Heads

[chevguy]

Hey guys, Finally got my 540 cube going in my 69 camaro, dynoed it and a little dissappointed with the figures, 480 rwhp and 650 ft/lb at 5500. This was a 502 that we tweaked so still running the ported edelbrock performer heads,air gap manifold and a cam which I now know is too small for a 540 cuber. My question is I will be over for SEMA this year and will be contemplating an upgrade to the top end, which is the best bang for buck cylinder heads in your opinon? I am looking at the 357 AFR Magnums atm but welcome more opinions. Ta, Ken

[GregWeld]

As you know -- the best way to make power is with a CAM that MATCHES the head flow... I'm sure I'm not telling you anything you don't already know - but just saying - it's the combo of all things - Cylinder pressure - cam - heads - timing...

Have you played with any of the computer simulation software that you can mix and match heads and cams etc??

[chevguy]

As you know -- the best way to make power is with a CAM that MATCHES the head flow... I'm sure I'm not telling you anything you don't already know - but just saying - it's the combo of all things - Cylinder pressure - cam - heads - timing...

Have you played with any of the computer simulation software that you can mix and match heads and cams etc??

Actually I should have clarified a bit more, yeah I know the whole combo has to be matched, I am looking at making approx 600 rwhp by 7500rpm, running 11.4 cr with a total timing of around 28 deg(due to the cr and still running 98 octane). Was looking at the heads 1st as the other ancillaries(valve springs,cam,manifold etc) while very important are relatively cheap compared to the heads. Haven`t looked at software simulation so might have to chase that up for a look,can you put in specific heads into the program or just intake flow figures etc? Little bit sceptical if it`s only generic values as head designs can flow the same figures but work a fair bit differently due to valve layout, chamber design etc etc. I prefer getting opinons from people who are running the gear but will definately check out the software side, thanks.

[speedjohnston]

My guess is that the 357 heads would be a tad big on a motor looking to make 600hp at the wheels and you may hurt some hp. I would consult with AFR before picking your heads. Also, 7400 rpm is high with a big motor like that. keeping the rpm lower will make your motor live longer and you can easily make 600+ rwhp without going that high. :cheers:
I have 2 buddies that each have 540's that made about 795hp and the other about 805 hp on pump gas on an engine dyno. If your interested I can call them and see what heads they are using.

[speedjohnston]

I called anyway. :lol: The one is a 555 with 355 heads that made 807hp @ 6800rpm (engine dyno) with 8.75-1 compression. The other I think is 540 with 345 heads 11.xx something compression and made 795-798hp @ 6500rpm. I used 355AFR's on my 581 but I have a blower and wouldn't have gone quite as big had it been NA.

[chevguy]

I called anyway. :lol: The one is a 555 with 355 heads that made 807hp @ 6800rpm (engine dyno) with 8.75-1 compression. The other I think is 540 with 345 heads 11.xx something compression and made 795-798hp @ 6500rpm. I used 355AFR's on my 581 but I have a blower and wouldn't have gone quite as big had it been NA.

Awesome, thanks for that, as I this will be yet another outlay that will no doubt cause a healthy debate between the wife and myself:) I would like get it right. You are right, the lower rpm i can make the power I want, the better.

[chevguy]

As a further question when/if I do this head upgrade, will a victor jnr make a reasonable upgrade to my rpm air gap or is it not worth the extra expense?

[CamaroAJ]

maybe i missed it but are you running a auto or manual transmission?

a friend of mine has a 502 bbc and it makes just under 700 flywheel but only 425 rear wheel on the dyno. tci told him to ignore the numbers because of the torque converter. the car was running 10.00's in the 1/4 in a 4300lbs '79 trans am though so 425rwhp wouldn't be enough to do that.

[speedjohnston]

Myself and one of the previously mentioned run edelbrock intakes with the Reher morrison mod. I can't compare vs others though but they are a very good intake. I'll see if I can get a part # from my buddy, mine is slightly different for the blower application. (although I'm sure it would work fine, it may be a little larger?)
I would agree with camaroAJ except that your numbers should be proportionate, and the torque is so much higher then the hp. It doesn't sound like thats what you're after?
Have you been able to run it at the track? What altitude are you at? do you know of any other cars that have been on this dyno you can compare to?

[chevguy]

Running a t400, altitude is roughly 40ft above sea level.Hav`nt run it properly down the strip yet as when I attempted it with my 295 street tyres I covered about 3 miles on the 1/4 :). I have heard the dyno I used is 'tight' and you can safely add 30-40 hp to the figures. Just bought some et streets and fitted caltracs but hav`nt been able to run it yet. I know the best test is the strip but the bloody weather won`t clear up to allow a meet. As previously posted I will be over for SEMA in a few weeks and thought I may as well pick up my gear while I am over there.

[cp87]

I would say the cam is your hold back. I am running a small magnum cam 550 lift with merlin 230 valve heads and my motor dyno at 542 hp but my cam killed me with a 5500 rpm limit. I believe this is the biggest hydraulic cam that was available at the time until it switched to the 575 solid