fuel issue solved!:grin: went to t&t last night and had no fuel problems, 5500 in 1st, going thru the lights in 2nd at 5200rpm. best time was 15.6 at 90mph, 60ft was 2.3737 my reaction times were poor .2-.4 will post time slips tomorrow there was 2, 87 grand nationals there last night, 1 turning mid 12's the other mid 13's, the mid 12's on street tires, 13's on drag radials. big car swap meet in 2wks, be looking for some drag radials right now i'm running 275-60-15's street tires with 30lbs air and getting wheel spin off the line:
time slips not coming out dark enough to attach 1st run-footbrake 1000rpm, rt .2406, 60ft 2.41, 1/8th et 10.28, mph70.90, 1/4 et 15.78, mph89.77 2nd off idle, rt .4822, 60ft 2.46, 1/8 et 10.33, mph 70.72, 1/4 et 15.84, mph 89.39 3rd footbrake 2000rpm, rt .2071, 60ft 2.37, 1/8 et 10.16, mph 71.41, 1/4 et 15.62, mph 90.13 4th footbrake 2000rpm, rt .4330, 60ft 2.37, 1/8 et 10.17, mph 71.21, 1/4 et 15.65, mph 89.61 shifting into 2nd at 5500rpm, going thru lights in 2nd at 5200rpm
the by pass around the elec. fuel pump with check valve installed cured the fuel starvation problem with the mech. pump having to pull through the elec. pump.
ok, got the holley 750dp on and jetted as close as i can get with back road testing.( not alot of straight roads around here) holley is a lot more responsive than the Q-jet, worked on getting the primaries dialed in, got them real close to perfect and the secondaries still need some adjusting. have a t&t this weekend and will use 1/4mi. speed to dial in secondary jetting and then hopefully have the time to start fine tuning the squirters and cams
Bruno and I have had discussions about this. I like to err on the side of caution when it comes to fuel supply. The Stage 1 fuel pump is probably fine up to about 450 HP or so, but above that, you are reaching the limitations of the stock Stage 1 fuel pump, and the very worst thing for an engine is lean out induced detonation at wide open throttle. Just ask Phil Sedlon (70 gsconvt) about that one, http://www.v8buick.com/showthread.p...gasket-is-the-least-of-my-problems&highlight= Seeing how far the Stage 1 fuel pump will get you can be expensive in other ways.
finally made it back to the track yesterday, strange happenings, 1st run 3/10 slower time and 3mph slower than best run with q-jet, (jetting i'm sure). 2nd run 6/10 faster time but 10.2 mph slower, went from best of 19mph gain from 1/8 to 1/4 in last outing to 7mph gain this last run. went up for 3rd pass and the faint roughness/vibration that has always been there turned into very large roughness/vibration, shut it down and became a spectator the rest of the day. slight roughness has always been there under HARD acceleration but never in some what normal driving conditions, back and forth to town and test runs under 2500-2800 to dial in primary jetting on 750dp, throttle was very snappy off idle with primary set up but 60' times yesterday were about the same as before. torque converter?
Whatever it is, it's something big. Those are big differences. I would think that you could tell whether it was slipping or not? Have you been comparing your RPM through the traps to your speed? Any engine noise? Oil pressure? Have you looked at your transmission fluid?
car acted the way it always has,(6 passes since i fixed the fuel problem), but to loose 10mph when gaining 6/10's in et.? i'm shifting into 3rd at 5300rpm just before the traps on all 6 passes but the vibration suddenly going to almost violent from one pass to the next is what really has me worried, engine sounds good, oil pressure good, trans fluid not burnt, did not look to see at what rpm the vibration starts but it does it in 1st and 2nd. a slipping t/c feels just like a slipping clutch correct? it ran and sounded just like it always does coming down the return road it was my plan anyway this winter to pull the motor and find what my true comp. ratio is and then match the cam to that and then the t/c to the cam? motor only has less than 5000mi on it, hope to be able to leave the bottom end alone and a little clean up on the heads. i think the slow down is caused by whatever the vibration is the only changes from the first 4 passes and the last 2 was carb, comparing times and mph between all passes were all about the same except last pass loosing 10mph and gaining 6/10 et, and then the vibration! keith
Yes, like a slipping clutch. That would be evidenced by more RPM through out the run. That might explain the ET improvement and also the MPH decrease. I would think a converter going south would be really obvious to you. Not sure what to think. Vibration can also be caused by a bad tire/wheel, or badly imbalanced drive shaft.
vibration might be the balancer rubber has come out and the ring has turned. look at the timing mark with timing light. also look for rubber stiking out. Dan
eye balled balancer the other day running to see if it was wobbling and also not running and looked good, just a very small piece of rubber sticking out. never re-checked timing. and now that you mentioned it after the 1st pass i had to bump the idle setting up because it no longer wanted to idle, and the idle setting has remained the same for a few days pryor to that. i will go check it again and also check timing. took it for a ride this morning before airing rear tires back up and took it up to 5300 in 1st and felt like it always has but i will definitely check the balancer and timing out. the balancer has been on my list for replacement when i redo the motor this winter seeing how it is 48yrs old! one more thing, my mistake, i only gained 6/100's of a sec. and lost 10mph instead of 6/10's
realized after i said it that slipped balancer will change timing mark not timing. haven't checked yet, threw my back out so everything at a stand still for a few days
put a timing light on it and it now reads 45 deg. adv. from the 35deg i set it at in march(total timing) so yes it seems the balancer has slipped
