Hi there, I was wondering if anyone has ever put there 69 Z28 on a chassis dyno or engine dyno for that matter. I ran mine and was suprised at the low numbers it made at the wheels.(238hp, 240tq). I've read many articles on the DZ motor claiming close to 400 gross horsepower, I say horse####! If I had 400 gross horsepower, my rear wheel power would be in the 300 range. I should mention that the car is no slouch- 4.10 12 bolt with m-20 muncie. I've street raced a few musclecars and have won more than I lost- outran a Grand National four times in a row, an AAR Cuda three times, a 340 four barrel Cuda (modified) and a couple schoolkids' 5 liter stangs. All were on a 15-20mph roll. The only non factory parts on my Z is Flowmaster mufflers. I currently have the engine apart and have purchased headers w/X-pipe, ported the heads, put 2.050 intake valves and shaved the heads for some more compression. I have the factory replacement cam from CompCams(.485lift,.254 duration @.050 114 lobe sep. angle) What do you guys think? Is the cam good with this combo? Any suggestion/comments would be appreciated. Thanks for any input.

Scott Karam

[This message has been edited by DjD (edited 11-13-2000).]

Hi Scott,

Thinking about what your saying, "the car is no slouch" "and have won more than I lost" after complaining about the dyno runs and low HP... How high was the motor reving when these numbers were reached? If that puppy wern't twisting close to 8k you didn't wring it out very well...

When it comes to DZ's I recomend keeping them as stock as possible with min over bore on rebuilds to preserve the life of the block!
As for raising the compression, what fuel you plan on running?



------------------
...Dennis
The Cars:
'69 RS Convertible w/SS trim (http://www.camaroslimited.com/memberscars/den.htm)
'96 Z28SS #1679 of 2410 (http://www.camaroslimited.com/graphics/memcars/96ss.jpg)
The Club:
Camaros Limited Nor-Cal (http://camaroslimited.com)

Scott
My engine rebuilder let me run my Z/28 on his chassis dyno one time for free as a courtesy gesture. He would only take it to 5000RPM because he said it was running too rich and he didn't want to hurt the motor. Of course for $175.00 he would re-jet it and for an additional $75.00 I could have another try to see what the HP would be. Anyway the numbers at 5000RPM were 241.6HP and 273.9 Torque. The HP was climbing and the motor pulls easily to 7000RPM so I think it would easily get to 300HP if not 330HP.
I have 3.73 gears, M21 trans, S/R torquer 2.02 pocket ported heads, 242, 246 dur 5.10, 520 lift intake/exhaust 1.6 roller rockers, 9.7:1 compression, weiand stealth, 750DP AED Holley, balanced & blue printed, electronic ignition, headers, 2.5" X-pipe, and spintech mufflers.
This combination runs great.

When I ran my Z on the dyno, they spun it to 7200RPM and had some more to go but power was just starting to fade. I mix 113 octane with 93 and it loves it. The long duration cam feeds on compression so, since i need race gas anyway, I upped the ratio closer to 12.00 to 1 by way of .030 over pistons 60cc combustion chambers(shaved the heads .020).
Hey ScottB, excellent numbers! Your combo seems to be working great- if I were you, I would spend the money for the dyno tune, it's worth every penny.
Hey DJD, thanks for the reply man.

Scott Karam

'69 RSZ28 loaded with options

------------------

Scott,

Drop your a set of headers on it and also put some dumps just where the headpipes bend to the "X" at the same time to uncork it when wanted.

You will notice the difference, I do believe. pdq67

About 8yrs ago Musclecar Review wanted to do a shootout with my brothers '69z against a new Z so we pulled the engine and tuned it on a friends dyno. It had made about 320 corrected horsepower, my friend has been in the engine business for a number of years and the numbers were about what he figured they would be. BTW it had a Crane Cams factory blueprint cam.

Scott K,

The powertrain loss through a Muncie is about 18% of gross horsepower. You mentioned that they took the car up to 7200RPM, so what was the HP figure THERE???? What was your highest HP reading and at what RPM????

Rear wheel HP SHOULD be about 260-270HP.


[This message has been edited by sr71bb (edited 11-15-2000).]

Gee guys, my earliest gearhead bud had a 302, stock ( hot enough) and unless he was running his 4.56s he was getting eaten up by 5.0s.

I'm damn glad to hear you guys are running them and winning with them.

You really should try an L88 though.How does 437 at the rear grab ya!

http://www.camaros.net/forum/wink.gif

Scott, one thing to consider, and its all about $$$. My next step to bring my detuned L88 ( pump gas ) closer to stock HP specs , is the addition of a modern solid roller. Its long dollar for me, but Crane claims I'll see 35-50 more HP at 6000+.

Scott, just curious how these cams compares to the stock 302.

www.cranecams.com/master/apps/chevy27.htm (http://www.cranecams.com/master/apps/chevy27.htm)

I was thinking either #3 or #5, or if you like Comp Cams,

www.compcams.com/speccard/12-772-8.txt (http://www.compcams.com/speccard/12-772-8.txt)

------------------
Gene
Team Chevelle Gold Member /ACES
67 SS 427 Chevelle (http://www.chevelles.com/feature/october2000.html)



[This message has been edited by 427L88 (edited 11-15-2000).]

Sr71bb-

The 238hp was at 7200 Rpm and the 240tq was at 3900. I must say that my clutch was missing a couple chunks on the disc but it still hooked up.

427L88- The cams you suggested have less duration than my factory replacement but have much more lift. From what I understand, more lift is not going to give much more because of my lack of cubic inches. I'll know in a couple of weeks how my combo is going to run. I plan on putting the motor back together next weekend and I'll update this post then.
Thanks for the reply guys.

Scott Karam