Pushing the tuneup

Seeking advise on how far we can push our tune up...
Arias Hemi Chevy. Solid aluminum heads. 8/71 blower.

We have 1140F exhaust temp, only burning cad of the earth strap on plugs. not across base of thread yet.
We have 32 degrees timing on a Supermag 5amp
Not mashing bearings..

How much further can we take the timing and exhaust temp before risking hurting anything?

Cheers
Dave

 

pretty tough question to ask really... don't be fooled by egt. it is ONLY a number and not really comparable to anyone else's set up. it is just a number that is relative to other things you see when you assess what the motor is telling you. things like bearings (appearance/brand/oil/clearance), pistons, plugs, rings, etc are WAY more important than egt. egt is just a reference number for your particular motor.

not trying to give you a non-answer... just a realistic one. biggest problem is if you ask this question to the wrong person they will give you the wrong answer. and the next thing you know you're taking a bunch of fuel away, putting in a bunch of lead and ultimately picking up rods. just make slow deliberate changes and read all those indicators often until they start telling you that you've 'crossed the line'. sean

www.metalmafiaracing.com

 

Spend a little time learning "Bell curve analysis". It really applies to tuning a race car. It is sort of a scientific version of "sneaking up on it".

 

How much boost are you running what overdrive percent.I would try using boost before more timming and less fuel.

 

Boost is about 25lbs. Standard helix 8/71 spinning 40% over.
11/1 compression.
I run this thing in a FED, in Nostalgia class. 7.1 at 191
Trying to squeeze a 6.90 out of it.

Motor is stout. Merlin 3 race block. Crower billet 3.76" crank. Billet rods, titanium valves, etc..

3 plate AFT clutch, 3 speed Lenco. 33 x 12 tyres

Thanks guys

 

Believe me, not try to be a smart alek, but we run a 32% over 6-71 in a 2100# nostalgia funny car and we run 7.20's easy. Shifting @ 7200 RPM. Engine is a 477 Chevy, 10.5:1 CR with hat nozzles only. We get color to about the first thread and the timing is only @ 30 degrees. We feel 6.80's are very reasonable. We also run a PG
Have you had your fuel system flowed?
Are you running a high speed? (it helped our tune up)
What cam are you running?

Keith

 

Forgot to mention, Mike Canter's spark plug article is EXCELLENT reading.

Keith

 

Hi Keith,
Nice FC. I would like to see a pic. (Im also building a '70 Cuda FC)
In the dragster we have 8 x 40's in hat.
8 x 50's in ports
990 pump at 15gpm
pump sizer check valve at 30lbs with 65 pill
Main is 100
High speed opens at 50 lbs and has a 83 pill
Total pill area 0.01656sq inches

Cam is 720~750 lift at valve. 112 lobe centers. 294 degrees at 050"

The FED is overweight. 2000lbs with me in it.

Thanks for the help

 

All of my exoerience comes from a pro mod drag boat.I gain about .250 sec with a one tooth pully change.I would put a one size smaller pully up top and leave the rest alone and I bet you will get what you are after without blowing it up.Good luck and let us know what happens!!!

 

try putting some timing in it and a little fuel and it will respond mine would not run untill i had 36-38 deg was running a super 4 mag 32 is run with the msd mags

 

To muchTimming and not enough fuel is what melts parts.Boost just squashes parts.Take your pick!!! Its only money.