Big chamber vs small chamber

Well said Benchracer.

 

Wow,,,Will did i miss something here?? Seems you were just posting your "expert" advise, with a good attiude and some experiance,,,,but how does it go to a pissin contest???? Hay, it's Christmas almost so let's all enjoy this time off before we start all over again. Man I thought with some time off like holidays and "RETIREMENT" life was a little more mellow. Guest not? Warren

 

i have a brand new 526in brad moter , brad told me to run the lead as low as 27 when i met him in gainsville , also gene terenzio was flying back in the eary 70s at english town and i mean flying! when most of you were still holding your mommys hand lol

 

The inaccuracy of mag drives is probably the single greatest cause of parts damage in blown alcohol engines. Anyone who answers the mag lead question without first discussing which mag drive is being used is doing the recipient of the answer a huge injustice. It may sound corny, but it is imperative that the spark plugs all fire at exactly the intended number of degrees before top dead center each and every time without unintended random fluctuation.

My eye opener on this subject happened in 2000 at the Gatornationals. I had been observing random rod bearing hits in Jay Meyer's BA-5 alcohol dragster engine for several races, and had learned that this never seemed to correlate to a particular cylinder's having been lean, so I stopped chasing the problem with the port nozzles. Instead, I replaced the 1/2" diameter shaft in his mag drive with one that was about 13 times as stiff torsionally. Jay had been running 22 degrees of lead because he'd found that running 23 degrees hurt everything. What a difference! The car ran a low 5.50 and the engine parts all looked new. We bumped it to 24 degrees and with no other changes, the ET improved to something like a 5.48 with the same parts still looking new. On the last qualifier, we bumped it to 26 degrees, again with no other changes, and the ET improved to something like a 5.46. Will, were you with Jay then, and if so, how am I doing so far? It's been awhile.

Anyway, Jay ran a string of 5.46 to 5.47 times, won the race on a holeshot, and never hurt a single engine part. In the end, I found that a 452 cubic inch 10:1 BA-5 with a 2.15:1 overdriven "D" PSI at sea level to 2000 foot elevation in fairly dry air can handle a maximum of 27 degrees of lead. You can get away with 28 degrees maximunm with this same combination in humid conditions. A 526 cubic inch BA-5 at 1.92:1 and a somewhat higher compression ratio can get away with 1 to 2 degrees more lead.

I haven't found that a crank trigger offers any performance advantage over the internal trigger on a 44-amp MSD provided it is driven by an accurate mag drive. The internally triggered mag drive is, however, more reliable than the crank trigger. If it isn't there, it can't fail.

I don't have as much experience with other engines, so I don't feel qualified to comment on them.

Norm Drazy

 

Man, I am impressed with you, Will ! I never knew you were learnin all that time you were hangin in the pits??? I would always see you lookin for a meal or something to eat, like my Gumbo or Jambalaya. Even saw you "studying" a box or two of Twinkies,in Calaways trailer. Guess lots of calories can turn into smarts. So i'm gonna keep eatin too. All kidding aside I think your a "top student" of the game. WARREN DAUZAT
P.S. Speakin of "Games" care to bet on "dem tigers of LSU" ???remember last season. lol lol
You going to D4 banquet. we'll see you there.

 

How does 5.55@258 sound with a 526, only revving it to 9300 rpm.

 

Since Duane now runs an A-fuel car, it's probably okay to talk about this.

He used to run a 4.310 bore X 3.9 stroke engine with very high compression ratios that were in the range of 11.2:1 to 11.6:1. Duane had been hurting a lot of parts until I suggested that he add a couple of degrees of timing in low gear and pull a couple of degrees out of it in high gear. He did the second part, which stopped the parts attrition, but he never got around to stepping on it in low gear. (Who knows whether or not it would have worked.) The lead numbers were interesting: 25 degrees in low and second gear, and 23 degrees in high gear. Yes, he used a torsionally stiff mag drive. His engine developed monstrous torque that demanded a very tall transmission ratio. At Englishtown, where it went 5.26 and 268.85, he ran a 1.56:1 trans with a 4.30 rear and Hoosier tires.


Obviously, a high compression ratio deprives you of being able to run very much lead. The Grimes/Santos combination is at the other end of the scale in terms of compression ratio. Does anyone out there know how much lead it uses?

Norm Drazy

 

MY DAD TOLD ME THAT OPINIONS ARE LIKE HINEY HOLES,EVERYBODY HAVE ONE AND THEY ALL STINK.MERRY CHRISTMAS EVERYONE AND HAPPY NEW YEAR.

 

Obviously, a high compression ratio deprives you of being able to run very much lead. The Grimes/Santos combination is at the other end of the scale in terms of compression ratio. Does anyone out there know how much lead it uses?

Norm Drazy Yes

 

Gene, You'd think that all you would have to do is look to the TAFC class for the answer, but once again it's not so simple.

The TAFC performance really never took much of a hit, as the Gasparelli family proved at the Pomona season opener right after the rules change. What I believe really happened is that prior to the 1.92 rule, virtually everyone was running transmission ratios that were WAY too agressive, ranging from 1.64 to 1.76. The rear gears were generally 4.56, with 36" Goodyear tires, and shake they did! In contrast, the alcohol dragsters were having good success with transmission ratios in the 1.56 to 1.67 range with 4.56 rear gears and 36" Goodyear tires. This was despite the fact that the alcohol dragsters were running 450 to 472 cubic inch engines with the blowers at 2.15:1 versus 500 to 526 cubic inch engines with the blowers at 2.25:1 for the TAFCs. By pure luck (or maybe the NHRA had this in mind all along ), the reduced overdrive dropped the power curve right into the sweet spot it needed.

Since I think the alcohol dragsters are by and large running the correct trans ratios today, reducing the blower overdrive to 1.92:1 would probably slow them down by a tenth of a second or so.

Norm

 

Bonjour Norm Drazy.... (sorry , this is french speaking but Norm does speak french pretty good )

Just to clarify Norm , Duane's 5.263 ET at 268.71 MPH in 2002 in Englishtown has been run with a 1.60 Trans Ratio , the corrected altitude was -169 at that time. The run before , they ran a 5.280 ET at 269.13 MPH . That s enough about those secret !!!!! It take a awesome track condition and a shakeproof driver to do those number ( I Think ). We will try to improve our LEARNING curve again next season , Very interesting to see your comments on this site and again I am sorry for my poor english.

Serge TAD-182

[ December 11, 2004, 06:55 AM: Message edited by: Serge TAD 182 ]

 

Thanks for the input guys, i'll file this in my cranium for later use.

 

HAY SERGE, did you mean learning curve? "leaning curve" is very small radius before "kaboom time". lol lol Warren "cajun french speaking" Dauzat, Baton Rouge, La.
p.s. I too enjoy reading and learning from Drazy's post. Hay Norm too bad you have enough time on your hands to post daily because you can't sell new screw chargers. Keep posting and developing great products.

 

Hay Nitrotich , that s why I always apoligise for my english , but that time it was a keyboard error . ''Learning''was the right word , and about ''leaning'' ask Norm , you dont have to do much of this on a PSI set-up. SORRY FOR MY POOR ENGLISH....

Serge TAD-182

 

OH MAN !!!!

Another misspelling '' NITROTICH '' sorry ''NITROITCH''

Serge

 

"fee pa sa"
that's suppose to mean "don't do that" but I can't spell anything in french.......and almost nothing in english... lol lol
Warren Dauzat