Don Terrill’s Speed-Talk

A Cylinder head battle has recently occured on a mild street/strip bracket motor..... whats your prediction on the power of each? Here is the set-up and the 3 participants.

395 sbc
4.04" bore x 3.85" stroke
Weiand Team G intake
Hyd roller cam .544/.554 w 1.6's - 230/236 @ .050" - 112 lsa
approx 10-1 cr
1 3/4" headers

The Competitors:

1) Camel Back heads with a competition port job done by Mike Stark of CFM performance. 2.02/1.60 - 62 cc chamber

2) Off the shelf Dart Pro-1 Platinum 200cc aluminum cylinder heads - 65 cc - ($ 1460 cost)

3) Off the shelf AFR 195 Eliminator aluminum cylinder heads (street port, not the competition) - 65 cc - ($ 1485 cost)

Who wins ? How much HP of each ?

That's certainly an interesting test.

Do you already have dyno results?

I'd say it would be hard to get a camel hump heads to out power either of the others, but the fact he stayed with a 2.02" valve is a good sign.

Did the compression stay the same for all the heads?

Randy

Yes, I have the dyno graph. It is interesting.

Yes, CR was the same.... actually a hair higher with the camel backs due to 62 cc chamber..... other two were 65 cc.

No other changes were done to the motors, same dyno, same day.... each set was tuned for optimum power (timing/jetting)

All dyno results were corrected for fairness.

The guy who did this test has no connection or particular love for any of the cylinder heads, he was just trying to figure out which one would work best on his motor and the dyno operator was described by him as "Swiss" as in neutral.

He's pretty much a no-nonsense racer who is a straight shooter....

tod85 wrote:Yes, I have the dyno graph. It is interesting.

Yes, CR was the same.... actually a hair higher with the camel backs due to 62 cc chamber..... other two were 65 cc.

No other changes were done to the motors, same dyno, same day.... each set was tuned for optimum power (timing/jetting)

All dyno results were corrected for fairness.

Are you going to post the results ? I would like to see this as well.

I wouldn't be surprised if the old double humps held their own. Post the results please. would love to check em out.

Don

tod85 wrote:A Cylinder head battle has recently occured on a mild street/strip bracket motor..... whats your prediction on the power of each? Here is the set-up and the 3 participants.

395 sbc
4.04" bore x 3.85" stroke
Weiand Team G intake
Hyd roller cam .544/.554 w 1.6's - 230/236 @ .050" - 112 lsa
approx 10-1 cr
1 3/4" headers

The Competitors:

1) Camel Back heads with a competition port job done by Mike Stark of CFM performance. 2.02/1.60 - 62 cc chamber

2) Off the shelf Dart Pro-1 Platinum 200cc aluminum cylinder heads - 65 cc - ($ 1460 cost)

3) Off the shelf AFR 195 Eliminator aluminum cylinder heads (street port, not the competition) - 65 cc - ($ 1485 cost)

Who wins ? How much HP of each ?

1) Camelback = 505HP
2) Dart pro's = 500HP
3) AFR Elimin. = 530HP
Just a guess, as the info provided is slim pickin's...
There, now post the results....pleeeeeeeze

Brian

Alright, give me a minute or two.

The below color codes are:

Green: Baseline with camel back cylinder heads and a very, very old solid flat tappet grind back from the 60's or 70's (230/230 area) (Goes to show you how far they've come in cam technology and how these new grinds really help make some power)

The Camel Backs had previously received a competition port job by Mike Stark @ CFM performance and had 2.02/1.60 valves.

Grey: Camel back heads 62 cc chamber- with Hyd roller cam 230/236

Blue: Dart Pro-1 Platinum 200 cc aluminum cylinder heads 65 cc chamber(Cost $ 1460)

Pink: AFR 195 "street" port aluminum cylinder heads 65 cc chamber (Cost $ 1485) (These are not the competition ported AFR cylinder heads)

Conclusion: Considering those old Camel Backs are decades old, they held their own against the Dart Pro-1 Platinums (Good job Mr. Stark and CFM performance)

The AFR's did very well...... and its reported that the competition eliminators would have made another 30 HP on top of the 490ish they show here.

tod85 wrote:Alright, give me a minute or two.

B20Paul wrote:That's not really a fair comparison. All else being equal, iron heads are going to make more power at the same compression.

Interesting input.....

You must be referring to the camelbacks because the Darts & AFR's are both aluminum.

But, should I recast the camel back for you ? Not sure how to solve your problem with them....

B20Paul wrote:That's not really a fair comparison. All else being equal, iron heads are going to make more power at the same compression.

But the alum heads should have better chambers and ex ports...

As a note, I thought the camelbacks ported by CFM performance did GREAT !!! Thats a cylinder head close to 50 years old competing quite nicely with the Dart cylinder heads....... impressive in my opinion.

I understand what you are saying Paul about the iron vs aluminum..... but I will add, that the differences you are talking about usually amount in the area of 5 hp on a street motor like this one. Others on this forum could certainly give better input than I can considering we have a handful of engine builders here, but from the tests I have seen between aluminum and iron and everything else apples vs apples, the differences, if any at all, are minor.

Tony Mamo is going to like that test.