I got my first pull in for the season, and it was a learning experience. Definitely have more work to do on timing and jetting. I was using my 33 in tires with 4.56 gears, and was very disappointed when I couldn't get more than 5500rpm. We also have determined that one of the copper head gaskets is leaking into the water jacket causing the system to build pressure too fast. I'm going to run a compression and leak down check tonight to find out which side is the culprit.

But on the jetting/timing, what do you guys suggest? Right now I'm running 82s square in a 1050 dommy, and it is still rich. I have the timing set at 14deg. initial.

I did come in 3rd, so it wasn't all bad, but I'm sure that if the motor would have come up to 7000, then I would have gotten 1st.

what class are you running? what engine?

The motor is a 460 and I was running in a 6500lb 4x4 class.

Alan the tracks are going to dictate how much rpm your motor turn in the class you run and the set up you have ..
33" tires with 4.56 gears could have been just the right combo to hook really good to the track that night...
But if you would have had 4.88 gears you would have turned more R's but would you have gone as far..

There was this one truck last year that was running 4.56 gears and they did OK for the season .. but this year he put 5.18 in and just killed everyone at Oconto.. but this weekend they got there butts spanked ...Not enough wheel speed.

I found on most of my other motors that if I turned between 6200 and 6800 Rpm's I did really good.. any thing above that and I was just spinning my wheels going no where.

This year I'm turning way more r's but I'm still not winning all the time, but I'm in the top 5 so far this season ...
It's all reading the track and putting the power you have to good use when it's your turn to show what you got....


ShaZam

I understand about the tracks. I hadn't been to this track before, and it was a very warm day, so I figured the 33x12.5s would work better, but I was wrong. They hooked up too well. What is perplexing me, is with the gear my tranny is in, I should get 23mph at 7000rpm, and I would think that with the motor making close to 700hp, I would run out of traction before hp, and that wasn't the case. I knew within the first 15ft that the motor wasn't coming on like it should, and I felt my jetting isn't right. I started out with 90's and no powervalve, and it was rough, so I went to 92's and it seemed to run better, but lazy coming off idle, but when I pulled the plugs, they were black. So I ended up with 82s and no powervalve when I went to the pull, but I still didn't feel like it was right.

Where I live, I can't pull out onto the street and run it at WOT to get an accurate plug read (too many cops travel this road)

OK just going off memoir's here but I'd jet your carb. at 86 Sq. that where I ran my 435 and 501 with my 850 DP Holley.



ShaZam

We had our first pull also on Sunday. Running 4:10s and 33s we were pulling 7500. The track was hard. The new motor RPMS really fast. We were a little light for our class (4900lbs in a 5500lbs class) Still ended up with 295 ft pull.

For jetting and timing suggestion ,I would HIGHLY recommend hitting a chassis dyno. Its 100% worth it. You can tune by seeing the readouts (timing effects /air/fuel mixtures), without them it can be a guessing game. We went to one and picked up power all across the board from our intital settings. A buddy picked up 90 hp at the wheels from his first settings. In 2 hours or less you can dial in your ideal jetting and timing.

I'm running a 1050 dommy, that would make a difference over a double pumper. Does 34-36 deg total timing sound about right?

I guess it all depends. We are running a 1000HP from ProSystems. It was almost dead on until the hi rpm where it went really rich. We tried to adjust the hi speed air bleeds and it helped. But a change in jets would probably be the best. The carb has 84s & 92s w/ no rear PV .

For timing we started at 38* ( 468 w/ 13:1 and 45cc domes)We instantly picked up 20 RWHP w/a 2 degree bump to 40. We decided to leave it there because it was a conservative tune.

I still recommend trying to get on a chassis dyno.Its relatively cheap..usually about $100 for an hour.The guys we worked with were awesome. They helped us interpret and troubleshoot some issues we were having. If may have taken atleast 2 or 3 pulls to get the motor this dialed in. We were able to do it in 2hrs on one day by going to the chassis dyno.

oh BTW...the chassis dyno is humbling too. We thought the motor was in the 750 hp range,by the end of session it was putting 550 to the ground. We figure that is about or around 700hp on the motor.


.

What stall do you have??? With 33s you should just jump to the rpm with no probs. And what class did you pull in?? If they threw you in a mod type class the sled would have beeen set alot heavier. (what sled was it anyway??) There is a nasty red one up there that is a bitch to move.

Travis

The converter is a Coan 10" 3500 stall. I believe that the copper head gaskets are the root of my problem. I ran a compression test on the #3 cylinder and is was only at 85lbs. The setup is at 12.5:1 compression so 85 is way low. As I said earlier, I thought one or both head gaskets wasn't sealing properly and the blow by into the water system was the cause to building too much pressure causing the resevoir to overflow. And now that the compression test shows VERY low compression, I think it is confirmed. I'm told that the leak off into the water system is also what is causing the rich condition I'm experiencing. I am going to open uup the top of the motor tomorrow night, and hopefully Cometic will deliver the new head gaskets on Friday as promised.

I was pulling in a 6500 lb gas class. There was 2 other trucks that were in the same league as mine (or what mine will be when running correctly) everyone else was stock or very mildly built. It was a red sled, but I didn't pay too much attention to the name. And yes it did feel heavy coming off the line.

I was reading a thread on 460.com that the cometics are hard to get to seal. If you are having a sealing problem now, maybe the cometics won't work either. I think Shazam might know something about them.

If you guys are in Colorado its probably "Sudden Impact".

Indiana