Blower Basics UpdateQ. You did a story called "Blower Basics" back in the June '06 issue of SRM. While it was well written and informative, I was disappointed that more comprehensive dyno testing wasn't included, particularly on the Hemi. I realize the story was a general look at blown engines, but I was hoping for more than just peak numbers. I guess I should confess I have an agenda-I'd like to build a Hemi just like it and I'd like to know what it's going to do.
While I'm at it, I have another gripe; I think it was unfair of you guys to show a photo of a blown Olds on the cover and not feature it inside. Were you trying to fake us out? I know it sounds like I'm complaining a lot. I really do love the magazine, especially all the tech stuff you do. Your column is the first thing I read every month. But I'd still like to know, what are the chances of getting more info on the Hemi?Ken WrightVia the Internet
A. We'd say your chances are better than average, Ken. We intended to include more dyno numbers when the story originally went to print, but there were a host of factors that prevented us from publishing them at the time. We're not making excuses, but here's a little insight on the events that interrupted our plans.
As our blown Chrysler was being assembled at Pro Machine, the shop's owner, John Beck, was in the process of moving his entire operation from Placentia to the less-crowded environs of Chico (he can be reached at (530) 892-9711)-SoCal's loss is NorCal's gain. As John was winding down his operation, and before beginning the gargantuan task of packing up an entire machine shop, there were roughly a dozen engines to fire up and test; ours was one of them. With a couple days to spare, we strapped our Hemi to the dyno, but thanks to a water leak, all we were able to do was break in the cam and make a couple of pulls. While some decent numbers had been achieved, the decision was made to quit testing before we hurt anything. Besides, we were confident there was time to pull the engine off the dyno, fix the leak, and do more testing and tuning with time to spare; then things went from bad to worse. While we were making repairs, another engine was being tested when a bearing deep inside the dyno died and there was no hope of fixing it before John packed up.
With our deadline upon us, we decided to run with the information we had. Our intent all along was to examine blowers in general terms, and we had the dyno numbers on the Chrysler and a small-block Chevy to support the story, but then the Vrbancic brothers made a valiant effort to come to our rescue. They offered to put our engine on their dyno, and even though our deadline was past, we decided to go for it in hopes that we could somehow get the complete results in print. However, true to form up to this point, a snafu with the dyno mounting plate prevented us from testing on the scheduled day-we came close, but no cigar. Out of the goodness of their hearts, the Vrbancics made time for us the following week, but it was too late for us to squeeze in all the results.
We've wanted to provide that additional information on our Hemi for some time but haven't had the space in the magazine for it. But, because of your letter, and several others, we've decided to include it in this month's "Shop Manual" column.
As you may recall, this engine was a '57 Chrysler 392 bored .030-inch oversize. The block was prepared by John Beck, and virtually all the replaced parts inside came from Hot Heads, including the H-beam rods, Isky B-777 solid lifter cam, Smith Brothers adjustable push rods, timing components, oil pump, and the trick KC Racing pan. We used JE forged pistons, Total Seal rings, and stock-size stainless valves in the mildly ported cast-iron heads. Topping all this off is a two-lobe Weiand blower and a pair of Holley 600 CFM carburetors, while an MSD distributor provides fire in the holes. All things considered, this is a pretty tame engine without a bundle of exotic parts.
While we were happy with our original dyno results, we were giggling to ourselves when we had the opportunity to test the engine again. The engine fired immediately once it was installed on the Vrbancics' dyno, and other than a small fuel line leak that was easily repaired, it performed flawlessly. We were certainly pleased with a peak of 607 hp, but what's even more impressive is the torque curve, which is actually more of a straight line. At 2,500 rpm, it makes more than 500 lb-ft and it pulls like a freight train to 6,000 rpm. Keep in mind this is a street engine with not a lot of boost, a mild cam, and virtually stock heads on 91-octane pump gas.
Now that we've provided the information you were after on the Hemi, let's address the cover shot. We had scheduled a photo shoot of Ken Ferrell's blown highboy coupe in our studio about the same time we laid eyes on Denny Fahlschlemner's blown Olds at Pro Machine. Denny's engine was finished when we discovered it or we would have followed its assembly. Nonetheless, it was so cool-looking that it, our Hemi, and a blown chopped-and-channeled Deuce coupe just seemed like a natural cover shot for an issue with a piece dealing with superchargers; that's all there was to that.
OK, we've provided more information on the Hemi, featured the RetroTek coupe, but you're just going to have to wait and see where the Olds ends up. We will tell you it's a boy-has-hot-rod, boy-loses-hot-rod, boy-finds-hot-rod-again story.