engine size for max wedge build?

[6T5]

Building a max wedge setup...286 heads, xram, wedgie exhaust manifolds...etc.....already have the stuff, good condition.

From what I can determine the heads flow about 290-300cfm...the xram even a little less.

I have some "displacement choices" to make......................

1-426, have a '65 streetwedge block.

2-440. Again, I have a block.

3-426 w/ 4.15 crank for about 470

maybe really big
4-440 w/4.25 for 498

300 cfm will only make a certain amount of horsepower...big inch...small inch...Mopar, Chevy Ford, Hudson.....

In fact, I ran 300 cfm on some calculators and no matter what theoretical engine size, they all said 570 hp (which I think is optimistic).

So, which size engine for a rumpy street car? (727/3.91gears)


If you have direct experience please mention it. If you think "426 is just too cool, who cares about top horsepower" please give your opinion.

All responses welcome

Thank you

 

[SUPERSTOCKRACER]

There was a guy who built a 572 ci with a meg block with 286 heads max ported with extensive head work and intake porting. 15:1 compression in a 63 Plymouth belvedere with a fiberglass hood.
Car would only go a best of 10.13 in really good air at Atco. Never seen it go any faster than that.

Watch the white car in the left lane.
https://www.youtube.com/watch?v=g1Sn3zGG_aQ&index=13&list=FLM9_BKJgPRTfpVgks4hRA0A

 

[actionange1]

Was the white car Cortezzo?

Never the less for the engine build guy...
Build the 498
No replacement for displacement
good flowing heads and the RIGHT cam should get you into the 10s
But Max Wedge exhaust manifolds might not be the hot ticket for that number

 

[lewtot184]

the info i have says the heads only flow about 260cfm.

 

[6T5]

thanks guys.

So, you see that huge 572 only goes 10.13.....clearly the heads dictate the output. 10.13 is what I'd expect from a 426/440 with 15:1 , race cam and lightened car.

.maxie exhaust manifolds are a limit.......how much on 498?...anyone car to guess.?

 

[383man]

I agree as I would go around 500 cubes. You are only going to get so much with them heads but since you say it will be a street car you should limit your comp to about 10.0 even with quech since they are iron heads. But with some cubes you will get some good torque out of it. Thats why I went with 493 cubes as I am at just 10.6 comp with aluminum heads and using 92 pump so I wanted some extra cubes for the torque to get my heavy car moving. But I have a head that flows 329 @ .600 lift. I kinda wish I had went even bigger for more torque but the 493 basically did not need any clearencing and was less work then more cubes would have been. Ron

 

[SUPERSTOCKRACER]

My 500 Ci megablock indy head 440-1 that flows [email protected] with a original crossram and 2 Carter 750 carbs went a best of 10.31 in a 3650 lb. Plymouth savoy
As you can see those 286 kill the HP

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If you're starting from scratch, Go as big as you can go now since it all costs the same now. I'd go 572 over a 500 CI engine any day.
I'm dying to pull my 500 out of my 63 Plymouth and put in my 588.
But my son has 2 more years and he'll be racing it so I'll leave it alone for now till he gets used to the power.

 

[63 fury maxwedge]

I built a maxi stroker for the street. Thread is "Max wedge stroker". 555 HP at the crank.

 

[coronet65]

I agree with superstockracer I went with a 540.It has crossram with 2 750s.Also has max wedge exhaust. More than enough power for the street.

 

[dvw]

I ran a 498 with stock x ram and carbs, 670 roller 13-1. 10.13@133 at 3450lbs

 

[SUPERSTOCKRACER]

I ran a 498 with stock x ram and carbs, 670 roller 13-1. 10.13@133 at 3450lbs

Sounds about right. You're 200 lbs. lighter than me.
What heads?

- - - Updated - - -

My cam was a tiny .650 solid roller 13.0 compression

 

[6T5]

very good responses....thank you all...keep goin...

 

[6T5]

very good responses....thank you all...keep goin...

 

[383man]

I guess the question is how big is big enough that will be worth the cubes with them heads which can be the limiting factor ? Ron

 

[6T5]

Ron, I think you are on track there.

I'm thinking Chrysler did a pretty "matched-up" job with that manifold....all the way through the exhaust, for about 426 cubes... pulling at 4500rpm on up.

NOT THAT a few extra cubes wouldn't add grunt but a huge engine may just get "shut down" early, at 5000rpm (or whatever).

I'm thinking that might have a low end pull like a Cummins diesel. That may feel really good around town from a stop light..........but I don't think it would be very rewarding at the drags or out of town where you actually hammer the gas and do a long pull through the gears.

Take a minute and imagine that........think I'm correct? Thoughts?

 

[dvw]

Sounds about right. You're 200 lbs. lighter than me.
What heads?

- - - Updated - - -

My cam was a tiny .650 solid roller 13.0 compression

One of the first sets of out of the box untouched iron Indy's. Stock 63 dodge with S/S springs
Doug

 

[Bigal75]

Why not do a modern max wedge. 572, good heads and a custom sheet metal crossram. I don't know, just thinking out loud.

 

[SUPERSTOCKRACER]

Why not do a modern max wedge. 572, good heads and a custom sheet metal crossram. I don't know, just thinking out loud.

Sort of with a indy crossram. BTW that's not me near my engine.lol

- - - Updated - - -
modern max wedge.

 

[dvw]

I dynoed my old motor with the stock cross ram and the Indy cross ram. 658hp vs 713hp. Back to back on the same day no other changes except jetting. From 4000 rpm up the Indy was better. It ran the 10 teens with the factory 1963 cross ram.
Doug

 

[6T5]

New stuff would be nice but I already own the entire original setup, in good condition and my car is an original/old school type of build.

It's just a street hotrod. I'm building a blown 392 for a 1965 Logge type altered so I need to keep perspective on just how crazy my door car really needs to be.

thank you guys, good thread...