FE Power Forums > The Road to Drag Week 2011
August 14, 2011 - The Road to Drag Week 2011
plovett:
X2 on the cam phasing possibly being off. I tend to think it has to be something drastically wrong to have lost that much power. Incorrect cam phasing could affect the idle, too.
For sure swap pans or just drain some oil to see if something is there. I don't think that would account for such a huge loss, though. If there are multiple things wrong it makes it that much harder to track 'em down.
JMO,
paulie
jayb:
The confusing thing is that the engine ran so well last summer, and the only thing that is different is the oil pan. Joe has a good suggestion, and I will try dropping a quart and running the engine, but right now during the dyno pull you can see the oil level in the pan drop below the bottom of the sight gauge. I wouldn't dare run it any lower than that at the track, and since the oil level is down that far in the pan, using Joe's logic I think that the pan is probably not the problem.
Last night I went back and reviewed the dyno data from last year's runs that netted 960 HP, and strangely enough the air consumption of the engine is about the same as it was last summer. So maybe my power calculation based on cfm is off; I'm not sure at this point. I'm going to give SuperFlow a call this afternoon and ask if they've ever seen a problem like this caused by the dyno's absorber. I would think that if I was down that much power the engine wouldn't be running right, but it sounds just great on the dyno. Go figure.
Also I've tried all the electrical stuff, including replacing the plugs and wires, and making sure they are properly connected at the terminal ends. Also swapped coils around just to check, and tried to change to a different EFI box, although I didn't get far enough along with that. I tried different race gas, checked the timing multiple times, and also timed the cams when I installed them in the engine last week.
I've thought about the rings as a potential problem, but wouldn't I see a fairly drastic leakdown number if the rings were shot? Leakdown on most of the cylinders is less than 10%.
Right now the biggest issue to me anyway is the engine leaking water into the crankcase. I need a solid fix for that if I'm going to take this engine on Drag Week, and I'm not sure that the ceramic seal is going to give it to me. One idea I've been considering is to seal the engine again on the dyno, and then run it up to R&R Performance and have Ron dyno it on his dyno. At least then I would know if the dyno is the issue.
Various Plan Bs are circulating in my head right now. I have my 510" SOHC ready for assembly, and I could throw that together next weekend. But that would take enough extra time that I probably wouldn't want to try to get it in the Shelby clone and still make the event, so I could just stuff it back in the Galaxie and take the Gal to Drag Week again. Kind of hate to do that because I'd be down on power compared to the last time I went with the Gal, and probably wouldn't be fast enough to win, but at least I'd make it. I could also resurrect my Mach 1 for another pass in Street Race power adder, although again it probably wouldn't have the oats to win the class.
Still doing lots of thinking on this... ???
machoneman:
My take is......it's the dyno.
Read the post earlier this a.m. and thought about it for a few hours. Engines that far down on power (-16% or so by my math) must exhibit some pretty distinctive issues that even w/o a dyno one could detect like lazy acceleration (how about acceleration per second now versus last year's data?), fuel consumption, total timing, spark quality, etc. all of which you checked. Oh, and an oil pan that killed 150 hp? I don't think so.
If the engine isn't bucking, backfiring, running lean, burning up coils, et al and the rpms accelerate like a banshee while NOT under the dyno's load (don't know if you can do this on your dyno stand but....) methinks the problem lies in the one part of the absorber you could not get apart. Your idea of quickly whipping the motor, as is, on your local shop's dyno is a capital idea :)
I'll eat my hat (or yours) otherwise!
plovett:
Man, I hope it is the dyno. That seems like it would be the best possible news at this point.
paulie
cammerfe:
I'll tell a really stupid on myself. Had exactly the same sort of results over a winter when Brother Lon and I were running his TP-equipped '67 Mustang. First trip to Milan in the Spring and, although everything ran perfectly, we couldn't get out of the 13s. After several passes, and nightmarish thrashes in between, we found that a linkage arm was bent and we weren't getting WOT. Ten seconds with a pair of pliers and everything went back to normal.
And as a touch of SOHC development history, did you get a set of the very first design heads installed, by accident? The first design had the plug in the technically perfect position. But the rest of the engine didn't like it. When they moved the plug to the present position, with no other changes, they gained over a hundred horsepower! (It's easy to tell the difference, since the first design had the plug wells on the bottom edge of the cam covers, instead of the top.)
KS
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