View Full Version : need help 496 bbc!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
ok guys i've been reading up on all your posts and i know ya'll can help!
sat was our first truck pull,track sucked very bad! but anyway to my problem over off season put different intake and rebulit carb i get to the line hook to sled hold at 3000 and ease out of clutch once it starts to grab falls on its face ! no sputter just flat on its face timed in at 36 but one ques should dist be locked? i personally though it was loading up? would love all opinions next pull july 4th thanks guys i love this site!!!!!!!!!!!!!!
P.S. after getting embarassed i did as my quote says!!!!!!!!!!!!
sds10racer
05-31-2009, 05:07 PM
sounds like a fuel supply or pressure maybe.
tcarda
05-31-2009, 07:02 PM
How big is the camshaft? If your running a pretty good size cam, you need to come out around 5000 - 5500 rpm depending on where your cam makes the most power. If you trying to get a 30,000 lb sled moving, you need to be at or close to peak power. Are you running a twin disc clutch so you can come out at a higher RPM?
cam is a doug hubert solid roller 714/714 so prob to big to only come out at 3000 but it pulled away last year not the best but it got off the line
i have a centerforce dual friction clutch can i take off that high with it?
TS1955
06-01-2009, 04:09 AM
ejm, You said over the off season you changed intake & rebuilt carb. Did you run this engine before? Did it run OK then? Did you go from a dual plane intake to an open plenum?
TS1955
dparker
06-01-2009, 06:17 AM
ok guys i've been reading up on all your posts and i know ya'll can help!
sat was our first truck pull,track sucked very bad! but anyway to my problem over off season put different intake and rebulit carb i get to the line hook to sled hold at 3000 and ease out of clutch once it starts to grab falls on its face ! no sputter just flat on its face timed in at 36 but one ques should dist be locked? i personally though it was loading up? would love all opinions next pull july 4th thanks guys i love this site!!!!!!!!!!!!!!
P.S. after getting embarassed i did as my quote says!!!!!!!!!!!!
Lock the distributer, set your timing at 40 degrees. Advancing your timing a bit will help it starting the pull. If it was loading up could be running over your needle seats. Make sure your fuel pressure is under 7 1/2. If it fell on its face when you hit the gas, go up on your shooter size. If your running a dominator carb, shooter should be 40 to 45 on racing gas. See if any of these will help.
One other thing for what your doing that cam should be advanced 2 degrees to a 108 centerline. Just wanted to add that. If you didn't degree your cam could be some of the problem.
tcarda
06-01-2009, 09:42 AM
cam is a doug hubert solid roller 714/714 so prob to big to only come out at 3000 but it pulled away last year not the best but it got off the line
i have a centerforce dual friction clutch can i take off that high with it?
What is the durations @ 0.050? At 3000 rpm you are not making any power and need to come out higher. My 469 had a 706/706 lift cam, but I can’t remember the durations off hand and I had to bring mine out at 5200 –5500 rpm depending on the track and sled I was pulling on. The problem with that is that your single disc Centerforce clutch will not last long. Do you have a Lakewood housing or steel flywheel in it to protect your feet incase the single disc comes apart? I have seen one cast iron flywheel come apart and two clutch units grenade and went up and out through the cab. Once clutch went through the glass of the truck and nobody knows where it went.
i did run this motor last year but i went from dual plane to singlei will do some checking on my carb and lock the dist in thanks for help ill let ya'll know when i get time to mess with it
well i finnaly got time to work on it since our next pull is on sat. come to find out 1 plug wire was burnt and grounding on header and i must have used a bad timing light cause it was advanced about 5 deg to much did that and hooked up to a tractor and it was the best it has ever ran!!!!!!!! i'm pumped up to let it loose i'll let u guys know on sun or mon how i did at the pull on sat. thanks to all help!!!!!!!
well got rained out but let ya know next sat
i told ya'll i'd get back!!!!!!!!!! hey it ran like a mutha but broke dive sheft so i got it fixed and will give results fri night or sat
nice bitten track!!! but all and all hey i got first ran good and hooked like nothing i've eever seen thanks for all help, eric