Southern Automotive 428 engine

[MaxMcQueen]

I'm the recent owner of a Superformance Cobra with a 428 engine built by Southern automotive. They advertisment on the site is saying that their single four barrel 428 engines are able to deliver 460 hp. My car is provided of Edelbrock performance RPM heads as option. I would like to know your opinion if my engine could be really in the 500 hp region with these heads fitted or this could be an insignificant mod.... (they don't claims any improved power for the options list).

[ERA 778]

Give Bill Parham at Southern a call. I am pretty sure he can give you a good estimate of the power on your engine.

Hal

[1795]

Bill Parham is quite knowledgeable and easy to talk to. It is quite possible that you could be in the 500 hp range depending on the build. The 428 has a great deal of low end torque and you will be surprised how it just jumps when you touch the throttle.

[RACERAL]

Are they box stock heads... i bet you could sell the heads easy and pick up a set or Blue thunder "worked on heads" from Barry at Survival and hit your mark.

[Dimis]

Originally Posted by RACERAL

Are they box stock heads... i bet you could sell the heads easy and pick up a set or Blue thunder "worked on heads" from Barry at Survival and hit your mark.

Except for one small wrinkle...

As I understand it, the exhaust ports on a BT won't match up to the headers from an edelbrock.

However there are other options for heads if you're interested in going down that path, and the edelbrocks can even be worked to flow a little more.

Check in with Brent Lykins, I think he may have a set of BBM heads in his sandbox you might want to play with.

[DanEC]

I'm assuming they use a dyno to verify their horsepower claims. Part of the answer to your question will depend on what head they use on their 460 HP package stock. If it's a stock police interceptor or plain stock 428 head then I would believe that even a stock set of Edelbrock heads would add some HP. If the stock head is a Cobra Jet head and has been re-worked at all, then their may be some difference, but not a lot. They should be able to bump the compression up a little with an aluminum head, but only a talk with Southern Automotive can see if they take advantage of that.

For what it's worth - my Keith Craft 428 uses a set of 1961 steel 390 high performance heads (401 HP version) that Keith ported, polished, and fitted with larger valves - pretty much re-worked 427 LR heads now. When it was on the dyno I discussed with the operator what he thought the HP increase could be if I installed a set of Edelbrock heads (we didn't get into details on which version or re-worked or not). He said from his experience, it probably would pick up about 35 HP typically.

[blykins]

I dyno'd a 428CJ yesterday with factory heads and intake. Only real upgrade as far as performance was a hydraulic roller cam, along with a better valve job with Ferrea valves. The heads flowed about 250 on the intake side, which is right around where the Edelbrocks flow out of the box without any port work.

This engine made 422 hp @ 5500 with 466 lb-ft of torque at 4000 rpm.

I have rebuilt engines from Southern Automotive where they have used Edelbrock heads, and they did not do any port work to the ones that I have seen.

With that being said, I would imagine you're somewhere in the 425-450 hp range, even with the Edelbrock heads.

[DanEC]

Originally Posted by blykins

I dyno'd a 428CJ yesterday with factory heads and intake. Only real upgrade as far as performance was a hydraulic roller cam, along with a better valve job with Ferrea valves. The heads flowed about 250 on the intake side, which is right around where the Edelbrocks flow out of the box without any port work.

This engine made 422 hp @ 5500 with 466 lb-ft of torque at 4000 rpm.

I have rebuilt engines from Southern Automotive where they have used Edelbrock heads, and they did not do any port work to the ones that I have seen.

With that being said, I would imagine you're somewhere in the 425-450 hp range, even with the Edelbrock heads.

The same day I was at Keith's shop watching my dyno run they had I believe 3 stock-part, restoration 428 CJs finished, dynoed, on stands and bagged up. I asked the dyno operator what they tested at and from memory he said around 425 HP also. Not bad for an engine Ford advertised at 335 HP.

[MaxMcQueen]

Thanks to all. About 460 hp claimed by SA, I am asking.. Are both your engines dynoed at 422~425 hp after the same engine blueprinted process? Look at their page of specifications.

[Bill Bess]

Sounds like the same SA motor I have...runs great, tons of brute power and has been bullet proof. 7 year's 21000 miles.
SA builds good stuff.

[DanEC]

Originally Posted by MaxMcQueen

Thanks to all. About 460 hp claimed by SA, I am asking.. Are both your engines dynoed at 422~425 hp after the same engine blueprinted process? Look at their page of specifications.

Mine is stroked and built fairly mild on compression and cam, but with a 427 dual quad intake. It tested around what they are claiming for yours - 470 hp. Basically, it's close to a 428 CJ build but with 30 more cubic inches and 40 - 45 more HP. Your engine probably has a bit more cam than mine and possibly a bit more compression.

[FatBoy]

Bill is a really good guy and will stand by his products come what may. He often CNC ports his Edlebrock heads as he has on the engine he built for me. They're nicely machined and matched to the intake manifold.

Paul

[MaxMcQueen]

Originally Posted by DanEC

Mine is stroked and built fairly mild on compression and cam, but with a 427 dual quad intake. It tested around what they are claiming for yours - 470 hp. Basically, it's close to a 428 CJ build but with 30 more cubic inches and 40 - 45 more HP. Your engine probably has a bit more cam than mine and possibly a bit more compression.

So do you think my engine should be good for ~470 hp as yours or with the option heads even something more?

[DanEC]

No one can really tell. They aren't posting their cam and compression information on the website that I can see. Results will vary with engine condition. But, if you have re-worked steel 428 heads and switch to a set of re-worked aluminum heads and and are careful with the port matching you will undoubtedly pick up some more power.