Edelbrock headed 408 Stroker

[blownhemi]

Nothing too crazy, this is a 408 we built for our 1970 Dart Swinger that we're giving away.

OUR Project Swinger is just about finished and one of the last pieces of the puzzle was the 408ci Chrysler stroker we put together with more than a little help from Edelbrock, Precision International and Powerhouse Engines.
The aim was to come away with a pump-gas, hydraulic-cammed Chrysler small-block that could make around 500hp without being too extreme. To that end, we’ve used a set of mildly ported Edelbrock Performer heads, an RPM Air-Gap intake, CP pistons, Scat crank and rods, and an Edelbrock 800cfm Performer-series carb.
We also tested a much more expensive race-spec Holley carb for comparison (over double the price), and while it did make more power, the Edelbrock unit resulted in a much smoother power curve and still produced over 500hp and 500lb-ft. All below 6000rpm!
Here we show you a little of what went into the final assembly, and then it hits the dyno.
For all the details, grab the March issue of Street Machine, on sale 19 February.

http://www.streetmachine.com.au/street-machine-tv/1502/video-project-swinger-engine-dyno/

 

[BrianT]

Sounds very close to my build. Nice numbers.

 

[stroked340]

Thanks for sharing the video having withdrawals from all this snow..what cam are you using...your build is very similar to my 416..

 

[rumblefish360]

NICE!
For being 150 cfm down on the carb tests, the Edelbrock did very well. It appears that the torque line did not dip as much in the beginning. Am I correct?
Also, how much if any vacuum did the Edelbrock pull?

 

[blownhemi]

Thanks for sharing the video having withdrawals from all this snow..what cam are you using...your build is very similar to my 416..

We're using the Lunati 243/251 @ 0.050 hydraulic roller. It seems to have worked very well. The engine could use more cylinder head but Edelbrock sponsored us for the build so we used what we were given. The heads were given a clean up and flowed about 450hp.

NICE!
For being 150 cfm down on the carb tests, the Edelbrock did very well. It appears that the torque line did not dip as much in the beginning. Am I correct?
Also, how much if any vacuum did the Edelbrock pull?

The Edelbrock carby impressed the hell out of me. The curve was beautiful and smooth and the more we leaned it out on the secondaries the more power it made. We actually ran out of jet. It was pulling 2.8inches on that video run, we did try a two-inch spacer (to even it up with the Holley) and it made another 7lb/ft but no more horsepower, and it was pulling 2.6inches on that run.

It'll be a great street engine.


Originally we approached Edelbrock about this deal because we wanted to use their Victor heads but no one could give us a date as to when they would be ready. They were a little hesitant to supply the Performer RPM heads because they weren't sure that they would hit out 500hp target but decided to take the punt and it's worked out nicely.

Not bad for a hydraulic cam, dual plane, pump gas small block Chrysler. The winner of this car is going to be very happy.

 

[rumblefish360]

Thanks. I don't know why Edelbrock wasn't sure you could make the mark. I'm not going to say it is an easy thing to do but it is becoming more common place to see such powerful mills.

I think the biggest problem is people will just throw any cam at such a project with a long arm and ported heads and expect magic.

 

[blownhemi]

Thanks. I don't know why Edelbrock wasn't sure you could make the mark. I'm not going to say it is an easy thing to do but it is becoming more common place to see such powerful mills.

I think the biggest problem is people will just throw any cam at such a project with a long arm and ported heads and expect magic.

Very true. I think Edelbrock were just being cautious. I guess they've been burned my making big claims in the past, plus they didn't know if we were just a bunch of monkeys throwing parts together.

This isn't my first Mopar Small block, but it is my first stroker small block so I sat down and did a lot of research before I started ordering parts. I would have been happier with the Victor heads but I knew the Performers would make the grade.

Normally I assemble my own engines, but with this being a magazine giveaway project, I left the actual nuts of bolts of the build to the professionals; in this case Powerhouse Engines. Those guys build a lot of top killer combos here in Australia, especially those in the 'burnout scene' where a 1200-1300hp blown methanol engine will sit at 8500rpm for a couple minutes at a time. Johnny from Powerhouse is meticulous in his machining and has plenty of good gear.

My boss just said he wanted the car to be capable of 11-second quarters. So with that in mind I aimed at 450-500hp. But being a magazine build I wanted to ensure it made the numbers so I erred towards the high end. Plus 500hp always sounds better than 450hp.

I knew the heads were good for at least 450hp out of the box but when we flowed them they actually came up at 510hp capable. The guys recut the seats, smoothed the ports and worked the short turns and that was about it (they ended up flowing about 540hp). They haven't done many Chrysler small blocks so they didn't go crazy on the ports, especially around the pushrod tubes.

I probably over-cammed it to be honest, I could have gone for the next cam down in the Lunati catalog and still made the numbers, but I'm happy with the overall combo.

I just can't wait to drive it for a little while (and maybe take it for a run down the quarter) before it goes off to it's new owner.

 

[rumblefish360]

Humm, maybe so, but it can be a little hard sometimes to nail down the cam selection first time out on a target HP build. Picking one that falls short by 10-15 HP would just be fustraighting and the only end up spending on another cam to get it done? Ugh! I think that cam is going to work really well with a set of 4.10 or 4.30 gears for an Ace street strip ride.

Did the Holley pull any vacuum? I didn't think the Edelbrock would pull that much vacuum.

 

[rumblefish360]

I also noticed the way you state head flow. It is odd to see it stated that way. How do you go about rating them for the way you do. I am used to seeing heads rated by way of cfm.

 

[blownhemi]

Humm, maybe so, but it can be a little hard sometimes to nail down the cam selection first time out on a target HP build. Picking one that falls short by 10-15 HP would just be fustraighting and the only end up spending on another cam to get it done? Ugh! I think that cam is going to work really well with a set of 4.10 or 4.30 gears for an Ace street strip ride.

Did the Holley pull any vacuum? I didn't think the Edelbrock would pull that much vacuum.

The Holley pulled about 0.6inches at 6100rpm. And you are right, it would have sacked to just miss the mark of I'd gone for too small a cam.

I also noticed the way you state head flow. It is odd to see it stated that way. How do you go about rating them for the way you do. I am used to seeing heads rated by way of cfm.

I guess that's just how we do it down under. Some people do quote cfm, but alot of people don't know what cfm means in terms of horsepower so alot of the time we convert to horsepower capabilities to help them make sense of it all.

I do have the flow figures somewhere. Out of the box they matched the published figures on Edelbrock's website. The boys didn't go crazy on them, mainly they just smoothed out tool marks and the short turns. We kept the valves, springs and guides. We ordered the roller cam spec heads so we didn't have to buy more stuff.