Centrifugal supercharger and effect on peak HP RPM

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My427stang
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Centrifugal supercharger and effect on peak HP RPM

Post by My427stang »

I am doing a nice little 347 with a Novi 1200. It'll be mild, but looking for some experience with peak HP RPM and the centrifugal blower.

AFR 185s, single plane, TBI, 9:1, trying to keep it mild for the street with a 5900-6100 rpm peak. Toying with a 206 duration intake with plenty of split and approx .580 lift but feel it may be too small

Thoughts? I'll play with LSA to hit my idle and expect about 10 degrees more exhaust, but wondering if the 260/206 intake is too small, feels it to me but I assume the decent heads and huffer will carry it higher

Thanks in advance
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71 F100 SB 4x4, 461 FE, 4 speed, port injected EFI, 3.50s
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Re: Centrifugal supercharger and effect on peak HP RPM

Post by F-BIRD'88 »

I would use one of those Ford "alphabet" 303 roller cams.
Eg. B303 or X303. ??? . about 220@ .050". advance it a bit..

E303 cam. I guess.. Degree it in and advance it
5 to 6 degrees. 110 LSA 104/116
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Re: Centrifugal supercharger and effect on peak HP RPM

Post by F-BIRD'88 »

I think the single plane manifold is a big mistake.
A dual plane high rise RPM type intake will put critical torque right where you want it for street.
"mild"
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Re: Centrifugal supercharger and effect on peak HP RPM

Post by blown265 »

G'day mate

The last couple of boosted engines we've built for street/mild strip (one positive displacement and one turbo) both use solid flat tappet cams around 240@50".

The turbo motor is 383ci and the PD is on a smaller 265ci. Both cars have no shortage of mid range hp, and both used single plane manifolds and good heads. (think strong NA combinations with boost)

I feel 206@50" is leaving streetable power on the table.

Regards
Paulie
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Re: Centrifugal supercharger and effect on peak HP RPM

Post by plovett »

I think you are right that the heads and blower will carry the rpm higher than it would otherwise go. However, I still think the cam is too small for the target rpm. Maybe 10-15 degrees more on the intake?

Is the 5900-6100 rpm target a peak hp target or max (shift) rpm?

paul
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Re: Centrifugal supercharger and effect on peak HP RPM

Post by frnkeore »

Mild? 10 - 12 lb boost?

I would agree with with a 180 manifold, you don't get much boost below mid range. A 7121 or Air Gap.
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Re: Centrifugal supercharger and effect on peak HP RPM

Post by Joe-71 »

Build the engine as you would for normally aspirated, and then add the blower. For the SBF street engines with blower, we always use a camshaft in the 224-232* @.050 and had lobe separation of 112-114* for idle. The smaller the engine, 224*, but at 347 ci, I would not be afraid of 228* @ .050" and 112* LSA. Joe-71
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Re: Centrifugal supercharger and effect on peak HP RPM

Post by My427stang »

Today is follow up day LOL

I ended up going 215/227, 112 LSA on 108. I kept the Vic Jr, had some slowdown fitting the Super Sniper into the Vortech enclosure, but done now, hope to have it on the pump in early December.

I also felt it needed cam, as you guys did, but I did not want to go too high as street toy. I expect it to be pretty fun with EFI, good heads, and 10 lbs boost
Bullock's Power Service, LLC
Plattsmouth, NE
70 Mustang, 489 FE, TKO-600, Massflo SEFI, 4.11s
71 F100 SB 4x4, 461 FE, 4 speed, port injected EFI, 3.50s
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