Building a true 500hp SBC

[C20-67_N_MO]

Okay I know this might be a stretch but how hard would it be to make a SBC to pump out 500 real wheel horsepower?

I've got a good stout 383 short block I'm starting with and want to add my Edelbrock #2201 roller camshaft .538/.548 lift. Since I do not have heads yet would think it would have to be a very good flowing head to get to this number.

Any thoughts or suggestions appreciated.

[71Dragtruck]

Marv D on here runs stout small blocks and knows them well, if he doesn't chime in do a member search and try sending him a message or email.

[hotrod 80]

Your going to need a good head for sure . 210 minimum . My hydralic roller 385 made 499 on its last pass with the Wallace caculator MPH/weight/et type deal . It can be done .

[Marv D]

There are a lot of variables that can effect 'RWHP' so lets talk about flywheel HP.

First question is what fuel?

Keep this simple rule in mind...
The fuel you run
dictates the cylinder pressure (compression) you can build,
which dictates the minimum 0.050" duration of the cam you run,,
which dictates the effective RPM of the motor.

It's a bit counterproductive to say.. "I want to use 'this' cam and make 'this' HP". Not saying it can't work,, just that you may throw an additional $1000 at it trying to make a $300 cam work!

That said,, 500 is about as easy as falling off a log these days,, but you will have to follow what I call Roger Rule #2
(Roger Copeland being a wise old friend that taught me buttloads about just general engine building)

His favorite comment is

Make your choices, pay your money, and live with the results

So choose a fuel and we'll talk

[C20-67_N_MO]

More than likely I'll be running 110 octane rating that is being sold at my local gas station.

So now the question would be how much compression can I get away with?

[Marv D]

Lets clarify,, 110 octane is open to inturprutation.
The ONLY octane were interested is MOTOR OCTANE

Find out the TRUE MOTOR octance of the fuel. Crap thats sold as 110 can be as low as 102 MOTOR octane and have a buttload of exageration in their 'label'

A fuel like VP - 12 is 108 motor octane, 110 research octane it will support a 13:1 motor spinning to 7500 EASILY

C-14 will take a 14:1 SBC into the 9000rpm range and above.
As RPM goes up so does the requirement for MOTOR OCTANE,, that research or R+M/2 is not applicable to our motors and the type of use.

Here's just a few examples of how wild the advertised octane BS can vary.
this will download a pdf with some examples of popular race fuels

If the 110 is E-45 or something like that,, we need to get someone like Shaun that is familiar with that fuel. It's a WHOLE different ball game than just race 'gas' with a 110 motor octane.

Next HEADS are where the power is made. PLAIN AND SIMPLE!
I suggest everyone pick a budget JUST for the heads,, then DOUBLE IT. Then you will have something you can grow in to as the need for faster faster faster hits you.

So what kind of a budget are we dealing with? If your starting from scratch,, and don't have a friend with a pile of used parts to offer for penneys on the dollar..... you can easily put something together in the 500HP range for around $5000,, but it won't be the most reliable parts out there. Add another 50% or so and you'll have something more tolerable of hard abuse.

[Super73]

Or.. You could spend $5k and have a turn key LS swap with a few upgrades that runs on 91 and makes an honest 400rwhp. Starts every time and loves to be beat on. It is still a SBC, just not the traditional one

[C20-67_N_MO]

Originally Posted by Super73

Or.. You could spend $5k and have a turn key LS swap with a few upgrades that runs on 91 and makes an honest 400rwhp. Starts every time and loves to be beat on. It is still a SBC, just not the traditional one

I would go LS but since I have a very nice 383 SBC this is what I am using right now.

[franken]

What do you plan to do with this engine?
HP is a somewhat fictional number based on torque times RPM.

[C20-67_N_MO]

Its going to be a pro street engine in a 1970 Chevy C10 SWB truck.

[Super73]

Decide on your max rpm and the fuel you are going to run.

More times than not the intake is going to be decided based off RPM window.

Buy the best heads you can afford. Focus on mid lift flow vs peak flow. For what you are doing, I would happily take a head with better flow at .300-.500 than a head with a few cfm more at .600. Try to get the most flow from the smallest valve/runner combo possible to aid in velocity.

Have a custom cam ground. The valve events will be mostly dictated by RPM, where to close the intake and how much overlap. Exhaust valve opening is a little less important but the earlier it happens the more time it has to release the burnt gasses preparing for the clean charge to come.

After that is done, mill the heads to achieve optimal dynamic compression based on the fuel you are going to run.

The initial header tube diameter should be as close to exhaust port cross section as possible but not smaller, then be stepped up from there. IE if exhaust port cross section is 1 1/2", start there then grow the tube to 1 5/8 then 1 3/4 before the collector. Exhaust exiting the port is extremely hot and dense, velocity is high. As it cools it expands and velocity slows requiring more room to flow adequately.

Just some thoughts..

[tinydb84]

Originally Posted by Super73

The initial header tube diameter should be as close to exhaust port cross section as possible but not smaller, then be stepped up from there. IE if exhaust port cross section is 1 1/2", start there then grow the tube to 1 5/8 then 1 3/4 before the collector. Exhaust exiting the port is extremely hot and dense, velocity is high. As it cools it expands and velocity slows requiring more room to flow adequately.

Just some thoughts..

I always wondered why they did this with headers. Learned something new today.

[RocketChevy56]

Wow, me too. I have never thought about it that way before. I was always curious why they were more expensive too! Cuz they work!! lol.

There is a lot of good info here for everyone that is at this point in their build. Although I'm not at that position in my builds, I'm going to keep a close eye on this one. Far too good of info in one place

[GMR-PERFORMANCE]

Marv.. you mean that you cannot just throw parts at a build and claim it makes 500 HP??

Here is a set up that will make those numbers and then some

400+ CI
RHS 225 heads ( light work over)
11.1 comp ratio
Howards retro roller 243/249
PP hurricane intake
950 HP carb ( AED super mod)
Hooker super comp headers

I am well over the 500 mark and that is my parts list. Now I am running a dart block zero deck .. Block that is stable is worth power. That is pump gas BTW. Now the tune and how you tune it, weight gear ratio ALL play a role in getting a high comp engine to run on pump gas more so heat.. I am running a 7730 box to control timing, retard on timing to start. Its not a simple thing but in the end I would bump up to the 421 CI range build to have massive mid range tq and let the HP fall where it may.. Just an opinion.. Broad tq curve is a huge fun factor HIGH hp only type set up.. can be..

Cam card for what is listed

CAMSHAFT: Performer RPM Roller Hydraulic
CATALOG #2201
ENGINE: Chevrolet 283-400 c.i.d. V8 (57-86)
RPM RANGE: 1500-6500
CAUTION:
Use stock ratio rocker arms only.
Duration at .004" Lift: Intake 296° Exhaust 300°
Duration at .050" Lift: Intake 234° Exhaust 238°
Lift at cam: Intake .359" Exhaust .365"
Lift at valve: Intake .539" Exhaust .548"
Timing at .050 Lift:
Open Close
Intake 10° BTDC 44° ABDC
Exhaust 56° BBDC 2° ATDC
Lobe Separation: 112° Intake Centerline: 107° ATDC
Exhaust Centerline: 117°

[hotrod 80]

I ran a simailar cam to this^^^^^ with good results .

[GMR-PERFORMANCE]

Originally Posted by hotrod 80

I ran a simailar cam to this^^^^^ with good results .

.. But a 383 with that cam and 500+ hp..

[C20-67_N_MO]

Originally Posted by GMR-PERFORMANCE

.. But a 383 with that cam and 500+ hp..

Okay I know this camshaft may not be idea but for now it should be fine.

[hotrod 80]

Originally Posted by GMR-PERFORMANCE

.. But a 383 with that cam and 500+ hp..

Well similar . Mine was a bit bigger Comp XR 288HR

[Super73]

If your goal is 500hp to the rear wheels, it is going to take a lot of planing. I just looked up that cam and even with awesome flowing heads, I don't see 500rwhp.

Example and I know they are different platforms all together but my combo is:
13-1 compression 418" LS motor
My heads flow 35x cfm on the intake side
I run a Super Vic intake that has been ported to match the transition in to the heads (heads touched up a little as well)
I have a 254/260 hyd cam with .62x/.63x lift
2" headers in to a 3" X-pipe with dual electric cut outs
I run E85

I make 521rwhp through a power glide trans with pretty decent sized converter (5k on the brake and flashes to 4,600 off the 2-step).

Just food for thought.

[fastbagged68]

I'm with Super73. 500rwhp will take really good planning.
Look in to air wolf cylinder heads. http://www.j-performance.com/index.p...d=44&Itemid=61
You are going to need a custom ground cam, ported intake, badass heads and at least 11-1 comp.
Just for reference, I had a 434 sbc, 14.5-1 comp, 27x-28x dur @ .050, afr heads, milled and ported, victor jr, 1050cfm 4150, 1-7/8 stepped 2" headers. Made 602hp at 6200, 587lbs at 4900-5100rpm. This was on an engine dyno.

[GMR-PERFORMANCE]

Originally Posted by C20-67_N_MO

Okay I know this camshaft may not be idea but for now it should be fine.

This is the issue on the net . You ask,.. we tell you,...then you say. " but for now it should be fine" WTF.... if you know so much go build the engine and stop asking newbie questions.

[C20-67_N_MO]

Originally Posted by GMR-PERFORMANCE

This is the issue on the net . You ask,.. we tell you,...then you say. " but for now it should be fine" WTF.... if you know so much go build the engine and stop asking newbie questions.

Now look! Just because I ask questions and then say it should be fine doesn't mean I know everything. Just saying I'm starting with this camshaft then will upgrade it later.

Yes I realize that this magical '500hp' number seems lofty but it still can be done with a little work and research of the proper parts.

[Super73]

It can, absolutely. But I think what a lot of us are getting at from experience is doing it once costs about 1/3 to 1/2 as much as doing it again and again. Having grown into what I have today, I have been through:

2 different short blocks
4 sets of heads
2 intakes (Porting the second one at a later date)
4 cams
2 sets of headers
3 exhaust systems
2 sets of injectors
2 different fuel pumps and redoing all the fuel 3 times
5 different converters
2 different transmissions
2 different rears
3 different gear sets
3 different tire sizes
2 different wheels
3 different rear brake set ups

And much much more.

Now, did I learn a lot, oh heck yeah I did. Did I spend a lot over the years. Uhh Huhh.

You can either come up with a great plan from the start that will do what you want based on your end goal, or, you can do it the way a lot of the rest of us have. Painstakingly slow buying and selling new/old combos for pennies on the dollar, doing and redoing because you are not happy with it.

Just food for thought.

[71Dragtruck]

Like 73 said, I'm at.

3rd motor with several changes made to the first 2, soon to be 4th complete motor
4 gear changes, 2nd rear end
2nd 4 link system and coil overs
3rd set of headers soon to be 4 as won't work with new
3rd exhaust soon to be 4 as won't work with new motor
3rd intake
4th carb soon 5th as won't work with new motor
2nd ignition, soon to be 3rd as need a 2 step for trans brake
soon to be 3rd trans setup current won't work with new motor
3rd converter, again going to 4th as you guessed won't work with new motor
4th tire size change
2nd front suspension builds complete hub to hub, this time whole crossmember
3rd water pump setup
2nd shifter
3rd fuel system, 2nd fuel cell
2nd nitrous plate
5th set of rims
3rd fan setup
2nd rad

and the list actually goes on but I'm starting to get depressed thinking about all the cash I've spent.

As you can see there is a trend when you build a motor "to be changed later", now things like carb, headers, exhaust, converter, gearing need to be changed with to match the new combo.

[Marv D]

Originally Posted by 71Dragtruck

Like 73 said, I'm at.
.....
and the list actually goes on but I'm starting to get depressed thinking about all the cash I've spent.
....

Exactly,, I don't wanna play that game.



all I'll say is I made just a titch under 800 at the flywheel n/a single carburated small block on a SuperFlo engine dyno, with a cam that has just a little more than the 0.050" duration of the Edelbrock 2201,,

Edelbrock: 234/238 @ 0.050",,

the cam in my Nova : 250ish/ 260ish at 0.050"

well except mines .81 lift with a custom set of Jessel 1.7 / 1.8:1 shaft rockers for the Allpro 245 Rased runner heads,,, flowing 370ish

Your cam, my heads and I'm sure you can make your 500 RWHP

as a FYI heads and valve train ran me just over $9k


That's what were getting at C20
If the cam is "just fine" whatever HP number you end up with will have to be 'just fine' also.

Building a combination around an existing component (unless it's the heads) is quite counter productive to the budget. But so be it.

Choose a fuel spec, and choose a budget and then we could offer some realistic help on your combination