Mi16 Engine On Webers Rolling Road

[Banjo 1]

Who built the engine? With forged rods n pistons and carbs you wana be running a high compression ratio, should make more than 170 brake!

[brianthemagical 1]

when my car went on the rollers in feb 06 (std xu9ja) it produced 110bhp at the fly with 30bhp transmission losses. i have a printout fron 97 for my car which also shows 11o bhp at fly on some rollers in norfolk. not sure if my engine should have lost something or not but that should give an idea of accuracy. they do seem very good at sas.

[driversdomainuk 8]

Do you actually have the printout as from your post on the previous page you implied you didnt as you were going to ask them what revs they took it to? Surely they gave you a printout, if it doesnt have revs but just road speed you can (very tediously!!) work it all out going backwards as long as you know your gear ratios, work out tyre diameter etc which is what I had to do with mine. I am no expert but most printouts ive seen certainly of the mk2 Mi16's in zx's and S16's are still rising as they hit the limiter. Mine tailed off at 6600 which was at 168bhp but with original injectors which only flow to 180bhp and my cam profile is something like "2500-6500" so I presume its related to one of them

 

Here is mine so you can see I dont upshift until just before 7200 though as its still better to hold the gear as power isnt dropping off and means higher rpm/bhp when I go into the next gear

 

 

My print out, from a Bosch rolling road is very poor quality. it is sort of produced showing kw on vertical axis and rpm below. The graph is on this sort of tracing card, so when I put it in my pocket the coins etc damaged the surface...so I could not tell. There is probably a technical term for this but I dont have a clue. Only thing I know is that it was not on a nice clear printed paper readout.

 

Before you ask, he converted kw to BHP which equallled 167bhp

[monty69 6]

Best thing to do is check dizzy timing with stobe light an see what max advance it makes and at what revs. I bet a lot of dizzys are worn or seized. If need be make your own marks on ring gear teeth. Mine at about 28 degrees and 10 tickover. Made 179hp at 6700,s16 twin 45s, 150 mains 175 air correctors 38mm chokes. If you have roughly these settings with good filter and exhaust and cam timing bob on then it should make good power.

[boldy205 74]

Monty69: So where have you set the dizzy? is it on full advance? i to have put some timing marks on the ring gear but have not yet strobed it. All i know is the RR chap kept winding the dizzy up and the engine kept making power untill on full advance (and still needing more advance) with a 1.9 dizzy on a 1.9 Mi16 with twin 45s with 36mm chokes.(otherwise Std.) .It does not 'pink' at all though, just a but 'jolty' on light throttle. Made aprox 170BHP. Just getting round to Megajolt ignition system so the results will hopefully be good!

[monty69 6]

The dizzy adapter has several stud holes for dizzy to be put in different position if full advance/retard is needed. i locked engine at crank pulley with pin which is 90 deg before tdc on s16 and think mi. Make sure is on compression stroke an not exhaust by making sure cams time up. Then marked tooth of flywheel with a mark on engine. Get assistant to turn engine slowly and count number of teeth on flywheel. might be easier to mark each ten as you will lose count!= Then divide teeth by 360, this tells you what one degree is. mine was 134 teeth divde by 360 = 0.37

so one degree is 0.37teeth

10 deg is 3.7 teeth

30 deg is 11teeth

Yours may be different.

I marked starting point (90deg before tdc) From this you can work out tdc and its easy.

tdc - (33teeth AFTER 90degress) Make sure assistant turns engine clockwise so flyweel will turn anti looking from gearbox side.

10 deg btdc (3.7teeth before tdc)

30 deg btdc (11 teeth btdc). Hope this helps. Rolling roads arnt always accurate for engine hp. Use strobe light set to zero off number 1 plug lead and see what mark lines up, should be near the 30 mark you made. See what revs full advance is made. Check idle advance. mine has no vac advance due to pulsing from port takeoff. Pulls very well all way through revs with 38 chokes. MAKE SURE IT GETS FULL THROTTLE!

Edited October 9, 2007 by monty69

[dean 0]

well my old mi on 45s got 171 and that was a standard engine and using standard management just had the ignition turned up by 3 degrese and the rev limter up to 7100rpm