Porting Dart Wissota Head - Iron Eagle 165cc S/S

[68maliblue]

I'm working on a pair of Dart 10024361 Wissota Spec heads. These are Dart Iron Eagle S/S 165cc heads with a 67cc chamber and standard intake and exhaust ports and 1.94 intake/1.50 exh valves. They seem to have a nice combustion chamber and very good casting quality. They are going on my son's budget 383 build and I'm looking to pick up any air flow possible on these heads as the ports and valves are on the small side. We have blended the bowls and will be trimming down the guides. Looking for any tips on getting more airflow out of these heads from those of you that have worked on these before. I know there are a lot of better heads out there for a reasonable amount of $$$ but these have been sitting on my bench for years so the price is right for this project. We are working with a late model 880 block so we will be running a mild hyd roller at 217 deg int/225 exh @/050, 108 deg LSA and .495"/.500" lift. Any input on these heads would be appreciated. Thanks.

[F-BIRD'88]

If you pick up David Vizard's book How to hot rod your sbc on a budget you will find relevant guidence on similar sbc heads as to what to do. Eg .wp S/R , chev camel backs, vortecs... Its essentually the same job on those heads. A 1205 gasket size opening is more than plenty.
Concentrate on the port roof, common wall and pinch.
Create 2 strong flow paths around the valve guide.
Embrace and enhance the natural port "bias" as explained by DV in his book.
The port floor only needs cleanup.
Profile the SSR to the bowl.
170+/- ish finished port volume. 235 ish cfm @.500"
170-80 ex is plenty. Again roof, guide boss profile.
Look at what DV lays out for you in the book.
Can do 30° back cut on both valves.

U can flow the garden hose thru the ports to see where the flow is in the port and into the chamber.
If you want more than say 240 cfm go to a 2.02-1.60 valve set. But 235 cfm and 1.94 is good for your purpose
Do not open to 1206..
Do not get all hog wild on opening up the bowl under the valve job. Leave a venturi contour under the valve job.
.88% of valve seat diameter.

[mag2555]

What Intake Manifold are your running, as these heads can be ported to out stripping the common iron stock 2 plane intakes around, and even the tad bigger intakes like the Edelbrock performer.

Out of the box the heads flow enough at .500" lift to make 380 to 400 hp , but the Exh to Intake ratio with that 1.500" valve is only 65%. ( even the Vortec heads with the 1.500" valve flow 20 cfm more !) so you really need to run 1 3/4" headers and pick up that added 4 to 5 percent of flow above .300" lift that the headers will provide.

It really sucks when a novis spends 2 weeks of spare time porting the heads then only gaining 15 hp due to the Intake being a choke!

[68maliblue]

Thanks for all the input. The plan is to run an edelbrock performer rpm manifold. We don’t have a manifold yet so if there is a better option let me know.

[F-BIRD'88]

That intake is very good for your job.
Its fine as is. Those 165 cc port Dart heads are very good
(As a start point) especially with correct porting, for this.

With this head on a flat top piston 383 sbc you will be able to creatively carve the combustion chamber for better flow and still end up with a 10:1 cr.
Especially if you are going to go for the larger 2.02-1.60 valves on this.

[steve cowan]

I'm working on a pair of Dart 10024361 Wissota Spec heads. These are Dart Iron Eagle S/S 165cc heads with a 67cc chamber and standard intake and exhaust ports and 1.94 intake/1.50 exh valves. They seem to have a nice combustion chamber and very good casting quality. They are going on my son's budget 383 build and I'm looking to pick up any air flow possible on these heads as the ports and valves are on the small side. We have blended the bowls and will be trimming down the guides. Looking for any tips on getting more airflow out of these heads from those of you that have worked on these before. I know there are a lot of better heads out there for a reasonable amount of $$$ but these have been sitting on my bench for years so the price is right for this project. We are working with a late model 880 block so we will be running a mild hyd roller at 217 deg int/225 exh @/050, 108 deg LSA and .495"/.500" lift. Any input on these heads would be appreciated. Thanks.

I have a set of those heads on my 383 sbc at the moment.
Mine are 178cc after some work.
My car weighs 3650 with me.
60 ft - 1.57
330 ft - 4.72
660 ft - 7.40 @ 91.46 mph
1320 ft - 11.74 @ 113.92 mph (best mph)
I can give you all the details of engine and head work if you like but I want to point out this was the first set of heads I ported myself so I am far from an expert.
I am using a comp 235 SFT cam
As cast airgap intake
950 ultra Hp carb
I have used 1 3/4 four into one pipes
I am using a set of 1 5/8 tri -y headers and 2 1/2 exhaust system at the moment which is
Still testing in progress.

[68maliblue]

Steve Cowan - it sounds like you’ve got a good combination there. Any details you are willing to share on the head work you’ve done on those heads I’m interested in hearing. It sounds like these heads are better flowing than I expected for their small runner size.

[steve cowan]

Out of the box
65 cc chamber
169 cc intake runner
67 cc exhaust
Intake throat was 88%
Exhaust throat 85%

On my bench the heads flow very close to what Dart claims 210-138 cfm @ 0.500"
On the intake port the Port was noisy above 0.600" lift and airspeed was 480 ft/sec @ 28" over SSR.
PRP as cast was 1.90" I made mine 1.98"
Radius not factored in.
The pinch is small in my application but I wanted to see for myself how this effects everything.
I layed the SSR down 0.010" at a time and tested until I was around 380 ft/sec over the SSR at the apex in the centre of the Port with pitot laying along port floor.
Speed at back of pinch was 360-370 ft/sec
Total height of SSR at the apex off the head deck is 1.050".
I thinned guide boss, took out minimum material on the floor, walls and bowl area around guide boss.
Intake throat was big already which is a shame, after 5 angle valve job and blending bottom cut the throat is 89%.
Only blended top cut into chamber and knocked off casting in chamber, I did not work on unshrouding in the chamber.
After port was completed it poured at 178cc.1.94" Intake valve.
My # off my bench
200-124
250-172
300-206
350-222
400-239
450-252
500-258
550-261
600-262

Exhaust I done very little and made some mistakes to the guide boss which caused turbulence alot worse than as cast.
The exhaust port is extremely noisy above 0.500" and the airspeed on the Port roof was crazy fast @28 "
With a decent valve job and blending radius and layed SSR down this helped alot. I did not bias the ports at all because at the time I didn't really understand or know how to bias a chev exhaust in the right fashion.
Exhaust #
200-105
250-132
300-150
350-159
400-165
450-173
500-174
550-177
Airspeed on roof of Port with a short pipe was 320 ft/sec @28"
Intake to exhaust ratio -67%.
I recommend you machine the stud bosses down 0.050" as my rocker geometry is not exactly where I want it but I can't get a shorter pushrod length because the rocker will bottom out on screw in stud.
I flatmilled my heads to 64cc
There are some excellent head porters on here who can give better advice than I have done with these heads, I will be doing my annual freshen up at Xmas so heads will be reworked, set the pinch and average CSA of the ports,flat mill for more compression, machine stud bosses down 0.050",rework the exhaust port and bias and hopefully go over 200 cfm.
If I can achieve a good fast port for under 190cc with the 1.94" - 1.5" valve combo and try to make around 500 hp that would be awesome.
I hope some of this information is useful to you, best of luck.

[steve cowan]

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[travis]

I have nothing useful to add, other than to say very nice work Steve! I bet that thing has some pretty serious bottom end torque. Is that the 235/242@.050 comp “hi torque” solid?

[steve cowan]

I have nothing useful to add, other than to say very nice work Steve! I bet that thing has some pretty serious bottom end torque. Is that the 235/242@.050 comp “hi torque” solid?

thanks for the kind words Travis,
you are correct comp oval track 235-242 @ 0.050''
106 LSA 106 ICL 500'' lift
i have 1.6 rockers on the intake with a dual spring with 420 lbs/in spring rate -it is surviving at the moment.
i turn the engine to 6000 on the shifts and 6200 at the stripe

[mag2555]

Many times it really helps folks with little porting experience to have something to look at in front of them to guide them and to take size measurements from.

To that end I would see if thru local junk yards or engine shops that you try and find a 062 or 906 Vortec casting to look at and size up as these castings in stock form are very close to your 165 CC starting point , yet they flow 235 cfm on the Intake side and far better then your 138 cfm on the Exh side!

A few years ago I picked up 2 cracked sets from a shop for free to use as porting Mules

[68maliblue]

Those are impressive numbers Steve. Thanks for the pics they will help a lot. So far I've trimmed the guides and blended the bowls. Thinking about going to a 1.6 exh valve. The spec sheet on these heads lists the exh seat diameter at 1.65" so I think I should be able to get by. Not sure if this is the right direction to get more exhaust flow. It seems that a larger valve will help flow but bigger isn't always better.

[GARY C]

I like that head with Dart's chamber, Pro Top Line had the same size head years ago but it was just a standard D shaped chamber but made a good street head with a little clean up 240's at .500 lift.

[F-BIRD'88]

These heads are MUCH BETTER than the 180 cc port Iron Eagle head... You end up with a very good head.
That works , by starting with this good 165cc port with good chamber iron Dart head. Add porting and go.

The 235-242° 106 .500" lil oval solid Comp cam
Also works great on a 350 sbc with ported 305 heads (4416) poor man's racer with 10:1 for street strip poverty racing..