The V8 Owners Forum -

Hi guys,

I have a rebuilt SD1 v8 (3.5) in my stylus kit car. It's been on the road for 2 years now, and covered about 6000miles. The problem is excessive oil consumption, and occasional blue smoke from the exhausts. Apart from this it runs very well, and is pretty smooth and quiet. It's had this problem right from the start, and not just a recent thing.

The rebuild 2 years ago included a rebore (+20 thou). New vitesse pistons, new valve guides, new vitesse valves, new neoprene valve seals, new cam, new bearings throughout.

I reckon it uses about 1 litre of oil every 200 miles, which is excessive in my book! I get a lot of blow-by fumes from the filler cap too.

I miked the bores up after the rebuild, and they were spot on (3.520"), The ring end gaps were a bit on the large side, but within the allowed tolerance (can't remember the gap).

The rings were pattern ones from real steel, and looked a different design to the original worn rover items that come out. Would swapping them to OEM rover rings be a good idea? Do you reckon the bores would need re-honing after just 6000 miles?

What else would explain my oil consumption? (It doesn't leak either!)

Jeff

dodgy valve guides or maybe the rings just haven't bedded in very well.

Did you use normal oil, straight from the start or did you use running in oil? Normal oil can stop the bedding in process.

Mine uses a bit, but there isn't normally any noticable blue smoke.
I had a rebuilt b-series rebored, I just clapped it together and the pistons seemed pretty tight and ok in the bores what with having new rings and what hav ya, But 5000 miles in, was still smoking, took it apart, had the bore's measured and I think one was 10 tho oversize. The guy who did it overed to send us 1 over size pistion!! to put in the big hole. what a tit.

Don't woory about it, saves you changing the oil

!litre oer 200 miles would mean massive amounts of thick blue smoke would be pouring out of the exhausts! Thats more than my old kr1s 250 2 stroke used!

Not just a simple oil leak anywhere is it? Vauxhall (who i work for) say that upto 1 litre per 1000 miles of use is acceptable so if you haven't exceded that then you could consider it ok although i wouldn't be too keen on that if it were mine. What oil did you use to run it in on? And the rings, were the "total seal" jobbies? (check yer invoice if you still have it)

ppyvabw wrote:dodgy valve guides or maybe the rings just haven't bedded in very well.

Did you use normal oil, straight from the start or did you use running in oil? Normal oil can stop the bedding in process.

Mine uses a bit, but there isn't normally any noticable blue smoke.
I had a rebuilt b-series rebored, I just clapped it together and the pistons seemed pretty tight and ok in the bores what with having new rings and what hav ya, But 5000 miles in, was still smoking, took it apart, had the bore's measured and I think one was 10 tho oversize. The guy who did it overed to send us 1 over size pistion!! to put in the big hole. what a tit.

Don't woory about it, saves you changing the oil :lol:

Valve guides were new (as were valves), later type to take proper valve stem seals, so I can see them being dodgy.

I did use running in oil (from rimmer bros) for about 300 miles, then used halfords 'classic' 20W-50. I would have thought that the rings would have bedding in by now (6000 miles). I don't think I have any oversize bores, since I miked them all up, and the engine is quiet, even when cold (no noticable piston slap).

Worth changing the rings for proper rover items?

Jeff

ihatesissycars wrote:!litre oer 200 miles would mean massive amounts of thick blue smoke would be pouring out of the exhausts! Thats more than my old kr1s 250 2 stroke used!

Not just a simple oil leak anywhere is it? Vauxhall (who i work for) say that upto 1 litre per 1000 miles of use is acceptable so if you haven't exceded that then you could consider it ok although i wouldn't be too keen on that if it were mine. What oil did you use to run it in on? And the rings, were the "total seal" jobbies? (check yer invoice if you still have it)

Not much smoke visible, unless you rev it hard in neutral. You can also smell the burnt oil fumes on the overrun. Maybe 1 litre/200 miles is a little bit overestimated, but it's at least 1 litre/400 miles. I regularly take it to work (110 miles round trip), and after 3-4 trips the oil level drops from max to min on the dipstick. See previous post to see what oil I used.

The rings were not total seal type, just standard +20thou rings from real steel, although the oil rings had a slightly different design to the original rover ones.

Jeff

Just had a thought, is this a build up out of more than one engine? My first rover v8 used oil at this rate, I had the wrong dip stick tube and stick, I kept topping it up so it had an extra 3 to 4 pints more than it should have had it was this oil it was chucking out (mostly through the breather system. might be worth double checking how much oil you have in it, Drain it into a big buchet just in case

if it isn't it seems very high consumption, I would be looking for a broaken ring or top ring groves nipping the piston rings (has it been pinking?). Seems too much to me for valve guides. One of my minis many years ago consumed oil at 350 to 500 miles per PINT on investigation it turned out it has consumed a nut and washer (explained where the ones on the top of the airfilter went! ), half the nut was ebbedded in one of the pistons and the piston was cracked right down to the skirt, top ring in many bits and the second ring pinched.....
I think you need to have a good look at this engine.
Mike

kiwicar wrote:Just had a thought, :shock: is this a build up out of more than one engine? My first rover v8 used oil at this rate, I had the wrong dip stick tube and stick, I kept topping it up so it had an extra 3 to 4 pints more than it should have had it was this oil it was chucking out (mostly through the breather system. might be worth double checking how much oil you have in it, Drain it into a big buchet just in case :rofl

if it isn't it seems very high consumption, I would be looking for a broaken ring or top ring groves nipping the piston rings (has it been pinking?). Seems too much to me for valve guides. One of my minis many years ago consumed oil at 350 to 500 miles per PINT on investigation it turned out it has consumed a nut and washer (explained where the ones on the top of the airfilter went! :wink: ), half the nut was ebbedded in one of the pistons and the piston was cracked right down to the skirt, top ring in many bits and the second ring pinched.....
I think you need to have a good look at this engine.
Mike

Nah, built out of one engine. I did wonder about the dipstick, but it takes about the right amount to fill it up after an oil change (5.5 litres). I've also tried running it close to 'MIN' for a while, and it still drops at the same rate. No sign of pinking (running megasquirt-n-spark to run the ignition), and it runs really well.

I don't think the ring end gaps are tight, I checked them all before fitting. There were a little on the wide side in fact. I've heard the ring manufacturers make them this way to cater for careless builders who can't be bothered getting the gaps right?

I've also had the heads off since the rebuild (just to fit new stem seals just in case!), and no sign of anything amiss. Piston tops are fine, bore walls are fine (still see honing marks). Even done a compression test which was all good.

All this leads me to believe that the rings are just crap inferior copies.

Jeff

The rings arn't one of these asymetric profile sets are they? in the wrong way up?
Got the splash gaurds in the rocker covers so the oil doesn't go out the breather system (though I don't actually believe they do anything).

I am afraid I'd pull the pistons and re-ring, a pain but you won't need to do anything else, just make sure you put the big end bearings back as they came out. Be worth a recheck on the ring gaps and piston sizes while you are at it.
Mike

when you checked the bores did you check them for being oval? It wouldnt be the first time the rebore went off centre which gives you an oval bore. Fist thing you need to do is do a compression test to see if its bores and which ones. Also rings have a top and a bottom so they can be put in upside down causing problems as kiwi car said.

If you are using an edelbrock carb that might be th cause of the problem.

If you've not re-jetted it to suit your motor then they overfuel badly, according to Realsteel enough to wreck the rings and the bores.

If your not using an edelbrock then you can ignore all this! :

Just noticed your running EFI so forget this post!

Where are you based Jeff.
I have a leak down tester that will give you some definitive info, assuming you have a supply of compressed air to use it.
You are more than welcome to borrow it or come to me for a quick test.
It well quickly tell you if you have a problem with the rings.

sidecar wrote:If you are using an edelbrock carb that might be th cause of the problem.

If you've not re-jetted it to suit your motor then they overfuel badly, according to Realsteel enough to wreck the rings and the bores.

If your not using an edelbrock then you can ignore all this! :

Just noticed your running EFI so forget this post!

Yes an an running an edelbrock carb (megasquirt is for ign only).

I did re-jet it according to RPi's recommendations (12% leaner than stock, looking at the carb manual!), but it ran weak, and was hesitant when the secondaries opened. I then tried some intermediate sized jets, halfway between RPi's and the stock ones, which was better, but not entirely fixed. I'm now running the stock jetting and it runs a treat! gets 25mpg on a run and passes MOT's no problem. Plugs are the required brown colour too, so I don't think bore wash is the problem. The oil consumption issue has been here since the rebuild, so I don't think any subsequent wear is to blame.

Current betting is on rings installed upside down, excessive end gaps, or just crap cheap rings!

Jeff

mgbv8 wrote:Where are you based Jeff.
I have a leak down tester that will give you some definitive info, assuming you have a supply of compressed air to use it.
You are more than welcome to borrow it or come to me for a quick test.
It well quickly tell you if you have a problem with the rings.

That's very generous of you. Im based in Barry, south wales (near cardiff). I've already done a compression test (gauge in the plug hole), and it was fine on all cylinders. I think the spread was about 11.5bar to 12.5bar.

I'm pretty sure its the rings rather than the guides, due to the excessive oil fumes coming up from the lifter gallery.

Jeff

You are more than welcome mate. Shame you are not closer.
Certainly sounds like a bit of blow by then.

Has the sump been modified in anyway? it might affect the amount of oil thats being thrown about in the crankcase? john