guinness77
05-04-2006, 12:18 AM
Well the 400ex is broken-in now. That was a long 5 hrs. Anyway, a few folks wanted feedback on this key. Well, I think the manufacturer is right. This this is not for anything bigger than a 406. They really shaved off quite a bit of metal from that key. But for a stock bore, it's ok. I noticed there was a little improvement in the mid range. No change to low range. There was no change in the high end either, but it's VERY VERY likely that my valves need to be adjusted. This is quite common after a break-in that's come after a top-end rebuild. You can definitely tell the plug is firing earlier than stock... the sound is really cool. The earlier spark means you need a gas that burns slower. That means higher octane. I broke-in the motor with 100 and ran it dry. After that I put in 1 cup of 92. Yeah... you can run 92. You will feel just a little bit of knocking and pinging in mid range hard accleration. Otherwise it's fine. Then I ran 111 octane. The pinging was non-existant and there was a little improvement in performance. The air scoops helped the cooling. With this timing key you defnintely want to avoid gas that is less than 92. The key costs about 19.00 and you get a free flywheel puller from Curtis Sparks with it. For a final cost of $26.00 (shipping and handling was a bit), the mod does make a small improvement. But I have to wonder if the price of 6.50 per gallon for race fuel is worth the very minor increase in performance.