Rocker problem

[Sepi]

Engine is now driven only 270 km and I wanted to check valves as 3/4 side was quite noisy. First I found axial sideplay almost 0,8 mm in the middle for both inlet valves and wanted to add some shims. Soon I realised, something else was wrong as those 3 & 4 inlet valve Scat 1:1,4 rockers were seriously worned. Lubrication seems to be ok and I use Gulf 10-60 racing oil. It is just hard to believe as this is just bad luck. Anyone else have heard similar problems? Opinions to avoid this?

Engine has a mild JPM cam, lifters and alusticks. Scat lashcaps. DRD L 7 heads. Oilpump is Shadek 30 mm



#3 inlet rocker:

[modnrod]

Blue as well! That got hot. 

[richie]

Can you show picture of the adjuster screw end please? do you know how many turns the adjuster screws were out from all way in? its possible not enough as then the oilway is not open enough

[Sepi]

Yeah, hard to understand. All passes for oil are clear and when I opened the valvecover, oil spilled out as expected and if we think, usually 3/4 side will get oil propably more than 1/2 side.

These pics might give more ideas:





I cleaned #4 cylinder lash cap

[richie]

They really look like they didn't get enough lubrication to me, when you checked the oil holes did you check the hole in the adjuster screw aligned with the hole in the rocker arm? can you check how many turns the adjuster screw takes to be all the way out[so cup is against rocker arm] please

what is that on the lash cap on number 4 exhaust?

cheers Richie

[Fastbrit]

Are you certain you are not getting coil bind, or clearance issues between valve guide and retainer/collets? That wear looks pretty severe to me. But I also think your geometry is wrong and the adjusters need to be another two or three threads further in - oiling is possibly a problem, as Richie says.

[Sepi]

Richie!
It is exactly two turns and those holes align perfectly...

[Jim Ratto]

Are you certain you are not getting coil bind, or clearance issues between valve guide and retainer/collets? That wear looks pretty severe to me. But I also think your geometry is wrong and the adjusters need to be another two or three threads further in - oiling is possibly a problem, as Richie says.

Wear pattern on # 3 intake cap might indicate geometry is not correct, at least from picture. If the scuffer pad is wiping corner of lash cap (is it?) big problems will result.

[Sepi]

This was the view just after opening the valve cover of 3/4 side. There are some burned debris - maybe assembling grease or oil (270 kms only!) like the one on cyliner #4 lash cap. But as you can see the axle is really wet of oil. Engine cannot be overheating in any condition and harldy never gone over 4000 rpm



Both inlet valve rockers were out a bit as the side play was huge - maybe that caused something...

[jaqo]

I had the same problem with scat 1.25 rocker arms and scat lash caps - but I caught it earlier (after 30 mins od break in) so the damage wasn't so catastrophic. Besides similar looking wear  I also had the same rusty stains and some metal dust. After that I reshaped and polished the damaged rocker arms with 2000grit sand papaper, changed all the lash caps for the new ones and put a little bit of torco hp assembly lube on it - it looks like NEW now after 10 000km or more. Engine spec is scat c35, alum push rods, single hd springs
I think it could be either:
a)faulty material on the lash caps, or
b) since I didn't put any oil or grease on it when I did the assembly > it started to grind itself before any oil got there.
Oiling holes were aligned, there is plenty of oil squirting from between every rocker arm, geometry is spot on.

Maybe scat had a batch of faulty lash caps?

[Sepi]

I had the same problem with scat 1.25 rocker arms and scat lash caps - but I caught it earlier (after 30 mins od break in) so the damage wasn't so catastrophic. Besides similar looking wear  I also had the same rusty stains and some metal dust. After that I reshaped and polished the damaged rocker arms with 2000grit sand papaper, changed all the lash caps for the new ones and put a little bit of torco hp assembly lube on it - it looks like NEW now after 10 000km or more. Engine spec is scat c35, alum push rods, single hd springs
I think it could be either:
a)faulty material on the lash caps, or
b) since I didn't put any oil or grease on it when I did the assembly > it started to grind itself before any oil got there.
Oiling holes were aligned, there is plenty of oil squirting from between every rocker arm, geometry is spot on.

Maybe scat had a batch of faulty lash caps?

I'm also willing to believe there was a batch of some faulty rockers. The builder of this engine is propably the most reputable in Finland and yes, we are not playing with honda or To#¤ta, but an aircooled VW... New rockers are on the way

[Erlend / bug66]

When did you order the rockers?

I just got a set of Scat 1,4 rockers, and i could not see that they where hardened on the tips (blue)


Last sets I've seen has been blue.

[Sepi]

Engine was built during April - May 2012, but as my project took some years, the first start was done last year september with typical brake in and new oils & filter

[fish]

Looks like the large rocker pad contact area will create more heat due to incorrect rocker geometry and lack of direct oil lubrication/cooling, aligning the oil hole will only lubricate the shaft not the rocker pad.
Spray bars would be the only direct way to lubricate the rockers however the "Bob Hoover" lifter mod will provide more oil through the pushrods to the shafts and maybe the rocker itself if the rockers had oil divots on the sides.
Another way is to drill 1.5mm holes on side of the pushrods  providing rotating spray of oil.

You must have correct rocker geometry for any of this to work, the narrower the contact pad the better the geometry, there's a lot of reading material on the subject please study it carefully.

[Martin S.]

I remember Berg's instructions for setting geometry using his swivel feet adjusters was how many turns out from flush in the screws were supposed to be. I think it was one and a half turns out. In the pics we see here the adjusters look to be out almost all the way, like 10 turns or so. I guess that means the pushrods are too long, and/or there aren't enough spacers under the rocker shaft? Does that appear to be the problem with the setup? I remember having a difficult time deciding whether to use more spacers or shorten the pushrods.

[Jim Ratto]

Bill Fisher's HP Book has an excellent write up on how to set up valvetrain geometry.

[Sepi]

Of course we will check geometry when new rockers are here, but it is confusing still as exhaust valve rockers are ok

[Fiatdude]

I've got a set of Pauters in 1.4 that I need to make go away -- less than a 100 miles on them if your interested -- --

[j-f]

Of course we will check geometry when new rockers are here, but it is confusing still as exhaust valve rockers are ok

Maybe the cam is a split lobe? With less duration and lift on the exhaust?

[Jim Ratto]

Of course we will check geometry when new rockers are here, but it is confusing still as exhaust valve rockers are ok

Maybe the cam is a split lobe? With less duration and lift on the exhaust?

were valve stem heights all exactly the same? new heads, or refreshed heads with valve job?

[Sepi]

New DRD L 7 heads, but we will take measurements now as much as possible and compare the other 1/2 side head and rockers. That side is like new. New set of rockers are on the way, so next week we will know more

[Martin S.]

You can also check the surface hardness of the rocker itself by trying to scratch it with a file.

[max, Der Bahnstormerz]

Is it possible the valve is kissing the piston?