New Dart SHP 200cc Heads

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Callmewaylon
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New Dart SHP 200cc Heads

Post by Callmewaylon »

Does anyone have experience with the New Dart SHP Heads? I'm really interested in the flow numbers for the 200cc version. The Dart website still has all the old information and when I called the guy said they don't have a spec sheet to share yet. He did say that the reason they brought out a new version was new tooling was needed. They are now cast in China using permanent mold tooling. Been really considering the ProMaxx 200cc as well and would like to compare flow numbers. Summit does have some of the new versions in stock. You can tell because the p/n starts with "126" and the old version starts with "127".

All the articles I can find are really generic like the one below:
https://hotrodenginetech.com/new-dart-s ... evy-heads/
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Re: New Dart SHP 200cc Heads

Post by BOOT »

I considered buying one to make a video about and compare to the 180cc that I bought last fall But there wasn't enough interest to justify the cost. Plus it was a huge shipping PITA to get the New 180cc head. When I spoke to Dart they said the 200cc would be out sometime after the new year(2022) and I checked not long ago n seen it listed forsale on some sites.

The 180cc https://youtu.be/42R26b6_sjg
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Callmewaylon
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Re: New Dart SHP 200cc Heads

Post by Callmewaylon »

BOOT wrote: Fri May 20, 2022 11:14 pm I considered buying one to make a video about and compare to the 180cc that I bought last fall But there wasn't enough interest to justify the cost. Plus it was a huge shipping PITA to get the New 180cc head. When I spoke to Dart they said the 200cc would be out sometime after the new year(2022) and I checked not long ago n seen it listed forsale on some sites.

The 180cc https://youtu.be/42R26b6_sjg
Yes, I saw your videos on the 180cc version and Eric Weingartner talked about the new SHP's in his video from the PRI show. He said they looked similar to an "as cast" version of an AFR port. Other than that, not much out there. Any articles I can find are really generic with no flow numbers and even Dart wasn't much help when I called. It's like they aren't trying to sell them at all. The guy on the phone said they don't even have a spec sheet for the 200cc yet. They look decent, but probably risky to buy when they just came out........
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Re: New Dart SHP 200cc Heads

Post by steve cowan »

Callmewaylon wrote: Fri May 20, 2022 10:52 pm Does anyone have experience with the New Dart SHP Heads? I'm really interested in the flow numbers for the 200cc version. The Dart website still has all the old information and when I called the guy said they don't have a spec sheet to share yet. He did say that the reason they brought out a new version was new tooling was needed. They are now cast in China using permanent mold tooling. Been really considering the ProMaxx 200cc as well and would like to compare flow numbers. Summit does have some of the new versions in stock. You can tell because the p/n starts with "126" and the old version starts with "127".

All the articles I can find are really generic like the one below:
https://hotrodenginetech.com/new-dart-s ... evy-heads/
Do you have a engine size and application that you are working on?
I have 6 sets of Dart heads ranging from as cast 165cc up to 215 pro 1.
A couple of things I found as cast
Is they all are noisy on the flow bench.
What this means is the air usually does not know which way to turn in the port,this happens on intake and exhaust ports .
My opinion is looking at flow numbers is not the best way to choose a cylinder head in any application.
In a street car alot of people use cylinder head, intake manifolds, cams that are to big and end up with low speed drivability issues like reversion etc.
If budget allows buying cylinder heads/intake manifold correctly sized for your application will pay dividends in the long haul.
steve c
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Re: New Dart SHP 200cc Heads

Post by BobbyB »

steve cowan wrote: Sat May 21, 2022 12:16 am
Callmewaylon wrote: Fri May 20, 2022 10:52 pm Does anyone have experience with the New Dart SHP Heads? I'm really interested in the flow numbers for the 200cc version. The Dart website still has all the old information and when I called the guy said they don't have a spec sheet to share yet. He did say that the reason they brought out a new version was new tooling was needed. They are now cast in China using permanent mold tooling. Been really considering the ProMaxx 200cc as well and would like to compare flow numbers. Summit does have some of the new versions in stock. You can tell because the p/n starts with "126" and the old version starts with "127".

All the articles I can find are really generic like the one below:
https://hotrodenginetech.com/new-dart-s ... evy-heads/
Do you have a engine size and application that you are working on?
I have 6 sets of Dart heads ranging from as cast 165cc up to 215 pro 1.
A couple of things I found as cast
Is they all are noisy on the flow bench.
What this means is the air usually does not know which way to turn in the port,this happens on intake and exhaust ports .
My opinion is looking at flow numbers is not the best way to choose a cylinder head in any application.
In a street car alot of people use cylinder head, intake manifolds, cams that are to big and end up with low speed drivability issues like reversion etc.
If budget allows buying cylinder heads/intake manifold correctly sized for your application will pay dividends in the long haul.
Steve, are you flow testing for noise with the intake attached mostly? Can you elaborate on your technique? How many motors on your bench?
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Re: New Dart SHP 200cc Heads

Post by steve cowan »

BobbyB wrote: Sat May 21, 2022 3:44 am
steve cowan wrote: Sat May 21, 2022 12:16 am
Callmewaylon wrote: Fri May 20, 2022 10:52 pm Does anyone have experience with the New Dart SHP Heads? I'm really interested in the flow numbers for the 200cc version. The Dart website still has all the old information and when I called the guy said they don't have a spec sheet to share yet. He did say that the reason they brought out a new version was new tooling was needed. They are now cast in China using permanent mold tooling. Been really considering the ProMaxx 200cc as well and would like to compare flow numbers. Summit does have some of the new versions in stock. You can tell because the p/n starts with "126" and the old version starts with "127".

All the articles I can find are really generic like the one below:
https://hotrodenginetech.com/new-dart-s ... evy-heads/
Do you have a engine size and application that you are working on?
I have 6 sets of Dart heads ranging from as cast 165cc up to 215 pro 1.
A couple of things I found as cast
Is they all are noisy on the flow bench.
What this means is the air usually does not know which way to turn in the port,this happens on intake and exhaust ports .
My opinion is looking at flow numbers is not the best way to choose a cylinder head in any application.
In a street car alot of people use cylinder head, intake manifolds, cams that are to big and end up with low speed drivability issues like reversion etc.
If budget allows buying cylinder heads/intake manifold correctly sized for your application will pay dividends in the long haul.
Steve, are you flow testing for noise with the intake attached mostly? Can you elaborate on your technique? How many motors on your bench?
My bench is designed to flow up to 400cfm @ 28" depression, it uses performance trends soft ware.so on the smaller heads I can flow up to 45" depression.
Depending on intake manifold size and design you can lose 5-50 cfm just as a number.
I size the port for application first and if I am happy with results I then go after the intake manifold.
I look for 5 - 6% lose as maximum with intake manifold.
One of the best things I learnt early was not to chase flow.
If you make a port bigger it will flow more air usually but that is not always the best option.
Some good engine builders can make 600hp with 250cfm N/A
valve job first and work from there.
The smoother and more quiet a port is especially around the convergence point at high depression will always win in my opinion.
steve c
"Pretty don't make power"
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Re: New Dart SHP 200cc Heads

Post by mag2555 »

With heads that where developed with a big concern to wet flow as the Darts have been as late, noise is secondary to me in terms of the the intake port, in the exh port noise is very bad!
If I hear noise from a intake flow test when I have the intended manifold bolted up , then as long as I don’t see my vertical manometer bouncing around by more then 1/2” of depression and the swirl pattern I see is not reversing completely then I leave it be even if it cuts into air flow numbers seen by 5 cfm.
Higher air numbers without good atomized fuel in the chamber does not make the power level your thinking the air flow amount your reaching for should make!

Also consider the fact that at the max lift the motor is built to run at and at full throttle and in conjunction with the motors shift point that a depression of 28” may not be taking place , the motor may only be seeing 22” which can change everything!
At max intended valve lift and with the intake bolted on you should be testing from 20” on up to 28” and noting how things sound .
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Re: New Dart SHP 200cc Heads

Post by steve cowan »

mag2555 wrote: Sat May 21, 2022 6:41 am With heads that where developed with a big concern to wet flow as the Darts have been as late, noise is secondary to me in terms of the the intake port, in the exh port noise is very bad!
If I hear noise from a intake flow test when I have the intended manifold bolted up , then as long as I don’t see my vertical manometer bouncing around by more then 1/2” of depression and the swirl pattern I see is not reversing completely then I leave it be even if it cuts into air flow numbers seen by 5 cfm.
Higher air numbers without good atomized fuel in the chamber does not make the power level your thinking the air flow amount your reaching for should make!

Also consider the fact that at the max lift the motor is built to run at and at full throttle and in conjunction with the motors shift point that a depression of 28” may not be taking place , the motor may only be seeing 22” which can change everything!
At max intended valve lift and with the intake bolted on you should be testing from 20” on up to 28” and noting how things sound .
With manifold bolted up it usually settles port down as velocity is decreased, if the port flows more with manifold "on" at the same depression the cylinder head port is not up to scratch and I have had this a few times myself.
If your numbers convert back the same or better from higher depression back to 28" you are in a good place.
The piston demand at peak hp rpm at all crank angle positions pulls more depression than 28" .
On my cylinder heads at peak rpm of 6600rpm the piston demand is 605cfm at peak piston speed around 75* - 85* ATDC.
This is why I think testing at higher depression is a benefit.
If my bench pulled 60" that is where I would spend most of my time testing in my opinion.
steve c
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