E.T. loss ?
 

Hey guys dad has a ? for ya.... we put a new engine in his car just before labor day. The car ran fine BUT @ a race in late Sept. the car lost .12! Now we can't find it ? we have checked or changed everything! We've had jets in it from lean to smoking fat no differance . We have changed tires & wheels . Changed timing , fuel , launch points from 2000 to 3500. The car also lost about 2 mph? ( this is all 1/8th mile) Thing is it's running in better air now then it was Labor Day? 0h cam lift is good too?? Any ideas?

Re: E.T. loss ?
 

I'm going to assume no datalogger, Given the fact you;ve changed most everything as far as engine tune, i'd have to lookat torque converter? Really not enough info to make a really good guess however converter can definately cause this without any obvious symptoms. Joe

Re: E.T. loss ?
 

Torque Convertor.

Re: E.T. loss ?
 

That would make some since. The car also slowed in reaction time...as in dad went up some 10lbs in front air pressure to try & cut a light!

Re: E.T. loss ?
 

Greg,
I've been told that this guy does a Killer job building convertors.
Click here: http://www.ultimateconverter.com/testimonials.html

Re: E.T. loss ?
 

I agree, converter has a problem!!!

Shawn

Re: E.T. loss ?
 

Park the Nova; race a Maverick.

Re: E.T. loss ?
 

If it is the converter, there will be obvious symptoms and it won't last long.
Is the stall really high or low? Trap RPM real high?

Re: E.T. loss ?
 

Mark, I stated no obvious symptoms because most of the converter issues I've seen guys have other than an obvious ET change They are unaware of whats "different" during their run. With a datalogger it's pretty easy to see it, even a playback tach helps. A just complete failure is easier to diagnose than a damaged converter. You are correct in they should be seeing something different in stall speed or finish line RPM. Hope you all find your issue. Please post your findings. Joe

Re: E.T. loss ?
 

Just like the old days.........

Flying by the seat of your pants......

NO MPH............

A good place to start is SPRINGS or RINGS

Bob

Re: E.T. loss ?
 

When you changed jets did E.T. change? If it didn't pull rockers& intake put air straight (no regulator) to
cylinders check for air leaking through intake valves if can't feel air, spray soapy water look for bubbles.
DON'T WASTE YOUR'RE TIME WITH LEAKDOWN TEST OR COMPRESSION TEST the leak I'm talking about is so small a leakdown or compression test will not show it. I'm not saying this is your problem but I've seen this many times. One almost positive sign of this is jet changes will not make hardly any difference and car will be inconsistent . Have you broke any valvetrain or broke driveline and hit rev limiter hard?
Mike Taylor 3601

Re: E.T. loss ?
 

Greg: Something also you might want to check is the balancer, if you are using a stock one. I got tripped up by this many years ago. Outer ring slipped on hub, thereby showing incorrect ignition timing. Very easy to check.

Re: E.T. loss ?
 

Greg be sure to check battery and alt you may have a bad cell or shorted battery. Be sure the alt is not stuck on full charge causing power loss have seen regulaters stick, also have you noticed battery needs charged more often. Have you done any welding on car which could have caused diodes in alt to go bad. When you changed jets did plugs get darker or stay white. also check all ground wires ect may have a wire that vibrated loose after put engine in and at track few times. Have you changed fuel system, I have seen a few, fuel cells mounted real high in trunk and lets fuel siphon thru carb while sets in garage and causes rings to loose seal. sorry to keep rambling on but could be anyhting. All posts on here are possibilities.

Re: E.T. loss ?
 

Here's the best I can tell you as dad has the log book with him ( logs every pass no matter who is driving). this is a 1bbl carb running holley style jets... with an 82 in it the car ran hott real fast i mean 200 right after a pass ( to lean) with 89 in it the car you could see a trace of smoke coming out of the car as it staged. the 85 seemed the best so that's what was in it last weekend. Now then fuel system has been in the car for 3 years. the cyl head is fresh. the balancer is a maybe as it is stock. Thing is we didn't move the timing...the car right out of the box ran 9.50's now then it's running 9.70's (1/8) the last passes I made with the car were a 9.71 we then changed tires & it went 9.73 I then went up & tried to "flat foot" the car & it went 9.70. i then went up for the "dial n 4 dollars" & it ran a 9.709 on a 9.70 then 1st round it went 9.712...so it's running ok just slow? dad dose think it may be in the rings...don't know but we got rings in for the "good" motor so he's going to put it back together for the spring....that engine will run some 9.30's. THANKS for all the help...we're going to try it again this weekend & see if we can find anything....mean while we changed header this week....so who knows!

Re: E.T. loss ?
 

Update! well we figured it out! (i guess) 2nd round about 30' off the line it went BANG!!!!! took the pinion right out of it! guess it's been going out for a few weeks? ya know it's not good when we pushed the car up on the trailer with the shifter in park!

Re: E.T. loss ?
 

Glad to hear you found something..... good luck to you.