Im having a little trouble as to which heads I should put on my motor. The block is a gen VI bbc 454. Its currently getting some machine work done and im going with a stroker kit to make a total ci of 489. I have 2 sets of heads but not sure which ones are better, 14096188- rectangle port 118cc open chamber, or 10141279- vortec oval port 100cc closed. Im gonna run pump gas so i want to stay with relatively low comp and i have a high rise alum intake rectangle so im leaning towards the 188's. If anyone can offer any advice, it would be appreciated-Thanks
Thread: Which Heads Are Better?
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05-26-2010 08:34 PM
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05-26-2010 08:40 PM
I know absolutely nothing about motors, but to answer your question "which heads are better?" I would say it would be blonde identicle twins, 21~22 years old, bolt ons, half drunk, and no gag reflex.... but thats just one mans opinion.
We now return you to your regularly scheduled thread.P-4077 "The Swamp" S.B.Y.C. and Michigan medboat mothership
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05-26-2010 09:32 PM
What pistons are you using? I have a 489 stroker, with large oval 820's w/ 2.19 1.88 valves, 110cc chambers. I use flat tops with -3cc relief, that gives me 8.9 comp and I have been running 89 octain. The key is get a cam and valvetrain from RMbuilder. Then it will really run!!
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05-26-2010 09:35 PM
Now that is too funny!! You know the blonde gag reflex thing.
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05-26-2010 09:56 PMThe 188's are the way to go. You can get some nice gains with a die grinder opening up the bowls under the valves and by unshrouding the exhaust valve a bit. The most important thing to do is get your quench set correctly. That's the gap between the piston and the head at TDC. You don't really want it much more than .030". Quench causes turbulence in the combustion chamber during ignition. That unleashed more horsepower and it also hel;ps hold off detonation. It's set by decking the block.
A set of manley or Ferrea stainless valves on the intake and absolutely use Inconel on the exhaust- you'll see power gains and much greater reliability.
Lastly, definitely talk to Bob Madara about the cam- he's on here as RMBuilder.
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05-26-2010 10:41 PM
That sounds a little high, I used to think I ran higher comp but I was corrected by RMbuilder when he set up my cam last year. Flat tops usually have valve reliefs, head gaskets also need to be considered. Either head would be a good choice, but if you use the vortecs you may want to look into bigger valves. You can't really go wrong with the rec heads, port and polish work would help either one. It is a lot of work but it pays off.
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05-26-2010 11:04 PMIf you've got a high-quality die grinder it goes quick. Using one of those $69 Sears pieces can be misery. The worst part is the millions of razor-sharp needle-like shavings that fly everywhere
But you're right. It does pay off. I neglected to mention port-matching the manifold.
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05-26-2010 11:08 PMP.S. In a 454 with 30 over, zero deck and .030 head gaskets, using -3cc flat tops, you're right around 8.25:1. Good for a blower motor.
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05-27-2010 09:04 AM
You will want to use small dome pistons or the comp. will be too low. Unless you zero deck the block, it will be under 8.0-1. The common Fel-Pro blue gaskets are .042 thick.
Big boats rule!
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05-27-2010 10:21 AMThat combo is about 8.6. Still too low. I would use the right piston and not compromise on the head.
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05-27-2010 10:56 AM
Oops, I was thinking 454.
Big boats rule!
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05-27-2010 11:00 AM
If it's a stroker, it's too big for oval ports imho. The Vortecs are not the greatest heads on a 454 let alone 489. Their flow numbers are similar to a good small block head. They are also more detonation prone than an open chamber head.
Big boats rule!
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05-27-2010 12:26 PM
Check out this article, I found this about 4 years ago when I was researching heads. I have not personally used the vortecs but they seem pretty similar to the large ovals I am using. If you have not bought your pistons, the other guys are right you could get one with a slight dome and get your comp up. Througout the years I have run several different combination. At one time I had the peanut port head with the 489. It ran pretty strong but ran out of steam at about 4800 RPM, I was only running 8.6 comp. I can run my large ovals up to 5600 RPM, with the smaller 110cc chambers I am at now at 8.9 comp.
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05-27-2010 06:33 PMYour best bet is to call BOB Madera , or MER Performance, both are very nice people and will ing to help !!!!
U tell either what your plans are and they tell u what u need and where to get it at best deal !!!!!
No need to listening to 20 people on here...everybody here does not know your boat or engine plans !!!!!!
just my 2 c
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05-28-2010 09:15 AM
Rm builder has me running at 9.3 to 1 compression. I am running premium gas 91 to 93 octane just a few cents more a gallon but I think bob wouldn't steer me wrong in that sense... the 9 to 1 dosent seem too high to me.. and I am running stock heads just have had them flowed and gasket matched
Now recruiting Mississippi power boaters.
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