Has any one ever experienced pipe surge? I have been told that this happens when the pipe dosen't get hot enuff. Any ideas on how to fix this problem?

Pipe surge is normally brought on by porting to increase peak HP more than with a cold pipe. What happens is that when you port for peak HP numbers you generally end up creating a vary narrow powerband. If the powerband becomes narrow enough, there is usually quite an abrupt leap in HP when you hit it or come on to the pipe. Hence the term 'pipey'. I guess a cold pipe that gets the right amount of heat in it just as the machine comes on the pipe could contribute to the effect.

As far as keeping heat in the pipes, you can wrap them or have them ceramic coated, but you want to be careful . Too much heat in the pipe can and will lead to detonation.

Had that problem with a 99 ZX440 w/high compression heads installed. I needed to run 114 octane fuel and load the engine as much as possible so that I could get enuf heat into the pipe. There are different ways of loading the engine but I needed to add a ton of weight in the primary.
Good luck.

dunittoo how much weight did you need and what kind of compression did your motor pull?
thanks weston

If you can afford to retard the timing a dgree, that will put a extra heat in the pipe, too.

Sorry can't remember what the compression was but it had a very tight squish. They don't run that tight in any 440's after 99. The amount of weight you add depends on your clutch setup, I added 5 grams. Your compression also would make a difference on the amount of weight you add. I know others that were running 7 or 8 more grams than stock with that clutch setup.
That sled was awsom, stole alotta $$ at the race track, all the way up to 700 class sometimes. A 99 zx440 placed 3rd at Hay Days last summer.
Do you have a 99 ZX440?
Dynamo Joe sells a good clutch kit for 440's

Dunitto...Do you know what the squish was on the 440 you refer to? I think that all of the production engines have to much squish gap.

dunittoo: yeah it is on a 1999 mxzx 440 right now I have goodwin heavy pins at full load (22 grams of pin weight).my compression is 185. Who was running this sled at haydays?

Idooski: I my squish measures .050.

Im looking for ways to load the hell out of this motor to build pipe heat dont really want to change the timing (last resort) When you back out of the throttle and the zoomies go away you better hold the hell on 'cause this thing really rips.
later

What pipe/pipes do you have on it? Can you wrap it or part of it? Ceramic coat? Not good to close the vents. The engine needs the air too.

I think that .045-.050" would be real good for that engine.

idooski it has the factory pipe with the clamshells and the insulation. any ideas on how to load the engine harder?

I guess I'm just not quite sure what you want. What are you doing with it and what do you want to do? What set-up are you now using and what reaction? Once we know more, we may be able to toss you a bone or two.

I talked with Tom at the race dept on Friday...I don't know about changing the timing as a last resort.

Tom Writes:
Yes, I can reprogram the ignition box for drag racing. Unfortunately, programing the box will increase the "wack offs".

There are 2 things you can do to reduce them. 1st - warm up the engine on the line by accelerating 3-4 times until the pipe is hot. 2nd - clutch so it pulls the engine hard. Set the primary clutch so it engages around 5500 RPM, and when you accelerate for the holeshot, the engine should run at 8200 RPM. As you move down the strip the engine RPM will climb to 8400.

Try
19/43 gearing
Work with the driven spring @ about 15-18 lbs
===================================

Joe Writes:
Tom forgot that the 99 is an 8500 engine. The 00-03's are 8400 engines.
So for the 99, it should be [8400 tach rpm to 8600 tach rpm] knowing tachs are out.

The helix you have starts pretty big. And from what Tom says about loading hard, I say that 22 grams is plenty hard.
More ways to get the exh pipe hotter/quicker is to run 40 or 45 pilots and the needle on #3 or #4. Need fuel to be put into the exh pipe to get it hot. Not enough fuel, not enough heat.

The timing advances very quickly. The timing advances with engine revs from engagment to near peak rpm. Have to slow down the time it takes for this engine to get to its peak. Have to make it labor more.
So lets add what you have going for you right now:
*Large helix angle off of start.
*Pretension is set at 18 lbs
*22 grams of flyweight....WOW!

Can add to loading by lowering gear from the original 21 to a 20, 19 top gear.
I think that further loading must be done thru suspension work. Lighter torsion springs and the rear/rear shock rebound valve stack changed to slow the rebound.
The pipe is really hard to get hot quickly if you spin the track off the line.
You need to load the engine with the chassis transferring making the sled hookup hard.
When you make the engine labor because you have traction, the engine builds HP Quicker.
Have to think that when under acceleration you want the "Chassis" to have its FULCRUM point around the bolt of the front swing arm.
Rails flat on the ground and you do not want them to come off the ground under acceleration.
You pin the fuel and you want the sled to transfer "teeter totter" around that front bolt...forcing the
weight of the chassis thru the center coil over shock...pushing the front of the rails on the ground.
You do not want the front of the rails to come off the ground, right?!
This will load the clutches heavily.

For fun how about taking the secondary spring out and install the beige spring @ 18 lbs and see what happens.

........damn but these 99's can be trouble :angry:

Sorry can't remember the squish, I didn't write much down when I had that sled, live and learn. The 99 did have the highest compression head inserts of all the 440's, 15.5 I beleive.

My mistake, it was 1st at Hay Days, Billy Howard.

I tried wrapping the pipe & I tried a cdi box from a cross country race sled that had it reprogrammed but no difference. I added as much weight as the primary would handle before losing r's and then had to rev the #### out of it on the stand just before the race. Most places wouldn't give you that much time at the line.
I think Joe is probably on to something with loading the engine harder by using the suspension, and using bigger pilots. It is also absolutely necessary to run 114 octane.

I know what you mean by "hang on when the zoomies stop" it's like hitting another gear.