Hi Guy's
Thought I'd reveal the results from the engine dyno on my 496, although I was not overly thrilled now that the dust has settled I'm thinking that the figures are not too bad but the package is as follows Gen VI block, Eagle crank & H beams (6.385), SRP 18cc pistons, big solid flat tappet, Merlin III alloy's 310cc with extra porting, Victor Jnr & an AED 950 HO modified.
She ended up making 600HP @ 6000 & 570ftlb @ 5250.
My dyno guy commented that maybe the heads are not as nice as first thought & a solid roller & some AFR's would have definitely improved the numbers which I agree but anyone had much success with the Merlin III's, I would like to keep these heads & possibly upgrade to a solid roller to try & crack around the 640-650 HP & 610 ftlb approx.
Do any of you think it possible, I would love to here some comments from you guy's with regards my results I'm from down under & any info much would be appreciated as there are not too many 496's running around here but still a few big blocks any how especially in Camaro's, Chevelles & Nova's around my area.
Thanks Guy's.

I think I would be looking at that big solid flat tappet cam.

Got any specs on it?

what cam is it? it does seem a little shy of what might have gotten. what dyno was it?

Hi Guy's
Yeah it is a Crane solid 272 & 280 @ 050 with 659 & 679 lift I think a 110 LC
I know it is big but would sound typical old school, I built a friends 510 using the same cam & I know you shouldn't expect what works in one will work in another but tried it anyway.
Thanks.

were the exhaust temps and fuel numbers right? the dyno guy should spot it if anything is very far off.

The horsepower and torque peak are too close together, only 750 rpm spread. Should be nearly twice that. The torque peak is about right but something is limiting the RPM's and power from going on up.

What about valve springs? Any chance they would be to weak and losing valve control?

The carb and intake should be good for at least 6500 maybe more. A cam with that much duration should peak power much higher than 6000.

What kind of headers? Collector length?

How much has been done to the heads? Any flow numbers?

I am not picking or trying to be critical. I just doesn't make sense that the peaks are so close. Just trying to figure it all out. Best of luck with your project.

Hi Sleeper
Yeah I agree with what you are saying but valve springs were good Crane items & using hooker competition pipes, the heads were cleaned up with further porting & were flowing 342 cfm @ 0.700" on the inlet & 251 cfm @ 0.700" on the exhaust with 73% E/I ratio.
I believe my choice of camshafts is the main problem but like you mentioned it should have peaked higher than 6000.

Cheers

Why so much cam with so little compression unless the heads have been cut a bunch & the block zero decked?
You have a cam that should go to about 7500 & be in a 12.0+ engine & you probably have closer to 10.0 if that.
You have an intake & heads that should make peak in the 62-6500 range
The first thing I would change is the cam to something with about 15-20° less duration ;)
I think just that change would pick up torque by 20-40 lb ft & lower it closer to the 4500 RPM range

I do not think the HP is that far off on an honest dyno with the parts you have but I don't use those heads so this is just an opinion :)
I do agree it should be a few hunderd RPM higher though,,,,,,

My buddy had some merlins and the vavle job wasn't up to par. I don't think you have enough compression for the cam.

Thanks Guy's
Appreciate the input everyone, I do have a couple of solid rollers in mind especially now that Isky have what seems a more reliable E-Z roller wide foot print type roller lifter but might wait till finances improve a bit from memory one of the cams has 258-266 @50, & the other 262-270 @50
Thanks again.