BAE 3, 4, & 5 fatheads

Discussion in 'PSI Superchargers Tech Questions' started by general23cmp, Aug 29, 2004.

  1. general23cmp

    general23cmp New Member

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    What kind of performance differences can be seen if one was to have simiar spec'd engines with these different heads? I have the opportunity to purchase, for a reasonable price, some older BAE 3 fatheads, but should I just bite the bullet and get the BAE 5 fatheads? I understand that they do not accept all the same parts between them.
     
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  2. d johnson

    d johnson Top Alcohol

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    the fat head 3 are all by them selfs the intake will fit form all fat heads, the rockers are not hte same 3 are all by them selfs headers are not the same form 5, the headers form the fat head4 will fit, tha fat 5 heads hase a higher exh port and a longer vavle, thay flow beter at high RPM, i have run them all 3 4 5 i liked the 4 thay have a 98 cc chamber and dont have the high exh port thay run all same parts as 5 but the headers and exh push rods, the fat head 3 heads have a 123cc chambers and piston wont worke form the 4 and the 5, good luck hope this helps
     
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  3. topalky511

    topalky511 Member

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    hey d johnson seeing as you have run all three of the fatheaads is there much power from the 3/4/5 i am running the fathead threes we have had problems breaking exhaust rockers but have had some steel ones made hopefully that will fix the problem, i am looking at upgrading to a set of 5's will i pick up a great deal of power or is it only a minimal gain, thanks for any help you can offer
     
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  4. d johnson

    d johnson Top Alcohol

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    i have run the 3 and i like them i did have some broking exh rockers but all and all we run good with them, we run all fast 8 stuff and dont run the motor to 10.5 rpm but run it to 8500 rpm, run 6.02 at 233 mph lap after lap, the only bad thing with the 3 is geting parts piston are not the same as the 4 and 5, i run the 5 now and hade some bad luck so cant say a lot about them yet, the 4 and 5 are about the same tha exh port is higher in the 5 but the rest are about the same, with a psi blower you can run beter with the 5 but with roots the 3 and 4 work good hope this help,
     
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  5. jpruett

    jpruett New Member

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    we switched from 3's to 5's this year . after finally adding 2.5 gal per minute, we noticed dramatic increase in performance. the 3 rocker stands were constantly breaking where we haven't broken stand all year since switch. the black exhaust rockers break on the 5's, but the new grey ones haven't broken yet. hope this helps.
     
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