BB Aluminum Heads

[451Mopar]

We had an engine come to us, built by someone else, to be stroked and rebuilt. It was a .060 over 440, L2355F pistons, Torker II intake, 750 cfm holley, Crane hydraulic roller 230/236 @ .050. .528"/.539" lift, stock RPM cylinder heads. We dyno'd it before we tore it down.

RPM................TQ/HP

3000.............458/261
3500.............497/331
4000.............492/375
4500.............510/437
4700.............512/458
5000.............510/485
5400.............482/496
5500.............468/490

IQ, did you flow the stock heads. Curious what they flow?
Also, In your opinion, how well built and tuned was the engine?

Just curious if the power (or lack of it) was due to the parts combination, or how it was all put together?

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Here's my current projected combo, but may change depending on a few factors (stroker is tempting):

446
Shooting for 11.5:1, but will prob end up just over 11:1
Victor heads
Victor intake
Hyd roller. 230/238 @ .050", .606"/.588", 114 LSA
TTI 2"/3.5"

Pump gas, mild idle.

575 hp at 5750rpm
600 lbft or so at 3800 rpm

Not sure what your point was comparing old cars to new cars?
I have a 6.1L Gen III Hemi, and the heads outflow most aftermarket big block heads, so they have a ton of power potential, but I wanted to keep the old school big block in the '69 Coronet R/T convertible. On that car I chose the stealth heads because they have a near stock external look and they flow a bit better than stock iron heads. My '71 Charger has a 500" stroked 400, that uses ported Max Wedge Edelbrock Victor heads, and a custom 0.700+" lift cam, but I have had issues with the cylinder heads center rocker stand breaking on both heads (700+ lb open spring pressure.) I have fixed that, but that's another story.
My first stroker engine , the 451 400 block was built in the late 1980's, and used Brodix B1-B/S heads. At the time the only aluminum head choices were Mopar Stg6, Original Indy 440, Original B1, and the B1-B/S, and the Stage V Hemi Conversion head. I may have left one out, but there was not much choice, and the only one that would bolt up to a stock big block port intake manifold was the B1-B/S (the stage VI had raised ports, I think a RB intake would fit if the heads were on a B block, but spacers were needed for a RB block.) The Indy EZ and Edelbrock heads would come years later.

 

[IQ52]

IQ, did you flow the stock heads. Curious what they flow?
Also, In your opinion, how well built and tuned was the engine?

Just curious if the power (or lack of it) was due to the parts combination, or how it was all put together?

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Average machine shop/garage build, 20% leakdown, cylinderwalls out of round, cam bolts cutting into the timing chain cover.

Good parts though, like billet timing chain, Harland Sharp rockers, heavy wall pushrods.

The cylinder heads were flowing a little less than the advertised flows and actually some of the best stock RPM flows I've seen.

We had to do some tuning to get that much out of it.

 

[Herr_Poopschitz]

Not sure what your point was comparing old cars to new cars?

I didn't compare old vs new cars...? Unless you meant something else...?

 

[67Satty]

IQ, did you flow the stock heads. Curious what they flow?
Also, In your opinion, how well built and tuned was the engine?

Just curious if the power (or lack of it) was due to the parts combination, or how it was all put together?

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Average machine shop/garage build, 20% leakdown, cylinderwalls out of round, cam bolts cutting into the timing chain cover.

Good parts though, like billet timing chain, Harland Sharp rockers, heavy wall pushrods.

The cylinder heads were flowing a little less than the advertised flows and actually some of the best stock RPM flows I've seen.

We had to do some tuning to get that much out of it.

Could have been that the cam was too small to take full advantage of the heads' flow potential?

I was speaking to a head porter about the possibility of doing some work to my stock 452 heads. He recommended just doing a (what he called) an econo-port job (bowl port, backcut the valves), putting in 2.14/1.81 valves and a multi angle valve job. He said with my .534 lift cam, there weren't any gains to be had doing any more than that.

 

[IQ52]

Could have been that the cam was too small to take full advantage of the heads' flow potential?

I was speaking to a head porter about the possibility of doing some work to my stock 452 heads. He recommended just doing a (what he called) an econo-port job (bowl port, backcut the valves), putting in 2.14/1.81 valves and a multi angle valve job. He said with my .534 lift cam, there weren't any gains to be had doing any more than that.

It sure could have used a bigger cam.

So did you ask the porter what kind of cfm difference he is getting from start to finish? Because it isn't too difficult, if you know what you are doing, to gain 50 cfm @ .500" with a 2.14 valve in a 452 cylinder head.

 

[Herr_Poopschitz]

Could have been that the cam was too small to take full advantage of the heads' flow potential?

I was speaking to a head porter about the possibility of doing some work to my stock 452 heads. He recommended just doing a (what he called) an econo-port job (bowl port, backcut the valves), putting in 2.14/1.81 valves and a multi angle valve job. He said with my .534 lift cam, there weren't any gains to be had doing any more than that.

I've never heard of anyone spending a lot of $ on heads to 'match' a cam outside of class racing w/ certain restrictions, and I'm pretty sure your car doesn't fall into this category. Maximize the heads first...cams are cheaper to swap and therefore experiment w/ or correct...would you agree?

 

[IQ52]

I've never heard of anyone spending a lot of $ on heads to 'match' a cam outside of class racing w/ certain restrictions, and I'm pretty sure your car doesn't fall into this category. Maximize the heads first...cams are cheaper to swap and therefore experiment w/ or correct...would you agree?

No hard and fast rules here. It often depends upon the budget. We will do what the customer wants. But I have a set of 370 cfm @ .700" EZ heads on a 10:1 440 with a XE285HL cam.

 

[67Satty]

I'm not talking about spending a lot of $, just install the larger valves, bowl port, backcut valves, multi-angle valve job. Head guy's prices are very reasonable and he has a good rep. My existing heads are fresh and have good springs, locks, and retainers so I'm starting to think maybe I should work with what I have.

 

[IQ52]

I'm not talking about spending a lot of $, just install the larger valves, bowl port, backcut valves, multi-angle valve job. Head guy's prices are very reasonable and he has a good rep. My existing heads are fresh and have good springs, locks, and retainers so I'm starting to think maybe I should work with what I have.

The 2.14/1.81 done like that will maybe get you +10 cfm @ .300" and +20 CFM @ .500". Not done right and you will lose cfm with a 2.14 valve. Seen it! Get flow numbers if you gunna pay for the work!

 

[67Satty]

So maybe another 40 hp tops if everything is done right? Hmmm, might have to think about this.

 

[IQ52]

What happened to the OP, Challenger340?

If I was Bob I wouldn't bother. He asked about Stealth/RPM combinations and whatta we been talking about?

Everything but.

 

[Herr_Poopschitz]

He's got a thread over on moparts that I figure he was going to recreate here.

For what it's worth, I don't understand the tease of dyno/tech info, then having everyone beg for it for days and never returning...the thread is bound to go on tangents...

 

[Garys1969RR]

My combo is: 451 stroker, 509 cam, ported 915 heads with larger valves. Don't have a dyno, but a horsepower calculator estimates 417 flywheel horsepower. That is, a 12.58 ET @ 109 MPH, in Denver. I was hoping for 450 to 475 horse with this combination. But I am happy with the ETs so far. 500 horse power on a street motor is quite a bit to corral.

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Will be changing to Perf RPM heads next month, see what that will do.

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Oh yea, 3600 lb car

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Max RPM about 5000 thru the lights