7 port ignition mapping issue.
Turbo Mini Forums

Ive got 60mm Trumpets and Throttle bodies are 90mm in length. Im using normal size vale stems.

I cant remember flow figures, but it was about 12% better then a fully modified race head.

Fueling is spot on at 12.8AFR all the way.

Edited by alaskanow0 on 1st Sep, 2012.

Class C 3rd Place Avon 2011 14.18 @101mph

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

On a dyno, you adjust in 1/2 degree increments to find optimal admitted but just adjusting a couple of degrees cos someone said it helps is just daft, as I said. They design a cam to do a job, you select a cam to suit the engine.

Edited by paul wiginton on 1st Sep, 2012.

I seriously doubt it!

I like the super clean engine bay btw kudos!

I reckon that the intake tract is ca 25 cm long now. And to be honest that is very near 4th harmonic for 7.5K and really should not be the problem. you could try 13 inches chord lenght for a peak rpm of 7500 or for 6.5K 11.8 inch (4th) or 15 inch (3rd hamonic).



is the fueling spot on on the ecu or on the dyno wideband ?

the CSA of the port entry is a good 40% too big according to pipemax (it tends to be not far off).
according to my iterations/dead reckoning ( very dead i might add) the port entry CSA is just about right for 14000 rpm. :)

That sir, is not rust, it is the progressive mass reduction system

http://aseriesmodifications.wordpress.com/

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

I seriously doubt it!

I totally understand both of your points, but I was recommend to alter cam timing, by very experienced engine builder, tuner & author, with 40 years experience building performance engines and lots of data with different cam timing form the dyno. Im no expert, I can only trust people, who have nothin to gain from sharing this information and such experience.

To be a fair, he does have very little experience with the SW10, but knows the Kent 286 extremelly well.

With regards to the cam choice. I would have prefered a milder spec cam, but I'd already bought the cylinder head and was told it would be a waste of time with the head. As already agreed the head needs revs to excel.

I still think the camshaft is the right choice, but the choice of a Webcon 7 Port head for normal roadgoing mini was the wrong one. Also should have gone with a 3.44 FD.

Edited by alaskanow0 on 1st Sep, 2012.

Class C 3rd Place Avon 2011 14.18 @101mph

Talk to Swifty about the cam, see what he says. He is the ONLY person I trust when it comes to these things

I seriously doubt it!

I plan to speak to Nick on Monday. Tomorrow am going to double check cam timing is at 106 and investigate spring heights and crush.

Class C 3rd Place Avon 2011 14.18 @101mph

Let us know about the springs, its interesting

I seriously doubt it!

Vizard would recommended 106 degrees, because that is what the 286MD Lobe Seperation Angle (LSA) was ground on. The SW10 is NOT the 286MD. The SW10 is ground on a LSA of 108 degrees. I think either yourself or Vizard has been missled in thinking that the SW10 is the same as a MD286.

The LSA is a fixed figure, not a variable one. It is the figure that the inlet and exhaust full lift occurs when the cam is timed straight up. The MD286 is timed straight up at 106 and the SW10 timed straight up at 108.

advancing the SW10 by 2 degrees will give 106/110 timing.............It's not the same as the MD286 timed straight up at 106/106. This is the point that Paul is trying to put across.

While in some situations advancing the cam will produce results, it is far better to start with the cam timed to the manufactures figures, and then advance/ retard on the dyno to see that the change nets a worthwhile result. If you do not have the ability to advance or retard the cam, nor the time or money to do it while on the dyno, then you'd be daft not to time the cam straight up in the first instance.

That aside, your issue with excessive ignition timing needs to be bottomed out. I'd do as Robert suggests, but use your own timing marks on the pulley, which have been set using a DTI gauge to find TRUE TDC (this might be difficult with the head on). Set the cranking advance to zero, set any zero adjust on your timing light to zero, disconnect all injectors, and then turn the engine over on the starter while strobing the timing marks you made at TRUE TDC to see if they line up. Adjust the 'sensor position' under 'general engine settings' to get the marks to line up. If all you have used is the Crankshaft scope in DTASwin, it can still be a good way out. The scop is only used to determine a starting point to get you going and tune from there.

And also make sure you have no timing compensations etc.

Does the datalogging or real time display indicate the same value of 47deg ?

When using TPS as main load, it would be easy for other compensations to be applied unless you have zero'd them.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Ok guys I get you point, Im going to put the cam back to 108 anyway. The sensor postion is based on number of missing teeth and fine fined with on timing gun, the Dta crank scope was way out. Head is off, and I've double checked TDC with DTI. Do you think I will be able to check timing with the head off ie, if I disconnect fuel pump and just plug TPS in and set others sensor to default and set advance to 0 across map. ??


The advance amount in Real time mapping also matches the ignition map. There are no ignition corrections being applied only fuel ones.

Edited by alaskanow0 on 2nd Sep, 2012.

Class C 3rd Place Avon 2011 14.18 @101mph

How can you check timing with the head off ?

You'd need the engine running to verify ignition timing.

Or do you mean cam timing ?

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Ignition timing from cranking. It's was just a silly thought.

Edited by alaskanow0 on 2nd Sep, 2012.

Class C 3rd Place Avon 2011 14.18 @101mph

dont see why not matt , spin it over with the head off, and plugs in the leads ,althuogh you may not get enough spark energy with no compression to trigger the strobe .

but you might get a bit messy from the oil and water spraying about ?

i hvent really thought this through though ,there maybe some obvious reason my pea brain hasnt thought of lol.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Class C 3rd Place Avon 2011 14.18 @101mph

Ok, ive removed some valves and my findings are

Valve Length 3.57

Actual Fitted spring length 1.357 v 1.375 spec from minispares.

The springs are

http://www.minispares.com/product/Classic/...h/classic/valve springs.aspx|Back to search


Cam lift with 1.5s is 0.437
minus valve clearence 0.016

Total compressed height on full lift 0.935

Spring is not fully compressed and well over 0.050thou between coils.

Edited by alaskanow0 on 2nd Sep, 2012.

Class C 3rd Place Avon 2011 14.18 @101mph

Do the valve guides bind with the topcaps ? I have had that happen with the valve seals being chewed up (Checked coil bind, but did not check this)

I prefer using the dead stop method instead of DTI ( 10mm down the hole note degrees divide by two). I find that easier to find TDC with the amount of dwell. I tried it with a sparkplug deadstop i fabbed ( to doing it with the head on)but that does not work well IMHO as the piston rock makes accurate reading impossible. In your case I think the angle of the plug is almost horizontal so not much use anyway.

That sir, is not rust, it is the progressive mass reduction system

http://aseriesmodifications.wordpress.com/

Im even more confused now as to why increasing tappet clearance improved things.
I tried those valve springs on Pete Baldwins recommendation but I found they were bouncing from 6k revs, Calver checked them for me and although he found no problems with the springs my problems went away when I fitted Swifty springs

I seriously doubt it!

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Wouldn't increasing the valve clearance delay the opening of the inlet, causing a higher vacuum in the cylinder before the valve opens. Wouldn't this cause the air to be drawn in at a faster rate to fill the cylinder, and have the effect of higher air speed through the ports...I could be WAY off though!

https://www.facebook.com/pages/Fusion-Fabri..._homepage_panel

www.fusionfabs.co.uk



1/4mile in 13.2sec @ 111 terminal on 15psi

Class C 3rd Place Avon 2011 14.18 @101mph

The DTI method works just fine, as does the spark plug stop, since piston rock will be the same at both measuring points.

Class C 3rd Place Avon 2011 14.18 @101mph