[GOAT8U2]

Hey everyone, I'm looking for some input from the other KRE D port Pontiac customers. I don't really know much about the company even though I've owned this car since 1996 and I'm in a spot where I would like to rebuild the engine with some performance heads on it. To get a build done right now is nuts so I'm looking into all options to do it right and soon.

I'm going to do a stroker 400, run at least 11:1 compression with a hydro roller on E40 fuel etc.

I was looking at the D Port 325CFM and possibly 340CFM heads and a bonus is that they're in stock and about 2 weeks to do.

Please comment on anything positive or negative about these heads please.

Anything to note vs Edelbrock E heads?

[chuckies76ta]

I'm running two sets on both 468 Pontiac engines. They were both done by Dave at SD Performance. Dynoed both engines and made 600 H/P and 600 torque. In my opinion very good heads.

Charles

[tom s]

I ran a set of 290 CFM SDs heads with a road paver cam at 10.25 CR on a 455 and made just under 600HP with a 2-4 tunnel ram intake.Sold the engine and its in a 70 GTO and hauls butt!Tom

[firechicken]

I have KREs done by SD 290s as well and have run them with boost for about 10 yrs now with no issues.

[GTOLou]

KRE did mine - within a couple of years of them coming out. I've had them well over 10 years. 310cfm. Very happy with them - make great power. Recently changed cams and had to do some spring upgrades, etc.

I'd still have SD do a set if I bought the KRE dports new. Pretty sure he sets them up w/ longer valves stems - option for more lift. Dave does all head stuff very well.

Other option for low buck would be those speedmaster round port deals.

[ta man]

I've had the same set of SD's 290 cfm KRE heads since 2009...had them "upgraded" a few years back...according to Dave Bisschop at the time everything checked out great with them.

[JLMounce]

I have a set of as cast d ports straight from Kauffman. Still to date one of the best upgrades I did to the car.

I have a bit over 10000 miles on those heads without issue.

[slowbird]

It's a nice head but i get get them ported by anyone else just not kre. I own a set of them and the port work i wasn't crazy about. Having them fixed up now.
But the are proven to make good power

[GOAT8U2]

Thanks everyone, it's pretty clear these are proven and can make some power.

Chuckies, what compression and cam acheived those power numbers?
I'm looking for 600hp+ and it sounds like D Ports can do it.

Fire Chicken, what head gasket are you running, psi level and compression? This sounds interesting as a back up when things get boring around 600hp in a 4100lb car.

[Cliff R]

I own and use one of the very first sets ported by Dave at SD performance and they have been fine now for over 10 years. I opted for a 76cc version to get the compression to just over 11 to 1. I teamed them up with his "Old Faithful" HR camshaft and it's proven to be a perfect pump gas engine combination. Idle quality is excellent, makes 13.5 vacuum at 750rpm' and idles nearly dead smooth. In full street trim the car runs bottom 7's at 95-97mph in the 1/8th mile on DOT's in pretty hot/humid weather.

Cranking pressure is right at 200psi, static compression is 11.3 to 1. It will run on any octane of pump gas w/o detonation but it doesn't like 87 octane in really hot weather as it "bucks" the starter just a tad on a hot restart.

I also tested some of the very first sets of the KRE aluminum "D" port heads and built one of the first engines dyno'd with them. I also supplied my old 455 for their dyno testing and the Ventura for the drag strip testing of those heads. Those articles made both HPP and Popular Hot Roddings "Engine Masters" edition.

Since they were released I've built quite a few engines using them. Stone stock with nothing more than a gasket match to a stock intake gasket and mild hydraulic cam a 455 build will make 500hp without much effort. 600hp is easily within reach and you don't need 325-340cfm intake runners or a monster cam to get you there. I even did a 428 build with them with stock "D" ports and a mild HR cam and it cranked out 497hp/540tq and didn't need a lot of RPM's to get those numbers........Cliff

[chuckies76ta]

Originally Posted by GOAT8U2

Thanks everyone, it's pretty clear these are proven and can make some power.

Chuckies, what compression and cam acheived those power numbers?
I'm looking for 600hp+ and it sounds like D Ports can do it.

Fire Chicken, what head gasket are you running, psi level and compression? This sounds interesting as a back up when things get boring around 600hp in a 4100lb car.

The compression was right at 10.5-1. We used SD Performance Road Paver cam. 246/252 dur @ .050" lift .608"/.608" lift with 1.52 ratio rockers 112 or 114 lobe sep.
My wife's 68 Firebird ran a best of 10.89 @122 mph with 3700 lb. TH400, 3.73 gears, 28" slicks. This was at sea level track. Heads flow around 300 cfm as I can remember. Hydraulic Cam with solid roller with .005 lash.



Charles

[Cliff R]

I've built several of these engines with the "Road Paver" cam and remarkably they idle really well considering the size of the cam. I would NOT go less than 10.5 to 1 compression with it however. Even the OF cam starts to get a little "soft" at idle if you get down around 10 to 1 static compression. I did two of these engines closer to 10 to 1 with the OF cam and both only make about 10-12" vacuum at 750rpms and noticeable "lope". My 455 with 11.3 to 1 compression is nearly dead smooth at idle in comparison, and throttle response and power right off idle considerably better........Cliff

[Steve C.]

SD Performance KRE D-port 300-305 cfm CNC ported heads.
10.5:1 compression ratio
Comp part # 51-000-11
Grind # P8 3115B / 3116B HR112.0
.006" - 306 / 314
.050" - 246 / 252
0.4000" lobe lift intake & exhaust / 1.52 rocker ratio
112 LSA
Crower solid roller lifters w/ .005" lash
Minimum 150 lbs seat pressure after run in

.030-over 455 / 4.250" stroke
Torker II intake port matched to the heads w/1-inch open carb spacer
Holley HP950 carb
1.75 headers

588.5 HP at 5800 rpm
600.6 ft.lbs. torque at 4600/4700 rpm


.

[firechicken]

Originally Posted by GOAT8U2

Thanks everyone, it's pretty clear these are proven and can make some power.

Fire Chicken, what head gasket are you running, psi level and compression? This sounds interesting as a back up when things get boring around 600hp in a 4100lb car.

Dave gave me an 82 cc chamber on my heads to go with my 30cc dish pistons for 8.2:1 cr.

Cometic mls head gaskets.

Tiny twin turbos, tiny cam, non intercooled I run around the street at about 9 psi on 92 octane.

On C16 I've run 18 psi at the track but that is unusable on the street and really, almost dangerous to be honest.

[73LeMans]

I'm actually surprised no one mentioned the dport exhaust limitations, at least for conversation sake. For the 600HP the OP needs, there isn't one Id agree, but when you want to make more power (and we all do) wouldn't it be easier with a real set of headers to mate up?

I've got KRE dports - excellent head, and like others, its the best upgrade I ever made to the car. My 3700+lbs barge ran 10.6x with them. But if I had to do it again today, Id go with KRE high ports. At least then I could I get an off the shelf Dougs 2"in header in there to move some air.

[slowbird]

Originally Posted by 73LeMans

I'm actually surprised no one mentioned the dport exhaust limitations, at least for conversation sake. For the 600HP the OP needs, there isn't one Id agree, but when you want to make more power (and we all do) wouldn't it be easier with a real set of headers to mate up?

I've got KRE dports - excellent head, and like others, its the best upgrade I ever made to the car. My 3700+lbs barge ran 10.6x with them. But if I had to do it again today, Id go with KRE high ports. At least then I could I get an off the shelf Dougs 2"in header in there to move some air.

The exhaust is a limitation but it can be dealt with. Imo up to 750hp the heads/exhaust are fine beyond that it'll get tougher.

[firechicken]

Dug out my flow sheet for reference.
My chambers are actually 89 cc.
Heads were done in 2008.

The exhaust port is pretty darn good...

[ta man]

Yours actually flow more on the exhaust then my current heads.

[73LeMans]

I get ya guys.....I have similar sheets. I'm not saying the port can't flow some air....everyone here is proving they work very well, I'm just saying finding a header that doesn't restrict all that port work as you seek more and more power is a challenge.

If starting out fresh, as the OP is, I'd recommend, as folks did when I was switching to aluminum, to spend a bit more money on High Ports and deal with a cheaper and more readily available header as you inevitably continue to replace them. The growth potential is a bonus.

I digress. This is moving away from the OPs original intent of the thread.


Another positive on the KRE head for me was a lot less timing was needed to make great power. IIRC 29 was my last setting (2013)

[GOAT8U2]

Anyone get the 325 or 340cfm D Ports through KRE?

These seem like a decent way to keep things stockish
BUT maybe at that point the High Port just makes more sense.

I don't mind getting a new header but at 3.5" flanges at the collector that changes my exhaust too. Kind of a PIA if it's not really with it for a street guy like me.

I do not track the car, I'm 100% street and convertible.