Dart NEW REVISED SHP SBC Cylinder Heads

[RevTheory]

They look really sweet so far. I watched a video Eric Weingartner did on a different head where he talked about getting a little more detail (paraphrase) out of assembled heads so that's the way I went. I got the ones assembled with low-rate springs for a hyd/flat cam since I wanted beehives anyway.

They had green masking tape over all of the coolant holes and along all four edges of the deck. No burrs, no nicks thus far. I think I'll have the shop sink the exhaust valves as they're a little proud but I'm really pleased. I may find a shit-show when I pull the valves but I can't be anything other than really impressed so far.

Now Jeg's throwing both heads in one box and kicking it out the door is another story but you can't really complain when shipping is free with a purchase over $250. The individual packaging from Dart was great.

[BOOT]

Yah my plat pro1's had green tape. Guess Dart doesn't care about Bare head customers, prob picks the better heads to assemble. I don't use a single part that they ship with assembled heads these days and got enough of take off stuff already LOL

The main thing that bugs me is the plugs holes, this side has spots on either side so be sure to check yours.

[steve cowan]

Rev or Boot
Any chance of looking at factory valve job please

[RevTheory]

Rev or Boot
Any chance of looking at factory valve job please

I surely will. Been going seven days a week since late Sept. and my garage is a disaster.

[BOOT]

Waiting to see what they say and if I'm gonna get a 3rd head LOL https://youtu.be/g3hEUp-_MWU

[steve cowan]

Hey Boot
Do the new heads have provisions for a 3/8" pushrod??

[RevTheory]

I pulled the valves from two cylinders for a look-see. To my less-than-experienced valve seat configuration eye, the intakes look really good. I'm unsure about the exhaust so me thinks I'll likely have the shop sink them .025ish, I'll throw a radius on there and then have them stone a 45* seat. I need to do a quick lap and see how that looks. Opinions surely welcome.

I'm a little curious as to the parting line under the seat. It's on both intakes that I pulled and pretty much full circumference.

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[BOOT]

Thx for sharing some pics of your heads.

Appears your assembled heads may have the same plug hole defect. I'd tear em down completely and inspect them still(would any brand), had a friend who bought Dart assembled BBC heads and found two broken keepers about a decade or so ago. Think the Plat Pro1s that I bought New were in 2007

same defect.jpg

same defect2.jpg

[steve cowan]

Are you guys going to run 3/8" pushrods??
My trickflow heads are same setup as new dart 180 with pushrod hole on intake.
Look at my older SHP 180 heads

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[RevTheory]

Steve, I tend to doubt that my application requires it and to be honest, I haven't really looked into whether or not they'll fit. The machined hole measures .625 in diameter.

I did measure a port and got 1.91h x 1.06w with 3/8 corner radii (need to remember the math for mcsa )

I measured 1.82 for the throat- 90%

I get somewhere between 1.88 and 1.896 for bowl width measured just at the top of the guide. I'll do that one again with fresher eyes.

[steve cowan]

Steve, I tend to doubt that my application requires it and to be honest, I haven't really looked into whether or not they'll fit. The machined hole measures .625 in diameter.

I did measure a port and got 1.91h x 1.06w with 3/8 corner radii (need to remember the math for mcsa )

I measured 1.82 for the throat- 90%

I get somewhere between 1.88 and 1.896 for bowl width measured just at the top of the guide. I'll do that one again with fresher eyes.

On my 180 heads the pinch is 2.27" it did blow through a couple but I repaired.
I suspect your rpm range will be 6000 max so those heads won't need a lot of work.
I am receiving my new pistons in next week or 2 for my vortec block,Scat 3.75" crank ,6 " rod.
I remember you asking about the piston skirt coming through the bottom of the bore so I went tighter smaller ring pack and shorter skirt so that should help the situation.

[RevTheory]

Well, they port up pretty well. They have that damn head bolt boss on the common-wall side so I wasn't too comfortable going after more bowl width as that boss would jack up my transition into and out of more width at the apex so I went up on the roof a little. I did get *some* width on both sides but not like you'd probably expect. It pours right at 185cc now: 1.88 mcsa and right at 91% throat. Chambers now pour 70cc so I can run 5cc valve reliefs and get 10.35:1 compression.

Couple of shots along the way:

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Edit: Oh for frick sakes. If anyone knows how to keep it from rotating pics, I'm all ears.

[1980RS]

Well, they port up pretty well. They have that damn head bolt boss on the common-wall side so I wasn't too comfortable going after more bowl width as that boss would jack up my transition into and out of more width at the apex so I went up on the roof a little. I did get *some* width on both sides but not like you'd probably expect. It pours right at 185cc now: 1.88 mcsa and right at 91% throat. Chambers now pour 70cc so I can run 5cc valve reliefs and get 10.35:1 compression.

Couple of shots along the way:

IMG_0240.jpg
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Edit: Oh for frick sakes. If anyone knows how to keep it from rotating pics, I'm all ears.

Do you feel reliving the area on the quench side of the chamber on the exhaust side helps much and I do see people do both sides, Does it help flow ?

[RevTheory]

Do you feel reliving the area on the quench side of the chamber on the exhaust side helps much and I do see people do both sides, Does it help flow ?

I don't know if it shows up on a bench or not. The idea is that when the piston clears the quench, that little cut gives a place for the exhaust to slow down and turn into the still-open exhaust rather than getting shot straight over the top of the valve at high speed. I've never tried it before as you can tell from my ugly cuts, lol.

I'm having a hard time getting the lighting right and I think my iPhone may be "fixing" the very thing I'm trying to show with a pic but this is about all I know to do without a bench. I think I've hit all the spots that would keep a head from making the turn and flowing out to high lifts. All I can do now is send it to a buddy who has a bench and see how it does.

If it's above 300 avg. fps and doesn't back up at high lifts, I'll be a happy boy.

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[1980RS]

Do you feel reliving the area on the quench side of the chamber on the exhaust side helps much and I do see people do both sides, Does it help flow ?

I don't know if it shows up on a bench or not. The idea is that when the piston clears the quench, that little cut gives a place for the exhaust to slow down and turn into the still-open exhaust rather than getting shot straight over the top of the valve at high speed. I've never tried it before as you can tell from my ugly cuts, lol.

I'm having a hard time getting the lighting right and I think my iPhone may be "fixing" the very thing I'm trying to show with a pic but this is about all I know to do without a bench. I think I've hit all the spots that would keep a head from making the turn and flowing out to high lifts. All I can do now is send it to a buddy who has a bench and see how it does.

If it's above 300 avg. fps and doesn't back up at high lifts, I'll be a happy boy.

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Those heads look great to me.