Long ago in what almost seems like another life I used to run a shop in Belleville's west end. It was called Power Tune Up. To put it in perspective this was about the time Bill Jenkins book The Chevrolet Racing Engine first came out. At the time Bill had written that to date his best result had been 637 hp which was and is pretty impressive. At the time I ran a 63 Dodge post car powered by a 426 Hemi. I had traded a real nice 383 I had built for the damaged hemi and had redid it with 12.5 to 1 and a real good Sig Erson cam (999xxx) that is now no longer available. It was a pretty good working car in it's day and in fact was I believe Belleville fastest car at least with doors at the time. Trap speeds at Cayuga regularily exceeded 120mph and in the early 70s that was pretty darn good. I used to park it every night in my shop on the old chassis Dyno. One afternoon I was closing up for the day and a 66 or 67 Chevelle pulled up out front. The driver and several loyal minions got out and filed into my shop walking into the dyno scope room and circling the front of the old Dodge whose hood was open exposing the big hemi. I remember they walking like little roosters, their chest puffed out and their arms held like their chest muscles were so big they wouldn't hang straight down. I realized I had just experienced a Trenton Invasion. I walked in behind them. The leader who drove the Chevelle spoke. "How Much Horsepower does this thing have?" he asked belligerently. I replied," Using the weight of the car and the MPH in the 1/4 mile it works out to right around 550 hp." (This method was developed by DR Dean Hill of U of Nebraska and was used by Chrysler in much of their development work to judge track HP. It is reportedly accurate with in 2% and I still use it today. It used to be on the back page of a NHRA rule book.) "Is that all?" was the reply. "My Chevelle, out front, has 660 hp from a small block and I drive it on the street!" I swallowed hard resisting the urge to smack him 'longside the head. Bill Jenkins had only gotten 637 to date with all his experience and knowledge and here was a fellow walking around in public who had 660 hp and was driving it daily on the street. Amazing to say the least! I found my footing and spoke slowly and softly. "Do you hang around Trenton A&W?" I asked. "Yes ." came the reply. "Well " I said, "When this car is at the A&W it has over 1000HP!" Not another word was spoken. He turned, walked to the door with his loyal minions following behind him. Several looked back at me like I had just run over their pet poodle. I now know who he was and recently met some more of his family. They will never know this tale but I never forgot it and I never spoke with him again. I still smile everytime I think of it
don
I just realized this photo is so old it says CHARGEX on the rear fender instead of VISA!
-- Edited by Don on Wednesday 17th of September 2014 12:54:02 PM
-- Edited by Don on Wednesday 17th of September 2014 12:54:37 PM
Brilliant Don.The A&W Dyno effect - how true.I recall a TV show some time back where they dydo’d popular muscle car engines from the 60’s to see if their HP ratings were accurate – an L88 Chev, 427 Ford, 426 Hemi, and I think a Buick or Oldsmobile, things like that.Most were over the factory ratings by enough to give bragging rights to their supporters but not as much as some people were claiming.But the Hemi – over 800 HP – STOCK!Supposedly rebuilt to absolutely stock condition with original can, pistons, intake, etc.No wonder they did so well in NASCAR and NHRA, eh?I’m not an expert by any means, but 300 HP more than the others would seem a bit unrealistic.Maybe the 426 was fueled by root beer?
-- Edited by TIME TRAVELLER on Wednesday 17th of September 2014 10:18:13 AM
-- Edited by TIME TRAVELLER on Wednesday 17th of September 2014 10:18:42 AM
-- Edited by TIME TRAVELLER on Wednesday 17th of September 2014 10:19:32 AM
The TV show was dream car garage I believe. One thing to remember is that while a dyno is a great tool, that you should always use the same one to gauge any changes since some dyno's tend to give higher readings than others. This is especially true with chassis dyno's. Mustangs are known to be conservative compared to a Dynojet for example.
I have dyno'd a bunch of stock (except for an overbore) motors on an engine dyno when I worked at a engine shop and found that when in stock trim they were usually pretty close when using the same correction factor they used back inthe 60's - SAE J245 and J1995 which was a bare, unladen engine, with optimized timing and a free flowing exhaust similar to todays magazine dyno runs and known as gross numbers. They also used cooler inlet air, and closer to seal level (60 degrees, 29.92 hg) to give the numbers a bit of a boost. A well rebuilt but stock 1969 440 magnum will do about 380-390hp and was rated at 375hp by the factory using these gross correction factors.
Most aftermarket shops use J607, which tends to give similar numbers to the old gross correction factors since it uses similar atmospheric conditions. Its actually pretty interesting because some motors will really surprise you with healthy power and some really "hot" motors are really dogs. The only way you can tell without running them down the strip is a dyno.
It is super easy to make a 300hp 350 chevy, but you would not believe how many people manage to screw it up, and have a 250hp 350. If you asked them how much power it made before they dyno'd it, all of them swear it will make at least 400hp.
-- Edited by RacerRick on Wednesday 17th of September 2014 10:26:10 AM
:>) Aint it the truth. Apparently as I was later told he had headers that were worth 70HP according to the ad. He had a 350 Hp cam so there is 120 HP right there. The Holley carb and z28 manifold was good for 83 HP and the Accel coil and distributor had to give at least another 60hp just because. So now were are up to 563 on a 300 Hp small block. 20 more hp for the cloyes roller chain and 20 hp for the pretty aluminum rockers and we are now over 600 HP! And so it goes. That was how and still is how some figure it. If it doesn't show on the MPH I have a hard time swallowing it. And you are so right. Same dyno same air conditions same temp is the only fair way. And flow benches aren't a whole lot different. Same bench, same values same air same temp etc.
Thanks for a look into the dyno world.
don
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SR Dragster because old people need to have fun too!
But the Hemi – over 800 HP – STOCK I remember the show. The hemi build was a cheater but the host didnt know. Doesn't matter anyway. I remember saying to my wife as much as I like the mopar on top that is hardly an as produced motor.
It was a superstock engine, not a 10.5 to one 284 duration .484 lift two inline carters stocker like everyone who ever bought one to drive had.
don
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SR Dragster because old people need to have fun too!
Ah I remember that wagon well, Bob. You were often at Cayuga when we were. Is that when you ran at the Winternationals? Ever wish you still had it? (or maybe you do!) Me I have a soft spot for wagons In fact just 2 hours ago we were coming back from town getting some 94 for the rail. We were driving the MAX Wedge as momma don't allow no gasoline in the Dodge Journey. I said to her. You know the car I miss the most? It is the 383 powered white 64 Dodge Wagon we had back in the day. I should never have sold it. (It was its engine I traded for the hemi and stuffed a used 440 in the hole and sold it.)
don
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SR Dragster because old people need to have fun too!
I don't know if I ever want another car. There was a lot of time spent changing valve springs, cams, dykes rings, and checking the pistons for cracks etc. trick 4 speeds with spur cut gears , clutches and on and on. As time went on the 283 managed to bend a 12 bolt so the tires toed in. In a different body I was lucky to win Class on a hole shot at the NHRA Summernationals in July of 81. I miss the old days of Indy and Englishtown. After getting hit by a drunk in 85 my health hasn't been the greatest (29years and still hurting). In hind sight I'm lucky to have 3 "Wally's" or when mine were presented to me they were called "Oscars" to look at and remember the good old days. Great memories of an NHRA tear-down adventure with all the name people most guys read about in magazines (you learn a lot of speed secrets in the tear-down barn) .
-- Edited by RWW on Wednesday 17th of September 2014 05:02:51 PM
