Heads

[CHRISTINE]

Im looking at buying a new set or a used set
which is better a dart platnum 200cc 64cc or a rhs 200cc 64cc imca mod

[CHRISTINE]

Nobody has anything?

[joedoozer]

4M has gotten crazy lately, and people are just not replying like they use to.

You will get 2 types of responses on threads like this. The first will be the "I need more information" kind. And ask you crazy stuff like the color of your seat cover and how many axles your trailer has. And the second will be the "I run this and I am awesome" response haha.

Without knowing the color the seat cover this is a tough question . A quick answer is the Darts. For the one reason they support a higher lift cam than the RHS 200cc intake runner head. You can get the Dart heads that have a max lift all the way up to .680 or something like that.

You mention the RHS head as an option. Why not a World Product head? They are comparable in price.

[DaveBauerSS6]

RHS bought out the Pro Action line years ago. At the end of the Pro production there was alot of quality issues. Prior to the quality issues I purchased the Pro heads because of the chamber design. The Pros had a tighter heart shape and would introduce a better swirl to the cylinder; the Darts were the same old shape as the 60's OEM heads. Dart introduced the Platinum series with the high swirl chamber sold now.
I would be careful buying the Pro, some had issues. I've had years of good use out of the early ones.
I also run a set of Platinum's and have been very happy with them. I would stay away from the older Darts, giving up some power.
Good luck.

[parrot69777]

Joedoozer has a point about the way some people deal with things on 4m...too many people bashing others because they have either never tried it or someone has a better idea. Too many people on here claiming they are all that and a bag of chips. Much easier to not make a comment than listen to someone argue or rant & rave.

I have been doing cylinder head work for around 20+ years. This is what I know from the experience I have.

Pro Topline went out of business due to bankruptcy and RHS bought them out. Other than cracking inbetween the valve seats...a problem they have had since day one.....the only other problem I have seen is the way the intake manifold fits. I have yet to see an engine that someone has had to silicone the entire top of the manifold to make it seal. This is all due to a narrow but tall intake runner. If they had made an intake to it properly....would have been the best thing since sliced bread.

Dart and World Products use to be the same company. Back then the heads were made by World Products and the head was called Dart sportsman. Somehow the powers that be got into a fight and broke up. World Products then called their design the Sportsman II. The new company became Dart and continued on with the Dart Iron Eagle.

I personally think the Sportsman II heads are the best there are....as long as you are needing a 200cc runnner because that is all they make. The most recent World Product heads have fast burn chambers, raised valve cover rail, and machined for centerbolt type valve covers. Dart makes good heads as well...as long as you stay away from the platinum series....have seen quite a few of them crack like the RHS heads do.

I would run Sportsman II heads for a 200cc runner and the regular Dart Iron Eagle for a 180, 215, or 230 head. I buy up as many of the used sportsman II and regular Dart Iron Eagles as I can to rebuild and sell....considering the price is right.

[dynoman14]

World Products / Dart
Gary St.Denis cast the heads in Canada for cost and legal issues, Him and (not a nice word)(not a nice word)(not a nice word)(not a nice word) Maskins had a falling out and that created World Products and Dart.

Pro Action / RHS
All of that is correct, the new heads flow great but the velocity is down...something is missing. The original heads had an acceleration ramp at the beginning of the short side radius ( kinda like a raised runner deal, because the limey used the same core boxes in the 23* heads that he used in the 18* heads ) that ramp is not there any more. I am guessing the original casting boxes stayed in New Zealand and are awaiting the expiration of the 5 year non-compete clause.

Not to throw you a curve, if they are legal, I prefer the small or large port bowtie vortec. They have about 20% better flow to volume number than anything else out there in the price range, and they promote a lot of tumble if you measure it. That in iteself is worth about 20-25hp on the engine dyno and it does not show up anywhere much. There is a lot more to making power out of cylinder heads than just raw flow numbers, if that was the case the 302 Boss would have made 1000hp off the showroom floor. It did end up making about 650-700 in Trans-Am when they figured out making the ports way smaller made a ton more torque and power. That was about 50HP more than the 302 Chevy and gave Ford/Gapp&Roush many Championships before GM caught back up.

I would build the big volume vortecs with stock hollow GM valves and a decent set of sprnigs and they should turn 7500 easy on just about any SBC. If you can't find them or need help with the package just hit my PM or e-mail.