New best for my vortec headed 350 powered Camaro. I set my total timing up to 36* instead of 34* and changed spark plugs to the appropriate TR55's for vortec heads.

Best pass of the night:

60 foot: 1.95
1/4 ET: 12.45
1/4 MPH: 110.29

I am excited, this is still with stamped steel, stock rocker arms, a 650 cfm carb and shorty headers!

 

Congrats, whats your build man?

 

350HO crate engine, bumped compression to 9.9:1, XE274 cam, 1.5 stamped rockers, 3000 stall, 3.73's, posi, radial T/A tires .

 

Thats awesome, I think I ran too much compression, I used domed 10.7:1 pistons...and I'm pinging like a **** on 93 octane. How much advance are you running? I don't know how much lower I can go. Hows that 274 as far as driveability?

I'm running the XE268H and I'm having really bad idle problems, what kind of spark plugs you running? You running a cold or hot plug?

 

NGK TR55 plugs. Yeah you are running a ****load of compression for such a small cam. The XE274 is great for drivability, still good with power brakes too! I would almost go XE284 with that much compression.

 

55 plug huh...so your running a pretty hot plug?

Well everyone who helped me build the engine told me that if a company advertises a piston to be a 10.7:1 piston with 64cc heads, that in the end you normally lose half a point of compression which would turn out to be around 10.2:1 which isn't unreasonable running 93 octane.

I kept retarding my car until it wouldn't drive anymore and it won't stop pinging. I think new spark plugs (maybe colder ones) might help but it just seems like maybe CR is my problem. The engine is so mechanically sound it has to be either carb or compression. Nobody I know can figure out why my car will just stall after 15 seconds in drive at a dead stop. The only idea is that my plugs are too hot, and are getting heat soaked which is causing the stalling, because it drives PERFECTLY, it's just dangerous because I stall in the middle of intersections waiting at lights like 2-5 times a day.

 

could be vapor lock. got any fuel lines sorta close to the exhaust?
and, is it running really rich at idle? when you go to start it back up after it stalls, does it take awhile to start, or does it fire right back up?
jeremy

 

It fires right back up, I have noticed that if I stall and restart it right away, I only get about 5 seconds of idle time before it starts to stall again. Whereas if I drive for a sec, and the engine gets load around 15-20PMH I will get the full 15sec. The longer I drive, the longer I get at a stop before it stalls. I've driven around the block, then sat in front of my house to diagnose the problem and see what affects the stalling.

My engine had major vacuum issues when we first tried tuning it. Like 7inches of vacuum at 700RPM. We went through 3 points distributors and it would NOT hold idle under 1000RPM. We had a dead spot between 500RPM and 900RPM. Basically, it would idle at 500RPM BEFORE vacuum advance kicked in, but if you tried to get it to idle at like 750 the vacuum advance would kick in and rev it to like 1100. We had a dead spots between 500-700RPM, where either you had no vacuum advance and the idle was too low to go into gear, or the vacuum advance would kick in and it would rev way too high. We thought we had a vacuum leak but it made no sense, we redid the intake manifold, that sucker is not leaking.

The engine was not behaving properly from the start, the only time we could get it to be decent was with the new accel HEI distributor we put in. Now it idles anywhere we want, but everyone whos helped me work on my engine says that something is wrong with it. Mechcanically it's sound, but something is making it not run right. My boss helped me build the engine. he is completely over his head, he told me that my engine should not have such bad vacuum and that it should not be so sensitive. I mean, Comp cam advertises 15inches of vacuum at idle, I could barely pull 10 with the accel unit. And that was with a 750 Idle out of gear. I have since jacked the idle up to around 900 out of gear so i probably have a little better vacuum. When we reved the engine to 2000RPM out of gear while tuning it would pull 17inches of vacuum. We checked for leaks.....and it idles decent, which is what is so weird, because it will idle SOO smooth and then suddenly get rough and stall. Its not like I have a rough idle all the time. My brakes work fine....nothing makes sense.....

 

Grats. Thats an excellent time. My lil bro has a similar setup with the protoplines and forged flat tops (9.8:1) with a 284 cam. Excellent drivability. Taking it to the track Friday, and hopefully click off some good runs b4 the end of this season. This has really got my hopes up!!

Peace,

 

Let us know how he does!

 

Sweet Time! Right now i have a L31 vortec 350 with a zz-4 cam, TPI, i am expecting low 13's or high 12's when i get it tuned and easy high 12's with some new gears and a converter.

My next few projects are wheels, tires, bw9 with 3.45 or 3.23? gears.. upgrade the brakes all around, aluminum DS, Black T/A 4th gen leather, Eibach Prokit springs, LCA lowering brackets, new shocks and struts, STB, panhard bar, then finish the paint and then after all that.. i will be looking to go to a little more aggressive cam.

so far with a stock chip i pulled 13.6@99.4x with street tires hurting my 60ft.. 2.0x and 2.73 gears with stock converter. Once i get it properly tuned i should see a lot more mph.. thinking 104-105mph with a low 13 or high 12.

 

You asked for an update on times, and so here we go:

R/T .537
60' 2.376
330' 6.224
1/8 9.256 @ 82.35
1000 11.839
1/4 14.020 @ 103.69

I'd say I'm overcammed or undergeared one With the 274h and
3.23 gears I ran a 13.7 @ 100mph, now with the new 284h, and
3.42 gears I'm running these times. The tranny is a t-56 6 speed,
launched on bfg drag radials at 15psi from 4200rpm.. bogged Strangely enough,
the car only lost by 1/2 car length from a 10mph roll against a
ls1 with longtubes up to 90-100. This tells me that the car is really
sucking it up downlow.. Those 1/8 times don't look to impressive
either... I'm not timeslip expert.. could somebody please analyze my
timeslip and let me know what you think? All shifts were made at
6200rpm on that pass, and the car felt like it had some more in it..
I have shifted it as high as 6600-6800rpm before and it still felt
like it was pulling.

I'm running the car one more time this season and the following
changes have been made:

More precise carb tuning
Removed advance spring, and set the total timing higher.

The car seems to have really picked up in the 2500-3500 range,
whereas previously it would feel like an on off switch at 3500rpm.
Hopefully this can help me get back some of my ET, until I can
get some 4.10's and dart 200cc's on it

As previously mentioned.. The car has Protopline 170cc vortec
heads, with 2.02 1.60 valves and a mild port job. I'm running a ~9.7
compression ratio. It utilizies stock 1.5 stamp steeled rockers,
and a holley double pumper 750 carb with 1 3/4 SLP midlengths..

-Josh

 

That 60' time isn't too impressive either, I would think with good tuning, traction, and that T56 you should be able to pull 1.9xxx 60's.

 

The 284 is going to want a lot more gear. What kind of distributor are you running? Is it a daily driver? I would consider locking the timing out on your car to pick up some low end torque. I locked the timing out on my car and the difference is huge. Just be sure to run good gas.

 

Running an HEI ignition.. I just rebuilt it a few weeks ago, because I forgot to unplug the battery when I welded the loudmouth up *doh*

Bad 60' is from bog.. I barely got to make any passes to test my launch.. I've never seen a car bog dumping it at 4200rpm.. So it was quite strange. However, it sure did seem to pickup alot on the bottomend of the spectrum locking the timing down.. I think that it won't bog quite so bad now. 4.10's will be here in the near future.. I have a feeling that will make all the difference in the world

As far as my timeslip goes.. Does it look like I'm doing most of my pulling on the topend, or is it fairly evenly distributed? 21mph between the 1/8 and the 1/4.. Is that pretty good topend? I was really impressed with the reaction times on all my slips were all in the .500-.540 range.. The times I was not impressed with.. I would have figured 13.0 at least. All my friends think carb'd cars suck, and I can't prove them wrong due to the crappiness of my cars setup Their time is soon...