ESE's works engine tuner

[G Jones]

I tested a pipe set back to back, one with as you say the "bumps" ground off the other with every joint hammered flat.
This is easy if you are using gas with the very soft mild steel ferrox rods.
The hammering can be extended each side of the join line and makes a nice smooth transition, especially in a tight turn up near the cylinder.
Bottom line is that the hammered pipe made around 1.5 Hp more all the way up to the same power at peak, and same in the overev.
I tig every pipe now as its way cheaper consumables and faster, but the tig rod filler in small holes is too hard to hammer flat, you have to flap wheel the
bumps, but if I was going for the ultimate setup I would gas a pipe and charge a cheap more to do it.
Most people wont pay for this and wouldnt notice the difference anyway.

Thanks for sharing the "gospel" - just curious about smoothing out the "bumps" - what do you do about the closing joint - or is there always one joint with some bumps ?....

[wobbly]

I always finish at the rear cone, and use a solid mandrel rod the same dia as the stinger hole, clamped in a vise.
I have several with a smooth long radius ground on one side of one end.
Sometimes I actually mark on the mandrel where the end of the cone should sit, to have the join
exactly over the rad, but you can always hear the sound change when hammering the pipe metal onto the flat mandrel surface
and juggle the pipe position as you move around the joint.

[speedpro]

I made the rear cones and welded that to the centre section on the new pipe for #3. This time I just spent a bit of time getting it pretty right tacking it on before I finished welding it and didn't bother with further finishing. Being the largest diameter portion of the pipe I figure it's the least critical joint. I really would have preferred to finish the header portion a bit better as there are definite "joints and sections" rather than a smooth curve.

[2T Institute]

Huge EGT temps mean Jack Shit, I have seen idiots with a stock head TZ350 running 2 base gaskets that saw 1360 for 20 laps without seizing.
But funnily it was 5 seconds off the pace of a properly tuned one running 1245/1255 on AvGas.
Getting the max com and max advance possible for the fuel ,without deto is the key - and for AvGas or up to 110 race gas ,mid 1200s at max power means you are on the money.
One jet leaner , if it only sees around 20 to 30* hotter, means the optimum is back one jet richer, as the perfect scenario is 50 to 60* per jet change, as this always gets back to the max power available.
Sure the oil must be good with so many top teams running it, but telling me you have seen 1300 ( like some sort of red badge of courage ) just means the rider wasnt watching the gauges/and or ignored
the warning lights ( and should be shot ) or someone made a wrong tuning call on an engine that wasnt on the money to start with.
On unleaded it would be detoing unhappily around 100* richer at 1200 if tuned to the edge.
If it was really on the limit, it would have locked up at 1300 ,no matter what oil was on the bore.

No it's jetted on the money at 1250F each time it hits the track, but there is a certain amount of time it takes to get the carbs/airbox/fairing back on and be out on the dummy grid and in that time 'something' changed and EGT's were regularly hitting 1300 at the end of the straight, the rider owns the bike,pays the bills and ultimately it is his decision what to do when the EGT starts flashing.He decided to go for it, taking T1 at full noise with his hand over the clutch each lap. Other oils hit 1300F once or twice in a race and the pistons show the deto or go bang. His opinion was the xeramic oil saved a seizure.

[wobbly]

But its still my firm belief Lozza,that with another 1.5 degrees of advance or another 1/2 ratio of com the engine would have siezed when pushed to 1300.
With the jetting on the money at 1250, then logic dictates that it would also have been faster, running normally with the extra advance or com.
The only reason an engine doesnt sieze when running at 1300 is that its not maxed out at 1250.
Like I said running the TZ350 with super low com, it ran all day at 1300 + but was dead slow.
If the engine saw deto when running at 1300 before, I simply cannot see how changing the oil can make that deto go away - sure a super oil
can prevent a lockup by simply being a better lube on the bores - but somehow killing deto .Na, that would mean the oil affects the octain rating of the fuel - making it illegal
and it certaily isnt in CIK.
As you say - something changed, to allow ( and cause ) that mental temp to occur, and whatever that issue was, it increased the thermal death limit of the
engine,and thus by inference,it must have reduced the performance level to allow that to temp happen as well.

[F5 Dave]

With my egt sitting safely on the shelf as it has for last couple of years after a false start & loss of drive to re-experiment (I'd inserted the tip too far in on a tiny 50cc pipe and it was overheating the returning charge I believe as when I removed it the power returned),


annyhoo. You're stating the temps as constants. is this assuming that the position of the probe is i the correct place in the pipe? Or could you distort the readings required by placing in incorrect place or wrapping the pipe? perhaps they would only get cooler than danger zone.

[wobbly]

I have had the probe anywhere from the flange face ( like Aprilia did ) to around 75mm from the cylinder.
The tip would normally be in the middle, but on the dyno I have done tests with it only 10mm inside the pipe.
Never seen any difference in the readings, as Robin Williams said " its hot, damn hot ".
But wrapping the header is a very bad idea, overheating the return gas slug causes deto, so no free lunch there.

[husaberg]

If the engine saw deto when running at 1300 before, I simply cannot see how changing the oil can make that deto go away - sure a super oil
can prevent a lockup by simply being a better lube on the bores - but somehow killing deto .Na, that would mean the oil affects the octain rating of the fuel - making it illegal
and it certaily isnt in CIK.
.

But doesn't all premix oil effect the Octane? just some worse than others......
I guess you are meaning a positive effect? rather than a less of a negative one than previously was occuring?

[F5 Dave]

Never seen any difference in the readings, . . .

Ok got it.

i mentioned wrapping as a variable someone might be employing that might get different results. I I haven't wrapped my pipe since the 90s when I'd seen it on GP bike pics but a Cameron article sorted me out explaining the sled origins.

[wobbly]

The egt readings converging to 1250* for Avgas or up to around 110 octain leaded, at peak power, is just another piece in the jigsaw of trying to optimise the com and advance of an engine
to achieve the ideal BSFC for the fuel being used.
Not enough com and or advance and the egt will run hot, needing more fuel to lower the temp.
This energy carrying fuel mixture is then not being used to create power, but simply lower the egt.
As I have said before the synergy of fueling, com and advance can be detected easily on the dyno, and on the track.
If you progressively lean down and get to just on 1200, then go down another ( Keihin/Dellorto ) jet size, the egt will rise another approx 50* if everything is on the money.
If you only see 20* rise, you are operating on the cusp of diminishing returns due to too much advance, too much com, or too small a stinger.
An engine running in this zone will react badly to even small increments in RAD.
If by chance it then runs any leaner due to a drop in ambient temp say,it will sieze, any richer and power will drop.
Going the other way, if you see 1250 with the single jet change, and then the RAD makes it go leaner, and it jumps up to 1300, then the engine wasnt BSFC optimised in the first place.

[ken seeber]

Wobbly,

Your acronym RAD, what is it? Really Awful Detonation, Replace After Detonation.....?

Keep up the interesting flow of info, it's great

Thanks

Ken

[wobbly]

Relative Air Density.
Each 3% away from your dyno baseline of Air Temp, Humidity, and Pressure is a one jet change, and should get you back to your best power egt.

[F5 Dave]

The egt readings converging to 1250* for Avgas or up to around 110 octain leaded, at peak power, is just another piece in the jigsaw of trying to optimise the com and advance of an engine
to achieve the ideal BSFC for the fuel being used.
Not enough com and or advance and the egt will run hot, needing more fuel to lower the temp.
This energy carrying fuel mixture is then not being used to create power, but simply lower the egt.
As I have said before the synergy of fueling, com and advance can be detected easily on the dyno, and on the track.
If you progressively lean down and get to just on 1200, then go down another ( Keihin/Dellorto ) jet size, the egt will rise another approx 50* if everything is on the money.
If you only see 20* rise, you are operating on the cusp of diminishing returns due to too much advance, too much com, or too small a stinger.
An engine running in this zone will react badly to even small increments in RAD.
If by chance it then runs any leaner due to a drop in ambient temp say,it will sieze, any richer and power will drop.
Going the other way, if you see 1250 with the single jet change, and then the RAD makes it go leaner, and it jumps up to 1300, then the engine wasnt BSFC optimised in the first place.

I better save that somewhere. Thanks for the insight.

Time to pull out the egt again. After finishing the triple port barrel. . .

and then theres that job in the bathroom. . .

[Frits Overmars]

and then theres that job in the bathroom. . .

You talking about a daily occurrence? Like BYO (bring your own paper)?

[F5 Dave]

I'm only 46 so fortunately that's still a 5min operation. No a year ago I bought a section of acrylic sheet to make a moisture trap over the bath/shower above the shower curtain. It's been hiding and yesterday I dragged it out,clamped it to a table with a 200mm sewer pipe off cut for a radius and bent it slowly with a heat gun. Worked a treat. Re measuring to do the other side. But then I'd have to put it up.

Well winter's almost over,(with some poetic licence) don't really need it in summer. Won't store so well now. Better things to do in the garage.