[twooldgoats]

Originally Posted by Glenn Lever

I’m a believer in routine. Do everything the same way each time. No time to teach someone new the routine each time.

Exactly! Volunteers from pits=recipe for disaster


Jim

[Glenn Lever]

Ok, I have increased my HP by about 100 Horses (from guessed at 524 (engine was dyno on gas at 524 and then convertered to alky) to the 652 Hp we just dyno at).

I would like to avoid changing the gears in the rear end, so I am looking for a tire height calculator based on HP, RPM, weight, and gear ratio.

I went through Wallace racing calculators and did not find one.

Any help?

I want the engine RPM at about 6,200 at the end of a ¼ mile
Weight is 1690 with me in the dragster.
Horsepower is 652
Gear ratio is 3:70

With a calculator is that the height on the side of the tire or the grow height?

[johnta1]

I just added a calculator for that.
(didn't realize I didn't have one there )

Tire Calc

You'll need to know the approximate MPH that you will run.

Also, the diameter will include any 'growth' the slick may do.
Some companies have the growth of the slick.

[Glenn Lever]

Originally Posted by johnta1

I just added a calculator for that.
(didn't realize I didn't have one there )

Tire Calc

You'll need to know the approximate MPH that you will run.

Also, the diameter will include any 'growth' the slick may do.
Some companies have the growth of the slick.

Ok, I did something wrong

I first used the ET/MPH/HP calculator to get MPH (HP = 652, and weight = 1690 which got me 167.4 MPH which seems about right as I was running 155 MPH with 524 HP)

Plugged 167.4 MPH, Gear Ratio of 3:70, and RPM of 6200 and it gave me 27.22 inches. I'm currently running a 31 inch tall tire. I should have to go to a taller tire to keep my RPM down???????

[BruceWilkie]

MPH = (rpm x tire diameter) / (336x gear ratio) NO slip solid lock up.

IF Automatic you need to adjust for slip. 355 is a reasonable factor to replace 336 for guesstimation if actual slip is unknown.

Neither accounts for tire growth. If you have estimate of tire diameter at the speed you anticipate your answer will be close to reality.

Some samples...

With no slip.... MPH = (6200 x 33) / (336 x 3.7) = (204600) / (1243.2) = 164.575.

Auto trans reasonably efficient convertor... MPH = (6200 x 35) / (355 x 3.7) = (217000) / (1313.5) = 165.207

FWIW (6200 x 31) / (336 x 3.7) = 154.6 MPH ...Tire growth would affect the 336-355 factor range if running an automatic. If you are direct drive running a true 155 mph at a true 6200 rpm you have very little tire growth.

[johnta1]

Glenn, I get 33.49"?

Are you using 3.70 and not 3:70 for gear ratio?

[Glenn Lever]

Originally Posted by johnta1

Glenn, I get 33.49"?

Are you using 3.70 and not 3:70 for gear ratio?

I used 3:70.

33.49 sounds about right. I have a freind that has 33.5 on wheels with the right bolt pattern. I'm hoping to be ready to try them this weekend.

THANKS

[Glenn Lever]

Well it has been a terible start to the season.

After three cracked heads, I gave up and purchased new heads.

The coolent system has not been working well, even with the lines from the rear of the head.

Talked with Meziere and I believe they have me on the right track. See the attached.

We will attempt to test some of the suggestions tonight.

I will then be out of town, but on return will remove the filler from the high presure side, and install an expansion tank on the face of the pump and put my filler there.

Meziere does not offer one for Pontiac, but does for SB BB chevy and BB Ford. See the example below

[Glenn Lever]

Went to the track tonight (my wife and I)

First run went dead right. I purchased a cloth tape and we very carefully taped the tires. Both were at 8’ 3 5/8”. Left tire at nine pounds right was at 5. I do not have the slips in front of me but remember it to be 8.86. I had to get out of it and shifted early to keep control.

Second run I gave up on measuring circumference and set the right tire at 5 and left tire at 7 ½. Went much straighter and got back to what we ran two weeks ago 8.68.

Last run I bumped up the launch to 4500 and shifted at 6300. Ran 8.61 at 156.

I did not change the jets, air was at 2500, the hot cylinder (8) was at 980 degrees, the normally cool cylinders (center) were at 1200, number two reads -258 (I think the wire is not connected)

For some reason I did not get data on the last run, engine temp never went above 160 on the return road on the last run. Normal is 180. Also when I went to turn off the track the low oil pressure light came on for a second and then went back out. I really wish I had the data from the last run. One other thing is at the top end it sounds like I’m on the limiter, which is set a 7000, but the data recorder says 6300 for the two runs that I have data for. 6,300 makes sense for 156 MPH

[twooldgoats]

Originally Posted by Glenn Lever

...... One other thing is at the top end it sounds like I’m on the limiter, which is set a 7000, but the data recorder says 6300 for the two runs that I have data for. 6,300 makes sense for 156 MPH

Glenn, what ignition box are you using? I found out my MSD 7530T has a rev limiter that kicks in after X seconds and it was set at the factory at 9 seconds and some ridiculously low RPM, so the car always ran poorly during the shutdown and on the return road to the pits. Shutting off the engine in the pits reset the timer, so it didn't happen again until the next pass. It took a careful reading of the instructions (not real clear) and some checking to diagnose the problem.

Jim

[Glenn Lever]

Originally Posted by twooldgoats

Glenn, what ignition box are you using? I found out my MSD 7530T has a rev limiter that kicks in after X seconds and it was set at the factory at 9 seconds and some ridiculously low RPM, so the car always ran poorly during the shutdown and on the return road to the pits. Shutting off the engine in the pits reset the timer, so it didn't happen again until the next pass. It took a careful reading of the instructions (not real clear) and some checking to diagnose the problem.

Jim

MSC 6AL-2 I'll look into it but do not believe that this box has the timer.

[Glenn Lever]

I’m having problems tuning this engine.

EGT’s are high 1300’s in the tube but believe it is burning fuel in the tube as the plugs show little or no heat.

Timing is set at 28, have tried higher but does not seem to like it (higher EGT’s) (ET go slightly better .02)

It seemed to like fuel being added went as high as 200 jets all the way around and reduced the high air bleed to add even more fuel. Could get no heat in the plug readings but EGT’s did get cooler.

Last run last night was with 180 jets all the way around with the stock high air bleed .025. still not heat in the plugs, EGT’s up to 1345, AD at 1600. Seemed to sound better (crisper)

KRE heads 74CC chambers CMC ported to flow 340 CFM, 2.19 intake valve,
Edelbrock 2956 Victor port matched
Ohio Crank Forged (stroked) Displacement is 461 (1970 400 block)
KB Pistons 941-30 - 4.155 bore
pro-warrior 6.8 H-Beam rods
Balance assembly
Crane Cam Solid lifter
@.050 Intake opens 33 BTDC closes 63 ABDC max lit 105 duration 276
exh opens 73 BBDC closes 31 ATDC max lift 111 duration 284
with 1.5 ratio
1.6 roller rockers
1050 Quickfuel Alky carb
MSD 6Al-2 Box
MSD Distributor (no advance), advance set at 28 degrees

Anyone with a similar set up, what are you running?

[Probird]

I would say you are definately getting false EGT readings. It's burning all the excess fuel in the headers. I'm not running the same heads so I'm guessing thats why I run more timing, in the 36 degree range. Alky is hard to tune by plug readings. It burns real clean and won't look like a gas plug. I run an NGK -8 plug. It's hard to give any jetting recomendations as every carb builder builds them different and jetting is way different. The jets in my carb are 142's, but there is a hole drilled above the jets that adds extra fuel. Have you tried a higher heat range plug? How much water temp do you gain on a pass? Sorry, not a lot of help.

[twooldgoats]

Get rid of the carburetor.It's a needless complication. Get a Ron's Toilet. Simple and a snap to tune. Later, when you add a blower, you can still use the Ron's system if you want on top of the blower.

http://www.killerrons.com/

JMO.

Jim

[Glenn Lever]

Originally Posted by twooldgoats

Get rid of the carburetor.It's a needless complication. Get a Ron's Toilet. Simple and a snap to tune. Later, when you add a blower, you can still use the Ron's system if you want on top of the blower.

http://www.killerrons.com/

JMO.

Jim

It is such a big change late in the season, it I make that kind of change now the rest of the season is gone.

[Glenn Lever]

I post this to help any suggestions on the above request on tuning suggestions

Update on this weekend’s racing / testing

Had a flat tire on the way to the track, blow a hole in the side of a tire.

Put the shade canopy up and the wind promptly blow it back down and broke a leg (on the tent)

First run was a test and to warm everything up, red lite (only one for the evening!), a step in the right direction. No changes were made (timing at 28, jets at 200, high air bleed at .023), was slow at 8.72 in the quarter with the air at 2383 ( this was the only run for the evening that we got ¼ mile times as this was a gasser even and that is 1/8 mile

Second run, we put the timing up to 30 degrees, no other changes, air was better at 2262, it started hard, had a slightly better ET, slightly higher EGTs. 1/8 mile was 5.519. Still no heat in the plugs

Third run, we put the stock high air bleeds (.025) back in (has the effect of going down four steps in main jets), timing still at 30 degrees (started hard), air was a little worse at 2378, EGTs were slightly higher, no heat in the plugs, and it ran slower at 5.543. Still no heat in the plugs

Fourth run, ran the same setup. Had a very hard time getting it to start in the staging lanes, cranked over but would not fire, this may have been my problem as the starter had complained of fuel coming out of the overflow and I dropped the level of fuel in the tank. The pickup is quite a ways of the bottom off the tank. Air was better at 2257, ET was 5.527. Still no heat in the plugs

Fifth run of the evening was the first run of eliminations, we took the timing back to 28 degrees, I had an Ok light for me .596 and would have won except I broke out by .020. Air was better at 2210 and the ET was better. Still no heat in the plugs

Ok , so we ran two test runs and to a big swing at it.

Sixth run, took all the jets down to 184, timing back to 28, I was early on my shift to second by 500 RPM. We compared 60 foot RPM, on the data logger and looked to be going in the right direction. EGTs were still higher in the pipes, but still no heat in the plugs. Air was better at 2050 ET was slower because of the shift to second at 5.575

Seventh and last run, went leaner still. Went to 180 jets, except one of the jets had bad threads and could not get it to start, so used a 184 in that position. Air is now getting really nice at 1965, best air I have seen. Still no heat in the plugs, pipe EGTs are no frightening at 1390s, but STILL NO HEAT IN THE PLUGS. ET was better at 5.523, ¼ mile was 8.686

Still the thinking is to go leaner.

Club racing this Wednesday August 15, if the weather is go will try it

Gasser Gold Cup is Friday, Saturday, and Sunday August 17,18,19

Special Thanks to Steve Walczak http://www.ss3raceteam.com/

[johnta1]

I'm with the Ron's Toilet setup.



You would probably be dialed in right now with the Ron's setup.



Anyway, I'm not a alky carb guy.
But if you're leaning it down and the EGT isn't going higher, then there is something not right.

Either it's so rich and like you said is burning in the exhaust, or the egt meter isn't right.

I'd lean it more and see what the temps are.
Make sure you don't burn a hole in the pistons though.



Good luck, Glenn.

[Glenn Lever]

Originally Posted by Probird

I would say you are definately getting false EGT readings. It's burning all the excess fuel in the headers. I'm not running the same heads so I'm guessing thats why I run more timing, in the 36 degree range. Alky is hard to tune by plug readings. It burns real clean and won't look like a gas plug. I run an NGK -8 plug. It's hard to give any jetting recomendations as every carb builder builds them different and jetting is way different. The jets in my carb are 142's, but there is a hole drilled above the jets that adds extra fuel. Have you tried a higher heat range plug? How much water temp do you gain on a pass? Sorry, not a lot of help.

Tell me a little more about your setup, please.

[BruceWilkie]

Plug reading for alky... http://www.wallaceracing.com/plug-reading-lm.html scroll down some to see the alky notes.

Also might try advancing your cam 2 degrees from where it is and see if it improves or gets worse. If worse try retarding 2 degrees from where it is now... if either shows improvement in egt more importantly plug reading, talk with whoever speced your cam.

[Glenn Lever]

Originally Posted by BruceWilkie

Plug reading for alky... http://www.wallaceracing.com/plug-reading-lm.html scroll down some to see the alky notes.

Also might try advancing your cam 2 degrees from where it is and see if it improves or gets worse. If worse try retarding 2 degrees from where it is now... if either shows improvement in egt more importantly plug reading, talk with whoever speced your cam.

I have read this
http://www.dragstuff.com/techarticle...ark-plugs.html

I have read yours, and will read again.

Here are some shots of the plugs pulled last night.