SkiDoc

iTrader: (4)

Anyone using Dart Big Chief heads naturally aspirated. Pros and Cons? Thanks, Eric

n20michael

I have used both Pontiac and Olds versions of the Big Chief heads in various drag racing applications over the years, but, never on a boat, the Pro's are they make alot more HP and flow A LOT more air than a conventional port head, espcially the 14 degree and later style. The Cons are mainly cost related, they wont use a traditional rocker system [you must use pedestal rockers, such as Jesel or T&D] and they are somewhat limited in the intake department, especially if you wish to run a "cast" intake, they are available now, but, aren't cheap, in other words not much, if anything, from a "regular" BB head will bolt on a Spread Port head. In a naturally aspirated configuration you would either need to have some serious cubic inches underneath them, or be running the engine at an RPM level that would warrant using them.

If price isn't an object then you can also run a "Chemi" cylinder head, designed and sold by Sonny Leonard, they use a Chevy/Hemi design that makes well over 100HP more than a Big Chief, I have seen these heads on a Naturally Aspirated BB make OVER 2000HP, but, again, they AIN'T cheap, expect to shell out around 20K for the heads, and NOBODY makes a cast intake for them.

Michael

SkiDoc

iTrader: (4)

Thanks for the reply, I've already got the heads, intakes etc...on some of Kurt's marine motors that I bought. They have T&D shaft rockers and a solid cam. I am trying to decide which way to go. If I stay with them I am going to have to redo my Stellings tails. Recommend new springs at 75 hrs. More maintainence than I really care for. If I put some AFR's or Darts with hyd. roller, they might be better for my purpose. Any one want some Big Chiefs?

HotPursuit

Bill just had his power redone and made 1300+ with big chiefs. 598s 1471s and meth injected. I personally dont like all the extra weight and length of the push rods,valves,and custom everything.

n20michael

I would go with a set of Dart 320's or 360 depending on how big the motor is, good shaft rockers, and a hyraulic roller shaft, tons of power, low maintainance, and should you ever need to change anything most of the parts are "off the shelf", I agree with Hot Pursuit, they really aren't worth the hassle for the majority of applications

SkiDoc

iTrader: (4)

Or I could go big and put a milder hydraulic cam and use some blowers to increase intake velocity. This would probably set the OSO record for fastest junked bravo.

ezstriper

I think the ports would way to big for most all marine apps, they make tons power, but at much higher rpm than most boat engines wil never see..and in the mid range it would be a dog... also not sure how many people even make exhaust for them for marine use as they are different...Rob

GPM

I run the Big Dukes with a Procharger, 2.375 CMI's, the Big Cheif has a bigger intake runner, on a N/A motor I doubt you would have much bottom end.

HotPursuit

[ This would probably set the OSO record for fastest junked bravo.[/QUOTE]

Spend the $$$$ on some 6s first..

Young Performance

Eric,
I was good to talk to you the other day. Everyone else seems to have the same opinion that I have.....that are not very practical for what you are trying to do. Like I told you, they are WAY to much head for 700-750 hp engines. Let me know if I can help you in any way or if you have any more questions. Thanks, Eddie.