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Alum. head combustion Chamber cc's?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Emmettology 101, May 30, 2002.

  1. Emmettology 101

    Emmettology 101 3/4 ton status

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    Alum. head combustion Chamber cc\'s?

    Someone told me that all factory and most aftermarket aluminum heads have a combustion chamber of 64cc, is this true?

    I am buying a friends truck and it has a set of Trick Flow heads on it that have been shaved. THis raised the comp ratio up and now should have race fuel run through it. He told me that he was going to run some thick copper head gaskets, but have been told they leak. I am not sure on the pistons f they are dished, flat or domed, but can find out....

    What I am wanting to do is get the compression ratio down to a pump gas size for a DD. He has been running it with pump gas an retarded timing and he said it runs fine, but to run at normal timing it needs race fuel.

    The engine is an 89 350 block with a 383 Scat Crank, KB pistons, Trick Flow heads and I am not sure on the Cam and Rods....

    Anyone?

    Thanks!!!
     
  2. TopOff

    TopOff 1/2 ton status

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    Re: Alum. head combustion Chamber cc\'s?

    I believe Trick Flow makes 74 cc heads too.

    I was looking at these but I too need all the ccs I can get... so I kept my stock 76 cc heads.

    Check with www.summitracing.com
    I know it is in there catalogs.

    I have not been able to find any other alum heads in this high ccs. I think I found some 72 cc once. the reast are 64ccs.

    Good luck.
     
  3. dyeager535

    dyeager535 1 ton status Premium Member

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    Re: Alum. head combustion Chamber cc\'s?

    I haven't really delved into the aluminum head arena much, but I *do* know that due to aluminums properties, you can typically run a bit higher compression than iron heads, with the same grade of gas. I *think* GM has gotten up to 10:1 compression on 87 octane with aluminum heads, but don't quote me on that.

    As well, I'm not sure that if its got domes on it, and shaved heads, you will be able to make enough of a difference in CC's with a gasket alone, to change the fuel requirements...I'd imagine if its got domed pistons and shaved heads, and he already has to run it with the timing retarded, you would have a hard time getting compression back down without changing pistons at least. I'm no expert engine builder of course, but this makes sense from what I've seen on the topic...
     
  4. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    Re: Alum. head combustion Chamber cc\'s?

    AFR makes a set of heads for sbc with either 56cc, 63cc, 68cc, 70cc, 74cc, 76cc depending on what head you are wanting. I took this info right out of their Nov. 1 2001 catalog.
     
  5. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    Re: Alum. head combustion Chamber cc\'s?

    AFR makes a set of heads for sbc with either 56cc, 63cc, 68cc, 70cc, 74cc, 76cc depending on what head you are wanting. I took this info right out of their Nov. 1 2001 catalog. I am not sure if they list every head they have on their website or not but here is the link. www.airflowresearch.com
     
  6. JoseK5

    JoseK5 Registered Member

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    Re: Alum. head combustion Chamber cc\'s?

    Aluminum heads come in different compression ratios, the newer vortechs come in 64cc,. It is also true that aluminum heads can tolerate higher compression ratios. The best and safest way to lower compression ratio is to change the pistons, however thicker gasket from reputable brands, and a professional installation should enable you to safely lower the compression ratio. I run 10.25:1 compression with premium fuel, no problem, altough I do not know if I will get any detonation if I run 89 octane fuel.
     
  7. Emmettology 101

    Emmettology 101 3/4 ton status

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    Re: Alum. head combustion Chamber cc\'s?

    Well, without talking to my friend I think I have narrowed the heads down to the Trick Flow 23 Degree heads with a 64cc camber. He first tried using the heads with the stock TBI and then went to a carb...... So the heads are the 87 and later style.....
    Now I just have to find out what pistons are being used and how much was shaved off the heads....
     
  8. NITRO

    NITRO 1/2 ton status

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    Re: Alum. head combustion Chamber cc\'s?

    i use C16 in the 555 blown beast... so u may wanna just use premium on somthin like that. just experiment.

    NITRO
     
  9. Twiz

    Twiz 1/2 ton status

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    Re: Alum. head combustion Chamber cc\'s?

    Running a thicker head gasket to limit combustion should be used as a last-resort, In My Opinion.

    The thicker head-gasket will increase the space between the quench-zones, makeing the camber lazier. Possibly increasing it's sensitivity to detination.

    The pistons should be changed, to achieve the desierd compression ratio.
     

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