[Car_Overhaul] One Thing Leads To Another..

[Kane 34]

Right quick question for you all. I've been out and stripped the head down tonight and have found some issues which I think shouldn't be there.

 

Firstly when removing the lifters I found one of them was extemely easy to compress so it looks as though the initial thoughts on a dodgy lifter was correct. I removed the piston assembly and briefly inspected the components but couldn't see anything in particular that would be causing it to fail. I've got spares anyway so that one will be replaced.

 

Next was to check of any apparent piston/valve contact which looked promising as there didn't seem to be any whatsoever. I decided rather than running the risk of assembling the head again and finding there was in fact a bent valve, or several, it would be better to remove all the valves and have them sent off to be checked.

 

Here is where the second possible issue turned up. Upon removing the exhaust valves I found quite a large build up carbon all over the back of the valve head and lower stem. Now I'm not sure if this is normal but it was more than I'd expected to find considering the engine has done less than 1000 miles since the rebuild. Here's a photo of one of the exhaust valves, apologies about the piss poor photo was struggling with my phone.

 

 

I tried cleaning it up with a little degreaser but it was fairly difficult to completely clean.

 

When I removed the inlet valves I found that several of them had a layer of carbon build up on only one half of the back of the valve head. After a quick search it seems as though this indicates either worn valve stem seals or worn guides. I had the seals replaced when the engine parts were away so that points to worn guides right?

 

Annoying thing is is that I had asked if the machinist could check the guides for wear when they had the parts but obviously this was overlooked! Here's a quick picture of the inlet, again apologies for the poor picture.

 

 

You can see there that the left hand side of the valve head has carbon but the right hand side is relatively clean.

 

Before I go and get my head sent away yet again to have the guides replaced could someone please confirm for me if they are the most likely cause of the issue.

 

Cheers

 

Kane

[dobboy 231 2 Cars]

10/10 for perseverance Kane

[mrfirepro 127 1 Cars]

Holly s**t Kane , your not having much luck......

 

Is that a wear ridge on that valve? (might just be the light)

 

On a positive note I've got some spare inlet and exhaust guides left over from my build if you need one or two.....

[Kane 34]

I like to think of it as one of life's many lessons learned as opposed to continuous bad luck, that way there's less likelihood of me setting the f***ing thing on fire!

 

I'm not sure to be honest Paul, I'll have to double check. Has anyone got the tolerances for stem wear on mi16 inlet and exhaust valves? Those spare guides could be very helpful indeed, I'll be in touch if I do find out that they are required

 

Going to give a local engine reconditioning company a bell on Monday morning and explain my situation and see what they recommend. Its looking likely that the head will have to be sent off with the valves to be checked which is a tad annoying.

[welshpug 1,661]

I'm sure a haynes manual will show how much side to side movement is acceptable on the valve head, you can check that yourself.

 

carbon on the valves may be from poor combustion with bent valves.

[JeffR 51]

Valve guide clearance to valve stem for Mi16 inlet & exhaust=0.022mm, 0.0008" (after pressing the guides into the head).

Edited January 11, 2015 by JeffR

[Kane 34]

Got my old man to go out and have a quick look at the side to side movement of the valves in the head while the motor is in bits in his garage. Not 100% sure if this is how you are supposed to perform the check but essentially what he did was lift the valve head of its seat by a couple of mm and give it a wiggle. Got a quick video which shows quite a lot of movement on the exhaust valves. While on the phone to him he mentioned he'd checked the inlets and they looked to have a lot less movement but still unsure as to whether they are outwith the specs listed above as we don't have a gauge to check.

 

Here's the video:

 

http://vid1288.photobucket.com/albums/b491/KHarrison31905/VID-20150121-WA0002_zpsshaqxxow.mp4

 

Now I know it is difficult to tell from a video but it does look as though the side-to-side movement is more than it should be, any thoughts?

 

Measurements of the exhaust valve stems seemed to show a slight difference along the length indicating wear, unfortunately the readings he's called off are over 7mm so seems the gauge is incorrect. Either that or there has been aftermarket valves fitted at some point with larger stems, although unlikely I think.

 

I looked out the receipt from gardias engine services the other day and had a read through of all the works completed on the head while it was away. It seems everything was noted apart from valve guides. Valves were back cut, seats done, skim, clean etc etc. I had asked for them to be checked and if anything was required then to go ahead so I guess it could be an oversight if they are worn. f***ing annoying thing now is that if they are to be replaced the seats will have to be recut again, or so I'm led to believe.

 

What was also a little reassuring to see is that the pistons had been refaced and the valve cut outs machined. Now it doesn't specify the measurements but this gives me a little more faith that the valves haven't clashed with the pistons and it was in fact the suspect failed lifter.

Edited January 21, 2015 by Kane

[Kane 34]

So yet another set back with the motor today..

 

Heard back from engine resource and looks like there are two bent valves in the head which I'm not 100% sure if they occurred after I fitted or were like that already. As I've mentioned earlier there were no apparent signs of contact on the pistons but I didn't check valve clearance at the time so could well have happened because of my lack of attention to detail during the build. Never mind onwards and upwards.

 

What has really pissed me off is the clear oversight of the previous engine work I had done. Turns out not one, not two but ALL of the exhaust valves guides are out of spec so the valves are slopping about. They will all need replacing! And just to rub salt in the wound it seems the inlets aren't far behind!

 

Unfortunately I don't have the spare cash at the moment to rectify all 16 guides so I reckon only the exhaust will be replaced. The bloke at the machine shop says they will be ok for now but how long they will last is anyone's guess.

 

I'm waiting for a quote coming back for the work tomorrow but out of interest what is the typical cost for replacement guides, fitting and what's the going rate for standard valves nowadays.

 

Cheers

 

Kane

[Anthony 1,003]

It happens, don't kick yourself too much over it - at least you've found the issue and no serious damage done

[GLPoomobile 958]

Weird, I thought Gardias were extremely well regarded for head work!

[Kane 34]

That's the main reason I opted to front up the extra cash to get everything sent down to a specialist who comes so highly regarded. Doubt I'll be a returning customer now after this experience.

[Anthony 1,003]

Disappointed to hear that as he's always been spot on with me, and has certainly picked up on worn guides for me in the past

[welshpug 1,661]

Really depends what you asked them to do specifically, and what you were charged for, I'd check that and see what they say also, if its something they overlooked they may sort something out for you.

[Kane 34]

I did ask at the time for the guides to be checked. I had a long list of work done at the time as my intention was to build an engine that I could essentially fit and forget, barring oil changes, so I made sure when I was doing my research to list everything that might need done and ask for it to be checked. I just find it strange that something like this could have been missed considering both the valves and seats has work done on them.

 

I did check my receipt the other month and there was no billed item for valve guides which I didn't think was too strange as I wouldn't imagine it would be something that would be charged considering the size of the job. Obviously I should been more thorough in future but having asked for the parts to be looked at initially I'd assumed that it would have been done.

 

To be honest my patience is drawing very thin with this car at the moment and the last thing I want to do now is to send off more stuff down south only to be left waiting for a considerable time to get it back.

[dobboy 231 2 Cars]

Kane, not sure if it'll be any help but i was recommended "The Engine Room" in Motherwell, they seem to have a decent reputation.

 

And there is nothing more frustrating than paying good money for the work that you just can't do yourself, and then having to wait and wait.

 

Oh and i phoned a well known pug specialist about fixing mines for me today, lol at their price! They must think they're doing brain surgery.

 

Can no one on here help this guy out and do a fair days work for a fair days pay?

[Kane 34]

Thanks Jack, I've got the parts at engine resource in Dundee who have also been recommended. Bonus is they're only a drive away as opposed to the other end of the country. I should receive a quote tomorrow for the work so will see what they come back with.

 

You never know I might have it back on the road for longer than it takes to run out of a tank of fuel.. bit of a dreamer!

[Kane 34]

Got the quote back from engine resource and although it is a fair price it's expensive nonetheless. Before I go and fork out more money has anyone got a spare mi16 head in good working order that they're willing to flog? Ideally has to need no work doing but may consider something that needs a slight skim.

 

I'll pop a wanted add up later tonight but thought I'd post here first. Any help would be great.

 

Thanks

 

Kane

[Kane 34]

So since I'm going to be spending yet more money on this car I thought it would be a good idea to confirm a few things before I build it back up.

 

Firstly what markings, if any, do standard xu9j4 cams have? I want to double check that the ones I have are not aftermarket items so I know what valve clearance I should be checking for.

 

Now from what I've read on here I should check valve clearance by installing the valve in the head without springs, retainers etc. Torque down the head to first stage with head gasket fitted then using a dual gauge check the total clearance between head and piston. Can someone confirm that the measurements I'm looking for at TDC are 2.5mm inlet clearance and 3mm exhaust as a bare minimum? Also, is it recommended to check valve clearance on every piston or is it safe to assume that if one is correct then the rest will be very close if not exactly the same?

 

I'm going to re-read up on cambelt fitting procedure to ensure that I'm not out by one tooth or more but if anyone could offer advice relating to this issue it'd be much appreciated.

 

Oh and anything else you can think of would be great.

 

Thanks in advance

 

Kane

[petert 588]

Inlet: 2.0mm 6 deg ATDC would be absolute minimum with hydraulic cams

 

Ex.: 2.5mm 6 deg BTDC

 

Your procedure is correct. Just drop the valve onto the piston. Don't forget to subtract the cam lift @ TDC figure from your total (or dropped) figure.

[welshpug 1,661]

you can run quite meaty cams over Mi16 pistons compared to the later 16v engines

[Kane 34]

Ah ok so valve to piston distance - cam lift @ TDC > 2.5mm (inlet), 3mm (exhaust). Thanks for clearing that up Peter.

 

Just before I go and search (feeling lazy on Monday morning) what is the lift @ TDC for a standard mi16 cam?

 

Thanks again

[petert 588]

Inlet 0.032" to 0.050" depending on which pulley is used. Exhaust 0.032".

[Anthony 1,003]

Judging from Petert's website, it's between 0.032" (#2) and 0.054" (#4) depending on which cam pulley - that's about 0.81 to 1.37mm in new money.

[Kane 34]

I checked the pulley numbers at the weekend and both are No. 2 so I'll go by 0.032". I also took some photos of the cams which I'll post up later. Looking at previous posts on here I reckon they are standard but people's thoughts would be helpful.

 

If it does come to it and my clearances are not correct would the best option be to buy a thicker head gasket? If not what other options are available without removing pistons to have valve reliefs deepened.

[welshpug 1,661]

you can go thicker on the gasket but only +0.2mm afaik.