Engine planning

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5.9magnumjeep
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Engine planning

Post by 5.9magnumjeep »

It may be an odd question, but I have been in a bit of a analysis paralysis with planning my street/strip big block 454 build.

Here’s what I know that are certainties in my build:

1. 4” stroke stock forged crank
2. 6.135 scat rods
3. 049 cast iron heads
4. Edelbrock rpm air gap intake manifold
5. Pump gas
6. Carbureted

What is left to be determined:

1. Valve sizes
2. Port work after valves are done
3. Cam and matching valve train
4. Static compression ratio

Where I’m getting hung up is in what order do I make my decisions? Everything effects everything else.

My first instinct is I need to get the valve job done and do the minor port work needed, flow the head so I know what I’m working with. Where I’m at a loss is do I choose a static compression ratio and match a cam to it to get a safe dynamic compression ratio? Or do I spec a cam and determine what static compression is needed to run it?

I would like to see peoples thought process on the order in which they plan their motors.

As a caveat, I have done a lot of stock style rebuilds which is a lot simpler than making high performance determinations.

Thanks in advance!
BillK
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Re: Engine planning

Post by BillK »

I think one of the first things to decide is what vehicle is it going in and what are the performance expectations ? A 3800 lb Chevelle that you want to run in the 9's will need a lot different engine than a 3000 lb Camaro that you will be happy if it runs 11's.
Bill Koustenis
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Waldorf Md

www.enginerepairshop.com
5.9magnumjeep
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Re: Engine planning

Post by 5.9magnumjeep »

Model A Tudor, estimating around 3000 lbs. or less. I would like to be in the 10’s (would still be happy with low 11’s), I will be setting up a 4 link rear end, ford 9 inch, 30” dia tire. I have a TH350 with a 2500 stall converter, both in unknown condition at this time. Undetermined rear gearing as I need to pull apart the transmission and figure out it’s ratios.
BillK
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Re: Engine planning

Post by BillK »

So you will need around 520 horsepower to go 10.50's ? If I was doing it and did not have any parts I would do 4.250 stroke for the extra cubic inches. I don't like going over 9.5 to 1 with iron heads on pump gas so that limits power some. If you already have the 4" crank then its still doable but I think you will have to bump up the compression a little bit. Call your choice of camshaft guys and ask their recommendations on a cam. Heads should work with 2.19 x 1.88 valves.

Take a look at a couple of Marks combinations. Something close to the second one would be almost perfect for what you are doing:

https://vortecpro454.com/#xl_xr_page_engines
Bill Koustenis
Advanced Automotive Machine
Waldorf Md

www.enginerepairshop.com
5.9magnumjeep
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Re: Engine planning

Post by 5.9magnumjeep »

Thank you billk! I actually just started watching his big block in depth buildup with iron heads.

I already have the heads, block, crank, rods, and intake. I just don’t have it in the budget for getting a new crank and rods. However, if a 496 will get me to my goals and easier on the motor, that may be a necessary to save up for some new parts.
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