out with words and symbols

Noobz347 · Feb 11, 2017

I just grunt into the Google and it makes me sound essMart

5.0specialist · Feb 11, 2017

On a stock 5.0, the stock E7 heads would perform better on the street in the low and mid rev range.. IMO Sell those heads and get a set of gt40p heads or AFR165's if you want to go with aluminum.

Noobz347 · Feb 11, 2017

You would still have to spend about the same money to fully support the GT40 heads.

RaggedGT · Feb 11, 2017

isnt there a guy on here making like 350 + / - rwhp with ported e7's?

Noobz347 · Feb 11, 2017

Yes and he spent even MOAR money. It's not an easy thing to do. They're probably the most worked over E7s on the planet. hehe

High Flow Heads On Stock Motor

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