Cosworth YB Tappet issues. AGAIN.

[fingersnfumbs]

So, the engine has been totaly re-build. Its a Cosworth YB. N/A.
The head is ported, New valves, springs, guides etc. Its on twin 45's It runs as sweet as a nut.
BUT. One or possibly two of the lifters just wont stop tapping.
Truth is, sometimes it goes quiet until engine is hot.

I have changed the oil and filter twice.
Fitted new ENA lifters.
Cams are new mild road Newman.
Oil pressure is very good at 60PSI when hot.
The top end has plenty of oil around.

Im now desperate to cure this issue as its driving me mad.

Someone on another forum said clean the oilways in head but dont know where they are and as I said lots of oil in top of engine anyway. Also, as it sometimes goes quiet Im thinking no blockages there.
Also it has been suggested the bores for the lifters could be worn oversize, they seemed a good fit when I changed them. Im pretty sure the noise is on the exhaust side at the back. It is 100% lifter noise, not piston slap or valve contact, I have checked. I have had the cam cover off and cams are not worn at all. I did purge the oil pump with a drill before the cams where fitted and had good oil flow from oilways in bearing carriers.

Im reaching the stage now of considering buying another head and ditching the one I have but its not cheap especially when it will need porting etc.
Could it just be a new lifter or two needed even though they are new. How can I tell what lifter/s are faulty. Tried the squash test and even the quiet ones seem to compess easily. The Engine has done around 150 Miles now and still taps.

Really appreciate any suggestions guys, im desperate.!

[Graham]

its possible lifter bores are worn and the tappets don't always rotate, that will result in noise

[fingersnfumbs]

Um....I could check to see if they are rotating.
Suprised that makes a difference.

I will check.

Thanks Graham.

[stevieturbo]

No idea if that would cause a noise, but they have to rotate otherwise they'd wear badly....and over enough time I guess that wear could lead to noise.

[fingersnfumbs]

ok so I have wipped of the camcover and all lifter tops have a similar pattern a sort of star shape with flat ends if that makes sense.
I suppose the important thing is they are all very similar.

How about I run the engine and slip a feeler guage under each one, would that identify the noisey ones?
Trouble is when I do find them then what?

[Graham]

.

star shape doesnt sound right, but they could be because they are still very new. wear pattern should be circular. hydraulics run with zero valve clearance. so it depends why its noisy, but if its because the lifter isnt full of oil, which is usually because they are bleeding down due to foreign material in them, with the cam on the base circle you will be able depress the lifter if you push down on it

[fingersnfumbs]

Thanks Graham.
I will check each one.
Im tempted to order 8 more and change the exhaust side.
If they are still noisey I will know its not gthe actual lifters.
What do you think.
Worth a try?

[Graham]

.

star shape doesnt sound right, but they could be because they are still very new. wear pattern should be circular. hydraulics run with zero valve clearance. so it depends why its noisy, but if its because the lifter isnt full of oil, which is usually because they are bleeding down due to foreign material in them, with the cam on the base circle you will be able depress the lifter if you push down on it

[fingersnfumbs]

The saga continues.
I took out each lifter, cleaned them. Primed them full of oil and re-fitted.

Engine is now running on three cylinders.!
Im pretty sure when I primed the lifters they are now too full of oil and valves are not seating. Had real trouble getting cams back in as the valves needed to lift so much.
I did turn it over by hand and it turned OK before starting.
Compression test showed no compression on No1.
I have removed the cams and checked and cylinder No1 holds pressure well with all the valves seated so I dont think any valves damaged luckily.
Im tempted to just buy a new set of lifter but dont want to keep throwing money away.
Head off is a posibility but MLS gasket is a thick one and £200 pounds worth so dont really want to umless I have to.

All I really want is an Engine that runs without tap, tap, tap.

This thing is driving me mad.

[stevieturbo]

On the cyl with no compression, rotate the engine so the lobes are fully open and let them sit for a while. It may help them bleed down a little ( although could well take more force than that )

But it's an easy, zero effort thing to try

[alladdin]

on the old vauxhall lifters i remember we used to compress in vice and leave in pot of oil to fill up overnight as they were always a pain.

[fingersnfumbs]

I like the idea of compressing the lifters in a vice to prime them.
Im going to try that.

I put a borescope down one of the plug holes today, no piston or valve damage thank god.

[Graham]

i can understand compressing lifters, we often did/do otherwise you run the risk of having no compression when you refit used lifters as they expand when removed. but i have NEVER needed to prime them on any engine ( and we are talking 1000's of engines over the years) once back in they usually go quiet very quickly, the odd one takes its time, but once quiet they stay that way.

[fingersnfumbs]

So, Engine is all back together and running OK apart from yep you guessed it...Noisey tappets.

Im in two minds now how to move forwards.
Either buy another set of Hydraulic lifters or Buy new solid profile cams and go the solid route.
At least with solid lifters I know I can end up with a quite top end.

Whats your views guys.?

[fingersnfumbs]

So, Engine is all back together and running OK apart from yep you guessed it...Noisey tappets.

Im in two minds now how to move forwards.
Either buy another set of Hydraulic lifters or Buy new solid profile cams and go the solid route.
At least with solid lifters I know I can end up with a quite top end.

Whats your views guys.?

[Graham]

So, Engine is all back together and running OK apart from yep you guessed it...Noisey tappets.

Im in two minds now how to move forwards.
Either buy another set of Hydraulic lifters or Buy new solid profile cams and go the solid route.
At least with solid lifters I know I can end up with a quite top end.

Whats your views guys.?

are you 100% sure you are not getting valve piston contact?

[Graham]

So, Engine is all back together and running OK apart from yep you guessed it...Noisey tappets.

Im in two minds now how to move forwards.
Either buy another set of Hydraulic lifters or Buy new solid profile cams and go the solid route.
At least with solid lifters I know I can end up with a quite top end.

Whats your views guys.?

are you 100% sure you are not getting valve piston contact?

[fingersnfumbs]

are you 100% sure you are not getting valve piston contact?

Hi Graham,
Yep Im as sure as I can be.
I did a turn over of the engine during build with plastacine on the piston tops and had 6mm+ clearance. Pistons are Wossner intruder type.
Cams are very mild Newman PH1 268 duration and 9.64 lift. 190lb double valve springs by Newman.
Compression ratio is only 10.5 to 1. So not pushing any boundarys.
It has run quite but not for long and then goes noisey again.

[Graham]

Hi Graham,
Yep Im as sure as I can be.
I did a turn over of the engine during build with plastacine on the piston tops and had 6mm+ clearance. Pistons are Wossner intruder type.
Cams are very mild Newman PH1 268 duration and 9.64 lift. 190lb double valve springs by Newman.
Compression ratio is only 10.5 to 1. So not pushing any boundarys.
It has run quite but not for long and then goes noisey again.

, the wossner pistons have decent sized cutouts so it probably not related to valve piston contact. but problem with doing a dummy build with Plasticine and new hydraulic lifters is that the lifters can/will collapse so you wont get a true reading of clearance. bak when we did vw stuff we used to use solid lifters to check clearance, then switch back to hydraulics

[fingersnfumbs]

Fair point Graham.
I should have said I used correctly clearenced solid lifters for the dummy build.
Im wondering if the valve spring pressures are too high for hydraulic lifters.
Cams are mild and are hydraulic grind, plenty of piston to valve clearence.
In fact the only real diiference from stock is the springs.
What do you think?

[Graham]

Fair point Graham.
I should have said I used correctly clearenced solid lifters for the dummy build.
Im wondering if the valve spring pressures are too high for hydraulic lifters.
Cams are mild and are hydraulic grind, plenty of piston to valve clearence.
In fact the only real diiference from stock is the springs.
What do you think?

190lb springs are ok on hydraulic followers

[fingersnfumbs]

New lifters are comming tomorrow.
I will let you all know if things improve.

[fingersnfumbs]

So,
Nerw lifters fitted and it ran great until hot then one or two lifters started chirping-in.
No where near as bad as before.
Im going to put some miles on and see if things settle down.

[Graham]

So,
Nerw lifters fitted and it ran great until hot then one or two lifters started chirping-in.
No where near as bad as before.
Im going to put some miles on and see if things settle down.

what oil are you running it on?

[xpackboy]

Early 2wd heads had some oversize tappers , graham goode sell them that might be your problem , think it was the first 2 on the exhaust side , to look at them you would never know but yhe standard ones are sloppy in the hole

[fingersnfumbs]

what oil are you running it on?

Oil is 10W/40 at the moment.

Xpack, thanks for the heads-up re oversized lifters.
My new ones are a nice snug fit so I dont think its that. Also head is a 4wd.

Latest new is is starts of noisey for maybe 5-10 seconds then goes quiet befor tapping once up to temp.

Pulling my hair out over this.!

[stevieturbo]

have you tried ear plugs ?

[fingersnfumbs]

have you tried ear plugs ?

I did try ear plugs but they just blocked up the oilways.

[costina]

Oversize tappet bores are stamped on the back of the head.
What pistons?
You haven't timed it up like a pinto? Easy done....

[fingersnfumbs]

Oversize tappet bores are stamped on the back of the head.
What pistons?
You haven't timed it up like a pinto? Easy done....

Prety sure the tappet bores are standard as nice fit with no sloppiness. Also im not aware any of the 4x4 heads had oversize.
Defo no piston to valve clearence issues.

Cams are timed as per Newmans spec. i.e. 110 Deg.

Still noisy but intermitent.

Very annoying.