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by **Sirshredalot** » Mon Aug 06, 2007 1:08 am

Usually,unless youre VERY lean youll get a surging at high rpm....like slowly opening and letting off the throttle in 100 rpm incriments.

I suppose it could be lean popping....but valve float does sound feasible.
If youve got a nasty lunati cam in there with thosefactory iron heads...thats my guess....valve float.

God bless
-Shred

by **katostud** » Mon Aug 06, 2007 1:22 am

before the tuning and bigger fuel pump it surged and didnt seem to wanna rev like it was running out of gas. now it revs and wants to keep reving and will keep reving but right at about 6000 rpms i get a few pops and bangs but it will keep reving

by **Caveman** » Mon Aug 06, 2007 1:25 am

I think you should look at your tune. Is the Distributor up to it and plugs wires you could have a misfire. The valves???

by **katostud** » Mon Aug 06, 2007 1:54 am

i have a good hei new plugs gapped right and 8mm taylor wires. and i have the good z28 valve springs

by **Sirshredalot** » Mon Aug 06, 2007 11:50 am

The "z28" valvesprings are only rated for .525" lift.

Check your cam specs....might be valve float.
Also...I have never spun an HEI unit past 5500, but i hear they arent great for high RPM use.

God bless
-Shred

by **katostud** » Sat Aug 11, 2007 2:47 am

i got it tuned pretty good now. im at 74 jets in the primarys and 84 in the secondarys and she rips. were going to the track next week with some jets and see what we can get out of her. its running really good now

by **Caveman** » Sun Aug 12, 2007 12:41 am

What was the final fix?

by **katostud** » Sun Aug 12, 2007 1:17 am

i bought a proform main body and one of the primarys and one of the secondary squirters werent drilled out all the way. then we drilled out the squiters a few thousands and switched jets in the primarys and no more bogs or flat spots

by **katostud** » Tue Aug 14, 2007 11:00 pm

put in roller rockers the other day and just finished tuning a bit more today shes running like a top. ended up with 74 jets in primarys and 86 in secondarys seems thats what she likes. now im ready for the drag strip on friday

by **2lucke4u** » Wed Aug 15, 2007 12:56 am

Kato
Those 86 in the seconds will kill your hp on the top end,I was running 84's and after dyno tuning ended up with 78's,we picked up 20hp and the tail pipes cleaned up to a 12.50 f/a ratio,,when you get to the track try them out and then go down 4 sizes and see the diff,,you may like it better,,who knows,,your cam may be bigger than a .550 lift and need the bigger jets,,
Charles

by **katostud** » Wed Aug 15, 2007 1:12 am

i been waiting 4 u to chime in 2lucke. im going to be bringing jets with to the track but from the playing we been doing these seem to be working the best. it was poping a bit on the top end so we put in the 86 jets. i have a k&n volicity stack,k&n 4 inch filter,k&n filter top and 1 inch carb spacer. it says with the volicity stack it leans it out so to richen it up.

by **2lucke4u** » Wed Aug 15, 2007 2:05 am

Kato
make sure to pull a plug from each side after each run or jet change,,the plugs will tell you a lot,,mine after the first dyno run were black with carbon and unburnt gas,the best way is to just keep track of your runs and make notes on the time slips,thats what we do and it helps,,we also put the outside temp and air pressure in the slicks,engine temp,,anything that could make a diff,,notes will help,,
Charles

by **katostud** » Wed Aug 15, 2007 2:32 am

thanks. we been righting down everything we been changing. my dads an old school car guy and had a speed shop for 23 years. when we get to the track were gonna shut it down right at the end of the pass and check plugs. so far they seem nice golden brown. im finally brining him back to his good old days sence we been working on the vega. im a young buck but know a little bout a little. i buy it and he makes it work. hes a chevelle guy and has a 67 that he will be doing up here soon. i told him to bring it. haha thanks to u guys i got a hell of a headstart

by **2lucke4u** » Wed Aug 15, 2007 3:34 am

Kato
We will be waiting for the numbers on that puppy,,you will find a short list of things to do/change after your first trip to the track,,don't forget your buddies on the site, we want to be a part of the process,we are always good for a extra tenth or two,,lol

Charles

by **katostud** » Wed Aug 15, 2007 3:57 am

thanks buddy. im going tomorrow to get whatever jets paps doesnt have. if we get enough runs in ill try them all. you guys are what made me decide to keep my vega and get back into it. im disabled from a bad car wrec few years ago and was gonna sell it tell i found this site. u guys rock. im young and broken but i cant shake the fast car thing. i learned not to ride with idiots but with me driving and a few certin others im getting over my fear of fast cars

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