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Discussion Starter · #1 ·
Has anyone step up to these heads? I'm starting to plan a build. The bottom end will be built around the top end.. they do require a 4.155 bore or larger.. thinking big bore and short stroke
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You should do it

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Dart has some heads for these engines which have some very nice combustion chambers.

It would help if you provided a link to which heads these are, and what the spec's are, particularly since these heads appear (at first look) to be of a splayed design.
 
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Discussion Starter · #5 ·
Dart has some heads for these engines which have some very nice combustion chambers.

It would help if you provided a link to which heads these are, and what the spec's are, particularly since these heads appear (at first look) to be of a splayed design.
 

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Ooooh

Blower 1,500 not turbo.
 

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There is quite the knowledge here for you.

Gonna like to see what you do.

What will the transmission be?
 
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1500hp... at the crank. thats with blower and no2
Well, congratulations you picked a nice set of heads.

These heads are what I call a 'Splayed Valve' design.
That means the valves are canted, while the ports are symmetrical, and not mirrored.

-here is that info-
Valve Angles: Int = 10° x 4° / Exh = 6° x 4° Canted valves with swapped Intake and Exhaust locations

Should be good for 1222 to 1251fwHP, NA Application,
with an internal engine volume of around 500 CID.

Also, the combustion chambers are for NA Engines, where
very high compression is desired, as the available sizes
runs from 38cc to 57cc.

Also, these heads are built for high lift NA Engines.

Notice that the flow goes to 456 CFM, but that flow
number is given at 1.00" of valve lift.
***Not Recommended For Street Use..lol

In an NA Engine we attempt to reduce 'Low Lift' flow
and enhance 'High Lift' flow.

Our engines are equipped with DD / PD Blowers.

And our camshafts do not use much positive overlap
which occurs at low valve lifts.

So we desire to enhance low lift, as well as mid lift flow,
as the DD / PD Blower makes the mass charge available
to the cylinder as soon as the intake valve is cracked.

Finally, look at the valve seat angles.

Available in 55° to 60° angles.
Helps to enhance flow, but not good for long term street use.

Pistons required are custom made.
Lifters must be offset by 0.150".

Valve Covers: 68000090 – Fabricated Aluminum w/ Dart Logo

Block Use: Dart LS Next Blocks with Standard lifter layout or Dart Prostock layout

--------------------------------------------------------

What size engine are you building?
What blower are you using?

Cheers
 

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Discussion Starter · #16 ·
Well, congratulations you picked a nice set of heads.

These heads are what I call a 'Splayed Valve' design.
That means the valves are canted, while the ports are symmetrical, and not mirrored.

-here is that info-
Valve Angles: Int = 10° x 4° / Exh = 6° x 4° Canted valves with swapped Intake and Exhaust locations

Should be good for 1222 to 1251fwHP, NA Application,
with an internal engine volume of around 500 CID.

Also, the combustion chambers are for NA Engines, where
very high compression is desired, as the available sizes
runs from 38cc to 57cc.

Also, these heads are built for high lift NA Engines.

Notice that the flow goes to 456 CFM, but that flow
number is given at 1.00" of valve lift.
***Not Recommended For Street Use..lol

In an NA Engine we attempt to reduce 'Low Lift' flow
and enhance 'High Lift' flow.

Our engines are equipped with DD / PD Blowers.

And our camshafts do not use much positive overlap
which occurs at low valve lifts.

So we desire to enhance low lift, as well as mid lift flow,
as the DD / PD Blower makes the mass charge available
to the cylinder as soon as the intake valve is cracked.

Finally, look at the valve seat angles.

Available in 55° to 60° angles.
Helps to enhance flow, but not good for long term street use.

Pistons required are custom made.
Lifters must be offset by 0.150".

Valve Covers: 68000090 – Fabricated Aluminum w/ Dart Logo

Block Use: Dart LS Next Blocks with Standard lifter layout or Dart Prostock layout

--------------------------------------------------------

What size engine are you building?
What blower are you using?

Cheers
Leaning towards a smaller ci. setup. Bore has to be 4.155 with the dart heads therefore it comes down to stroke as the determining factor.
Like to use a Kong 2650 blower if it can get me there.
 

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Leaning towards a smaller ci. setup. Bore has to be 4.155 with the dart heads therefore it comes down to stroke as the determining factor.
Like to use a Kong 2650 blower if it can get me there.
If you are still considering moving forward with those heads you really need to consider how high you would have to spin the small motor to be equivalent to a 500 CID engine which those heads were made for.

I don’t really think you want to do that.
The term RPM means Ruin Peoples Motors..lol

What size engine are you considering building?
 
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