After some fun with getting the HT leads round the other way, it ran...

then it started knocking... LOUDLY!

quickly killed it and off came the cam covers thinking the timing was wrong and ive got bent valves... but it wasnt!

cranks over PERFECT (and pretty same quick with the plugs out, as fast as it is when "running")

but run the engine and it knocks VERY loudly. sounds like a top end noise.

run FINE tho.

compression of 180 on 2,4,5,6 170 on 1 and 3

what the on earth can it be! the timing is PERFECT, so valve to piston conact is almost impsible. all the cams are bolted down perfect too.

i REALLY hope i dont need to swap the engine out before the ring (not worth rebuilding a 24v imho)

 

Sorry to hear that Jim. I bet Tony will know as he has done a lot with the BOB cams. Why not send him a PM?

 

When you say it 'started' knocking - does that mean it didnt when you first started it but then did after a few seconds.....if so its got to be oil related I'd say???

 

Do those 24v lumps have hydraulic lifters??? If so i rekon they will be your problem. You have probably pushed some of the oil out of them. If you run it round the block the noise should dissapear as your lifters get some fresh oil.

 

If they hydraulic, maybe you didnt get all the oil out of one properly and you could have chipped a lobe?

 

Sorry to read about this Jim

No ideas sorry.

Steve.

 

Take it to Liam @ B.A.R.

 

where these new cams?

How did you run them in?

 

its a art changing CAM's in a 24v there are right ways and wrong whys to do it.


I will ask the man that knows

 

billy, i cant take it to BAR the car's stuck at southend

cam change procedure:

remove cams
refit new cams (didnt touch the lifters, just coated em in oil)
start engine (this was quite tricky as we had the HT leads on wrong and the plenum gasket was leaking)

when we got it running on more than 3, i kept it at about 2-2.5k for about 5 minutes (that was quite difficult when it was missing like a mofo)

put leads on right and got it to run proper, started it, ran it at about 2k for about 30seconds, then tapping starts so quickly switch off



The guy's gonna take the cams out again today and check all the tappets and lobes etc. plus give it a fresh oil change etc. and run it up.

i SOOO hope its something that simple, and i don't need to get the engine swapped out or stripped down... lol the money aint an issue, but time is, the ring's looming!

 

jim give tony a pm or put a thread up on if m8

 

stu will kill me, but f*8k it... lol

 

there should be a thread on there from when tony changed his might have an anser in there m8

 

Jim I hope I'm wrong but you might have killed the cam!

Alex

 

alex, there's 4 of them and i really dont want to put the originals back in

why do you say that anyway

 

Cams are REALLY sensitive to running in.

When new they must not idle or you will "knock them out" ie they end up knocking.

The are the most heavily loaded part of your engine. So you increse the revs to bring the oil supply up and actually reduce the load on them (idle is the most load, hence cam belts snapping on startup etc).

Alex

 

is there a way i can check em? they look ok

ps theyre not new cams theyre regrinds, i dunno if that makes any difference

 

Sorry to here this jim, sounds like a lifter hasnt filled up. not unusual when you fit a cam or cams in your case. pauls fiesta done the same when we did his head gasket

Liam

 

how do you re-fill it then

 

jim
bet you didnt wedge the cams forward when bolting the washers in did you?

tony!

 

what do you mean tony, the timing disc bits at the front? they're located properly, so it hasnt slipped timing wise (we double checked just incase)

what i dont get is how it doesnt make any noise when spinning over, just when started... its not like it wasnt spinning over quickly

 

ps i was spanner passer, i had a ford mechanic doing the work (stuXR4x4) and he's done it before (+followed the manual)

 

if you fit the cams in to the head, then try and bolt the chain wheel on the cam slides back about 1/8 of an inch,, this is enough for the flat of the washer to miss the flat on the cam.
this means the cam is NOT located and is NOT timed correctly.
.....

remove your washers and look at the back face, it will show damage if you got it wrong.

but if they are regrinds did you get verniors and time them up correctly? also have they been ground and the lifters dont reach now? do you know how much less the base circle is? do you need to fit shims under the lifters?

tony

 

Thats what i was thinking Liam, it was bloody noisy for quite a while after - but once the lifters had filled it was fine.

Very possibly could of been that Jim.

 

As i have said, this is what my money is on.

 

tony, those washers are located correctly, after what happened to beatmaster's engine (one fell off and got caught in the chain!) we double and tripple checked them! also like i said we've watched the engine spinning over and all the valves are closed when the pistons are at the top. it all looks to be 100% perfectly timed

the cams are regrinds but theyre only very mild. kents instructions are that nothng extra is needed, theyre 100% direct replacement. and theyre also timed to standard figures

 

Any news yet from they guy doin it????

 

YES. ITS ALIVE

was tappets afterall. new (well, 2nd hand) set in there now and all's good

aparently it idles a bit lumpy at 800rpm now, but i think thats to be expected with a cam change. its also given me an excuse to raise the warm idle to 1000rpm as its easier to map at 1000 than it is 850 (no interpolation)

i'm SOOO relieved its nothing major, as i was expecting to be buying new valves

 

id say it's a lifter too. run her at 3000rpm for a few more mins - u may find it quietens slowly.

 

Pleased it was something simple Jim

Lets hope it drives ok

Steve.

 

jim
quote"the cams are regrinds but theyre only very mild.

well to get any higher lift or replrofile the base circle will be less, i assume the lower base circle meant the lifter jamed,,, ya lucky this time!!

but 70%of the time the washer isnt located properly, it had to be my first suggestion.
tony

 

Good news Jim!

 

great news

 

Nice one.

 

tony, its obvious from your answer that you know HOW they regrind them to get higher lift... can you enlighten us. as we couldnt for the life of us work out how its done (i was told once but forgotten)

thanks guys for the kind words and advice

 

Nice one mate

 

it's bloody obvious jim if you think about it.

i'll try and explain it, but it's a bit tricky without pictures.

a cam lobe is effectively egg shaped right? the pointy 'top' of the egg (that you slice off and dip your soldiers in) is the bit that operates the valve (via whatever kind of follower).

the opposite side to that is the more rounded bit that is basically just part of a circle (the full diameter of which would give you what's called the base circle).

to get more lift from a regrind, you obviously cannot add material to the pointy bit of the egg, so you have to make the base circle smaller so that the pointy bit is now a larger proportion of the whole egg, thus becoming a longer lever to create more lift.

make sense?

 

Excellent Jimbo - will catch you on MSN chap

 

And then increase the length of the follower so that closed is still closed, but open is now further open. Hard to explain I guess this is where your problem was Jim, the followers were not taking up the slack.

 

Here you go:



on the left is th old one, on the right is new. You can see distance A is the same.

When they both spin round though, the bottom of the follower on the right hand one will be much lower down, so the valve will be further open.