cannot get top end

TALL · Post by **TALL** » Tue Sep 07, 2004 4:44 pm

Ok so I finally got my jetting to a point I feel is correct. 135main 50 idle and 200air on a 1955cc with 120 cam and 8.4comp. But I still cannot get the car to stop bogging out when punch it and hold the throttle. It is not out of sync because it is fine on the bottom end. The odd things is when I go through the gears it typically does not happen until third gear from any where between 4000rpm and above. I am inclined to think it is a fuel delivery issue. I use a stock pump and know others with similar motors who use a stock pump. My float levels are at 10 and 32.
I want my constant throttle. What are your ideas?
To see the past jetting issues search past post subject for "jetting"
Thanks

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Tue Sep 07, 2004 4:48 pm

What is your timing set at?

CHAZAVW · Post by **CHAZAVW** » Tue Sep 07, 2004 5:24 pm

what are you running?

kads
dells
weberbs

single or dual?

i have dual 44 idfs with 145 mains with 50 idle 50 acc. pump f11 e-tubes and 200 air correction on my 1914.... 044 heads and engle 110 with 8.72 to 1 c/r

TALL · Post by **TALL** » Tue Sep 07, 2004 8:04 pm

running dual weber 44s with around 32degrees full advance.

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Tue Sep 07, 2004 8:05 pm

trim the full timing down to 28. Above 5000 RPM you are overadvanced- guaranteed.

TALL · Post by **TALL** » Tue Sep 07, 2004 8:10 pm

overadvanced, never heard of such a thing, I will give it a try in the morning. What are you thoughts on the time when its below 5000rpm. I have it happen at 4000rpms as well and notice if back of the gas for a split second it will pick when stomp on it again. It like I flutter the throttle a bit, but only at high rpm.

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Tue Sep 07, 2004 8:43 pm

As piston speed increases the extra timing burns the fuel too fast and kills power. On the dyno the changes i see are drastic.

People set timing at 32 and THINK they are making more power when using the seat of pants type of tuning.. The reason the car feels faster is that you are increasing initial timing as well as full timing by 4 or so degrees. At the upper RPMs you can't feel the differences as much.

TALL · Post by **TALL** » Tue Sep 07, 2004 9:14 pm

interesting, thank you for the break down. I will post the results in the am on wednesday. Thanks for the help, again.

CHAZAVW · Post by **CHAZAVW** » Wed Sep 08, 2004 6:19 am

TALL wrote:running dual weber 44s with around 32degrees full advance.

i would then change the 135 mains to 145's or 150's.......

i have an oxygen sensor that i had hooked in the exhaust when i put in my carb jets.... like i said before i run 145s in my 1914...... so 145s or maybe 150s would do you good.....

but jake is right about the timing i run at about 28 total advance too....

TALL · Post by **TALL** » Wed Sep 08, 2004 3:55 pm

well is tweeked the timing from 10degrees static to 8 degrees and am waiting to borrow a timing light to see what that is at full advance. I think it will be close so I drove it and it did not seem to help that much. Could still not be at 28 degrees full advance.
What confuses me is when hammer down on it and hold it in second gear the car runs fines all the way through the rpm range. When I shift ( still hard on the gas) and try to take thrid or fourth gear into the 4000rpms it totally changes sound from the nice whine a motor should have to a low more lumpy sound. Sometime if I hold the pedal it will start to sound fine and then go back to sounding like crap.

Post by **sparkmaster1** » Wed Sep 08, 2004 4:07 pm

Check your fuel pump pressure. Also I'd change the screen in the bottom of your tank and make sure the breather's off the tank are working properly. Tim

gerico · Post by **gerico** » Wed Sep 08, 2004 4:22 pm

Do you have a stock coil??? If so you might try a hotter coil...could be ignition.

TKisner · Post by **TKisner** » Wed Sep 08, 2004 4:28 pm

Jake, would a mallory distributor allow you to run more initial timing while running less in the higher RPM's. Giving you the best of both worlds?

Super_PSU · Post by **Super_PSU** » Wed Sep 08, 2004 7:46 pm

i don't believe you specified which dizzy you're running..

either way, the advance mechanism should be adjustable.. i'm not sure how the vacuum diaphragm would work, but a mechanical dizzy requires only a tighter spring, leaving you with less advance.

i'm by no means an expert, but we played around with this on my old 009, so i know firsthand that you can customize both the advance curve, and the overall advance..

so it CAN be done....

TALL · Post by **TALL** » Wed Sep 08, 2004 9:08 pm

I am using a 009 and blue coil. I converted to a pertronix pointless setup a year ago. Was not able to get the timing light today but will have it on thursday.
Nothing left to do but get mad and beat the crap out somtething.

Sparkmaster, you may see me on your door step this weekend if this keeps up.haha