Sbc 283.

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JSC Zvezda
Posts: 3
Joined: Sat Feb 01, 2020 11:46 am

Sbc 283.

Post by JSC Zvezda »

Lots of interesting stuff around here.

Can someone give me an indication of the max hp output with a single turbo setup with lpg on a 283 chevy? I prefer to keep the setup with 1 425 mixer. Main goal is to create a smooth cruiser. But with some extra power when needed. Is it possible to flow max 600 cfm trough a 425 under boost?

I'm new here so any input is welcome.

storm
Posts: 706
Joined: Wed Jan 10, 2007 10:10 pm
Location: NSW, Australia

Re: Sbc 283.

Post by storm »

JSC Zvezda wrote:
Tue Feb 04, 2020 5:12 am
Can someone give me an indication of the max hp output with a single turbo setup with lpg on a 283 chevy?
Short answer is no, long answer is what psi are you going to push into this engine, what cam are you going to use, what heads have you got, what inlet and exhaust manifolds are you going to use, what's the desired rpm range, what turbo are you going to use? A naturally aspirated 425 is capable of approximately 300 HP, if you are pushing 14 psi (1 bar) through it you may be able to obtain 600 HP, that is if it will hold 1 bar of pressure. A 283 is capable of producing 300 HP naturally aspirated but it will be at high RPM, throw on a properly engineered turbo system and you will get over 300 HP if the engine is built for it. Unfortunately there are to many unknown variables to provide a reasonable and accurate answer to this question.

Just as an aside a 253 Holden V8 (4.2 litre) is capable of over 300 HP naturally aspirated but that is at about 6000 RPM.
Fuel flow requirements calculations
Engine air flow requirement calculation: CFM = Cubic Inches x RPM x Volumetric Efficiency (VE) ÷ 3456

JSC Zvezda
Posts: 3
Joined: Sat Feb 01, 2020 11:46 am

Re: Sbc 283.

Post by JSC Zvezda »

Ok thanks. So if I modify/ the mixer and limit boost to lets say 10 psi, 400 hp should be possible? That would be enough for me.

storm
Posts: 706
Joined: Wed Jan 10, 2007 10:10 pm
Location: NSW, Australia

Re: Sbc 283.

Post by storm »

C3H8 may be able to tell you what the 425 is capable of with regards to boost pressure but a 283 can produce 400 crank HP with 10 psi if built correctly and the owner understands that it will need alot higher RPM than a 350 or 400 would need.

Can I ask why do you want to use a 283? Even with a turbo or centrifugal supercharger a 283 producing 400 HP won't be as streetable as a 350 or better yet a 400 producing 400 HP. You'd be surprised at the amount of air you need to produce 400 HP, it isn't all that much. What you need alot of is fuel and to produce 400 HP you will need your fuel feed (lock offs, fuel lines, filters, and regulators) to be able to supply the fuel required. I, personally would be using 2 sets of lock offs (4 all up 2 on each fuel line), fuel lines, filters, and regulators to make sure even without boost pressure referencing on the regulator(s) that the engine would always have enough fuel available.
Fuel flow requirements calculations
Engine air flow requirement calculation: CFM = Cubic Inches x RPM x Volumetric Efficiency (VE) ÷ 3456

JSC Zvezda
Posts: 3
Joined: Sat Feb 01, 2020 11:46 am

Re: Sbc 283.

Post by JSC Zvezda »

The reason is that I want to keep the original 283 in the car. 1966 Impala. 95 percent of the time it will be just cruising around. So no need for a bigger engine because my substitute for cubic inches will be the turbocharger when I need it. Also the lpg prices in the netherlands are not that low anymore...

I think it might be safe to use an a/f ratio signal to cut boost when the engine tends to run lean? Thanks for your input and I will ask C3H8. Appreciate your info.

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