BBC oval ports
What are the best casting oval port? Rules say flat top pistion,hyd cam,any valve job, no port work,factory stroke.I am running the 049 head on a 30 over 454. Any help would be appreciated.
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Re: BBC oval ports
You're giving up too much compression. You need a set of closed chamber heads, 702, 290, 215.
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Re: BBC oval ports
Use the 215's. Milling them down to 100cc's or less is possible. I did engines for a bracket racer for years using those heads on 454's with .095 dome pistons. Over the years the car and engines kept getting refined and more modified eventually running in the high 9's at over 3800+ lbs.
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Re: BBC oval ports
Do all of the closed chambers flow about the same? Will they flow with the 049/781 heads to .600 of lift .I have cut my 049 's to 113cc so I'm not giving up much over a point I'm I
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Re: BBC oval ports
Getting the compression up as high as possible will do more than any small airflow difference. You can get the closed chamber heads down to under 100cc's without radical milling and intakes will still fit. Use a rectangular port dual plane intake on those oval port heads......the mismatch looks ugly but works better than most oval port intakes. If it's allowed install 2.19 intakes and you can go with bigger exhausts as well. 1.88's can be cut down easily or you can buy something a little smaller. The big valves really need valve bowl enlargement right under the seat.....that could be considered part of the valve job....if allowed....
Pistons at zero deck with gaskets that fit the bores as tight as possible without hanging into the cylinders..... Low compression BB's act a little lazy......even 1 point of compression is a big help and it is well worth getting it as high as possible......The heavier the car the more it helps getting it moving..... |
Re: BBC oval ports
You're giving up way more than you think. You have 113cc, but you can angle mill a closed chamber head and get down to 90cc or if your machinist is good. And 23cc or more is huge to a flat top 454. If you go from 113cc to 90cc, you go from 8.3:1 to 9.9:1 changing nothing else, a gain of 1.6:1 in compression, worth a ton in torque and HP.
Rich is correct, any minor loss in flow will be more than compensated for by the dramatic increase in compression. Ferrea makes the best flowing valves I've found for those heads. With the "any valve job" rule, you need to take them to someone who knows the heads, probably someone who does Stock and Super Stock heads, tell them you can run more lift than stock, but you can't port them. If you can find one, and it is legal, the old Holley Strip Dominator for oval ports is one of the best intakes ever made for them. The new Edelbrock dual plane stuff flows really well if you have to run a dual plane. |
Re: BBC oval ports
Guess it's time to find some closed chambers. I have the Ferrea 2.19 /1.88 in my 049's...........when i find some casting i will just switch everything over from my old heads. I think my intake will be ok it's a oval port RPM AIR GAP...........really excited about the new combo because it's very competitive with 8.4 to 1 comp. Thanks for all the help :D
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