80 replies to this topic

[mini_pooper]

KTS - accurate figures are important, so I welcome them with open arms 

 

I will see if I can connect up a hoover to the breather and at the same time try to put a carb airflow meter between the breather and hoover so I can see if there is still flow when I put my hand over the filler neck (without the cap on!) - it should not flow then if it's not leaking elsewhere... I have a flow meter that can easily be mounted in-line with a little ball inside :)

 

I will however check the dipstick grommet because I have always thought the rubber on it felt more like plastic than rubber, even through it is a new item! I can say with good certainty that it does not seal, it's only real function is to stop the dipstick dropping in or rattling! 

 

Cooperman - I certainly think the tolerances on new items are taking a wrong turn. The head gasket I had originally, which I replaced to stop it leaking, was an unbranded item, no markings, and I am told it came in an engine gasket set (so very likely a £5 head gasket). The one I have fitted now however is a genuine Rover branded one, so I assume older stock and therefore should be good quality and one would think unrelated to recent tolerance issues.

 

We'll see if it stops leaking once I have run it with water for a little while. Haven't started the car since last week because of travels 

[unburntfuelinthemorning]

 

Some more info from an old school expert Mr Calver - https://www.calverst...asket-problems/

 

"All you have to do is torque the standard head studs down to 42-45lb ft (a generous lee-way there I feel), DRY. That’s no lubrication on nuts, washers, or studs. ALL torque settings in the manuals are quoted with the relevant threads DRY. And that's the way they're done at the factory."

 

I know Mr Calver has always said the Torque figures are Dry, however, that's inccorect (not sure where he gets that from?).

 

From the Rover Factory Manual;-

 

 

All Torque Figures in the factory Manuals relation to engine components are oiled.

 

My 1980 factory manual under 'General Fitting Instructions' says:

 

"Always oil threads lightly before tightening to ensure a free running thread, except in the case of self-locking nuts."

 

The four studs which go throught the rocker pedestals always have oil (unless cleaned of course) on them whereas the five external ones are always dry which would prevent the head being torqued evenly.  They should be all dry or all oiled.

 

Mr Calver says to torque to 42 to 45 lbf/ft whereas the manual states 50 lbf/ft (as Haynes) and 40 lbf/ft for emission control engines (whatever they are in 1980 - Canadian ones maybe with the air pump (don't know why that would affect the torque settings)?).  I seem to remember seeing either 40 or 45 lbf/ft stated in a manual for Morris Minor A-series engines though.

 

I lean more towards the factory recommendations as they used to last tens of thousands of miles without problems.

 

Maybe you should use less torque the more that has been skimmed from the head as they could be more prone to distortion?

[Spider]

Yes, that is the advice from the factory (to oil the threads).

 

Wet vs Dry Torquing;-

 

I think I've once before posted about this (possibly reads as a bit of a rant and sorry for that).

 

With most fasteners in use, we don't care about the 'torque' needed to tighten them up. What we are trying to achieve is a certain amount of bolt or stud stretch. This stretch is the force that's holding all the parts together. 'Torquing' fasteners up, is a convenient and inexpensive method of getting in the ball park of achieving a certain fastener stretch, it's accurate to around +/- 15% however, that's on 'wet' (oiled) threads and fastener faces.

 

With dry fasteners, the amount of friction is so widely variable, that the accuracy is only around + / - 40%. Ideally, we want to be rid of that friction or if we can reduce it all together, then we want it as close as we can get it from one fastener to the next, especially with 'slab' items like cylinder heads.

 

To have fasteners in the sweet stretch range on items like Con Rods and Mains is very critical. If they are too tight, they can break of course, likewise, if they are not tight enough, they will also usually break too. Due to the very frequent cycling loading, if they are not stretched enough to start with, they will stretch and shrink back in use, however, when stretched, because they are starting off from a low stretch factor, they will reach the peak of their yield or exceed that easily and frequently (cycling) from initeria and then break in short time.

 

The ARP Book has some very good info on fasteners along with the hows and whys of tightening them.

 

In answer to unburntfuelinthemorning's question, I say no, don't reduce the tightening torque of the head.

[mini_pooper]

Afternoon all,

 

Dropping a quick update in between the torque posts! 

 

I had the car out yesterday, pulled the bottom hose and removed the coolant + flushed everywhere with the hose (also through the heater by pulling the hose off the heater tap). Left it all to drip dry while I did a quick check on the head torques at 45lbft (which I have used all along), of which each nut turned an unnoticeable amount, if anything. Reset valves clearances to be sure they were spot on.

 

Filled the system with deionised water ONLY, and started Bingo up to find no leaks whatsoever, even when at temperature, aside from 2 small drops from the head where I earlier had drips every 3-4 seconds. Took it for a long drive (100-110 miles) down to Lincoln and back to Cleethorpes via some B roads, and not once did the temperature gauge move more than a tad north of "Normal", cruising at 3500-4000rpm most of the way with ear plugs embedded deeply in my ears (even so - my ears are still sore!).   No mayo in the oil, no water in the engine bay, no oil leaks, and all the gauges indicated a happy engine was ticking away under the bonnet.

 

Happy days!

 

I did notice while the car was warming up that the misfire I had with the breather connected a week ago was still there for the first few seconds of warmup, even with the breather not connected. I theorised then, that maybe the misfire was not associated with the breather, but rather just a bit rough running after engine surgery, so when I got to Lincoln yesterday I plumbed the breather back on to test the theory while parked up (giving the ears a rest!) and gave the engine some blips on the carbs.

 

Aside from the engine idling a little lower, and slightly slower pickup (Indicating the carbs need a little tweaking to accommodate the breather tube), it sounded fine! Pulled the rocker cap off and it stalled, so it looks like this is the only way for the air to pass through. Since I did not have my carb-adjusting hat on (and my passenger was eager to keep "cruising"!), the breather came back off for the return to Cleethorpes, but I will be plumbing it back on again and adjusting the carbs to suit next time I'm out and about.

 

Again, happy days     Pics attached from yesterday's mini road trip!

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[KTS]

..i do so love a happy ending 

[mini_pooper]

..i do so love a happy ending 

 

Don't we all! 

 

Hope I'm not veering too far off the initial topic, but since the breather has been discussed on this thread before I will sneak in another sneaky question! 

 

I decided to connect up the breather again yesterday. Before I did anything, I checked both carbs were synchronised (which they were, phew! It's a boring job!) and connected a Gunson Colortune on spark plugs 1 and 4 to see what mixture I was currently running. This showed a yellow flame (a bit on the rich side), where orange is too rich, yellow is slightly rich, "bunsen blue" (dark blue) is optimal and light blue/white is too lean.

 

So, with that as a reference point, I connected up the breather and had to turn the idle up slightly to prevent it from stalling, which to me indicates something certainly changes when the breather gets connected up. Once it was stable, the Gunson colour tune was fitted to check if the mixture had changed. As far as I could tell, the colour (yellow), was unchanged from before the breather was fitted, so I thought I'd take it for a quick spin.

 

It's definitely a little bogged down, and there's a stuttering/misfire/hesitation just as the throttle is pressed very lightly, but nothing very noticeable when the throttle is pushed further aside from maybe a little less torque compared to before (might be in my head). You can feel the engine missing some beats between 1000 and 2500 rpm when you let go of the accelerator completely to slow the car down (for example approaching traffic lights in the distance in 4th gear and releasing the throttle). Idle is erratic too, and you can feel some misses when cruising with the throttle steady.

 

I've checked for leaks, of which I have found none, and haven't touched the timing at all during this process, so I'm thinking the mixture needs a once over. I have a little contradiction going on in my head however:

 

1) The colortune indicated the mixture is slightly rich, so logic says it needs leaning out a bit,

2) However my head usually associates bogging and misfiring/erratic idle with a mixture being too lean and one which needs richening....

 

I have to check the plugs now that the breather has been connected, however before connecting it, they were a nice light brown/grey colour meaning mixture was not far off. Maybe I'll fit new ones to see if the current ones are the fault. At least then the new ones will start off white and give an accurate colour in the current state of tune.

 

So folks, based on the above info and your experience, should I be looking to richen the mixture (my head is telling me so), or lean off the mixture (which the colortune, and therefore car itself i telling me)? **OR** - something else? 

 

Note there is a fast road cam in the car so that might make the mixture appear a bit rich at idle, although it was still showing rich higher up the rev range.

[Spider]

Some - not all - carbs with the CCV Ports had restrictors fitted to these ports and based on your findings here, I'm wondering if yours is one that does?

 

I'll dig out the parts book later and see if I can find what was fitted in the factory (no guarantees here).

[mini_pooper]

Some - not all - carbs with the CCV Ports had restrictors fitted to these ports and based on your findings here, I'm wondering if yours is one that does?

 

I'll dig out the parts book later and see if I can find what was fitted in the factory (no guarantees here).

 

Thank you, I look forward to hearing your findings 

 

Just for clarity, do you mean you think my carbs already have restrictors fitted and they are causing the misfire, or that my carbs should have them fitted and the absence of them is causing the misfire?   (does but shouldn't or doesn't but should) 

[Spider]

Sorry, I should mince my words a bit better!!

 

I suspect they currently don't have them and possibly should have them.

[mini_pooper]

Sorry, I should mince my words a bit better!!

 

I suspect they currently don't have them and possibly should have them.

 

Haha, no worries 

 

I've done a little reading on a Chevy forum and although a lot of it was unrelated (that topic was about burning oil), there was a note that interested me:

 

"Low idle vacuum motors (with big cams) need a PCV that works at low vacuum. They have a lighter spring that allows the valve to be opened more easily. Use one of these on a stock engine or one with good vacuum, and it's more or less an open port. Conversely, using a stock PCV valve on a low vacuum motor is causing the valve to not work correctly, if at all."

 

Now, my car of course does not have a PCV, but does have a relatively hot cam. If your thinking is correct with the restrictor, this could have the same effect as a PCV not working as intended...

 

Maybe there needs to be something restricting the flow through the breather when the car is at idle/part throttle and then opens up at higher throttle positions? I could look at fitting a PCV in line with the canister of course to do this...?

[Spider]

That's quite right what you've read up on the Chevy here and the short comings of a PVC Set up.

 

Crankcase breathers have a few functions, two of the more important are;-

i) to remove 'normal' fumes from the crankcase and burn these through the engine, this reduced the stink in the care and also assist the seals in the engine do their job, and

ii) to keep a more or less continuous 'air' flow through the engine to remove moisture and other harmful vapors from the crankcase

 

Just considering i) above, an engine is more likely to produce crankcase fumes under wide open throttle condition than at any other operation condition, this also happens to be when the manifold vacuum is lowest and is this set ups short coming.

 

A CCV (Closed Crankcase Ventilation) set up works a little different, it does not rely on vacuum but volume of air flowing. At idle and on the cruise, the engine will (usually) make lower crankcase fumes and also under these conditions, is't consuming much air volume (or the air flow is low), however under wide open throttle condition, when it'll likely be making the most fumes (blow-by), the air flow rate is high. It's a very effective system.

 

However, best I can determine, the 998 Copper was only ever fitted with a PCV System and never the CCV.

 

I did have a read back through your thread and I thought it was a build similar to a 998 Cooper, but as you've mentioned now, it has a 'Cam'.

 

OK, before we go too far, has it been set up on a rolling road? This would also be the opportunity to sort the need or not for restrictors in the CCV Ports and the RR man should be on top of this.

[mini_pooper]

That's quite right what you've read up on the Chevy here and the short comings of a PVC Set up.

 

Crankcase breathers have a few functions, two of the more important are;-

i) to remove 'normal' fumes from the crankcase and burn these through the engine, this reduced the stink in the care and also assist the seals in the engine do their job, and

ii) to keep a more or less continuous 'air' flow through the engine to remove moisture and other harmful vapors from the crankcase

 

Just considering i) above, an engine is more likely to produce crankcase fumes under wide open throttle condition than at any other operation condition, this also happens to be when the manifold vacuum is lowest and is this set ups short coming.

 

A CCV (Closed Crankcase Ventilation) set up works a little different, it does not rely on vacuum but volume of air flowing. At idle and on the cruise, the engine will (usually) make lower crankcase fumes and also under these conditions, is't consuming much air volume (or the air flow is low), however under wide open throttle condition, when it'll likely be making the most fumes (blow-by), the air flow rate is high. It's a very effective system.

 

However, best I can determine, the 998 Copper was only ever fitted with a PCV System and never the CCV.

 

I did have a read back through your thread and I thought it was a build similar to a 998 Cooper, but as you've mentioned now, it has a 'Cam'.

 

OK, before we go too far, has it been set up on a rolling road? This would also be the opportunity to sort the need or not for restrictors in the CCV Ports and the RR man should be on top of this.

 

Makes sense 

 

The engine is a standard A Plus (A+) bottom end with a Cooper 12G295 head, valves and +20 overbore for the flat top pistons, Maniflow small bore exhaust (3 into 1) and HS2 carbs of course. The Cam is a Fast Road HR270/2 Piper (I think they now use BP instead of HR as the prefix, although the spec is slightly different for the BP270).

 

Car goes great with lots of pull, and has been on the rolling road without the breather connected (vented to atmosphere) and so the CCV ports on the carbs were just connected to each other with a tube to prevent vacuum leaks.

[racingbob]

well didn't know that. have always added 30% Halfords blue straight away never had a problem and bk450 gasket

[mini_pooper]

Well, all looks good!

 

Breather is connected up and after giving the engine a little more fuel it has run beautifully! So beautifully in fact that since Friday afternoon until yesterday (Monday) evening, it has covered 800 miles 

 

Road trip from Lincolnshire to Surrey on Friday (250 miles) where we met up with family and decided to take a road trip with the mini and my father's Citroen DS for the extended weekend.

 

Across to Bristol on Saturday morning, then Sunday morning we drove to Bowood House for the car show being held there. From there we drove to Cardiff (Wales) for a concert (Don McLean) in the evening. Monday took us North through Wales until I ran out of fuel sitting in traffic (my mistake!) so the Citroen had to come to the rescue with some fresh fuel to get me to the petrol station. Pitstop in Hereford before the long drive back up to the Lincolnshire coast 

 

The car didn't miss a beat, although driving up the long hills in Wales with 27 degrees ambient outside did force me to keep an eye on the temperature gauge with only water in there   As an added bonus, I had a new set of Dunlop Aquajet/SP Sports waiting for me when I arrived on Friday evening which completely changed the car compared to the Falken tyres I was using!

 

Pics attached! (2nd, 3rd and 4th pics were just after fitting the new wheels, before hub caps came back on and before the suspension had a chance to re-settle so it's a little high) 

 

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[Northernpower]

Well, all looks good!

 

Breather is connected up and after giving the engine a little more fuel it has run beautifully! So beautifully in fact that since Friday afternoon until yesterday (Monday) evening, it has covered 800 miles 

 

Road trip from Lincolnshire to Surrey on Friday (250 miles) where we met up with family and decided to take a road trip with the mini and my father's Citroen DS for the extended weekend.

 

Across to Bristol on Saturday morning, then Sunday morning we drove to Bowood House for the car show being held there. From there we drove to Cardiff (Wales) for a concert (Don McLean) in the evening. Monday took us North through Wales until I ran out of fuel sitting in traffic (my mistake!) so the Citroen had to come to the rescue with some fresh fuel to get me to the petrol station. Pitstop in Hereford before the long drive back up to the Lincolnshire coast 

 

The car didn't miss a beat, although driving up the long hills in Wales with 27 degrees ambient outside did force me to keep an eye on the temperature gauge with only water in there 

 

You say you were kept an eye on the temp even though you only had water in. Water is a better transfer agent than coolant therefore it will run cooler with only water in the system.