Rover V8 cam chain alignment

[eliot]

History:
Rover V8, 3.9,Fully rebuilt engine, new bearings, honed,rings etc. Went for an IVA and it failed on 4000 hydrocarbons - which is huge. Engine has a RPI PIPER 285 cam in it. When I fitted the cam I wasn't quite sure of the correct alignment as there appeared to be two marks on the lower sprocket. Luckily I took the photo below for reference. Anyone know if I've aligned it to the wrong marks - or indeed where I should align such a cam.

And yes, that saggy looking chain was brand new....

[anonymous-user]

Simple answer: Turn engine right way up, chuck a tappet in the lifter bore for No1 cyl intake and exh, then stick degree wheel on crank, and check timing compared to where Piper say it should be...............

[anonymous-user]

ok, sorry, just read post correctly, i assume engine is now fully built up and running (otherwise an MOT would be dam hard! ;-)


(luckily, you only need to whip a rocker cover off to measure peak lift when the engine is installed ;-)

[eliot]

Thanks - that is becoming the plan, as we have eliminated most other things now. Just hoping for somone to go "ya drongo - you used the wrong marks"

[spend]

The crank keyway should point straight up middle of the odd bank, maybe the photo but that looks like its more than 2degs before TDC to me - which I assume is the target for the offset sprocket?

[anonymous-user]

Further questions for the OP:

Whats the fuelling systemm (MS etc??) (have you got any control of the End of injection position?)
Whats the warm idle speed, and what controls it? (can you wind it up a bit ?)


Assuming you have nice strong and even cylinder compressions, then idle HC's are very stongly affected by the above factors (as well as cam timing as mentioned!)

[eliot]

It was Rover 14CUX hotwire with dizzy when it failed. Failed at idle and 2k rpm at the VOSA test centre - in fact it was filling the entire bay up with HC and he was struggling to get a free air calibration. Has side pipes, both banks were the same - plugs were changed there and then with barely any difference.

Got back home and replaced the 14CUX with a Megsquirt 1 Extra just doing fuel initially. Set the idle fueling around 14.7, although it seems to vary a bit. Revving it up to about 2k results in hesitant and misfiring. The wideband goes very lean - which i assume is fresh air from misfires rather than it actually being lean. During this time it smells very strong to the point of stinging your eyes - but back at idle it will hold around 13-14afr - so not pig rich as the smell/stinging would suggest.
So then i thought maybe the sparks were poor - so i fitted EDIS coilpacks fired directly from megasquirt. still strong smell and stinging, but now it backfires very loudly with flames out both exhausts at 2k. Trigger log looks good to me - yet to get a normal datalog that i can share.

I was seeing a main voltage drop at the coil pack feeds - which i thought was the issue, hard wiring direct didn't make any difference to issue (although no drop now). I didn't do the wiring and there are elements of the wiring I want to check - such as voltage drop to the injectors etc. (I have scope to check noise etc).

So having done quite a bit on the fuel and sparks (which we were going to do anyway after the IVA) - I now have to consider more fundamental things wrong with the engine - so cam timing is my first port of call. Along with compression test etc.

Current check list:
Check the actual cam timing,
Strobe ign timing,
Check inj voltage drop
Get datalogs both on coil packs and dizzy.

[stevieturbo]

Sounds more like a poor ignition system or missfires. Plain and simple.

Test for spark power at each and every plug with a spark jumper or other suitable tool.
If using dizzy, check condition etc of all those workings. Verify timing etc

The chances of it being a camshaft problem are slim, unless it has massive overlap.

Or other possibilty is an injector just dumping fuel in.

Dont forget, a wideband is only of any use if the engine is running properly, so what you see on the gauge may not be correct. You need a proper gas analyser.

[eliot]

stevieturbo said:

Sounds more like a poor ignition system or missfires. Plain and simple.

Which is why i put the coil packs on it.

stevieturbo said:

Test for spark power at each and every plug with a spark jumper or other suitable tool.

Ordered 8 of those inline neon things. Pulling a lead of during it running on coil packs was producing 2" long sparks.

stevieturbo said:

If using dizzy, check condition etc of all those workings. Verify timing etc

again - why i went for coilpacks to eliminate the dizzy. Actually produces flames now - so i guess the coil packs are lighting up what the dizzy cant. Will do some logging in comparision.

stevieturbo said:

The chances of it being a camshaft problem are slim, unless it has massive overlap.

Agreed - looking that way now, Timo on V8owners posted picture of that wheel and it is indeed only 2' out.
Will DTI check it anyway though.

stevieturbo said:

Or other possibilty is an injector just dumping fuel in.

This has crossed my mind too - and now we are running MS, i can try some other injectors i have. Although its blowing 4000HC down both banks (side pipes)

stevieturbo said:

Dont forget, a wideband is only of any use if the engine is running properly, so what you see on the gauge may not be correct. You need a proper gas analyser.

Agreed - but its a little more info than we had before. Have been trying to purchase an analiser for last month or so, but they still seem to go for a good final price, despite being ancient ones (or out of calibration)


Cheers.

[stevieturbo]

Holy ......4000ppm HCC ???

I dont think Ive ever had one that high even with missfires.

After running like that, what do the plugs actually look like ?

If you can pick up a Snap On Scangas, they are handy portable gas analysers. Although the power connector's have a habit of breaking.
There's one on egay at the minute. Standard they are a 4 gas, or can upgrade to 5 gas.

You could try unplugging one injector at a time to see what effect it has.

But did you also say both banks are the same ? have you isolated gas analyser readings for each cylinder bank ?

Obviously compression is fine, timing is fine etc ?

Lifter preload or valve clearances ?

Edited by stevieturbo on Tuesday 20th September 22:48

[anonymous-user]

Does the engine ever run cleanly at higher loads/rpms ?? Does it have an audible misfire at any load/speed ??

[eliot]

stevieturbo said:

Holy ......4000ppm HCC ???

I dont think Ive ever had one that high even with missfires.

After running like that, what do the plugs actually look like ?

If you can pick up a Snap On Scangas, they are handy portable gas analysers. Although the power connector's have a habit of breaking.
There's one on egay at the minute. Standard they are a 4 gas, or can upgrade to 5 gas.

You could try unplugging one injector at a time to see what effect it has.

But did you also say both banks are the same ? have you isolated gas analyser readings for each cylinder bank ?

Obviously compression is fine, timing is fine etc ?

Lifter preload or valve clearances ?

Edited by stevieturbo on Tuesday 20th September 22:48

Yep 4000! Its a westfield with side pipes - similar readings down each pipe.
Not done a compression check - one for the list.
Cant check any timing with the nosecone installed - so thats coming off for Cam timing check and then checking ignition timing as well.(Coil packs running of a trigger wheel that was DTI'd to tdc)
I did the lifter pre-load,pedalstals were shimmed - as the valve seats had a 3 angle job on them.

[eliot]

Max_Torque said:

Does the engine ever run cleanly at higher loads/rpms ?? Does it have an audible misfire at any load/speed ??

gets to just before 2k ok, then as we get into 2k+ it banging very loudly to the point that you dont want to rev it anymore.
When it was running dizzy it wasn't quite so bad - but still stunk and makes your eyes water.
I must check yet again that i dont have a lead swapped or something on those coil packs.

[Pumaracing]

eliot said:

So having done quite a bit on the fuel and sparks (which we were going to do anyway after the IVA) - I now have to consider more fundamental things wrong with the engine - so cam timing is my first port of call. Along with compression test etc.

Struth, talk about doing things arse about face.

http://www.pumaracing.co.uk/diagnose.htm

[eliot]

Pumaracing said:

eliot said:

So having done quite a bit on the fuel and sparks (which we were going to do anyway after the IVA) - I now have to consider more fundamental things wrong with the engine - so cam timing is my first port of call. Along with compression test etc.

Struth, talk about doing things arse about face.

http://www.pumaracing.co.uk/diagnose.htm

Not really. This is not my car and its not in my garage and we are both busy people and I have to set him tasks that he can do on his own. And then i come round to move to the next step. (Indeed one option is to get car round mine and i can dig through this quickly)

Engine was ported and rebuilt by myself and late father about 7 years ago. Since then its been sat in a very slow westfield build. So thank god i did take photos of cam chain aligment all those years ago.

We have known from day 1 that we really should ditch the 14CUX and Dizzy - but i advised him to stick to known components (the engine and ecu was a runner before we removed the engine from donor) for the IVA and then we would change it out after.

Dizzy Igntion timing was checked before IVA with nosecone off - as thats the only time you can see the timing mark that i scribed using a clock gauge down #1 - timing wasn't very stable, but thats a clockwork dizzy for you.

After failing IVA i decided to fit megasquirt and a wideband - as it smelt rich and we could at least get a better idea whats going on. I know a wideband isn't going to help with HC problems - but its all more data that you can use to get to the end-goal.

I fitted a 36-1 wheel to the damper and aligned it on the 5th tooth after the gap - aligning the wheel using a DTI down the plug.
Fitted megasquirt fuel only - car started straight away, but without nosecone and radiator - so we refitted that so we could run it up to temp and make adjustments (therefore I cant strobe the distributor timing any longer)

Car still not right - so i said lets fit the coil packs, as it was easy and we done that in an evening. Again, cant check timing beccaus the nosecone is on.

That brings us up to today. I've outlined my next steps, check cam timing and ignition timing - now that we are pulling the nosecone.
Sure I forgot to check compression - will take my meter round if i remember it.
So fitting of MS, wideband and coilpacks were going to happen anyway - now we still having problems i need to go back and check other stuff whilst the nosecone is off(and drain coolant again). Once front end stuff is checked - it has to go back on so i can carry on. (yes we are thinking of getting some pipe extenders for the radiator)

If i said that cam timing is good and ignition timing looks good but running a stock ecu on a modified engine, everyone would be saying "check the ecu, air flow meter and sensors" etc -

So arse about face to an extent, but i like to think i'm eliminating varibles and introducing the ability to collect engine running data - which i hope as we move forward will help prove/eliminate stuff.

Eliot.

[stevieturbo]

If both banks are the same, then that would almost rule out a single injector or coil or cylinder problem.

So either ign timing and as you say cam timing. But the image seems to indicate cam timing is ok.

If it has side pipes....can you monitor on an individual cylinder basis if needed ?

Have you tried simply swinging timing in either direction to see what effect it has, even if you dont know the timing ?
How does it start ?

[v8 racing]

Hi Elliot, you have the cam timing going on the marks 2 degrees retarded, which to be honest is not going to cause your problems, however dont rely on what the jp says!! i have to go a whole tooth out just get it right sometimes!, it does need checking, the other thing the piper 285 came with 2 lca's one they did at 104 and one they did at 111, if you have the one at 104 you will get high hc's but even though it wont pass a cat test it should still run fine.

Edited by v8 racing on Wednesday 21st September 20:14

[eliot]

v8 racing said:

the other thing the piper 285 came with 2 lca's one they did at 104 and one they did at 111, if you have the one at 104 you will get high hc's but even though it wont pass a cat test it should still run fine.

It has to pass a basic pre cat test (3.5% co and 1200HC) as its going in for an IVA. Hmm

[v8 racing]

eliot said:

It has to pass a basic pre cat test (3.5% co and 1200HC) as its going in for an IVA. Hmm

If you are desperate to get your iva passed and then sort things when you guys have time, put some big shims under the pedastalls to give you a minus preload, ie 20-30 thou tappet clearence, obviously this is just a get the ticket fix!