Look at my sig and that will have all my info. Trying to find out how clode should I be near the 11sec mark. I and only getting 13.0 in the quarter and something is hold me back.

 

Looks very, very close to what I had many years ago and I dipped into the high 11's with a 383, 3.27 gears and 1-5/8" headers.

The 3500 pounds isn't helping. It could be any number of things. Having the timing off a few degrees or an incorrect curve could easily lose 50 HP. Jetting running too lean or rich. Traction problems from any number of things can lose time.

What's all the timeslip info?

 

I did a best of an 11.44 with my motor 2 years ago. The biggest difference is 10:1 compression, a hydraulic roller 246/254 .558/.558, and 1 5/8" shorty headers. It looks like you're probably overcarbed, but that shouldn't be hurting you all that much if at all. Seems like there's definitely something not working together there. I'd really like to see a timeslip from it.

 

Timing is set at 38 degrees total advance and I did degree the new custom isky cam I put in and set the valve lash according to the cam card. Squirters were change from the factory stock front 35 - rear 28 to front 42 - rear 45 at the dyno shop last year they said to get rid of a bog. I believed they also messed around with the idle mixture screws and I wish I actually knew what the air/fuel mixture screws were set from the factory so I can put it back to factory.

 

You've got a Holley 830 and it "was" jetted 35/28 and it's "now" 42/45? That sounds like the squirters, not the jets. What's the list number of the carb? I doubt the 830 would have anything less than a #80 jet.

The idle mixture screws are not air fuel mixture screws. You only need to adjust them so that the engine idles without running lean or too fat. Idle mixture screws are roughly 1-1/2 turns out for a base line adjustment.

I'd also recheck the timing marks. Use a degree wheel and piston stop to confirm the pointer is pointing to the TDC mark on the balancer when the piston is at exactly TDC. I put one engine together that had a pointer out. I was bumping the timing to 45* and kept going faster. After rechecking the marks, I found the pointer was out 8*. The 45* was actually 37*. If you don't have a degree wheel and piston stop, try bumping the timing up 2* at a time and see if the ET improves. 38* full advance. At what RPM is it at full advance?

You had the engine on a dyno? What did it dyno at?

How did you set the valve lash?

 

sorry, I did mean the squirters. The carb # is 0-9381. The idle mixture screws are to be set at 1 1/2 turns all the way around? I also found out that this carb is 4 corner idle and holley says to start at 3/4 turn out for each screw. I did use the degree wheel with piston stop to set the mark on the balancer when I changed the cam and it was 3* off that the timing tab was marked as. Full advance is at 3000 rpm.Engine was on a dyno last year, but I changed the cam, converter, fuel pump. Dyno numbers were 302.7 rwhp and 318.5 rwtq. Valve lash was set at the rockers with a valve lash feeler gauge.

 

Maybe I should change the squirters back to original.

 

My mistake, Full advance is at 4000 rpm.

 

Ok, So I've changed my squirters back to the factory 28 and changed power valves to 2.5 since I am only getting 5-7 psi vacuum. Should I change my full advance in the distributor to 3000 rpm?

Also, my 1/4 speed was only at 103-105 mph before the changes listed above.

 

Need some help/ideas.

 

Anyone?

 

valve lash a little too tight?

 

Something isn't right... I'm running quicker than you with smaller everything really. 355 cubes, 750 carb, AFR 195 heads, .525/.525 lift with 248 @ .050 solid lifter cam, 10.5:1 compression, Victor Jr. I do have a looser converter, 4,000 stall and 4.56 gears, TH400 and dual 3 inch exhaust. Even with my old 3500 stall, I was mid-low 12's. Only suspension changes have been the spohn torque arm and relocation brackets. Everything else is stock, no front sway bar but I do run the stock rear sway bar.

Post the info from your time slip if you can. Also, I noticed a big difference when the single 3" went bye bye.

 

So it actually might be the timing? I already replaced the mechanical fuel pump with a electirc race fuel pump and reg.. I also removed the front sway bar and even added 90/10 front struts. I just also changed back to 42 front and 45 rear squirters. When I changed back to original 28s all around, it was bogging or hesitating off the line.

 

What is your 60ft times? 13.0 at what MPH? I'd start by putting the total timing around 34* and putting your carb back to out-of-the-box settings. Work your way upward and not backward... Your motor on it's worst day should be running 11.90's.

 

My 60 ft time is 2.0 and 105 mph. I don't know what the out of the box settings were, but when I tried to use the out of the box 28 squirters the car was hesitating on hard launches. I also use an exhaust cutout when running at the drag strip.

 

Are you experiencing any traction problems? You should be 60ft'ing in the 1.6X's or at worst 1.70's. Get the model number of your carb and post it here, I'll get you all the specs for it. You need to put everything back to stock and start tuning in this order: timing, carb jetting, then lastly squirter / accel pump.

One last thing... How sure are you that your ignition is working properly? You're lacking so much performance I'd say there could be a very good chance you're only running on 7 cylinders.

 

I am definitely having traction problems and even went to a taller tire M/T ET streets 27x10.5x16. The Model number of carb is 0-9381 830 cfm Holley race carb w/o vacuum connecters. Changed dizzy to a pertronix race dizzy w/ mechanical advance. Had the heads off recently for a valve job and had them pressure check for any cracks and also changed plugs and wires. I also remembered that the thing takes off like a bat out of hell out of the hole, but horsepower starts falling off around 4300 rpms like I have no top-end power. Not missing or backfiring. Could it be the timing is too far advanced? After retarding my timing back 3*, my vacuum is now at 9psi.

 

88IROC350TPI, did you get any info on the carb yet?

 

ttt

 

Might sound dumb, but I haven't seen anyone suggest checking for if the linkage actually goes WOT.

Peak timing should be 36-38 degrees, and this may not happen until 4000rpm. That sounds like the same carb. I was running and it came with 78 size jets. The squirters you're talking about have nothing to do with how the motor runs other than the start when you move the throttle quick to WOT. What you want to change is the jets inside the fuel bowls. I was always blow-through with my carb, but I believe my front jets were something like 67. If your car drives around good, then you shouldn't need to mess with these. The rear jets are basically only used with WOT, so changing these will not change how the car drives other than basically WOT. Your times line up with the power you made on the dyno, but that doesn't match up with your mods. It has to be something simple 1. Fuel either too little or far too much 2. Timing either too much or too little or 3. Ignition isn't good enough to fire the charge.

 

definately should be a faster car. when it was on the dyno what was the air fuel ratios? i'd test for that and try to get the fuel mixture in line and then play with timing. it will want anywhere from 34-38 degrees so try the lowest and work up.

 

i think you have tooo much carb and intake.. a super victor and 830 should go on a wild 383 not a mild one.. a 750 and vic. jr. would be better suited.. but that wouldnt kill you that hard.. what do you shift at??


check your valves.. make sure ALL of them lift the same amount.. i had a cam go flat and it had great power to about 4000, then it struggled really bad..

 

Checked my cam lifts at all lifters and all are as specified by the cam card. Shifting around 6100 rpms.

 

i'm not a flat tappet guy but that duration seems to me that it will want you to shift more like 6500 atleast. Seems like a decent sized cam to me

Those heads tho i'm not too familar with flow on those. Any work done to them? More flow you can get the better with that cam/intake setup

 

i agree with Orr.. with that top end your motor should want to spin up to at least 6500.. i shift at 6700 with similar heads, less induction and a slightly larger flat tappet cam.. 260/260 @ .050, .592/.555 lift, 110 LSA..

is there a PV on the secondaries?? also could you get the jet numbers??

 

The jet sizes are 78 front and rear and the pv front and rear are 2.5s as my vacuum was only around 7-9 psi and holley informed me to get 2.5 pv for the front and rear. As far as flow number are:

.500
234-148

.600
243-163

 

I am scheduling some time here with the local speed shop to do a couple of dyno pulls and air/fuel test and see what they can tell me what I should try or due next. Maybe we can find out what is holding this beast back.

 

air fuel will give you an idea tahts for sure

 

how bigga converter ya got there?? check yer cyclinder cranking pressure, thats a healthy cam for 10.1... sounds bout like my big block, dog out the hole... i would say u need a good 3500+ stall...

 

Stall is 3500-3800.

 

I double checked and total advance is at 3000 rpm's. And changed my front jets to 74 from 78. Question though, since this carb is 4 corner idle don't I need to change the rear jets to 74 also? The jets in the rear are also 78 which was the front jet size also before I changed the front.

 

OK, made a few runs last night and after adjusting the carb and timing, I have the following:

1st Run before adjustments to carb and timing

R/T=.639
60'=1.928
330=5.630
1/8=8.641
MPH=81.92
1000=11.236
1/4=13.452
MPH=102.19

2nd run after carb and timing (best time)

R/T=.183
60'=1.827
330=5.408
1/8=8.342
MPH=83.79
1000=10.891
1/4=13.040
MPH=106.76

3rd run with carb adjustment

R/T-.064
60'=1.879
330=5.480
1/8=8.440
MPH=83.11
1000=10.994
1/4=13.161
MPH=106.44

I will be checking my spark tonight to see if I am getting a good spark at the plugs. I think the spark is supposed to be a solid blue spark?

Could the power wire to the HEI coil be low and would that kill my power?

I was thinking that either pwer gets to the cil in the cap or not, never thought of the power being low to cause anything like this lack of power. Is this true?

 

88IROC350TPI, I put my times up now. Does that help? It does seem like I have a rev limiter installed but I do not.

 

Well I've run a wire directly from the battery with a toggle switch to the BAT side of the dizzy and that still did not halp. It still seems like i am not getting the full spark from that dizzy to the plugs. Could a going bad ign. coil, ign. module or alternator cause these issues?

 

I ran 36* of timing in my 87IROC-Z 350 TPI, on
www.cardomain.com/ride/471099/8

As for your spark timing issue, remember the spark is usually about a second and a half millaseconds for the ignition, but it takes about 3 millaseconds to complete the burn. But you have to remember, the more rpm you run, the more advance the timing has to be, because theres less time to complete the
entire burn. You should be around 32-36* of timing for a N/A motor, with boost or nitrous, you need to take out a little timing, and even run cooler heat ranges of plugs depending on how much power adder you may be using.

I would suggest, check all your plug wires, check there ohm readings and the coils primary and secondary sides. Theres a whole bunch more of ignition stuff involved, but start there.

In my school books, for my classes where I'm getting my automotive technician certification, the books said, it may take up to 10,000 volts to jump the gap from the rotor to the post for the wire on the cap, for different cylinders.

It sounds like it may be your coil, could be faulty, there's usually anywhere from 1-200 turns in the primary side of the coil, and 15-25,000 of wire on the secondary side of the coil. Its when the power is removed from the primary side, that the spark is sent out of the coil. It's the power sent to the primary that makes the 400 volts, which is sent to the secondary, and when the power is released, the secondary, produces the 40-60,000 volts.

So maybe check out your coil.