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Location:
Tamworth
Registered:
August 2004
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18rg head casting
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Mon, 16 May 2005 11:21
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I have searched google and this forum looking for info on this.
still didnt answer my qestion.
I just bought a 18rg 88210 head with plans of doing the most radical mods possible for maximum airflow. Following the theory of airflow = horsepower(yer i know, u can have to much)
I belive there is many different port sizes, valve sizes,springs, compression ratios for the different model codes. However these points do not worry me because everything
i will be using will be brand new(except for the head casting)and i will be re-machining the valve seats, porting and flow testing the head anyway.
I am trying to find out if there is any difference between the MAXIMUM PORT SIZE CAPABLE(maximum being a safe amount of material between the port and water jacket)of different model codes.
Or which head can i acheive the largest port size without hitting water?
Or has anyone got pictures of cross sections of these heads or actually cut one in half to see wat material lies between the port and water jacket.
I do this sort of stuff everyday just not with 4 cyl. So porting, valve seat/valve machining isnt a problem, i have the ability and resources to do it myself, and the knowledge on hand.
I hope u can understand my text and please excuse my un-matured speech. I am just a young apprentice.
Regards, Jeff
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Location:
Nor Calif USA
Registered:
June 2002
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Re: 18rg head casting
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Mon, 16 May 2005 16:54
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| jeffro RA28 wrote on Mon, 16 May 2005 21:21 |
I have searched google and this forum looking for info on this.
still didnt answer my qestion.
I just bought a 18rg 88210 head with plans of doing the most radical mods possible for maximum airflow. Following the theory of airflow = horsepower(yer i know, u can have to much)
I belive there is many different port sizes, valve sizes,springs, compression ratios for the different model codes. However these points do not worry me because everything
i will be using will be brand new(except for the head casting)and i will be re-machining the valve seats, porting and flow testing the head anyway.
I am trying to find out if there is any difference between the MAXIMUM PORT SIZE CAPABLE(maximum being a safe amount of material between the port and water jacket)of different model codes.
Or which head can i acheive the largest port size without hitting water?
Or has anyone got pictures of cross sections of these heads or actually cut one in half to see wat material lies between the port and water jacket.
I do this sort of stuff everyday just not with 4 cyl. So porting, valve seat/valve machining isnt a problem, i have the ability and resources to do it myself, and the knowledge on hand.
I hope u can understand my text and please excuse my un-matured speech. I am just a young apprentice.
Regards, Jeff
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The EFI head is the head you can take the most material out
before you hit water. But, I wouldn't do that unless your going force induction.
when you hog out the ports like that you will have alot of air flow. But, you will NOT have the velocity (air speed)
that you will need in an NA engine to fill up the cylinder.
on the RG the exh ports are big enough. you just need to open up the intake ports.
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Location:
Tamworth
Registered:
August 2004
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Location:
Brisbane
Registered:
October 2002
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Re: 18rg head casting
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Tue, 17 May 2005 06:39
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can u flow test the 88210 head and tell us what she flows
if u could get other heads can u flow them so we have some info on what they actually flow at standard
i'm doing an 18RG tech article and would like hat type of info
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Location:
Tamworth
Registered:
August 2004
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Re: 18rg head casting
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Tue, 17 May 2005 08:35
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Mr DOHC, i will be flow testing the head before i biggin porting anyway, so that i can test which parts of the port need material removed and how much i improve the airflow from standard. I have no idea when i will do this because i just work on my stuff about 30 mins after i finish work everyday(the workshop must be clean and the days jobs finished before i start my own stuff) and there isnt any hurry for the engine as it wont be going in till i get my ra28 painted which will be next year. I will store it in my memory bank tho and when its tested i hope i remember to let u know.
Speaking of testing other heads, i am willing to flow test them if someone is willing to donate them(i here that some one on here has a garage full of them. i only have 1 18rg head and 4 18rc heads. Also i wouldnt mind preferably a rooted head that i can cut in half to see what my limits are as far as valves and port size. Which will benefit everyone that has similar plans to me.
I like the sound of the 18rg tech article, have u got much for it yet?
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Location:
Brisbane
Registered:
October 2002
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Re: 18rg head casting
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Tue, 17 May 2005 08:46
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i have a fair bit, put up a post about getting some rooted head donated, all mine are in good nick tho.
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