[engine_work] Xu9j4 Mi-16 Rebuild

[kyepan 291]

This evening i will be probably getting the lifters soaking,

What brand of carb cleaner should i use? as all the stuff in halfords looks useless.

 

just spoken to Paul Gardias, head is ready for collection! Was not expecting for another couple of weeks, so it's got it's three angle seats and back cut valves now.

 

Need to get the block cleaned also, and start doing the bottom end.

 

Cheers

 

J

[kyepan 291]

Today i picked up the head from paul gardias, and what a difference, needed four welds due to corrosion.

 

Quesitons - the valves were numbered by who ever did the head previously, now will the be numbered 1-8 from flywheel end , or 1-8 from cambelt end?

 

Because the seats have been recut, and will be lapped in, will it make a difference to put them all back in original number order?

 

 

With the three angle seats being cut he has taken a little off the tops of the valves.

 

Now i don't completely understand why, unless because the seat is now slightly deeper, the valve would stand proud, so he's taken the difference off.

Nothing else will change because of this? correct.. because the valve will be showing the same length to the spring and the lifter and the cam, have the same lift etc..

 

Finally because the head was cleaned up we got to see the head work previously done in more detail, including the exhaust valve guides that have been completely cut back... (not something paul himself recommends).

 

Once the lifters are apart i'll refinish them and then reassemble the head so it's ready.

 

ps, do valve stem oil seals come as a kit with all the related head gaskets?

[petert 587]

With the three angle seats being cut he has taken a little off the tops of the valves.

 

Now i don't completely understand why, unless because the seat is now slightly deeper, the valve would stand proud, so he's taken the difference off.

Nothing else will change because of this? correct.. because the valve will be showing the same length to the spring and the lifter and the cam, have the same lift etc..

 

The problem is not the overall length of the valve, but rather the distance from the collet grooves to the seat. This has been increased by the seat cutting process, reducing the installed height of the spring (less seat pressure). The only way you can correct this is to put at least TWO shims under each spring. They're dirt cheap. Do it.

 

If you're keen, measure the fitted length by installing a valve, no seal, retainer and collets. Put a length of tube in, in place of the spring, say approx. 30.0mm long. Then drop the retainer onto the tube. Add the drop distance to your 30.0mm, and that is your new installed height.

 

I would have left the valves at their original overall length (effectively now longer) as the hydraulic lifter doesn't have to work as hard is using reground cams.

 

Cutting the guides back just reduces the life of the head. The guides will wear out faster. OK for a race engine but not good for a street car that you want a decent life out of.

[kyepan 291]

The only way you can correct this is to put at least TWO shims under each spring. They're dirt cheap. Do it.

understood, where would i get these from, peugeot? done a quick search but keep coming up with solid 29mm od kawazaki 650 shims.

 

 

If you're keen, measure the fitted length by installing a valve, no seal, retainer and collets. Put a length of tube in, in place of the spring, say approx. 30.0mm long. Then drop the retainer onto the tube. Add the drop distance to your 30.0mm, and that is your new installed height.

so the tube of known length pretends to be the spring. does the retainer get fitted with collets? I'm not sure i completely understand peter. can you describe dropping the retainer onto the tube, and where to measure from to.. i can't visualise it.

 

I've measured all the inlet valves and their lengths and min diameters are below.

1 inlet valve l = 105.72mm Stem width b min = 6.97mm - the engineer said this one had been replaced because he had to put a chamfer on it.

2 inlet valve l = 105.66mm Stem width b min = 6.95mm

3 inlet valve l = 105.65mm Stem width b min = 6.96mm

4 inlet valve l = 105.70mm Stem width b min = 6.95mm it's 6.97 for most of it's length as are all the valves except 1.

5 inlet valve l = 105.56mm Stem width b min = 6.95mm

6 inlet valve l = 105.68mm Stem width b min = 6.95mm

7 inlet valve l = 105.74mm Stem width b min = 6.95mm

8 inlet valve l = 105.75mm Stem width b min = 6.95mm

 

rebuild manual says 104.48mm ± 0.1mm ... so mine are a mm longer than spec, most confusing, especially considering they have been shortened, would this not reduce valve seat pressure further.

 

rebuild manual says 6.98mm ± 0.015mm .. so again mine are all at least 0.01-0.02mm out of spec, with the exception of number 1.

 

and put them back in order 1-8 as marked from cambelt end to fly end ready for lapping in.

 

new seats - inlet

 

deburred journal - the bad one

 

exhaust valve guides

 

new seats exhaust

 

 

cheers

 

Justin

[kyepan 291]

so the tube of known length pretends to be the spring. does the retainer get fitted with collets? I'm not sure i completely understand peter. can you describe dropping the retainer onto the tube, and where to measure from to.. i can't visualise it.

After a swim and some curry, i've figured it out, you compare the known length Plus drop, with the installed valve height, which I'm guessing is the first compressed value given in the rebuild manual - 38.8mm.

 

and the tube has to be long enough to hold up the retainer where the spring would normally come into contact with it.. i guess it's just a question of accurately measuring the drop from the seat. I'll lap them in first.

 

MEASURING VALVE GUIDE WEAR

 

To check guide wear, some machinists insert a valve stem into a guide and "feel" for looseness by wobbling the valve. Others may use a valve seat pilot tool to check the guides. Though either technique will reveal badly worn guides, neither is a very accurate method of gauging guide clearances or wear.

 

The best way to check guide wear is with a gauge set designed for this purpose. A gauge set will give you precise measurements and can be used to measure any portion of the guide. To check guide wear (as well as taper) using a telescoping or split ball gauge, measure the guide ID at both ends and in the middle. Subtract the middle reading from the ends to determine taper wear. Compare the smallest ID measurement (usually in the middle of the guide) to the factory specs to determine total wear.

 

Valve stems should also be measured to check for wear and sizing. Nominal sizes vary quite a bit depending on the application, and there is no way of knowing if the valve has been replaced previously with one of a different size without measuring.

 

Many late model engines have tapered valve stems. Taper stem valves are ground with the stem diameter smaller at the head end of the valve. This is done to create a larger clearance at the head where the temperatures are highest. This reduces the change of galling with unleaded fuel and narrow three-angle valve seats. When measuring a tapered stem, check the outside diameter about an inch in for each end.

 

is there a simple way to measure valve guide wear in situe with either a vernier, or micrometer?

 

cheers

 

J

Edited July 21, 2010 by kyepan

[Sandy 191]

You can see the guide length has barely been reduced and the length of these guides is pretty substantial anyway. What it does tend to do, is wear a slight ridge into the stem over time, but that only really becomes a problem if you cut the seats again with the same valves.

 

Taking pictures of headwork is not generally a good idea, because they're rarely flattering and every expert with a mouth will tell you it's wrong, so here I am. Like so many "three angle" cuts, they look unfinished to me! That can be good for mid range power, but not so much top end.

 

The part number for the Mi16 spring washer is 095312 (71p) and it's 0.55mm thick, the older TU 8v one also fits, part number 095131 (56p) and it's 1.0mm thick.

[kyepan 291]

The part number for the Mi16 spring washer is 095312 (71p) and it's 0.55mm thick, the older TU 8v one also fits, part number 095131 (56p) and it's 1.0mm thick.

Thankyou sandy! will washer it up!

 

Understand what you mean about photos being unflattering, i was concerned about the uneven material around the seat, but have been told that it is fine, and taking a dremel and very small stone to it would be "unwise".

 

cheers

 

 

J

[Sandy 191]

It's very risky trying to tidy around a cut seat, certainly not something I'd advise for someone who needs to ask the question, I mean that in the nicest possible way! Also, and this extends what I said earlier; if you've paid someone to do the work, it's probably best to trust their judgement and not interfere with what they've done. I'm sure Paul will have good reason for doing what he's done and I'd be most annoyed if someone tried messing about with one of my heads, engines, maps, whatever! There's more than one way to skin a cat and just because it's different to how I would do it, doesn't necessarily make it wrong. Much like the valve size debate!

[kyepan 291]

certainly not something I'd advise for someone who needs to ask the question, I mean that in the nicest possible way!

You're right the thing I need to do most is not make mistakes, and keep the risk of that as low as possible, messing with the seats would be a prime candidate for both mistakes to happen, and feels risky. your right, if Paul is happy, then i should be happy, he's probably seen thousands of heads over the years. I did want to do an amount of blueprinting, but i don't think this qualifies as that.

Edited July 22, 2010 by kyepan

[Sandy 191]

The best bet is to work with what you've got and develop it for sure. Trying to make big leaps forward usually makes for a grumpy, peaky engine.

[kyepan 291]

A quick update

 

Have been lapping in the valves with the fine paste and some blue. The exhaust valves are done, it's quite a satisfying task.

 

Next i am toying with the idea of either just putting the head back together with a standard cam.

 

or

 

Sending one of the two standard cams i have to Peter T for a stage two. (which apparently does work with the "chip" he sells on standard management)

 

Either way the reason for mentioning, is i don't really have room to start looking at the bottom end concurrently with the head in bits. It feels like a good idea to complete one thing at once before moving onto the next.

 

pics to come...

 

an one last question, does the full engine seal set from pug come with valve stem oil seals?

[welshpug 1,657]

As far as I know you can go to stage 2 before needing to increase compression ratio due to the lower dynamic compression, I'm not sure when valve-piston clearance becomes an issue (not like the XU10J4RS, where its an issue straight away)

 

 

As for whether the engine kit comes with stem seals, not sure! does the head kit come with them?

 

unfortunately for the 9J4, ENGIN GASKT KIT 0197 J3 NFP - INJECTION AND XU9J4 doh.

 

same goes for the "VALV GASKET KIT"

[kyepan 291]

sounds like i need to get the burette out, dad has found the perspex with the hole in, then can calculate what the compression ratio accurately. Aiming for just under 11:1. Because they are regrinds, the max lift is actually slightly less iirc, but i could be wrong. Good point about the dynamic compression.

 

Sounds like i need to get the engine gasket kit and just see if they are in there, and go from there.

 

cheers

 

J

[Anthony 1,003]

Valve stem seals are normally in the head gasket set on Payen and similar sets, or can be purchased seperately.

 

With regards cams, whilst I believe that it "works" to a point, I don't think that Stage 2 is recommended for standard Mi management, and I can certainly imagine that you'd be right on the safe limit of the standard injectors if not exceeding it. If you're running standard management, I'd stick with a Stage 1 cam personally.

 

I'm not entirely convinced that 11:1 compression is a good idea on standard management either, certainly if it's 2-row without a knock sensor.

 

(ignore the above two comments if you're not planning on retaining standard management)

[series111 21]

Did you ever get a replacement for the broken crank pulley locking tab as i am sure i have spare one somewhere if you still need one...

[kyepan 291]

With regards cams, whilst I believe that it "works" to a point, I don't think that Stage 2 is recommended for standard Mi management, and I can certainly imagine that you'd be right on the safe limit of the standard injectors if not exceeding it. If you're running standard management, I'd stick with a Stage 1 cam personally.

 

I'm not entirely convinced that 11:1 compression is a good idea on standard management either, certainly if it's 2-row without a knock sensor.

I'm on three row, and he says his chip will compensate for a stage two, it will only be running standard management whilst it's run in, then it's going on bodies. Or if it blows up.... it's going to get rebuilt.

 

but ... that being said, too much compression / cam may be not what i'm looking for.

 

 

Did you ever get a replacement for the broken crank pulley locking tab as i am sure i have spare one somewhere if you still need one...

 

actually paul13 gave me an xu10j4rs one off the dead engine he pulled out of his car, are they interchangable?

[series111 21]

I'm on three row, and he says his chip will compensate for a stage two, it will only be running standard management whilst it's run in, then it's going on bodies. Or if it blows up.... it's going to get rebuilt.

 

but ... that being said, too much compression / cam may be not what i'm looking for.

 

 

 

 

actually paul13 gave me an xu10j4rs one off the dead engine he pulled out of his car, are they interchangable?

 

I am not sure as i am not familiar with the xu10j4rs engine but if you need the xu9j4 one just pm me also i hope the build carries on well as i no what you are going through as i rebuilt my last year .............

[kyepan 291]

i have to admit making a mistake.

 

leaving the lifters in degreaser has ruined them.. Now, leaving them in diesel would have been fine. But i used the wrong kind of degreaser.... and it's eaten through the surface, also contained water, so they rusted too. very silly mistake.

 

So if anyone has a set of lifters handy, pm me.

[Jrod 7]

I've a set of brand new ones if you are interested. Still in the little sealed oil tubs.

[kyepan 291]

many thanks to Jrod for the lifters..

 

So finally got round to rebuilding the head, bought the gasket set, have the valve stem oil seals... and lots of other seals that i don't recognize.

 

 

from the top left

 

1) valve stem oil seal, that one is easy!

2) gerbil cock ring?!

3)ermmmmm?

4)mmmmmm?!?

5) is the size of the cam shaft oil seal journal, but i have those separately, and it doesn't fit in the sparkplug well.

 

any help appreciated.

 

Cheers

 

J

[James_m 0]

No 2 looks like it might be one of the seals for the oil spray bar, but there is at least 6 of those. I don't recall using any of the others, 5 could be thermostat maybe?

[kyepan 291]

No 2 looks like it might be one of the seals for the oil spray bar, but there is at least 6 of those. I don't recall using any of the others, 5 could be thermostat maybe?

Much appreciated!

 

both would make sense, there are about 6-8 of them

 

i did guess at thermostat housing

Edited September 18, 2010 by kyepan

[Jrod 7]

2) Oil spray bar seals assuming there is 11

4) Cam cover oil seals

[kyepan 291]

Thanks again Jrod,

 

Quick question:how do you release the valve compressor gently, it seems to ping off and i'm worried about scraping up the bores of the hydraulic tappets... Tape around it?

 

cheers

 

J

[Sandy 191]

Use thumb pressure on the top of the upper thread to push against, to release the lever, rather than just pulling it.