Author Topic: Building a stroker 360 and need some cylinder head recomendations  (Read 9121 times)

Offline Barracudadan

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I am having a 360 stroker built up to a 408 and I need to get heads for this project. What should I go with cast or aluminum? I would like to get a complete set ready to bolt on out of the box if possible cost is also a factor. I have been searching all over the web for info on which is best and i`m still unsure. I expect this motor to be plenty fast enough for me with either type of head and I have no preference either way iron vs alum heads just want the best bang for my buck and best setup for what I am doing.

I don`t have the exact specs on hand from my builder but it will be a lower compression engine around 9.5 to run on pump gas.

Here is something I copied from a tech article at Hughes Engines which is making me re-think aluminum heads for my set-up.
 
Aluminum heads dissipate (get rid of) heat much faster than iron heads. The rapid heat loss from the combustion chamber results in reduced combustion chamber pressures (heat equals pressure); similar to the effect that lowering the compression ratio which lowers cylinder pressure. When switching to aluminum heads you MUST raise the compression ratio to prevent a power loss. This is a good opportunity for our customers to take advantage of our computer calculated compression ratio service. This software assures them of getting the maximum power out of their purchase; it's a no-charge service for our customers.

Aluminum heads will not automatically create more power than iron heads unless they flow more air and are installed on a higher compression ratio engine. In cases where you have a decent port job on a set of iron heads it is possible to bolt on a set of out-of-the box aluminum heads and lose power. Aluminum is automatically lighter but not faster. Yeah, yeah I've read all of those magazine articles that told you how they installed brand X widget and picked up 500 HP and 4 seconds in the 1/4 mile (we have even been the victim of these articles). What you must keep in mind is that those magazines and the writers (???) are paid by the advertisers, not by that $19.99 subscription you send in once a year. So you can expect that advertised products always look good even when they screw the test up and the "results" are not what they should be, (been there done that!). They are under a deadline and the rent has to be paid so the facts sometimes take a back seat. In some cases the engine would have produced more power with a set of well ported, iron heads, and at a lower price.  
Quick Facts: Aluminum vs Iron
 




Offline Mopar73340

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Re: Building a stroker 360 and need some cylinder head recomendations
« Reply #1 on: June 18, 2012 - 01:48:10 PM »
I used the Iron Rams ported by Hughes several years ago on my 408 build as I have a roller magnum engine as the RHS heads that they sell now were not available at the time. The aluminum Edelbrocks were available but I was also not intending for an all out race engine and wanted somewhat of a stock look. The iron heads saved me about $700 + -  over a set of aluminum heads. You will have to make a determination as the article states depending on the head material you choose to obtain the proper compression ratio etc. Again it's all about what you want and how much you want to spend.
« Last Edit: June 18, 2012 - 01:51:25 PM by Mopar73340 »
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Offline burdar

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Re: Building a stroker 360 and need some cylinder head recomendations
« Reply #2 on: June 18, 2012 - 02:06:36 PM »
I wouldn't just buy a set of new heads and assume they are good.  Have your machine shop make sure they are OK.  You don't want problems after the engine is in the car.

Offline HP_Cuda

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Re: Building a stroker 360 and need some cylinder head recomendations
« Reply #3 on: June 18, 2012 - 02:33:25 PM »

Looks like this statement needs to be clarified better:

"unless they flow more air and are installed on a higher compression ratio engine."
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Offline MizzouRT

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Re: Building a stroker 360 and need some cylinder head recomendations
« Reply #4 on: June 18, 2012 - 02:51:18 PM »
The general rule of thumb that I've always heard is that you should add 1 point to the compression ratio with aluminum heads.  So if you are planning on 9.5 with iron heads to run on pump gas, you should go with 10.5 with aluminum heads.  If the engine has not been built yet, you really should decide on what the head first, so you pick the compression ratio to match the heads.
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Offline HP_Cuda

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Re: Building a stroker 360 and need some cylinder head recomendations
« Reply #5 on: June 18, 2012 - 03:33:02 PM »

It depends on what type of motor you are building as well. You certainly don't want to run a higher compression ratio with Aluminum heads if you plan on running a blower.

 :bigsmile:
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Offline Chryco Psycho

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Re: Building a stroker 360 and need some cylinder head recomendations
« Reply #6 on: June 18, 2012 - 04:36:46 PM »
Hard to say what heads make the most power ....
The Eddy are OK but you have to check for core shift as they can be bad .
 The RHS heads are supposed to be very good
 We used the latest W2 heads & I was told that in stock car racing these heads are capable of well ove 500 HP with a 2 bbl carb but you have to buy everything to go with the heads , different intake , pushrods , valve covers , headers etc , very expensive .
 W8 heads & a R3 block can make 800 +hp
Indy has an LA X head I think not sure what that is about .
 THE arguement is if the alum heads actually disapate heat , one knowledgable person claims no but building a number of engines with alum heads & pushing the compression 1 point higher has never caused detonation problems so it must lower heat somehow .
 As for air flow the engine is an air pump so for the engine to work better , you can create swirl in the heads for better mixing & efficiency , you can also close in 1/2 of the chamber causing quench which resists detonation , Also allowing the engine to breathe better should make more power as well . SO I agree just bolting on heads may not increase power & could lose power . Years ago when the eddy RPM big block heads came out my friend figured this was the best move to increase power from his 440 , , the valve were not in the same place as the stock heads to the pistons had to be fly cut for clearance , new headers had to be built for the angled plugs , the rockers did not center over the valve tip ,we had to use lash caps & correct pushrod length , there were a few other issues . We proted the Eddy heads & removed ported 452 Iron castings & went to the dyno , for the "low" cost of around 3k his gain at the wheels was 3 HP !! :banghead:

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Offline bandt

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Re: Building a stroker 360 and need some cylinder head recomendations
« Reply #7 on: June 18, 2012 - 06:29:16 PM »
Just put together a new top end for my 340.

I bought the RHS 360 LA-X heads which fit the LA engine bolt pattern.
They also have the 360 MA-X head which fit the magnum pattern. They are a closed chamber cast iron head.  I upgraded the valves to 2.02 with a 1.92 exhaust. With pre 72 pistons the closed chamber along with the right gaskets it works out to about 10:1 compression. I am running a tight quench with a .054 gasket I have had no issues or pinging on 91 octane fuel. They make good power look relatively stock except for the Indy and RHS logos cast in. I suppose you could grind them off before you painted them. Really happy with the heads no complaints.

Brian

Offline HP_Cuda

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Re: Building a stroker 360 and need some cylinder head recomendations
« Reply #8 on: June 18, 2012 - 06:33:50 PM »

A motor is only as good as the sum of it's parts. So if you just decide to throw aluminum heads on a motor without regard to pistons, cam, carb, intake, etc then you probably will end up with a less than desired result.
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Offline bandt

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Re: Building a stroker 360 and need some cylinder head recomendations
« Reply #9 on: June 18, 2012 - 06:48:06 PM »
A motor is only as good as the sum of it's parts. So if you just decide to throw aluminum heads on a motor without regard to pistons, cam, carb, intake, etc then you probably will end up with a less than desired result.

Good point,

Cam selection is a huge consideration with any set up. Compression can be altered either way depending on the cam you choose.

Brian

Offline Barracudadan

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Re: Building a stroker 360 and need some cylinder head recomendations
« Reply #10 on: June 18, 2012 - 07:18:02 PM »
Thanks everyone lots of good suggestions! I have my choices narrowed down to an iron La style indy X head with ss 2.02 valves from Hughes Engines. For about $1279 a pair these are my first choice stock look which I like and good the most bang for my buck.
 My other choices are the Edelbrock aluminum heads there are two different models I found at Summit. One has a .600 lift and the other a .575 valve lift. Not sure which would be better for me I`ll let my builder tell me which is best.

With the iron heads costing less I may put the savings into a roller cam instead of the flat tappet.

Offline HP_Cuda

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Re: Building a stroker 360 and need some cylinder head recomendations
« Reply #11 on: June 18, 2012 - 07:23:54 PM »

Albeit more expensive but a full roller setup (roller cam, roller lifters, roller rockers) will give you more feedback without the added friction. Mostly folks running high rpm setups choose to go this way but torque motors can also benefit from the roller way!
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