Older Sonny's Dart 320 head program.

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mt-engines
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Re: Older Sonny's Dart 320 head program.

Post by mt-engines »

fordified wrote: Sat Mar 11, 2023 10:25 pm Scratch my original post.

I just looked online and those heads don't flow very much air.

Sell them and buy something better.
Its more than just flow. 370cfm can make 900hp

The port has to be sized for the rpm. If it isn't you won't make the power.
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Re: Older Sonny's Dart 320 head program.

Post by rapidride2 »

Working nights guys..

This is what I need to learn to be able to to make wiser choices in cylinder heads. Pinch, cross section, valve diameter vs bore size, runner size etc.

I realize there is pipe max, I saw where Chad Speier laid out on his website how he chooses a port, read some of Darin Morgans material....

My question is where is this basic material coming from? Not to mention different professionals opinions on the choosing the correct port.
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Re: Older Sonny's Dart 320 head program.

Post by Alaskaracer »

mt-engines wrote: Sun Mar 12, 2023 1:32 am
rapidride2 wrote: Sat Mar 11, 2023 10:28 pm Colorado, I understand his engine picked up a TON. Could it be he may have had a mismatched camshaft for the older 360 heads? .5 seconds is HUGE in my opinion. Maybe the blower and ALKY really liked the larger runner?
If it ran 15s, .5s quicker isn't much power.

But a 7 second car gaining .5 is yuuuge.
His previous passes at Bandimere Speedway were in the 7.20 range, with an occasional dip in the high 7 teens.....He's been 6.76 and 6.72 so far, still working on the tune....Previous mph was in the 195-198 range, now in the 208-210 range.....
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Re: Older Sonny's Dart 320 head program.

Post by Alaskaracer »

rapidride2 wrote: Sat Mar 11, 2023 10:29 pm I think I'd rather have the larger intake versus exhaust. I have no problem with a 1.900. If it would fit with a 2.300 intake.
You don't need nearly as big as an exhaust valve as you think. My new stuff is a 2.55" intake, but only a 1.81" exhaust... Exhaust is literally pushed out of the engine....You still need flow, and valve area, but it's way smaller than you might think.....my old heads have a 1.86 ex and the port flows a ridiculous 410 cfm.......new ones are less than that, but will still make WAY more power.....
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Re: Older Sonny's Dart 320 head program.

Post by Bigchief632 »

rapidride2 wrote: Sat Mar 11, 2023 7:45 pm Its been decades..

Anyone know someone who has an awesome program or hand porting results on these heads?

I have a set of good condition late 90s, Sonny's Dart 320 "supermod" heads. Not fully ported... i believe just "heart shape" chamber work. Plus I had Ron's porting open them up for a 4.500 bore many years ago. They've got a 2.25x1.88 valve.

I know there is better heads out now but wanting to possibly bring these back to life...they are in good condition. Maybe 2.300 valve and full port to get the most out of them.

Trying to weigh out the costs vs newer heads...
Gonna be on a 540+ci, mostly drag car for now.

Thanks
Those heads have lots of potential, lots of material in the right places. Those were usually the casting of choice for like v
Texas Pro Stock. 500+cfm. Obviously very heavily reworked, and now we have sr20's because of that class. How much power are you looking to make?

The example about the Dart 360, vs the AFR 385, I could see that happening. The 360's that were "reworked" obviously weren't really "reworked" to their full potential.
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Re: Older Sonny's Dart 320 head program.

Post by rapidride2 »

Bigchief632 wrote: Thu Mar 16, 2023 8:25 am
rapidride2 wrote: Sat Mar 11, 2023 7:45 pm Its been decades..

Anyone know someone who has an awesome program or hand porting results on these heads?

I have a set of good condition late 90s, Sonny's Dart 320 "supermod" heads. Not fully ported... i believe just "heart shape" chamber work. Plus I had Ron's porting open them up for a 4.500 bore many years ago. They've got a 2.25x1.88 valve.

I know there is better heads out now but wanting to possibly bring these back to life...they are in good condition. Maybe 2.300 valve and full port to get the most out of them.

Trying to weigh out the costs vs newer heads...
Gonna be on a 540+ci, mostly drag car for now.

Thanks
Those heads have lots of potential, lots of material in the right places. Those were usually the casting of choice for like v
Texas Pro Stock. 500+cfm. Obviously very heavily reworked, and now we have sr20's because of that class. How much power are you looking to make?

The example about the Dart 360, vs the AFR 385, I could see that happening. The 360's that were "reworked" obviously weren't really "reworked" to their full potential.
Would like to make 960hp on a 540 to 550ci.

I know of a 468 out there with EDELBROCK oval ports and a single 4150 carburetor pushing 3400lbs to 8.90s. On a 9 inch tire

He has old heads too...lol.
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Re: Older Sonny's Dart 320 head program.

Post by Abbottracingheads »

Those heads are not total junk. I can wake them up big time from what you tell me they are. Valve sizes would change.
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