Hot Rods Switching from cast iron to aluminum heads sbc, real life experiences

Looking for input on the best heads for the money. I have read all the magazine comparisons etc, but I don't know how much of the data is skewed by marketing dollars.
I have a set of 462's currently and would like to make the leap (when funds allow) but I want to make sure I get the most bang for my buck. It would be for a hilborn injected, solid roller cammed 301 in the Fly.


Tell me your real life experiences.

 

What CC combustion chambers and intake runner size are you looking for?

 

Air Flow Research
Cheapest--Nope
Hands down, best deal considering everything

 

I'de like to advise you,but A LOT of variables..... If you've looked at things,Car Craft did a head comparison test,with HP/Torque #'s,as well as cost. These were bolt on's,with no other mods= fancy rocker systems,porting,etc....... Also- keep in mind there is the intake/carb/exhaust combo's that gotta jive with everything....... If looking for some HP,they all have to co-exist,or you'll be wasting $ for a minimal gain. If you've read that article,then you have an idea,and not just who favor's what. If not- search for "cylinder head compare test",and it should help. Hope this helps.

 

Aluminum threads strip out, they are more prone to warpage, dissimilar metal corrosion, higher cost....but they look real cool...lol.
Hard to beat the HP they produce,along with weight savings...it would be a toss up for me.

 

Very true but, marketing aside, you can't argue with AFR's reputation in racing over the last 20 years. Bench racing b.s. and marketing hype only go so far.
Individual real world experiences are only relative to each engine/component combos based on numbers from the dyno.

 

I like the AFR's. I will be looking at a 62-65 cc chamber, a runner size of 190-200. It does look like I would have $2200 in a set of AFR 's. AFR recommends a 195 but if I ever motor up, it would be on the ragged edge. One other thing, I may convert to alcohol as well.

I would like to hear stories about performance gains, time shaved off E/T etc.

 

I would stick with cast iron if your running alcohol

 

From what I understand, One of the things with alum heads is that they will allow you to run higher compression. That being said you should be able to run smaller chambers compared to what you now have on the engine. (I guess somebody will school me on this if i am incorrect.) That should mean better quarter mile times.

 

I know you know this, but weight savings aside, aren't the chief advantages of aluminum heads is that they are easy to repair and they let you run more compression? If your compression is already set (the engine is built) and you are not going to be blowing up engines and damaging parts, it seems to me they will not offer you much of a bang for your buck. But I'm just a by-stander here, only having put a set of Corvette heads on my 350. I noticed zero gain. But they are shiny and do help promote electrolysis.

 

Well in real world experience.....I had an ancient set of brownfield's......sent them out for porting,along with my intake,(matched w/carb spacers)and had a custom set of header's made=Lemmon's. 1 7/8 to 2''.also,upped the carb=950cfm= $. The end result's were 12mph in the 1/4,and from a 10.60 to a 9.98.
yes- with aluminum,you can get away with about a point of compression,but if it's all out,race fuel is the equalizer.... On the weight thing- sure. weight savings equals something. depends on what you want to do,besides "aluminum",and goals...... And as far as worrying about stripping threads, I call BS. Never an issue at all.Gotta know what your doing just like anything else.
There are many advantages to be gained,but it's how they are executed that transpires the end result.......

 

Where are you at now for compression? Alky wants some big squeeze, so along with heads you will be looking at a cam and possibly Pistons depending on current Setup.

 

Look up nkb heads on eBay best bang for the buck, just bought a set myself

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And your results are?

 

I am about 12.5:1 right now with 64cc. I think one of the things being overlooked is the reduction in detonation. You can run more advance as well.

 

Then stick with the small chamber....... Valve size come,'s into play also.....I know you can't stick a fat valve into your castings.... You will benefit with the upgrade,but like I mentioned before,if you "up" one thing,the others have to match for maximum gain....... A bolt on =yes, maximizing=more to the story......

 

Holding up fine, flow better than pro comp and very close to dart numbers for fraction of the price.

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I like these. http://www.summitracing.com/parts/afr-1095/overview/

 

BRODIX IK-180

Another long story... sorry. I'll try to keep it short.
Years ago, I was at an antique scooter meet and this older guy was having troubles with his scooter. So, the right thing to do was to help him. I must have spent 2-3 hours with him and got him going again.

He was very pleased and so his friend introduced us properly. He said this is JV. I said OK, who is JV. Our friend said, "No, you don't understand, this is JV Brotherton. I said, "Who is that? He said, "MR. BRODIX"... I said, "Oh-k-a-y".

About an hour later, JV came over to my car and started asking me about it. What cam, what pistons what RPM, intake, carb, trans, gear, etc. He asked what size combustion chamber I wanted. I said, "I'm not ready to get a set of heads yet." He asked where I wanted them sent to. I said, "No, no, I'm not ready for a set of heads yet." He told me not to worry about it.

At the next meet he came over to my camp with a big box and dropped it off at my picnic table. When I opened it up there was a beautiful, brand new set of IK-180's. I told him I wasn't ready for this and he said that's OK, I need that scooter striped, my wife's car, my golf cart and a couple more scooters.

We made a deal that day, to never charge each other for our friendship. We've been good friends ever since. What a nice guy!!! It always pays to do what is right.

End of the story is... my car went from about 300 HP @ 390 TQ to 465 HP @ 590 TQ.
Thank you very much JV!

 

165 hp and 200 ftlbs tq jump - that's quite impressive don't you think? More than 50% and it just keeps getting better , Much like the story. Not sure how any of that's going to help root though.


The aluminum heads will allow you to take a more aggressive approach to tuning and let you run more compression. I don't thing the heads in and of themselves are responsible for any increase beyond minimal. Unless you can add 20 or 30 hp just from having them in the trunk

 

Well the ones I have are pretty restrictive by today's standards. I think just runner volume and valve size would make a big difference. My intake would go from 2.02 to 2.08 and the exh would stay the same.

Montana, that's a cool story. You never know who you are helping.

 

Some very interesting arguing points from the following article.
* a cast iron head on an engine without detonation issues would make more power (than an aluminum head)
* “You need to build more heat with aluminum to make the same power,” (as an iron head)


http://www.performanceracing.com/magazine/online_bonus_feature/hot_topic_iron_vs_aluminum.html


By John F. Katz
The weight-saving advantages of aluminum heads versus cast iron are obvious and widely accepted—especially in drag racing, where weight high up in the front of the car is especially undesirable.

“Cast iron has been used for making cylinder heads since the early days of the internal combustion engine,” noted Jack McInnis of World Products, Louisville, Kentucky. “Its primary advantages relative to aluminum are lower cost and durability. Aluminum’s significant advantages are light weight and relative ease of repair by welding.”

But could the thermal properties of iron offer a power advantage over aluminum? That question gets complicated.

“Thermal conductivity has been debated for many years,” said Kevin Feeney of RHS, Memphis, Tennessee. “Historically, an iron head was considered more durable, and able to make more power due to the fact that it would not dissipate the combustion heat as quickly. With everything else remaining equal, there exists some merit to this argument.”

Mike Downs of Trick Flow Specialties, Tallmadge, Ohio, pointed out that the thermal conductivity of aluminum is “four or five times that of iron. This means an iron head will usually operate hotter. On the positive side, this means the fuel is pre-heated in the intake runner and easier to ignite in the cylinder.

On the negative side, it means the preheated air/fuel mixture will expand, reducing the effective flow into the engine and increasing the risk of pre-ignition. A properly designed aluminum head will transfer heat more quickly to the coolant, leaving the intake runner cooler and therefore able to flow more air-fuel mixture into the cylinder. High-energy ignition systems easily compensate for the cooler intake charge and help achieve maximum fuel burn.”

“The greater thermal conductivity of aluminum is a great advantage,” agreed Chris Frank of Frankenstein Racing Heads, Joshua, Texas, “especially in power-adder applications. That ability to dissipate heat quickly allows for more aggressive tune-ups.”

“Aluminum heads dissipate heat quicker than cast iron,” echoed Torrance, California-based Edelbrock’s Smitty Smith. “This can be an advantage in elimination-style drag racing, keeping the head temperature consistent round after round.”

With aluminum, Tony Mamo of AFR (Air Flow Research), Valencia, California, concurred, “detonation is less likely in an engine on the ragged edge, as it won’t hold as much heat. But that also firms up the argument that a cast iron head on an engine without detonation issues would make more power for the very same reason!”

“You need to build more heat with aluminum to make the same power,” agreed Bill Mitchell Jr. of Bill Mitchell Products, Ronkonkoma, New York, “or compensate by coating the chambers to keep more heat in the cylinders.”

Machinability

“The machinability of cast iron is actually pretty good,” said Sonny Leonard of Sonny’s Racing Engines and Components, Lynchburg, Virginia. “The main hurdle would be during the CNC porting process. You tend to be machining in slender cavities, which dictates using less rigid tooling. This may require longer cycle times, which would reduce profitability.” That said, “cast iron does offer some advantages over aluminum. Cast iron has greater stiffness and damping characteristics, which may aid valvetrain stability. But the weight penalty is too great to really explore this option. The weight issue will always be the deciding factor.”

Added Carroll Carter of C & C Motorsports, Manassas, Virginia: “Aluminum is preferred over iron due to its light weight, intrinsic metal characteristics, and the ease of working with it. Aluminum is easier to machine and easier to repair—and it creates a better-looking product. Today’s advanced CNC machining centers and other computerized shop equipment are turning race engines into works of art.”

Additional Content: Visit Performance Racing Industry Magazine online for comprehensive feature articles on Drag Race Cylinder Heads and the 2014 Drag Race Market, as well as our exclusive report on Diesel Drags.

 

Well, I did not have double humps to start with, I had some small valve heads off a medium duty truck small block and that's why the big increase. I have before and after dyno sheets. Did I mention that it gets 20 mpg too, on mid-grade.

 

Yeah some place on another thread.
Along with 144 blowers adding tremendous amounts of power and flipping over T buckets.

 

AFR 210's get my vote. I ran a set on a 350 sbc for a year then stroked it to a 383. Excellent flow, room to grow, BIG power. In a 3500lbs fbody with 11:1 compression, victor Jr, 620 lift roller, 850 carb, th350, 4000 stall converter & 4.11's running 11:20's. Drove it to and from the track.

 

Interesting article. This statement smacked my in the face. This may require longer cycle times, which would reduce profitability.
That explains why they don't offer as many good cast iron options.

Cast iron is not a deal breaker for me. If we convert to alcohol, it may be beneficial to run the cast iron to build heat in the motor. I have previously looked at the World Sportsman II heads like these http://www.speedwaymotors.com/World-Sportsman-II-Small-Block-Chevy-Iron-Heads-Angle-Plug,1338.html

 

Gets my vote also, but with a 301 cu. in. motor (Roothawgs), 210's (may) be a bit big,
but he does have compression on his side.
It is really difficult to use others' combos as comparisons due to the endless combination possibilities but AFR's got a pretty good reputation of torque and h.p. gains across the board; with many years of proof (dyno sheets) documented by endless independent (professional) engine builders.
I have proof of results from my dyno sessions but this particular engine was planned for my street driven roadster and big h.p. numbers were not my ultimate goal.
Though even at 427 inches (small block) with a rpm limiting hyd. roller cam, my engine guy suggested the 210's, though (at the time) they offered 220's but they required shaft mounted rockers and they were not needed for this application.
Roothawg--
You could go 10 different directions and still come up with great results, considering your 462's (w/202's) were installed on 350 horse 327's way back in 67.
I would first follow up with what 31Vicky submitted, these are (some) of the who's who in the high performance engine building world. Also consider Kenny Duttweilers input.
Regardless of the heads you choose; divulge your entire engine/vehicle plans to them including your plan to (change) to alcohol.
Doug

 

I got a set of trickflo twisted wedge heads on my 355 that I like really well. I don't think that they make the twisted wedge heads for the SBC any more, but if I found a pair I would drop cash on them in a "heart beat". These cost me 1200 bucks in '97, I think they still sell SBC heads in the same price range and they'll tweak whatever you get from them if you ask.

 

I am offsite (stuck in St Louis) or I would have all of my engine specs handy. I am running a solid roller in the .600 range, can't remember the grind dumber off hand. Hilborn Injectors running 7a nozzles and a -0 pump. I run a glide with an 8" converter and a 5.13 gear.

I have provided AFR all of the actual specs and the 195 Eliminator is what they recommend. The were afraid if I increased my runner volume it would lose the velocity required. I was afraid of painting myself into a corner if I ever wanted to motor up to say a 406 or larger. Then I would have a set of high dollar heads that were too small. I doubt I ever will have the $$$ to build a large CID sbc, so I am pretty safe I think.