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Discussion Starter #1
Hey guys, I took the nova to the track yesterday and I have to say that I had NO idea how hard the car would launch off a T/Brake. It about snapped my neck out of whack. Is there something to use on your neck to keep your head from snapping back like that? No matter how hard I tried I couldn't keep my head from whipping back like that.

My second question is, I was having a detonation issue and I had the timing set at 35* locked out dist. Well I only had 1 more time trial left so I just backed the timing to 30* it still did it only worse. After that I decided to call it a day. I thought backing the timing off would cure this problem especially
5*. I'm running a 750 Vac/Sec with factory jetting, rear jet extensions, and a 3.5 power valve, on a single quad t-ram, and I'm running 110 race gas. I didn't check any other spark plugs but the #1 cyl. plug had black specs all over the porcelain. What is causing the detonation? Is it because of only 1 carb on a t-ram?

I'm thinking now that the timing issue is fixed and I can finally tune the carb in, that I might stick the 2 carb top back on????What do you guys think? Suggestions and or thoughts are appreciated.
 

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they make neck collars but i dont know how well the stop your neck from snapping back maybe a head rest or something on your roll bar or a seat with a built in head rest

as for the detonation issue i dont think your having a timing issue i think it maybe a fuel issue running 110 race gas shouldnt detonate unless your running a high compression motor was it detonating at the top end or as soon as you stood on it. you may need to jet the carb up and put a quicker spring in the vac sec side if it was me i would ditch the vac secondary carb in favor of a mechanical secondairy carb jmo though exspecially if you decide to change the top and go with 2 carbs on top :yes:
 

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I can't imagine a 11.68 best car footbrake launching that hard to be hurting your neck...what were your 60' times? Slicks?

Are these aluminum heads? Compression? Small block or big block? Depending upon the engine combination, running high octane race gas actually decreases performance
 

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Is there something to use on your neck to keep your head from snapping back like that?
They are commonly referred to as MUSCLES--if you can't hold your head up on an 11 sec. pass, you'll be in trouble if you ever start going fast.
 

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well,,

cut him some slack ,, first transbrake experience and all ,, :eek:,,

don't know much about your carb ,, but i've never heard anything at all good about a single 4 tunnel ram , unless its a sheetmetal deal ,, i think i'd switch to the 2x4 top or go to a victor jr/team g /strip dominator style intake.

What converter , headers , cooling system - electric drive or ?? , what water temp are you seeing ?? , was the engine decked to 0 ??, what head gasket thickness , what size chamber in the head , what size dome on the piston , cyl head material ?? where did you get the gas AND HOW OLD IS IT ??

You mention rear jet extensions and stock jetting , share what sizes they are and i'm guessing you added a metering block or did this carb come factory with a secondary metering block ?? Have you checked the power valve to see if it is stuck ?? What spring is in the secondarys ??

be nice to see if you can post some pics of the engine ,, need input
 

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Discussion Starter #9
I can't imagine a 11.68 best car footbrake launching that hard to be hurting your neck...what were your 60' times? Slicks?

Are these aluminum heads? Compression? Small block or big block? Depending upon the engine combination, running high octane race gas actually decreases performance
Yes...My thoughts exactly:D
They are commonly referred to as MUSCLES--if you can't hold your head up on an 11 sec. pass, you'll be in trouble if you ever start going fast.
Well, forget about the neck question, it obviously was a stupid question. If some of you guys can't imagin this happening in a mid 11 sec car, then it must not be so! Besides that, it's not the whole pass, it's just the launch. I have a new full race th350 and a 5000 stall with a t-brake as uppossed to the soft th350 and 2000 stall footbraking. The car leaves alot harder than it used to.

Actually, I don't know what the car runs yet. I have been shifting with a forward shift pattern for years, and now, with the reverse shift pattern, I kept shifting into neutral. I just couldn't get my brain around the new shift pattern. Oh well it will come. Out of three time trials, one was a full pass, but it was detonating so bad I couldn't keep my foot in it all the way down however I kept pushing the throttle down on all three runs, and all three gears, it just didn't want to go. The detonation would sart at about 4-5 thousand rpm's

Now for the motor. It's a 355 with trickflow aluminum heads, the compression is 11.47:1.

Is it possible that the carb is just not the right one and it doesn't matter where I put the timing, it's going to detonate? Or, a combination of that and the single top t-ram?

Thanks to all that gave consructive help.
 

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Discussion Starter #10
cut him some slack ,, first transbrake experience and all ,, :eek:,,

don't know much about your carb ,, but i've never heard anything at all good about a single 4 tunnel ram , unless its a sheetmetal deal ,, i think i'd switch to the 2x4 top or go to a victor jr/team g /strip dominator style intake.

What converter , headers , cooling system - electric drive or ?? , what water temp are you seeing ?? , was the engine decked to 0 ??, what head gasket thickness , what size chamber in the head , what size dome on the piston , cyl head material ?? where did you get the gas AND HOW OLD IS IT ??

You mention rear jet extensions and stock jetting , share what sizes they are and i'm guessing you added a metering block or did this carb come factory with a secondary metering block ?? Have you checked the power valve to see if it is stuck ?? What spring is in the secondarys ??

be nice to see if you can post some pics of the engine ,, need input
The engine was not decked, but with taking all the measurments it comes out to 11.47:1. You can see some of the other specs of the motor in my last post. The jets are 72front 78back. The gas was a brand new container, now that doesn't mean it's not old, but they do keep their containers sealed off from the environment.
Here is a pic of the motor, it's with the 2X4 top on though.
[/IMG]
 

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from the pics

#1 spark plug wire looks like its begging to burn to the header and short out , i think i would run the plug wires from behind the valve cover and under the headers with 90 degree boots on the plugs

describe your fuel system ,,, maybe there isn't enough fuel delivery , 110 fuel should be more than enough until you go over 13-1 or so ,,

you could turn your shifter around if that would help with the shift problem

I've always heard a single 4 tunnel ram has lousy fuel distribution,,, maybe some cyl's are leaning out and detonating,,, maybe 3-5 4-6 are ok , and 1-7 2-8 are going lean ,,
 

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Discussion Starter #12
#1 spark plug wire looks like its begging to burn to the header and short out , i think i would run the plug wires from behind the valve cover and under the headers with 90 degree boots on the plugs

describe your fuel system ,,, maybe there isn't enough fuel delivery , 110 fuel should be more than enough until you go over 13-1 or so ,,

you could turn your shifter around if that would help with the shift problem
The spark plug wires are fine, it's the angle of the shot that makes it look like it's being burnt by the header.

I've always heard a single 4 tunnel ram has lousy fuel distribution,,, maybe some cyl's are leaning out and detonating,,, maybe 3-5 4-6 are ok , and 1-7 2-8 are going lean ,,
That's what I'm thinking is happening too. The fuel pump is a stock one, but I had 2; 650cfm mech secondaries on this same motor, and it ran great at WOT.

I think I'm going to put the 2X4 top back on and see how that goes.:yes:

Thanks for your help.:)
 

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When you figure out the detonation issue, drop the octane and find another 20 h.p.! I run my 615 h.p. small block on 91 with more compression than yours--My 14.5-1 engine ran best on a mix of a couple gallons of 108 mixed in about 5 gallons of 91. Went 6.39/106.75 on that mix. Too much octane will get you nothing.
A stock fuel pump isn't going to supply enough fuel--when you had 2 carbs, you twice the volume of fuel in the bowls which probably would have run out before the end of the track too.
 

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i've saw

some friends go race gas only and slow up too. If you don't need it , it doesn't do ya any good. Do a compression test , see where your are there. Whats the specs on ur cam ???

I'd say your close to being able to go pump fuel if ur cam is decent sized. Pump fuel in this area is declining in quality though. 100 octane Avgas mixed with some pump fuel might be a nice comprimise. Prolly a good bit cheaper for a motor on the borderline. I was told to add an oz. of 2 stroke oil for every gal of Avgas though. Been a while though.
 

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we added it cuzz

the guy that built my last one told me , to add a lil 2 stroke oil because Avgas was " very dry" as he put it. He told me he tried several engines on his dyno comparing race gas to Avgas ,, usually 8 hp difference is all he said he ever noticed.
 

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Discussion Starter #19
When you figure out the detonation issue, drop the octane and find another 20 h.p.! I run my 615 h.p. small block on 91 with more compression than yours--My 14.5-1 engine ran best on a mix of a couple gallons of 108 mixed in about 5 gallons of 91. Went 6.39/106.75 on that mix. Too much octane will get you nothing.
A stock fuel pump isn't going to supply enough fuel--when you had 2 carbs, you twice the volume of fuel in the bowls which probably would have run out before the end of the track too.
I ran the 2 carb setup at the track a dozen times or so and it never missed a beat. I took it off because it ran like crap around town. that was before the locked out timing though. I will try the fuel mix though. I usually dont run full race gas I mix it 50-50 with 91. Thanks for the ideas
 

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Discussion Starter #20
some friends go race gas only and slow up too. If you don't need it , it doesn't do ya any good. Do a compression test , see where your are there. Whats the specs on ur cam ???

I'd say your close to being able to go pump fuel if ur cam is decent sized. Pump fuel in this area is declining in quality though. 100 octane Avgas mixed with some pump fuel might be a nice comprimise. Prolly a good bit cheaper for a motor on the borderline. I was told to add an oz. of 2 stroke oil for every gal of Avgas though. Been a while though.
I did a compression check on it a while ago and 140 seems to stick out, or maybe it was 170?:confused:?:confused:?:confused:?:confused:?.
Anyway, what would be a compression number that I know I could use mostly 91 with? I can do another test.

My cam is a comp solid [email protected] and .525 lift. on both intake and exhaust. Part# 12-224-4 if you would like all the specs.

Thanks
 
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