I just started my 455 and the engine is running way too rich. Two years ago it was dynoed and it was ok. The engine was taken apart because the compression was too low 9 to 1. The heads were milled so that it know has 11 to 1 comp. The heads are stock T/A SE, Cam T/A 210s,Intake Wildcat Dom. port matched to the heads,Carb 1050 Holley #9375 it has 94 jets on all 4 corners. The way the engine is described here it ran fine on the dyno, other than the power being down. It only made 510 HP. The plugs were pulled and they looked great. So I have no idea where to go with this I jetted down the carb to 84 in the primary and change the plugs and still the same thing.When I shut he car off after two min. the plugs were pulled and they were black. While it idles it bellows black smoke out the right side tail pipe. I am so lost with this and so I am here to see if I can get back on the right path. The only difference from the dyno to now is the compression and the dist.
John, I took the carb apart there was not a dirt spot anywhere. I talked to Doug today to see if he could ask Scotty about it but, he was sure that he would be too busy to get on the phone, Doug thinks one of his guys reworked the carb. It makes me mad because I should be able to figure this out but it has me stumped. i have gone over the timing etc.
Larry, It has a Crane Conversion and I set the timing @ 10* BTDC. I did think about the ignition, but it does have good spark. This car just wants to sit,every time I get to the next phase of this car it is a battle. Thanks guys for your input.
Engie: What about your total timing? And the curve? Float setting? (as John suggested). Fuel pressure? What about trying another carb and/or ignition system. What kind of clearances are you running the valves at? Have you done a compression test? (to see if the cylinders have similar cranking pressures). What about a leakdown test? Where did you put the intake centerline at for the cam? Have you checked to see if your balancer is set at a true "0" for TDC? Go after the simple stuff first and eliminate each one and move on to the next. You cut .080" off the heads to get 2 full points? Did you redo the rocker geometry after that? Somethings clearly amiss....but that not news to you. Its just turning over enough rocks to find it.
Have you checked your float levels? Do you know if your power valve is still operational? Also might want to check and see if both your needle and seat assys. are in working order. Just a few so food for thought. John.
The engine has 180 PSI Compression,timing 36* total @ 2500 RPM, Intake CL @ 109*,balancer was checked it was off and adjusted,valve lash is set @ 22 cold the cyl. heads started at 59 cc now they are at 54cc and the block was set at zero deck,fuel pump is a stock S1,I plan on installing an inline pump once I am ready to drive it. I checked the float levels they are fine. Like I said the engine was fine during the dyno session,the engine was brought home taken apart the heads and block were milled the carb was wrapped in plastic and then it was put back together a started. It has been two years since the engine was taken apart but I do not think that would have anything to do with it.
Engie, Try a good CD type ignition. Borrow an MSD box from someone, and use the Crane distibutor to fire it. What plugs are you using? The MSD will keep a plug clean when lesser ignitions will foul the plug. It's worth a shot.
Engie: I'm not sure what plugs you're running, but I'd change plugs first. I'm running S3 al. heads and use a AR3910 plug. There's a thread somewhere about plugs with several mentioned that are working for others with al. heads. I'm going to cross over to NGK racing plugs to see how they work for an alternative choice. Never had a problem with the Autolites though and I have over a year of run time on pump gas with my setup. Next thing I'd check or change is the carb. Can you borrow another 4500 series and bolt it on to eliminate that portion. I agree with you an electric fuel pump is necessary to feed that carb once you get it sorted out. And a good hot ignition to keep the plugs clean and flame going under high rpm pressures.
Dave, I talked to a friend who has a carb that I can use, but I have to wait till Mon. to get it. I think that is where my problem is even though it was fine 2 years ago. I wish I knew the Holley like I know my Q Jet, I just never had any luck repairing them. Maybe I should buy a book and read up on them. The only other thing that is different is that the headers are smaller and it has a full exhaust. The headers on the dyno were 2.5 pri. and 4" collector. I do have the NGK # 7 plugs.
Going to a smaller header and full exhaust will make the car run richer if it was dyno'd with big headers and a short or nonexistent exhaust system. Changes in the exhaust set-up, especially header size, requires that the carb be re-tuned (idle mixture, jets, etc.) in order to compensate for the fact that the engine isn't breathing quite like it did on the dyno
