Has anyone dyno'd a stock unmolested Z28 to get an actual hp? I read they were 290HP rated from GM, but in reality were into the 400HP's.. ???
302 MO dyno results?
chedderboy
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Has anyone dyno'd a stock unmolested Z28 to get an actual hp? I read they were 290HP rated from GM, but in reality were into the 400HP's.. ???
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In reality it took quite a bit of work to get the horsepower over 400.
I think guys have mentioned more like 325 to 335 out of a bone-stock, 302 motor. Anyway, that's about what I figured I was getting out of my old junk301 years ago..
Hopped up ones seem to be in the mid 400's most of the time, like 440hp or so.
The little high-rpm buggers are a hoot to drive!
Road gears, just roll her outta the hole and when she hit's 3,000 rpm NAIL HER!!
Or drag gears, side-step the clutch at about 4 to 4,500 rpm and GO!!
The little motor tends not ta be able to get out of it's own way until it is as the 2-stroke guys say, "up on the pipe", then it turn's into an animal!!
Dr. Jeckle and Mr. Hyde motor for sure!!
pdq67
Hopped up ones seem to be in the mid 400's most of the time, like 440hp or so.
The little high-rpm buggers are a hoot to drive!
Road gears, just roll her outta the hole and when she hit's 3,000 rpm NAIL HER!!
Or drag gears, side-step the clutch at about 4 to 4,500 rpm and GO!!
The little motor tends not ta be able to get out of it's own way until it is as the 2-stroke guys say, "up on the pipe", then it turn's into an animal!!
Dr. Jeckle and Mr. Hyde motor for sure!!
pdq67
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About 15 years ago there was a dyno run done on a stock 69 Z/28 302 as part of a resto series: about 325hp/6500 for the '346' cam, 345hp/6600 with the '140' off-road. The June '88 Hot Rod did a feature on one of Penskes' '68 T/A Camaros with dyno sheets from Traco: 402hp/6800 with an Engle cam.
Todays' NHRA stock-class motors do around 425hp, that is with a non-stock cam and race gas.
Todays' NHRA stock-class motors do around 425hp, that is with a non-stock cam and race gas.
As others have indicated, the reality for the stock motor was not nearly that high, and time slips from the era indicate this. However, as with other small blocks, the little motor responded well to performance enhancements. Another little issue is the camshaft. With open headers and a few other Mods, Desktop Dyno puts the max horsepower at 7500 RPM, which would require a higher shift point for best ET- wow! Modern cams can improve upon this if desired. Also, here is a link to a very cool article on the Z28 for racing:chedderboy said:
http://www.yearone.com/enthusiast/restoarchives/spring98/sp98engineassembly/engass.htm
Enjoy!
Rob
A stock DZ/MO 302 puts 230-240 SAE Net horsepower to the rear wheels. 1/4 trap speeds of 96-98 mph seen both currently and documented in road tests back in the day confirm this.
Keep in mind that a stock 426 Hemi 'Cuda only puts approx. 300-320 to the tires.
The horsepower ratings back then were gross ratings which were much higher than the net horsepower ratings used today.
Keep in mind that a stock 426 Hemi 'Cuda only puts approx. 300-320 to the tires.
The horsepower ratings back then were gross ratings which were much higher than the net horsepower ratings used today.
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Ok, that's good to hear. I'm going to have my car done in June with Doug Thorley Headers, Flowmaster exhaust, 4053 holly card, rebuild ingition system, and possibly a new camshaft. I'm thinking I'll pay a little extra for a baseline dyno reading before any of the work just to see what the net gain will be.... I wish I knew what camshaft was in the motor!
Would adding the super-dooper Z28 off-road camstaft be too much without the cross-carb setup? Should I stick with a the 30-30 factory camshaft from CompCams?
Would adding the super-dooper Z28 off-road camstaft be too much without the cross-carb setup? Should I stick with a the 30-30 factory camshaft from CompCams?
So I am still kicking around my re-build, and am looking at the CompCams Nostalgia 30-30+ solid (12-673-4), the 282S, or the 284S. All have tighter lobe centers than the Fact Z Cam, which I hope will make more torque at a lower RPM. Looks much better on DD2000, whatever that is worth. Note also the -140 Cam has a tighter LC than the Fact Z Cam. I feel one thing for sure you will need to do is get your Dist set up with the right curve, and do some porting on the cylinder heads if you run the stock ones. I also plan to use the WISECO pistons...chedderboy said:
Rob
I know we are chatting about stock 302's as well as "balls out" ones but for better street manners I want to mention.................
As stupid as this sounds the little-bitty OLD -097 Duntov solid cam in a 283/292/301 will still get up and talk to you!
Spec'ed like 287(270?)/228/287(270?)230, 110.5/108, .385"/.385" net lift!!!!! Like I said, a little-bitty bugger that will STILL "haul the mail"!!!
And it will have a better, although nothing to write home about lower to middle range, than the 30-30, imho
Crower lso makes a dandy solid for this, imho..
PN 00320; 264/230/270/236, 112/108, .458"/.467" gross lift.
As does Isky with their Z-20, 268/228, 112/108, .448"/.448" gross lift..
I ran my old junk301 with the old Duntov as a daily driver for quite a while and it was always a hoot up top!!
NOT as "knarly" as the 30-30, but my compression was probably 3/4 a point lower too......
pdq67
As stupid as this sounds the little-bitty OLD -097 Duntov solid cam in a 283/292/301 will still get up and talk to you!
Spec'ed like 287(270?)/228/287(270?)230, 110.5/108, .385"/.385" net lift!!!!! Like I said, a little-bitty bugger that will STILL "haul the mail"!!!
And it will have a better, although nothing to write home about lower to middle range, than the 30-30, imho
Crower lso makes a dandy solid for this, imho..
PN 00320; 264/230/270/236, 112/108, .458"/.467" gross lift.
As does Isky with their Z-20, 268/228, 112/108, .448"/.448" gross lift..
I ran my old junk301 with the old Duntov as a daily driver for quite a while and it was always a hoot up top!!
NOT as "knarly" as the 30-30, but my compression was probably 3/4 a point lower too......
pdq67
olympic69 said:
I chose the 12-673-4 cam for my DZ. Comp makes an Ovate spring for this cam that fits the original spring pocket. I didn't want to cut up my original heads (porting/screw in studs), so I stored them and put on a set of Edelbrock 6089 RPM heads. On the Dynojet it made 280hp at 6,000rpm and the torque peak came at 4,200rpm. The cam definitely woke up the low end and it pulls hard to 6,500rpm which is as high as I go with my original short block. The weird thing about this motor is that it 'feels' faster than my 11-sec 427 Camaro and my buddie's LS1.
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