Dart Pro 1 head thickness (FYI)
#21
Charter Member #601
Charter Member
Hey.. keep this one going.. I am looking at new heads too!! What can one buy out of the box, so you dont have to deal with people! Sell me a head that works in a box and I will buy it! I am interested in experience with the Big Chief heads.. would love to make some serious power with my 565" motor. But dont want a drag race motor..
Thanks
Dick
Thanks
Dick
#22
Charter Member #40
Charter Member
Mr. Gadgets/
If your looking for some 14 degree or 18 degree Big Chiefs, give Tom a call down at Champion in Palm Coast, FL 386-446-4488. He has a couple pair for sale. One set KE owns and are basically new.
If your looking for some 14 degree or 18 degree Big Chiefs, give Tom a call down at Champion in Palm Coast, FL 386-446-4488. He has a couple pair for sale. One set KE owns and are basically new.
#23
Geronimo36
Gold Member
I'll stick with my Merlin's. A friend of my had the Dart's and cracked one after about 50 hrs. Made the motor a milk shake and had to be torn down. When he contacted Dart they said they were having problems with the heads on marine applications. so he went out and got the Merlins and the motors have been running well ever since.
the Dart's are definetely lighter, and you could tell that the merlin's had much more meat on them.
Just one of my experiences with the Dart's.
the Dart's are definetely lighter, and you could tell that the merlin's had much more meat on them.
Just one of my experiences with the Dart's.
Last edited by Panther; 12-15-2002 at 08:06 PM.
#24
Geronimo36
Gold Member
Mr. Gadgets,
I had experience with the Big Chiefs once before. I worked on a boat about 5 yrs ago that was running the Big Chiefs. Made a sh%& load of power. the problems started when it dropped a valve twice. i was told this is common on a Big Chief in a marine application. the motors were 598's and made about 850hp, not too shabby. Other than dropping two valves they made ton's of power.
I had experience with the Big Chiefs once before. I worked on a boat about 5 yrs ago that was running the Big Chiefs. Made a sh%& load of power. the problems started when it dropped a valve twice. i was told this is common on a Big Chief in a marine application. the motors were 598's and made about 850hp, not too shabby. Other than dropping two valves they made ton's of power.
#25
Registered
Mr Gadgets, from what the gentleman in the Sonnys booth told us you are probably looking at a realistic cost of about $8000 to $10,000 dollars to convert to Pontiac heads. The particular heads he showed us had 80 CC combustion chambers which would mean most pleasure boaters would need new pistons to keep the compression in pump gas regions. That along with a completely new solid roller valvetrain and offset Jesel type rockers it gets pretty salty pretty quick. Another thing to ponder about these type of heads is they start really shining in the 6000 to 6500 RPM and up range. Most Bravo guys just don't like this much RPM nor do they like the lopey idle produced by the cam it takes to get there. I may be wrong, but I feel the Pontiacs will only provide minimal gains in the 5500 to 6000 RPM range over a good set of fully ported Darts or Brodix standard type heads. Hey Gadgets, I think you should do it and give us some real first hand experienced answers to how they work. Does anyone remember the class 1 Mercruiser race motor from a few years ago? It had around 12.5:1 compression with solid valvetrain and custom big chiefs. I think the motor was 498" and made 900 HP an something like 6800 RPM. I need that motor for the WETTE VETTE!!! It was only available with the #6 I believe.
#26
Charter Member #40
Charter Member
Wette Vette/
I have some ex-class 1's. The 14 deg Big Chief does take it's own piston, I was running a 9:1 and just tried to put a steel merlin on to see what kind of valve clearance i would have with the chief piston. I could probably get it to work but the valve on a normal Chev head really doesn't work with a Big Chief piston and vise versa. These heads are the ticket for big cubes and especially with a blower!
I have some ex-class 1's. The 14 deg Big Chief does take it's own piston, I was running a 9:1 and just tried to put a steel merlin on to see what kind of valve clearance i would have with the chief piston. I could probably get it to work but the valve on a normal Chev head really doesn't work with a Big Chief piston and vise versa. These heads are the ticket for big cubes and especially with a blower!
#27
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Join Date: Oct 2000
Location: Fresno, CA, 93722, USA
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Originally posted by bobby daniels
BEAK BOATER DUSTIN HAS TESTED THE DARTS AND IT MAY BE A VENDOR OR SPECIAL SUPPLIIER TO HIM ! THE AIR FLOW 315 AS YOU SAID IS A KILLER HEAD ITS EXHAUST NUMBERS BLOW AWAY
THE DARTS AND IS A MUCH STRONGER HEAD THE 335 AFR ARE THE ONES I 'VE RUN ON 540'S WITH WHIPPLES 3.0 LITERS AND 10 TO 14 71'S THEY WILL DISTROY THE DARTS AND LIVE FOR EVER.
THE BLOWER WILL HANDLE AND DOES BETTER WITH SLIGHTLY SMALLER INTAKES BUT THE EXHAUST NEEDS CAM DURATION AND GREAT FLOW ALL THE WAY OUT THE PIPES ,ITS BEEN PROVEN OVER AND OVER AT LAKES ALL OVER ,
JUST WATCH WHAT MAN. TELL YOU THEY MAY HAVE HIDDEN ADJENTAS
DUSTIN I SAY AGAIN IS GOOD THOUGH
LET ME KNOW IF YOU NEED ANY HEADS ,JUST PM ME THANKS
MY 2 CENTS WORTH
BEAK BOATER DUSTIN HAS TESTED THE DARTS AND IT MAY BE A VENDOR OR SPECIAL SUPPLIIER TO HIM ! THE AIR FLOW 315 AS YOU SAID IS A KILLER HEAD ITS EXHAUST NUMBERS BLOW AWAY
THE DARTS AND IS A MUCH STRONGER HEAD THE 335 AFR ARE THE ONES I 'VE RUN ON 540'S WITH WHIPPLES 3.0 LITERS AND 10 TO 14 71'S THEY WILL DISTROY THE DARTS AND LIVE FOR EVER.
THE BLOWER WILL HANDLE AND DOES BETTER WITH SLIGHTLY SMALLER INTAKES BUT THE EXHAUST NEEDS CAM DURATION AND GREAT FLOW ALL THE WAY OUT THE PIPES ,ITS BEEN PROVEN OVER AND OVER AT LAKES ALL OVER ,
JUST WATCH WHAT MAN. TELL YOU THEY MAY HAVE HIDDEN ADJENTAS
DUSTIN I SAY AGAIN IS GOOD THOUGH
LET ME KNOW IF YOU NEED ANY HEADS ,JUST PM ME THANKS
MY 2 CENTS WORTH
Dustin