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Old 12-21-2008, 11:27 AM   #1
KeyBlazer
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BBC 454 build questions

Have a 454 sitting in my storage from a TBI 1990 Suburban.

Not sure where it will end up, maybe in my 73 Blazer.
Wanted some input/ideas on a suitable build..
Have not full stripped it yet, but the crank was a little scored.
Money is an issue at the moment but as and when I have funds I want a plan.
So crank needs a grind, or maybe a .250 stroker but that means rods too and up goes the cost.
I am sure the block needs boring.
I have a set of +60 forged pistons that have raised domes... will post pics when I dig them out.
Heads are peanut ports.
Should I keep the TBI setup that I have and mod it?
What is a reasonable power output to aim for?

Give me ideas?
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Old 12-21-2008, 01:10 PM
Posted in reply to KeyBlazer's post "BBC 454 build questions"
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Let me say that you can build some serious power with a 454 base. You really first need to make a choice if you're going with a carb or FI. I would ditch the peanut port heads and find some"781" heads and have them fitted with the 2.19"/1.88" valves and blend the bowls. Forget about the forged domed pistons you have, those will give too much compression and definately not wanted or needed for a truck engine. You should be looking to keep the CR close to 9:1-9.5:1 to keep it pump gas friendly without pinging issues. You can ask Burt4x4, Dremu, Greg72, bp71k5 how they like the engines i've built for them. Brian (bp71k5 is a 350 but all others are BBC's).
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Old 12-21-2008, 01:21 PM
Posted in reply to 4X4HIGH's post starting "Let me say that you can build some..."
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Cool!
Can you give me some idea as to numbers(HP/TQ) or improvements compared to stock?

What was the specs of the builds you did?

I am stuck between FI and Carb... I would love th go the injected route with the edelbrock or an aftermarket setup, but thats $$$, so I am stuck with the TBI that I have, with mods or swapping to a carb.
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Old 12-21-2008, 01:33 PM
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I can't remember the specs on each of these engines and i thought i had saved them but i can't find them right now. I can tell you though that i did a mild build on Dremu's 454 and it was making something like 580 ft/tq. PM Aaron (Dremu) i'm sure he'll remember the numbers or even have them saved.
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Old 12-21-2008, 03:36 PM
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What were the 781 heads generally used on?
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Old 12-21-2008, 05:08 PM
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336781.....73-85...oval...OPEN...454, 118cc chamber, 256/114cc ports


Taken from the Mortec page here...
http://www.mortec.com/bbc.htm
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Old 12-23-2008, 09:58 PM
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depends on what your using the engine for. if your towing heavy loads the peanut port heads work fine. just grind the crank and put some forged flatops in it and rebuild the heads. an rv cam with .500 lift 214* /222* in/ex duration at .050 with a 112 center and youll have a torque monster. the cam specs listed are from an engle rv101/104hyd cam. i built this combo for a 30ft class a motorhome and used the stock iron intake with a quadrajet and thorley headers. coach weighed approx 20k lbs with my enclosed trailer with my dirt toys in it. i pulled the whitwater grade on the 10 in palm desert in the hammer lane no problem.

all depends on what your intended use is as to which direction to go.
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Old 12-24-2008, 09:37 AM
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Sounds good!
Is there anything that you can do to the peanut port heads to improve things?
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Old 12-24-2008, 02:38 PM
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a good three angle valve job is about it. if you doing stuff like mud bogs or sand where you need higher rpms then i would go with the bigger oval port heads, but for low rpm torque you dont need em.
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Old 12-24-2008, 03:04 PM
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The "781" heads with the 2.19/1.88 valves will make tons of low end torque and still pull good up into the higher RPM range. Peanut port heads are only good for very low end torque and there are really no aftermarket intakes that match the ports of those heads.
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