A/F Question

nitro

WILL I am goin to take a stab at this.. I dont think fuel likes the combustom chamber of a non hemispherical style head at 90+% and the motor is not as forgiven. But i am sure we will get a better answer. ?

 

Few have tried...

Ask David Baca about running an Olds on Nitro.

 

The http://www.alanjohnson.com/ajpframe.htm 481x as well as the Miner Brothers hemi has a 4.84 bore spacing which allows for a slightly larger bore;4.5, I would think this would be good. The 481x has 6 bolts around each cylinder 5, 1/2' , 1, 7/16' . 2 spark plugs might be a problem but 15:1 wouldn't. In the late 70's early 80's they're were quite a few injected chevy's, they don't like blown nitro but I think it'd fly.

 

Olds

I think I can give you good answer . Please dont go there. Mike

 

Is this a trick question??? Will, you know they wont allow 5' bore space in TAD. Remember the Walt Austin 4.9 bs ford deal? That was before they made the rule. No new combo's.

 

Don hudson and kosky racing

Id like to know the more specific problems with this. Just out of curiosity and because its easier and cheaper to learn from other peoples mistakes.
I wanted to do this in the 90's when we had one of those ten ton Whipple's on a short deck 481X and couldn't make it work. We had high speeds on it and I know now it was a mistake. This was before I new about taking fuel out of the lower gears. Speaking of low gear lean outs why not put a high pressure check on a screw blown motor like a roots blown pro mod so you don't start the melting of the pistons in the staging lanes?
the short deck 481X is also shorter than a short deck Hemi.

 

KB/OLds?a-fuel

My good friend Carl Mcgee of Victoria, Texas ran a Mckinny dragster with the KB/Olds engine combination. I did my best to tune the car but did not have very good success.
When we started out there was only one 44 amp magneto on the engine.
Anytime we ran more than about 19gpm at the hit it would drop cylinders. We tried everything Including adding a lot of weight to the clutch in an attempt to load the engine more. Also ran up to 70 degrees of mag lead and ran varing combinations of nozzle areas with no improvment. Next we installed a second 44 amp mag driven off the front of the cam. The motor instantly had a much healthier sound at idle but did not improve the performance at all. It still dropped cylinders at the hit when attempting to put enough fuel in it to produce power.
We had a blower manifold with the short runners that we thought might be a part of the problem as well as there were no down nozzles. All the fuel went straight into the manifold port. Still used one non check and two nozzles with checks.
This car ran as good as David Bacca & Ray Strasser. The reason I know this is that I talked with both and actually had all their run sheets with data.
The best we ran was a 6.20 @ 24? mph.
After three years of beating our heads against the wall Carl sold all the kb stuff and put a 421 cid hemi in it. The car ran a 5.51 at the Houston Nationals the first time out whch was not great but a big improvment.
In retrospect I think a big problem with the KB/Olds was the placment of the second spark plug which was very close to the original location. The manifold would have improved performance with longer runners.
If I knew then what I know now I would have increased the compression which would have probably made it possible to increase the gpm's that the engine would have burned. Also a camshaft with shorter duration would have helped.
I do think it would have run much better but have no idea how much better.
These engines produce good power on alcohol and gas. I see no reason they could not be competetive if you had a big enough budget to make lots of laps and change a lot of parts.
We had a lot of fun and never hurt any parts. That is one tough engine.
BobHolley

 

Brendan Murry will be running an Arias on Nitro in the NTF racing this season...I think he ran an Arias on alky before, so I can't claim to know if he has any past history with the combo....hell, The Over the Hill Gang with Kelly Brown did well in Top Fuel about 20 years ago with it.....of course neither of these combos can be prepared to a current/modern TF set up/tune up.

 

Veney's injected big block chevy 'Vega half way through the page merge collectors

http://www.classicfunnycarboard.com/cgi-bin/ikonboard/ikonboard.cgi?;act=ST;f=1;t=8413;st=130

 

olds

Hi, I built kb olds allan johnson stage IV with dual spark plug. Mike from R
age built the injector and fuel pump. Last year I was ready to try it but I could not find any nitrométhane. I hope I will find some this year.... Let you know how it goes
Later I will show you a pic of the engine.
I don't understand why this would not work with olds when some people can do it with Harley Davidson (nitrobike)
I cross my finger and hope for the best...
Denis Choquette

 

Trying to remember the exact timeframe, probably late 1980's early 90's. Lee Jennings built an A Fuel dragster, KB Olds combo, with Ray Zeller tuning for division seven. They didn't run it very many times as I recall. I 'll have to ask them next time I see them.

 

My memory is fuzzy but I think the best we ran with it was 6.30's. Which at the time was not too far off from the competition. My dad built the engine. Basically just a big block chevy on nitro.

 

olds afd

Probably the LARGE pit explosion that the Jennings/Zeller Ols AFD car experienced had nothing to with the capability of that engine package.

How big is your development budget, though?

The 426 hemi combustion chamber, no matter how close it resmbles a '37 Harley and disregarding the fact that its combustion efficiency (on gas) might have been a step back from the 331/354/392 family, LOVES nitromethane.

Why bother with anything else?

 

I get the point but isn't a fathead chamber closer to a 331-392 than a 426?

 

pictures

http://www.dragracequebec.com/forum/viewtopic.php?f=5&t=2415

 

years ago my uncles went from a chevy to a hemi and i ask why the chevy kept blowing the combustion chamber out of the head between the valves ugly

 

Brenden Murry

Hi, I pit crew for Brenden from time to time, Not sure if this will help but he ran a 5.87 on Blown nitro with a New Century block, AJPE billet stock style heads, and a single magneto in a nostalgia front engine dragster, I would think with a 2nd mag, modern car, and say a AJ stg 4 head or Bac man billet head then a mid 5 seems possible at least...

Trevor Sherwood