In my original post, the title references a B&M 250 blower. I was unaware at the time that the blowers I was seeing were actually THE BLOWER SHOP blowers not B&M. So needless to say the title of the original post should be:

THE BLOWER SHOP 250 BLOWER AND A 598.

Last weekend we had rain so no plug info to share.

This weekend I plan to install a set of 2.5" primary/5" collector headers on it. Current header is a 2.250"/2.375"/4.5" merge set on it to see if it will chill out some down low and open up some on the top. No gear change yet still kicking around logistics of making that happen.

I do have one question for those who've dipped down below the 4.50 and faster range with blower combos.... What rear spline axles were you using? Current application in this car is 35 spline, never really planned to have the blower combo in this car long term but it just may stay in this one for a while. In my previous blown combo, I swapped to 40 spline axles figuring it was required, this one i didn't really anticipate the motor making this much steam so I didn't upgrade to the 40 spline axles on this car......YET.

If you have been sub 4.50 range in a blower car with 35 spline axles did you have any issues at inspection time? A few guys here had issues with 35's but they also routinely fought tire shake and both were hard tail mike boss cars. This one is a 4 link miller.

quote:

Originally posted by Triple Nickel:
In my original post, the title references a B&M 250 blower. I was unaware at the time that the blowers I was seeing were actually THE BLOWER SHOP blowers not B&M. So needless to say the title of the original post should be:

THE BLOWER SHOP 250 BLOWER AND A 598.

Last weekend we had rain so no plug info to share.

This weekend I plan to install a set of 2.5" primary/5" collector headers on it. Current header is a 2.250"/2.375"/4.5" merge set on it to see if it will chill out some down low and open up some on the top. No gear change yet still kicking around logistics of making that happen.

I do have one question for those who've dipped down below the 4.50 and faster range with blower combos.... What rear spline axles were you using? Current application in this car is 35 spline, never really planned to have the blower combo in this car long term but it just may stay in this one for a while. In my previous blown combo, I swapped to 40 spline axles figuring it was required, this one i didn't really anticipate the motor making this much steam so I didn't upgrade to the 40 spline axles on this car......YET.

If you have been sub 4.50 range in a blower car with 35 spline axles did you have any issues at inspection time? A few guys here had issues with 35's but they also routinely fought tire shake and both were hard tail mike boss cars. This one is a 4 link miller.

Ride it to the shift, if Northstar drops back to 6900-7000 rpm (observed stall), it'll tell ya at that point it has 4.40's power. 3.73 will cross 7200 rpm slipping 20% @ 155 mph.

A friend and I bought a pair of these Trans Specialties 10" north star converters second hand from another local racer who had them as spares, both fresh rebuilds from T.S., neither ever had fluid put in them following the freshen from T.S. One was lose, the other tight, both setup for blower applications, both setup for 4.50 or faster, but that's about all we knew about them.

I had the "TIGHT" one in my 565 with a Littlefield 14:71 HHR, my buddy had the "LOSE" one in his 522 with a SSI 14:71 HHR. I sold my 565 blower setup 3 years ago and gave him my converter. He swapped to it a year or so ago. This left the "LOSE" one on the shelf and available for my 598 TBS 250 build. That's how I came up with it and is also why I don't know 100% of the specifics on it. We did call TS back in the day with some of the numbers stamped on the pump side, but that was many moons ago and hard to tell if the guy we got them from had them tweaked when he had them, so we just ran them and they worked for us.

Based on his combo if the "LOSE" converter that is in my car now drops back to 6900 at the shift, it is on a 4.20 @ 170+ pass. The "LOSE" one has been 4.17 @ 171 in his car (4 link dragster, 522 BBC, 14:71 HHR, 20% OD, 4.11 gear, 35" Big Bubbas). That was at 7700 RPM at the 1/8 mile, riding the 7800 top chip for the last .4 sec of the run.

Lets hope it falls back to 63/6400 at the shift this weekend, if it stays up at 6900 after the shift i'm makin' way more steam than my chassis can handle oh and i'll run out of fuel pump too. Its only an Enderle 80A-1 pump, 7.2 GPM.

quote:

Originally posted by Triple Nickel:
Best pass without the blower was 4.77 141, but this car seemed to hang out around 4.80 range. That was with a lose converter that flashed to 6900, obivously i couldn't run that converter with the blower so this is a 10" transmission specialties built for blowers. Its so hard to determine exactly what it flashes to because i'm pulling timing but it appears to hit the converter around 5700/5800 and fall back to around 6300 at the shift so i'm thinking the converter could be loser which i'll work on that a little down the road.


Long term i'm considering a 3.73 rear gear.

Kris

This converter will be 6900-7000 drop back (observed stall) if it has 4.40's power now.

Did this converter go 4.77 141, drop to 6300? You might be talking about two different converters here.

This message has been edited. Last edited by: Mike Rietow,

No we got our wires crossed somewhere along the way....

The converter I call the "lose" 10" Trans Specialties converter was NOT in the car prior to the addition of the blower. When I put the blower on I removed a 9" FTI and installed the "LOSE" 10" TS converter. The flash and fall back numbers i have listed in this post are all from the 10". All runs with the 250 blower were with the "LOSE" 10" TS converter.

Best i can tell the "LOSE" 10" flashes to 5800/5900 with 10 degree of timing pulled and falls back to 6300/6400 at the high gear shift. It leads me to believe it would flash to 6200/6300 range with all the timing in, but it would be violent or at least that's my fear at this point.

With the 10 degree retard its packing the front wheels 10" or so high for about 40 or 50 feet at 1.02 60' and 4.452 at 152. Thus all the discussion about bigger headers and less numerical gear ratio.

I don’t think bigger headers are going to calm down a blower motor anywhere.

Just soften it with timing until you’re happy. I’ve pulled 18-20. Don’t be afraid to play with the shape. My fastest and smoothest 60s always had very jagged curves.

BJ is dead on with his comments, he knows blower motors! The larger headers didn't make any difference, but i like the way they look, they sound cool, and they are shorter so they tuck a little bit closer to the car. 2 cars in 1 trailer issue is a little better with the big 2.5"/5.0" header set so they will stay on there for now.

I agree with the timing comments, this weekend on Saturday I was pulling 13 (1 retard module, MSD 7AL3 black box, TS Timer, 0.030 sec activate retard and 0.600 sec back to full timing) for the entire race day. Base timing was 28 total. Was double entered till the third round. I was able to hang in there till the 8th round (finished the race on Sunday 9AM) and lost in the finals -0.0029 red to his 0.006 green. The car was awesome for the most part on Saturday but was a little lose on Sunday in the finals which we ran in the middle of junior dragster eliminations so there wasn't much heat in the track when we went down. I was 0.024 sec slow and could feel the car slipping from the top of 1st gear and after the gear shift. In the finals i had it dialed 4.52 and ran 4.544.

Sunday we only had 1 time trial, but the track looked good and had some sun early in the day so i wanted to go back to my original setup from the previous weekend. We put the base timing back at 30 and only pulled 10 vs. 13 (same timer settings) and picked up about 0.040 total. Went 4.48 at 155.9 but the race was canceled due to rain after the 1 time run so we didn't get to gather any data on that setup for Day 2 of the race.

I did notice something VERY interesting when swapping the headers. All of the exhaust valves are white. What causes this? When i read the plugs on Saturday with a brand new set of NGK 10's, hardly any of the cadmium was burned off the plug and the timing mark indicated it needed more base timing (timing mark was not in the curve it was closer to the electrode at 28 degrees). On Saturday I was concerned that the track would go away late at night, so I figured the lower timing would be better for lose track later in the evening. At 30 degrees the timing mark was better showing up in the curve of the ground strap, not quite to the middle of the curve, but still on the electrode side.

I'm not reading exhaust gas temperatures so I don't have that info available. Any ideas on white exhaust valves?

quote:

Originally posted by Triple Nickel:
No we got our wires crossed somewhere along the way....

The converter I call the "lose" 10" Trans Specialties converter was NOT in the car prior to the addition of the blower. When I put the blower on I removed a 9" FTI and installed the "LOSE" 10" TS converter. The flash and fall back numbers i have listed in this post are all from the 10". All runs with the 250 blower were with the "LOSE" 10" TS converter.

Best i can tell the "LOSE" 10" flashes to 5800/5900 with 10 degree of timing pulled and falls back to 6300/6400 at the high gear shift. It leads me to believe it would flash to 6200/6300 range with all the timing in, but it would be violent or at least that's my fear at this point.

With the 10 degree retard its packing the front wheels 10" or so high for about 40 or 50 feet at 1.02 60' and 4.452 at 152. Thus all the discussion about bigger headers and less numerical gear ratio.

I gotcha, we're on the same page, if it picks up 400 - 500 rpm flash stall at the hit putting the 10 back in it, it'll pick up the same rpm on the shift if the 10 is 100hp-6800-6900 drop observed stall. The white exhaust valves are most likely residual fuel on overlap vs fresh air/fuel. It's definitely not anywhere near lean you know this I'm positive. Burn 2/3 of the cadium on the ring, unless it's plenty good now.

I’m in the minority on this one, but forget about the strap. I live and die by the strap on a gas/nitrous deal, i intentionally ignore it on blown alcohol. Cad on the threads show heat on blown alky and unfortunately you can’t differentiate between fuel and timing. Mike Canter has some good info on blown alky plug reading and he agrees with my last statement... right before he starts talking about reading straps... we’ll just agree to disagree on that part

If any of the top face of the plug still has the cad after a pass, you’re safe. If the plug doesn’t look brand new, you’re not overly safe.

If you want to lean on it past the top face cad being totally burnt off, I’d be prepared to check a bearing every now and then, which probably doesn’t make sense for a bracket car.

quote:

Originally posted by BJs Wild Ride:
I’m in the minority on this one, but forget about the strap. I live and die by the strap on a gas/nitrous deal, i intentionally ignore it on blown alcohol. Cad on the threads show heat on blown alky and unfortunately you can’t differentiate between fuel and timing. Mike Canter has some good info on blown alky plug reading and he agrees with my last statement... right before he starts talking about reading straps... we’ll just agree to disagree on that part

If any of the top face of the plug still has the cad after a pass, you’re safe. If the plug doesn’t look brand new, you’re not overly safe.

If you want to lean on it past the top face cad being totally burnt off, I’d be prepared to check a bearing every now and then, which probably doesn’t make sense for a bracket car.

That really gives me pause thinking about it. I generally use the 2/3 ring and line on the strap. But.....it isn't overly safe regarding swings in weather and even when you start increasing boost. Easy to step on your weiner when you are spot on tune and start leaning on it unless you really add fuel at the same time and back off some timing. A friend of mine runs clean plugs like you and just adds a little boost to make up for the hp loss. I'm starting to think that is a good way to go.

ya, once you get a semi safe looking plug you still have to stay on top of it for weather and stuff. 50 grain drop in water is the one that’ll get ya. I junked a set of heads last year with the bbc when a cold front came in while I was pulling into the water box. It was on kill for 3300’. Weather was about 1600’ when I got back to the trailer.

On a conventional head bbc with chambers in the 114-120cc range with a lightly colored plug base thread, if you want to lean it out, dropping from 31 to 28 degrees first isn’t a bad idea. It’s all just heat. If the plug still looks ok with the fuel out, add a degree or 2 back in and see what it does. I always wanted to try 32-33 with more fuel but I don’t think there’s much there.

I was usually more of a 3 thread guy. Every time I got home I’d tell myself I wasn’t going to do that anymore. Let’s just fatten it up, add a little boost, and try to keep it happy. By q3 I always had it back on kill with the cad burned to the 3rd thread. Some guys say 3 threads is a time bomb. I agree on most combos, mine were a little odd like that. One wouldn’t fall out of a tree until the 2nd thread.

I always had some minor findings on a couple bearings every 10-20 passes. I had some general guidelines if it was just a couple bearings:

Babbitt squish: add 2 to the nozzle
Bearing pulled together: add 2
Babbit squished and pulled together: probably 3
Bearing backing plate squished: I moved about 10 nozzles on this one time. It looked pretty bad


Apparently the hardcore guys won’t touch a thing if all you have is babbit squish after 10-20. Not sure if they even replace the bearing.

None of this is really applicable to OP, just thought I’d share for some light reading.

I don't have trouble with head gaskets or bearings, or haven't so far. But when you add boost and run out of fuel pump unexpectedly, the leanest cylinder makes a piston look funny quick.

What is the highest compression ratio are you using with the little TBS 250 blower?
Are you running a standard harmonic balancer, or a special double keyway balancer?
Are you able to sandwich a crank trigger wheel in between the balancer and the lower pulley?
Thanks

We are at 13.7 on dads 598. We did double key the crank, but only because we were freshening the motor. We are also running a crank trigger. It’s a pretty simple setup and easy to do.

For what it's worth, I've heard as high as 15:1

On this motor I used a standard balancer with a single Key with no real issues in regards to the key transmitting the torque of the blower on only a single key.

The problem I ran into was the crank snout broke off at the first main right behind the timing gear. I'm still on the fence about the cause but it was a scat crank and the key ways were cut for 3 woodruff keys in a line. 2 for the harmonic balancer and 1 for the timing gear. The timing gear key cut was cut into the radius for the first main, right where you don't want a stress concentration. Based on the fracture surface of the failed parts this was the Crack I itiation point.

I didn't run a crank trigger wheel, rather I ran a crank trigger shell on the ATI balancer.

I'll have double keys on the new Callies crank,the key way doesn't extend all the way to the main bearing step up radius,and I'm considering a set back plate for the blower to get rid of the spacer pulleys and to get the belt as close to the first main as possible.

Still not sure about set back plate and a straight lobe rotor like the 250 blower. It's only 1.5" but I'm concerned about flow restriction out the bottom of the blower.