Newly rebuilt motor burning oil

Post by **dekker** » 03 Jul 2008, 09:48

Hi, think I know what the answer's going to be but thought i'd ask first.
The motor is a 1776 CT that I've rebuilt myself using mainly secondhand parts. After problems with no oil pressure due to air in oil pump (thanks for all the help previously) finally got it running. After setting timing, readjusting tappets and tweaking the carbs its sounds sweet BUT chucking loads of blue smoke out when revved.
I was hoping this would settle down but it seems constant. Engine has run for about 1 hour now, revved fairly hard during 20 min running in. Can't take it for a run as no T&T, expired whilst off the road. and good chance of getting pulled with smoke screen out the back.
Heads were good second hand and there seemed no play in valve stems/guides.
B&P were also second hand (90.5mm) that had been honed and new rings fitted. Must admit didn't check these as trusted guy I bought them off who said they were good. Yeah I know, pretty dumb.
In the future no money = keep things stock!
Need to do a compression test when I get my tester back from guy who loaned it but reckon it'll show I've been stupid not checking B&Ps first.
So......engine back out and new B&Ps this time?? Best long term bet?
At least I'm getting quicker at this lark.
Cheers, D

Post by **kevtherev** » 03 Jul 2008, 17:39

I'd be looking at new barrels... at least

or new first oversize barrels and pistons

Post by **Laurie** » 03 Jul 2008, 20:46

If the rings are new and the bores have been honed, I'd be inclined to give it a bit more time.

Also... I had a moment of panic a while ago when I fitted an engine to an exhaust that had had a major failure from its previous engine ie. burnt piston. It smoked like a bugger but it was just due to oil in the exhaust.

Ring spacing is important.. On flat engines 10 o clock 12 o clock 2 o clock

Post by **..lee..** » 03 Jul 2008, 22:48

and dont use good oil to run the engine in, the rings needs to bed in properly and you can glaze the bores if you run in with good oil.

Post by **dekker** » 04 Jul 2008, 08:53

Was careful spacing the rings and used std 20/50W mineral oil. Exhaust system from heat exchanges back is all NOS thanks to the wonders of E-bay. Will try running it for a bit longer and hope. Its got that smell that you get following M reg Mondeos up hills so not too hopeful.

Cheers, D

Post by **lloyd** » 04 Jul 2008, 11:52

Honed cylinders with new rings can take several hundred miles to seat in, as Laurie indicated. You can do a leak-down by putting air fitting in place of spark plug and hooking to compressor... Lock engine so cylinder you are testing is at TDC and listen to exhaust, intake and oil filler. Where you hear air hissing is where cylinder/valve is leaking.

Post by **Mr Bean** » 04 Jul 2008, 21:11

dekker wrote:Was careful spacing the rings and used std 20/50W mineral oil. Exhaust system from heat exchanges back is all NOS thanks to the wonders of E-bay. Will try running it for a bit longer and hope. Its got that smell that you get following M reg Mondeos up hills so not too hopeful.

Cheers, D

Oi you! Leave M reg Mondeos out of it will you. Mine has been running sweet as anything for about four years now. (Must admit to fitting short engine to it though as after purchase I replaced the missing thermostat, filled it with cats pee 5/30 oil and left a 125 mile each way smoke screen on my first long trip) Plus they do it best after a period of over run!
Regards
Ken