[engine_work] Xu9j4 Mi-16 Rebuild

[kyepan 291]

 

 

Plus a little bit of work with the angle grinder on the slam panel - stand by forum health and safety police!!

 

This is a video by the way.. Click to view

[DrSarty 90 1 Cars]

Good work Justin.

 

And you may choose to ignore this...but your lovely power cables between alt-starter-battery seem a little longer than they could be. Any additional cable adds resistance, so wherever practical (with a little slack for engine movement of course), I do my best to keep all power and earth leads as short as possible.

[kyepan 291]

Good work Justin.

 

And you may choose to ignore this...but your lovely power cables between alt-starter-battery seem a little longer than they could be. Any additional cable adds resistance, so wherever practical (with a little slack for engine movement of course), I do my best to keep all power and earth leads as short as possible.

that's just an optical illusion, look at where the connector would be when the battery is connected, vs where it is hanging.. i'll update some more later perhaps.

[kyepan 291]

So i've been meaning to continue the story for some while but not got round to it..

 

Here is my fuel rail conundrum - the previous owner did not use the outer rail, so it had no FPR, i needed a temporary fix to get me to mapping and back until it could come off the car and be properly tapped and bunged. Dons cowboy hat and spurs.....awaits abuse.

 

The hole had a conical top.

 

so I found something suitable to place in it that had a similar chamfer and diameter.

which happened to be a cut down mini wheel stud

 

filed the top flat so i could plate behind it.

 

Then used a dab of sealant around it and screwed on an alu plate behind it that I cut to size to clamp it in place.

 

I was superbly paranoid about this bodge

 

Note the s*itty blue hose clip.. more on that later.

 

here is a video of the engine running on a base map

 

Things to do before the mapping date, which was about two weeks away.

Get the exhaust fitted at long-life, tom (cheesegrater) use them and said their welding was quite good.

Time the cam - more on that later

 

In the mean time i also popped to see paul Guardias who kindly knocked up a shim for me to use the DW8 pulley that anthony very kindly acquired from a scrappy.

[welshpug 1,666]

ooo how thick was your shim? I need a 2mm one for my narrowed gti6 pulley.

[kyepan 291]

my measurements were a bit off...23,9 should have been 25, and 4.9 should have been 5. but you get the idea.

[kyepan 291]

I wrote a very long post explaining the next stage of the build, and then somehow during editing, i thought i posted it, and must not have so here it is again.

 

After going to long life and getting a nice stainless exhaust fitted to the car, it was one week to the mapping and the camshaft needed timing. I'd been waiting for a shim from Paul Gardias, and here it is.

 

Anthony popped over to give me a hand and Paul also came over to have a look at timing up a cam, as he wanted to see it done. The day turned out to be a long and ultimately frustrating episode for all of us.

 

 

First off, we discovered that the DTI needed modifying to get it onto the back of the lifter. We donned our stetsons, spurs and then delved into dads cave of a garage for something to extend the DTI with..and some minutes later were proud to have stuck a bit of welding rod in the end.

 

We also used some of the cut up old slam panel to making a plate to mount the dti onto, again a bit of Yee haww later, we were cooking with gas.

 

Finding TDC, I had fitted the timing indicator from later xu's but we still wanted to make sure we had one of the pistons at tdc, so a long socket extension down the plug hose sufficed to help us make sure we were on the money. Granted i can see why people mark up tdc when building engines, the amount of dwell at TDC where the DTI was not moving at all was enough to make timing a cam shaft off of that a total nonsense. Thankfully we had the marker on the flywheel, which we repainted.

 

At this point Tom (Cheesegrater) turned up with a slam panel he very kindly cut and welded with some threaded rod. He posed in the photo with his handy work.

 

Some of the welding he was keen to show to the forum welding police...

 

It is suprisingly strong, in fact, it's stronger than the un cut original! thanks Tom!!

 

 

 

Next the belt came off and we had to file the shim a smidge to get it to fit.

 

Then we had to file the inner section of the vernier to get that to fit, funny though because it fitted a cam we tried previously. Peugeot tolerances.

 

So then we got the pulley on, belt on, timed it up and ran out of travel on the pulley trying to get 0.65mm at tdc, bugger.

 

So apart it came again, belt off, then we smarted up and only moved the outer verner section ( a key point for later) Moved the pulley outer round to get more adjustment and off we went again.

 

By this time it was getting dark so we had to get "The Sun" out, it's the 400W halogen lamp...

 

Now i've been concerned about getting this bang on, and we did take our time to really get a repeatable result.

 

After all this we started it up and it ran, Paul yelled stop almost immediately, he has a keen eye for things.

 

It would seem the cam was wobbling, it was wobbling because when the outer got moved it got placed onto a raised part of the inner, on the piss... you can see it here..

 

This meant the outer and had to come off again, rocker off, belt off, the timing had to be done again. Que. sick feeling in pit of stomach... It was Dark, 10pm and we had already made a tiredness mistake, chances are we would miss other things out.. So we agreed to leave it for a few days.

 

This was tuesday, and I was going for mapping on the friday, the car was in maidenhead, i was in ondon, so what that actually meant, was after work thursday i would come back, and pull it apart , then get up super early friday and drive the 200 odd miles to cornwall.

 

Ant and Paul for some inexplicable reason seemed very keen to give me a hand!!!!!!

 

J

[kyepan 291]

So come Thursday, mapping was the next day, I managed to work from dads and came out from london the night before. By the time Ant arrived i'd got the rocker off, belt off, and outer pulley off. For the sake of worrying it was bent, Ant brought another outer he had harvested in the intervening period from the scrappy.

 

So off we went again with the timing, this time we got it bang on, better than bang on... I was being really fussy, so thanks for your patience guys.

 

Timed up, happy, off for a drive with ant, ran fine felt fine, pootled up to the motorway junction, sitting at the lights, we get a call from paul, who has just found the oil spray bars at the back of the garage!!!! s*it

 

We drove the mile and a half home very slowly.. Paul's eagle eyes saved me again!!! thanks paul... We all had a chinese to celebrate and finished about 10-11pm.. I'm still indebted to both of them. Thanks guys!

Edited July 15, 2012 by kyepan

[kyepan 291]

Friday - mapping day.

 

Up at 4:50am... 188 odd miles.. on a base map. So that's 65 odd miles an hour, trying not to use any throttle, with throttle bodies.

 

Left at 5, m4 to bristol at 6 ish, stop at some services somewhere on the m5 about 7:30, and arrived at about 9. No issues!

 

Sandy was already there with one of his customers, another 205 that hillclimbs. Sandy was just tweaking the map before an event on sunday. I think he may have a video of it. It sounded nasty!!!!! He was having a bit of fuel stand off, because the filter wasn't on... on it went and that disappeared.

 

I hope Sandy doesn't mind me putting up his video of it! (this is not my car, it's a hill climb car with Sandy's engine in it.)

 

My turn on the dyno came, and I was bloody nervous, I said to sandy that if the engine let go i would be gutted. He reassured me that was a very rare occurrence. Men don't make babies, like women do, we do build stuff and an engine is as fragile as a baby in some ways, it was my baby.

 

He quickly put the new connectors on the second injector loom, with new pins, properly soldered, he said it maps differently if soldered.

 

So we got the car on the rollers and off we went, gradually working up in load and RPM.. I asked Sandy to make it pop a little on Overun, because i'm a tart.

http://www.youtube.com/watch?v=N0I0gFF4W7o

 

 

Everything was going fine until smoke started coming out of the back end...blue ish smoke. We shut down let it cool, i contemplated how to get home.. how long the AA would take.

 

We fired up again and it was fine. Here is a video of him doing some of the higher load / rpm sites. Sandy said "its still bedding in" as we did the mapping, because it started asking for more fuel under load as he continued. It had done several thousand miles already since the rebuild!! But was actually running in as we gave it more fuel!

 

http://www.youtube.com/watch?v=7X4FTERY_VE

 

After about ten minutes, more smoke, this time much more, we shut down again and i started investigating for leaks, anything. under the car.. black stuff, dripping... AHHHHHHHH... underseal melting! Proximity of fancy manifold to body!! close.. heat.. melting, dripping.. etc.

 

Sandy said it was pretty much done anyway, and we could do the rest on the road, we went out for a spin, sounded great. Sandy trimmed some of the very light throttle advance to make it a bit more suitable to my tastes, as it will be driven in traffic alot, sacrificing a bit of light load efficiency. But there you go.

 

Big thanks to Sandy! His expertise and professionalism are a credit, and he really knows what he's doing, hence travelling 200 miles to see him.

 

I must admit i was a bit overwhelmed by the whole day and didn't really appreciate what I had until more than half way home. Sandy commented that it sounded like a super 1900 engine. On the way back i was grinning and jibbering like an idiot!

 

What's it making? lots of torque, everywhere, and lots of noise, when the throttles are open!

 

Got about half way back up the M5 and smelt fuel when giving the throttle a vigorous poke... stopped at the services a mile later to find the trumpets had come out, not enough silicone holding them in.. fuel stand off perhaps! put them back on and cable tied the filter in place to hold them there.. and continued without issue.

 

Stopped in to see Ant on the way back, had a bit of food at the pub and let him take it for a spin, it was wet, very wet, and so he mostly experienced wheelspin!

[Anthony 1,003]

Then we had to file the inner section of the vernier to get that to fit, funny though because it fitted a cam we tried previously. Peugeot tolerances.

 

So then we got the pulley on, belt on, timed it up and ran out of travel on the pulley trying to get 0.65mm at tdc, bugger.

 

So apart it came again, belt off, then we smarted up and only moved the outer verner section ( a key point for later) Moved the pulley outer round to get more adjustment and off we went again.

Your memory is playing tricks on you again J - getting senile in your old age

 

The cock-up with the vernier came about long before we started timing up the cam. When the vernier wouldn't fit the end of the cam properly and we were taking it on and off repeatedly and struggling fitting it around the belt each time, I separated the inner and outer sections of the pulley to make it easy, and once we'd sorted the inner, you put it back together with the bolts still loose - so it all looked fine. Unfortunately, neither of us spotted that the DW8 pulley will only go back together one way thanks to the small raised section, unlike most verniers that will go back together any way around.

 

When the bolts were tightened, then it pulled itself skewed but we didn't spot it initially and proceeded to time up the cam (and yes, needed to release the cambelt tension to knock the pulley back a tooth so that we had adjustment on the vernier to correctly set lift@TDC), although in hindsight I should have clicked that something wasn't right by the fact that I was having to undo the bolts more than usual before the pulley would move rather than just assuming that it was a bit sticky. It only became obvious when the engine was started, as then with the pulley rotating at speed, the skewed fitting showed up as a massive wobble.

 

Had the pulley fit on the end of the cam properly, we'd have had it all done in a single day - bloody French tolerances indeed

[kyepan 291]

you are correct, and have the memory of an elephant! french tolerances.

[Anthony 1,003]

Good write up though J, and from the short drive I had, the engine is a credit to your hard work and persistence

[petert 600]

Who said 0.65mm? I hope that's a typo, as it should be 0.065" or 1.65mm.

Edited July 16, 2012 by petert

[Anthony 1,003]

It was set to the figures on your website Peter - 1.65mm as you say

 

Interestingly, on the old standard #4 pulley, it was slightly retarded with something like 1.30-1.40mm @ TDC (can't remember the exact figure now) which I found strange as I through the #4's should be slightly over-advanced if anything?

[petert 600]

Yes, I would have thought the #4 would have given it a bit more than that, as a #3 get's it in the range 0.060-0.065".

[Anthony 1,003]

Thought as much.

 

I didn't look into why it didn't seem to be as expected as I was only taking a reference figure to go back to if needed. The crank/cam pulley timing holes all lined up though, we used the flywheel TDC location as per your website (which was verified using the dial gauge) and I double checked the measurement given that the first one wasn't as expected.

 

Strange. Still, all correct now with the vernier fitted.

[wicked 105 3 Cars]

How many bhp did it put on the RR?

 

Regarding find TDC; it can be tricky and you should not try to measure TDC with the DTI @ TDC.

 

This is how I do it:

 

 

- Mount a timing disc on the crank; 0 degrees at what you think is TDC

- Measure the piston height at TDC-x

- note the height:

-Turn the crank to approx TDC+x until the piston height is the same

- Look at the timing disc:

- If it deviates with lets says 6 degrees from x; turn the disc 3 degrees on the crank and start over until you find the height equal for TDC+x and TDC-x

 

- turn the crank to TDC and mark it (and lock it)

 

 

If you try to find TDC @ TDC, your measurement error is way too big and you can easily turn the crank a degree or 2 without moving the needle.

Maybe the picture makes it more clear:

 

 

 

Blue is the error in your DTI measurement and that translates to an error in you angle measurement.

If you also assume your measurements uncorrelated, then 2 averaged measurements are more accurate than a single measurement.

[wicked 105 3 Cars]

Example timing disc:

 

http://www.ebay.co.uk/itm/TIMING-DEGREE-DISC-A-MUST-FOR-ENGINE-REBUILDS-/120880900325?pt=UK_Motorcycle_Parts&hash=item1c251028e5#ht_500wt_1413

[kyepan 291]

The next day paul and i went out and shot a little bit of video on a private road.

[kyepan 291]

Soo....... here goes, have a look at these and let me know what you think.

 

The same day as taking the video with paul, I went to "surrey rolling road" an older dyno dynamics rolling road with a good reputation for conservative figures. (spin out of the way)

 

184bhp, 160 ftlbs of torque

 

Here's two graphs (both superimposed in photoshop as accurately as i can)

My pre exhaust / bodies / mapping run with the surrey run super imposed.

 

 

My post exhaust / bodies / mapping run at surrey, with the earlier run super imposed.

the second graph is more interesting because you can more clearly see the difference in torque.

The mid range dip has gone, and been replaced by a gradual up lift.

 

Cheers

J

[welshpug 1,666]

very nice, its removed the usual trait that most MI's have of the torque and power coming in with a wallop at 4-4.5k

[Anthony 1,003]

Interesting, as that's the first I've seen of the before and after RR graphs.

 

If ever there was a good example of the need to look beyond peak hp figures, this is it - "only" 15hp up on before at peak which doesn't sound like a great deal, but the difference throughout mid-range is huge (25-30hp) and certainly made it much quicker on the road from what I drove of it.

 

(obviously the usual considerations comparing the results from two different rolling roads applies!)

[Tom Fenton 1,547]

When we fitted bodies to our Mi16 it showed a similar difference, the numbers were nothing to shout about, but having driven it before the work around Cadwell Park for something like 200 laps it was very interesting to see the difference in the car, speeds at the end of straights, and the way it would pull up the Park Straight (up a bank) afterwards compared to before.

[wicked 105 3 Cars]

184 bhp with that torque curve from an 1.9 Mi16 is respectable.... *applause*

Edited July 18, 2012 by wicked

[kyepan 291]

Any more thoughts anyone? I really don't mind a bit of debate over this, it is what it is.