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Originally Posted by mike tkach
(Post 4655971)
did you notice the bore&stroke,not your ordinary 509,also not a pump gas combination,closer to drag race peice.add in.also used a camshaft with a 108 lsa.
Cam is big, peak is at 6400. The contest measures from 2500rpm but maybe it still favors a hard charger up top? I’d have to look at the calculation they use to figure that out. I’m thinking they used power and torque in it, which would doubly favor higher RPM power. people focus on bore and stroke too much. It’s nearly irrelevant from a power/torque standpoint. Total displacement is what matters. I think it’s still very relevant. People here build engines in this size range a lot. You could put this head, cam, and induction combo on a 530-572 and have an awesome boat motor. |
That’s a race car build. All you would need is a chase boat full of drives and 100 octane. Nice combo for a bracket car though, and would put we’ll set up chassis in the 9’s. |
I'm actually a little surprised it peaked at 6,400 in a 509 with 260 duration at .050. I understand the lsa differences in performance wider the broader and narrower the peakier but my question is duration vs lsa. I never really played with much do to majority of my builds have been for marine with 111-114 lsa. |
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Originally Posted by getrdunn
(Post 4656093)
I'm actually a little surprised it peaked at 6,400 in a 509 with 260 duration at .050. I understand the lsa differences in performance wider the broader and narrower the peakier but my question is duration vs lsa. I never really played with much do to majority of my builds have been for marine with 111-114 lsa. |
Originally Posted by hogie roll
(Post 4656025)
It was tested on pump gas. Cam is big, peak is at 6400. The contest measures from 2500rpm but maybe it still favors a hard charger up top? I’d have to look at the calculation they use to figure that out. I’m thinking they used power and torque in it, which would doubly favor higher RPM power. people focus on bore and stroke too much. It’s nearly irrelevant from a power/torque standpoint. Total displacement is what matters. I think it’s still very relevant. People here build engines in this size range a lot. You could put this head, cam, and induction combo on a 530-572 and have an awesome boat motor. |
not sure I understand the long stroke with stock 454 bore. with the 2.30 intake valves even with bore notching it seems like filling the cylinders would be tough. our open class motors were big bore, short stroke just for that reason and yes we spun them to 7800 the whole time although from time to time we could switch the program and run them to 8200 but only as a last lap drag race to the finish thing.
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Originally Posted by compedgemarine
(Post 4656118)
not sure I understand the long stroke with stock 454 bore. with the 2.30 intake valves even with bore notching it seems like filling the cylinders would be tough. our open class motors were big bore, short stroke just for that reason and yes we spun them to 7800 the whole time although from time to time we could switch the program and run them to 8200 but only as a last lap drag race to the finish thing.
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Originally Posted by MILD THUNDER
(Post 4656098)
4.5" stroke. Not your normal 4.00 stroke 509. That plays a major part. That cam in a shorter stroke, would likely spin much faster. Like the old 750hp supercat engines that turned 7000+
Id attribute the 6400 peak to the very tight lsa. Wider lsa’s can hang on up top better. |
If I'm not mistaking MT is trying to say that the 4.5" stroke is bringing peak hp down with the said duration @.050. Without looking into it more I would guess with a 4" stroke 509 ci would likely make peak hp above 7k. That's a given. |
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