Ive just put a fast road cam in my 2 litre Pinto which has also been recently re bored and new pistons and rings fitted, its got mega jolt ignition
and bike carbs. The engine is running well and pulls great, i think it might be running a bit lean as its popping on over run quite a bit. My problem
is that its blowing a lot of blue smoke, particularly at highish revs and when i 'blip' the revs up high. i'm thinking it might be
worn valve guides letting oil into the bores but ive also read that it may be oil getting up the bores past the oil control ring, ive had my co
meter in the exhaust and it does seem a bit lean on tick over but could it be over fuelling at higher revs. anyone any ideas before i take the head
off and get new valve guides fitted, alsoare those plates any good that can be fitted in the sump to stop oil flying up the bores.
The engine was using a bit of oil before i put the new cam in but seems to be blowing more smoke out now.
Any advice will be welcome.
Thanks
ian
Valve stem oil seals? did you re grind the valves in ? Were the followers/springs replaced as well as the cam?
Sorry for the q's
Rich
How long has the engine been re-built before you gave it high revs ? have you run the engine in
The exhaust popping may be because you have a air leek in the exhaust joint's
[Edited on 24/2/11 by jacko]
its had new valves, oil seals, followers and springs. valves were lapped in. engine was put together about 12 mths ago and has got a few hundred miles under its bonnet........
rings not bedded in properly and you've been giving it too many beans before you have worn in the new rebuild.
i would also whip the rocker cover off and see if the valve stem seals have lifted? this wouldn't give you clouds of smoke though , more like
small puffs
did you rebuild the head yourself? have you reseated the valves? if its new stem seals i would definately check them, are you using double valve
springs or HD singles?
[Edited on 24/2/11 by omega0684]
And its only just started being smokey? Think I'd be thinking about a compression test as a first step, what are the plugs like?
Cheers
Rich
think the valve springs are standard, def not double, i'll have a look at plugs tomorrow, what are my options if ive not bedded the rings in properly......?
quote:
Originally posted by Barksavon
think the valve springs are standard, def not double, i'll have a look at plugs tomorrow, what are my options if ive not bedded the rings in properly......?
Very, very, unlikely to be glazed bores unless he's filled it will fully synthetic and nannied it, which doesn't sound like it's the
case. The honing finish on the bore is very important though, if this wasn't done properly it will burn oil.
Not sure why the valve springs and followers would be relevant, but worn guides and stem seals will certainly give the symptoms the OP is seeing.
I think stem seals usually smoke badly on start up and overrun not when pulling hard. What arrangement have you got for the crankcase breather?
[Edited on 24/2/11 by Dingz]
quote:
Originally posted by Dingz
I think stem seals usually smoke badly on start up and overrun not when pulling hard.
Dingz
ive got the crank case breather outlet fastened to a small filter and the rocker filler cap outlet to a catch tank
quote:
Originally posted by Barksavon
Dingz
ive got the crank case breather outlet fastened to a small filter and the rocker filler cap outlet to a catch tank
I'd try connecting the crank case preather to the catch tank like Alex says ^^
pinto's are very 'heavy breathing' engines from the crank case
after that I'd try a compression test and then have a look under the rocker cover - just to try and eliminate possible faults before you take the
head off
it could be someing like a broken piston ring, but you might aswell check the basics first
quote:I think you can get smaller stem seals to cure that if need be
Originally posted by omega0684
MikeRJ: i have seen in some double Valve Spring heads where the inner spring has a tendancy to catch the stem seal when released from its compression state
quote:
Originally posted by omega0684
quote:
Originally posted by Barksavon
Dingz
ive got the crank case breather outlet fastened to a small filter and the rocker filler cap outlet to a catch tank
i would have the crank case breather feed intot he catch tank as well and then have a vent on the catch tank
quote:
I think stem seals usually smoke badly on start up and overrun not when pulling hard.