Big issue ! Now fixed,thanks

[MrD]

Righty following my post in the lec section,Car is running really quite bad,won`t idle propperly,and is sucking in air through the rocker cover breather pipe,it stalls it when i put my finger over it,thats after it makes a screeching noise,now this morning i moved the cam sprocket with a spanner,to try and free off the starter.Thought i may have made the belt slip a tooth or two.
Just been out and checked timing,number 1 at tdc in the middle of the dwell,plug number 1 at firing point on compression stroke,both marks lined up on crank and int shaft pully.

What have i done ? Car still performs ok,but it`s sucking in air instead of blowing it out.
Could i have a bent / sticky valve,or have i done something terminal ?
Are there more than one breather on the dx engine ?
Help
Need to do a compression test ,but don`t have one here now,as i sold it like an idiot ,thinking my car tinkering days were over

[Nate]

i'd be checking that with a vacuum gauge

http://moodle.student.cnwl.ac.uk/moodle ... gauge.html

connect the pipe on the gauge to the inlet manifold. use a T piece on one of the vac pipes going to either the dizzy or the carb

[MrD]

Been having a think,my vernier was at the limit one way,so in theory i could only go so far in the other direction,would it suck in like this if the timing was out ?
Think i might just take the belt off tomorrow and centre the vernier

Top bit of kit that !

[MikeH]

If it's got a bent or burnt valve, a compression test would show it up pretty quickly.

What spec is the engine, and what's the induction system? Sucking at the breather could be a sign of worn valve stem seals and guides. Has the head been rebuilt since you've had it?

EDIT: assume that's the engine spec in your sig?

[MrD]

Yeah engine is pretty standard ,just the cam,new hyd tappets,and vernier,i decided it would be cheaper going 9a,than spend money getting the extra out of this engine.
It has done over 230 thou,does not smoke at all,was really good on co last test.
It`s just gone all of a sudden,i have been giving it a lot of beans though,had the rocker cover off and all looks normal,not sure if this cam makes it an interference engine or not ?

[MikeH]

It probably is just about an interference engine. If you've been ragging it and it's a bit too lean (what colour are the plugs?) then you might well have burnt a valve. What petrol do you put in it? The cam will want a bit more fuel than the standard one, so you may well be on the lean side.

Sounds like the head probably needs a rebuild anyway. It can't be far away at that mileage.

A £20 gunsons compression tester will tell you if there's a valve problem, or turn it over by hand (using the CRANK pulley, not the cam) and stick a thumb over the plug holes in turn (in firing order), for a very rough version (cheap though).

[MrD]

Cheers for the info.
Did look at the plugs,and the are a light brown colour fawn brown,and yeah did think they looked a bit too light.
With the timing,is it possible it`s trying to suck on the out stroke,and blow on the in stroke ?
Going to whip the belt off,no cam belt cover so easy to get too.
Have been giving it a propper ragging,if i am honest,since getting the last bolt in the cage (not been able to get it in since fitting it ) it`s transformed the car by about 100% really is like a roller skate,think i have the same shocks as you Mike ?
And i have been taking advantage of the dry weather and country roads ..
Did also notice the other day,when trying to bolt my battery down again,keeps loosening off,that where there should be a pipe on the metering head,i had blocked this up,but whatever i blocked it with has come out,might not of helped things.And just thinking about that now,i hope that didn`t get sucked into the intake.
Why did i sell that flipping spare head,only got £5 for it on e bay too
Not sure if it`s going to be a head off job that i will bother,might just crack on with the 9a build,tax runs out end of this month,too,and work has been rubbish,not good being self employed when no work is coming in,starting to pick up now though.

Fuel,gets the expensive stuff,98 ron

[MrD]

How low would the oil need to be before the oil pump sucked in air like that ? I know my dipstick tube is bust but it can`t be that low,pressure gauge telling me normal pressure,but it is a cheap lec one.

[MrD]

I am suspecting head gasket fail now,mate still not got over here with the tester as yet,but i have a flexi usb single led lamp thing,which i butchered to poke in the bores.
1 Looks fine,nice and clean,2 black sludgy stuff 3 black sludgy stuff,4 nice and clean,suspect h/gasket i think,leaking between bores ?
Might fix it,while i wait on building the other engine,depending on the state of the head....... As looking at min £80 if i do it.

[MrD]

Right i did the compression test
1 was at 120 psi
2 was at 110 psi
3 was at 120 psi
4 was at 150 psi

Not sure what to make of that,test was done dry,with throttle closed
Going to do a wet test,with full throttle ? is that right,splash of oil in the bore,throttle open full crank for say 5 turns ?

[MikeH]

Start with a dry test and the throttle wide open. Wedge the throttle open with some tools stuck in the quadrant.
Wet testing an 8v is difficult, as the oil tends to sit in the dish of the piston. You can't really do it without a squirty oil can.

You just crank it over till the pressure stops rising - 5 turns should be about right.

[MrD]

Yeah did notice the dished pistons,was thinking of some vac pipe on the end of a can of 3 in 1 and try and get it down the side of the piston,would be a bit like key hole surgery...
Found this great bit of info on Puma racing site http://www.pumaracing.co.uk/comp.htm..
Will have to wait until Monday now,as the wife has got me planting the veg patch today

I didn`t crank it until it stopped rising,just stopped after say 5 cranks,so deffo need to do it again,engine was also cold,at time of test.
I just wacked out the king lead for the coil,is that right,don`t wanna damage anything else

[MrD]

Right i have been out and done another compression test,dry full throttle crank until gauge stops rising,which happened on 5 turns for each cylinder.
1) 8 bar on the nose
2) 8 bar on the nose
3) 7 bar on the nose
4)10 bar on the nose

Not sure what to make of it really,is it possible that i have a sticky exhaust valve on number 4 ? Or a breached h/gasket....3 bar difference between 3 and 4 ?

[james butler]

anything more than half a bar between cylinders usualy means the heads comming off anyway. sounds like headgasket but could be worse to be sucking at the breathers.

[MrD]

Yeah think 3 and 4 are breached,3 must be pressurising 4 ,but then i thought it would leak back,but i suppose 3 is on the comp stroke as 4 sucks in ? Think i will crack the head off if i get chance in the week,and hope it`s just a gasket,mate will lend me a head,as no point spending money on this engine,as building the 9a + Kr combo