[Cliff R]

Jeff Kauffman called a few weeks ago and asked if I would be interested in doing some direct testing with his new aluminum "D" port heads. The first part of the testing would involve removing the engine from my Ventura and taking it to KRE for some dyno runs. Then, swapping out the 6X heads for a set of KRE's new heads, 85cc CNC chambers (unported). The second part of the testing would involve some dragstrip runs to see how much if any the new heads improved track performance.

I thought about it for about a milli-second then gladly said, let's do it! I removed the engine yesterday, carried it to KRE, installed it on the dyno and made it ready for the testing. It was dyno'd EXACTLY like it is tuned for the street and track. I used two different carbs during the testing, a 1976 q-jet and a Holley 4781-2 850cfm DP carb. I race the car with either carb and it runs identical numbers so figured it would make similiar numbers on the dyno.

Part of the testing would also involve carefully measuring my 6X heads for chamber size and actual port flow on KRE's flow bench.

Well, the testing was done today, in the interest of space I'll just go over the highlights. ALL runs were made with both sets of heads using my modified 1968 iron intake that accepts either spread bore or square flange carbs w/o an adapter. We tested both carbs with each set of heads. Timing adjustments were made to find the best peak power numbers. With the 6X heads my 455 made 455hp and 530ft lbs. With KRE's new heads it made 495hp and 564ft lbs. The qjet made the highest peak hp runs with either set of heads yet gave up a couple ft lbs at peak torque to the Holley carb. Average power with either carb was within .2 hp/.2 ft lbs. No wonder it runs the same numbers at the track with either carb!

The chambers on the 6X heads were right at 91cc and flowed 231cfm intake/196cfm exhaust. The KRE heads were 261cfm intake/221cfm exhaust with 85cc chambers. Cranking compression with the 6X heads was just under 160psi, right at 175psi with the KRE heads. With either set of heads the best hp/tq numbers were made with 30 degrees of total timing. 93 octane fuel was used for all the testing.

Next step, off to the track for some timeslips!......Cliff

[GS470]

Pricewise, I think the out-of-the-box KRE heads are extremely close to what I paid for my 260+cfm 6X street/strip heads from Dave at SD Performance. If the KREs would have been available when I bought my heads, I would have given them serious consideration.

[lugnutt]

How much would the heads tested (Kaufmans) cost delivered to the customer? Just went to the site and the link was down.

[Redlined455HO]

I think we have confusion on which Underwood installed the KRE Heads. Dave has E-heads and has already dipped into the 11's in his 76 455/4 speed TA. His brother Rick won the KRE heads and swapped them for the 6X heads on the 400/auto in his 71 GTO convertible. The ET numbers posted Cliff are what Rick provided to me a couple of weeks ago.

[Skip Fix]

Heck if someone will pay the dyno time and gaskets I'll do a D port, RAIV and E head(KRE also if some one has them) on my next 455 on the stand now! We'll leave the same 239/247 @ 0.050 cam in it and 20cc dish pistons.

[Darrell]

Maybe I am way off here, but couldnt you have a set of 6x-4's ported to 260 and come up close to those same numbers? that would save allot of bills wouldnt it?

Larry dont your heads flow that good?
When is there enough flow? A streetable 041 cam can only use so much flow, what is that number?

[PONTIAC DUDE]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by PONTIAC DUDE:
Brian. there are others. Check with Phil Underwood (Dave's Brother). He is the dude that won the KRE heads at VMP.

He changed just the heads. <HR></BLOCKQUOTE>

Did Dave do any back to back testing (on dyno or on track)?
He had run his car quite a lot with his old combo and went right to the track after the installation.

If so, has he posted the results?

No he didn't post them. Don't think he will.

Where can I find them?
Might try and e-mail him., That would be the best deal.
[/QUOTE]

[Cliff R]

This is not confirmed, but I was told that Dave Underwood's car picked up a couple of mph and went .45 seconds quicker in the 1/4 mile....Cliff

[rascal455ho]

I want first dibbs on used KRE heads when you get done with them Cliff.LOL

[Cliff R]

At some point I will also do a cam test. The engine really likes the current cam choice as it makes good power everywhere. We tried some lower rpm pulls but the engine was very difficult to hold at low rpm on the dyno.

The engine is up and running, couple more minor troubles to work out, then off to the track. I discovered yesterday that the rockers were just brushing the valve covers so I'll need the thicker gaskets. I'm also going to go .050" longer with the pushrods to get the rockers exactly in the center of the valve tips. Weather permitting will get to the track this weekend.....Cliff

[BLANK1]

Congrats on your win Cliff. I was out loading my car and heard you had won. You have that car running some good numbers for a mild combo. Had a great time at the Nats. Can't wait til next year.

[rascal455ho]

Hey Dude did Trice run at Farmington a couple weeks ago?I could not make it.Just wondered how he done.

[slowbird]

Tom S: that is very interesting. Do you have flow # for the 980s and runner cc to compare with the KREs. I have never seen a pair of 980s (not even a picture) but have heard a lot of people so that they are one of, if not the best head Pontiac made.

[tom s]

dont have the numbers,did them long time ago,the intake is the bathtub I converted to fit the KRE heads,cut the water off,put the water from one of the new 66 alu tripower intakes to it.The ports of the intake are actually a little taller than the KRE ports so there is a little missmatch.Tom

[Brian Baker]

Darrell,

I hear ya', but like Cliff said that wasn't the point of the test. My 62's are race ported and only flow 254-cfm @ .600" (28 inches). I think a d-port flowing 231-cfm is more representative of what would be on a typical street engine. Porting a set of iron d-ports to flow over 250-cfm would obviously take more time (and cost more money) than it would to merely get 230-cfm out of them.

A gain of 40-HP and 34 ft/lbs. torque over that of the mildly ported 6X heads is a very good result, I think. I would imagine that had the 6X heads been unported, the gains would have been greater. Can't wait to see the dragstrip results.

[slowbird]

Also did you run the same intake on both heads. I thought that the 980 had a different intake style.

[PONTIAC DUDE]

Cliff.

You got different info then I was told. Hummmmmmmmmmmmmm.

[Cliff R]

I've been driving the car on the street since installing the heads. The engine makes more power at every rpm. It is not managable on street type radial tires. Prior to installing KRE's heads 1st gear was useless at any rpm or vehicle speed I could roast the tires. The tires wouldn't hold in second gear below about 45 mph. Currently, second gear is useless and I've even broke the tires loose a few times in high gear! The slight increase in static compression seems to have offset the slightly larger and better flowing runners as throttle feel off idle is just as smooth as the iron heads. For some reason that I don't understand, the engine idles a tad rougher with the aluminum heads and wants more fuel at part throttle? I made a few quick adjustments to the idle and part throttle mixtures and it responded perfectly.

The engine runs just as cool with these heads as the iron heads, but heats up to temps a bit quicker. With the iron heads it took at least 15 minutes to get the engine up to 180 degrees. The aluminum heads have the temps up to 180 degrees in about 5 minutes. No ideas about that one?

The ET Streets are in place and we're headed for the track early next week. Provided I can hook this thing up it should make for some improved runs over the iron heads. I'll make sure to post the results......Cliff

[80TA]

Well since it appears cutting my 6 x heads is nto that great an idea how much are these KRE heads and what type of compression will I wind up with using flat tops?Are they much cheaper than the good but very pricey e heads.Was thinking 9 to 9.5 to 1 would be all I want for compression.

[rascal455ho]

Real world testing it doesn't get any better than that.Can't wait to see the difference on the track.