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08-27-2017, 11:54 PM
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#1 |
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Member
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Overbore and intake valve size
'79 AMC 304/2 125/180- is there any advantage to boring .060 with a small(1.79) intake and 2BBL carb or will a .030 overbore be sufficient??
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08-28-2017, 12:09 PM
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#2 |
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Re: Overbore and intake valve size
Well,
Just looking at an engine as an air pump..... With a +.030 overbore the displacement is 308 ci With a +.060 overbore the displacement is 314 ci With a +.080 overbore the displacement is 318 ci If you make 1 hp/ci you would gain 6 hp going to +.060 plus the additional compression..... Just my thoughts, PS: Don't forget to stroke the crankshaft for additional displacement and compression With a +.060 bore and a .013 stroke you end up with 315 ci
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Bob Mulry 7516 STK A & M Motorsports Last edited by Bob Mulry; 08-28-2017 at 12:12 PM. Reason: more math |
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08-28-2017, 01:37 PM
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#3 |
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Re: Overbore and intake valve size
Is there any affect of over boring if the intake cant flow any more air?
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08-28-2017, 02:56 PM
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#4 | |
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Re: Overbore and intake valve size
Quote:
But shouldn't you build your combination around what you run and more cubic inches can't be a bad thing???????
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Bob Mulry 7516 STK A & M Motorsports |
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08-28-2017, 03:11 PM
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#5 |
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Re: Overbore and intake valve size
yes most definitely,it was just a thought. If you went from 030 to 060 and car slowed down with no other changes could intake actually slow it down in this case?
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08-28-2017, 03:23 PM
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#6 |
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Re: Overbore and intake valve size
In addition to more cubic inches, it will unshroud the valves and chamber which it is a plus for engine flow.
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08-28-2017, 08:22 PM
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#7 |
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Re: Overbore and intake valve size
Thinking out loud....the extra weight of the piston is of any concern? The cylinder fills to capacity regardless of any restrictions(valve size, head design)?
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08-28-2017, 10:00 PM
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#8 | |
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Re: Overbore and intake valve size
Quote:
Everything helps on a small motor, but make sure you concentrate on minimizing the deck height.
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"We are lucky we don't get as much Government as we pay for." Will Rogers |
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09-03-2017, 06:16 PM
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#9 | |
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Re: Overbore and intake valve size
Quote:
Jim Mantle V/SA 6632 |
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