CB forged 1.3s....I need your take on this...

[norris]

About a month ago I replaced some AutoCraft 1.25s in my 2276 with new CB forged 1.3s. Some might remember the thread. I was quite pleased with the installation and geometry setup in that no shims were required under the stands and only minimal side play shimming was needed. I had new ACN HD tapered aluminum pushrods cut to fit and all was well.....I thought.

I put about 250 miles on the set up and decided to check the wear patterns on the rockers and pushrods. Much to my dismay, I found pitting on several of the rocker arm swipes. The wear patterns were good on both the lash caps and the rocker arms. No pitting or discoloration on the lash caps.

I contacted CB. After a couple of days of answering their questions via email they asked me to send the set back for "testing". A week later they replied stating that the rocker arms had been heat treated properly and they could not figure out what had happened. Rather than send me a new set they said they'd rather refund my money, which they did immediately. They said that if they sent me another set of rockers they would be just like the set I had returned.

Understand that this thread is not about flaming CB. As far as customer service, they did a good job. What is in question here is what the hell happened? If any of you guys have seen this before I would appreciate you sharing your knowledge.

Just as a note: I run Amsoil Signature 5w30...have for years...through a Berg blueprinted 30mm. Oil pressure is 15lbs at hot idle and 45lbs at cruise rpm.
I used Crane Cam moly assembly lube on all wear points on the rocker arms at assembly. I used the AutoCraft lash caps as they looked and fit much better than the CB caps(again, they are smooth as a mirror...no pitting)

Thanks for your expertise!

Here's a pic

[Dan Ruddock]

I have heard good things about scat rockers. Mark at CB told me the whole rocker is heat treated on the 1.3’s but on the 1.4’s only tips are treated. All this stuff is made in China and that is part of the problem. Dan

[norris]

Thanks Dan....I think you're right, Scats are next up.
Just bothering not to have a definitive answer on the CB failure.

[vwracerdave]

Just curious what do you have your idle RPM set at? What valve springs are you using? What cam?
_________________
2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK
Featured in Dec. 2001 HOT VW's Magazine page 63

Watch my racing video's http://www.youtube.com/user/okvwracer/videos

[jfats808]

Thanks for catching that. I have a set of new 1.3s I need to take a look at now. Cb carries and produces top notch parts. No doubt they are inspecting that last batch. Scat rocker assemblies are always a good pick.
_________________
2276 IDA's 86C 11-1 DD !
2017 48 Trijet DRLA's W125

[SRP1]

The problem is heat treat, period.
Nevertheless you had an awesome set of rockers on the engine before, IIRC there was a slight bearing problem, but how many miles did they run before that happened? What was the reason to change them out vs repair?
Me...I would have fixed the Autocraft rockers and moved on, set up and shimmed correctly they work great. I have a set on my car from 1992, still going, original parts. Maybe you had some other problem happen?

[norris]

[norris]

[SRP1]

Well that looks like an oiling problem, or the side play was to tight.
The Autocraft rockers need to run a just little loose, side play about .002-.003" and they need a little lash when cold. Reason being is they dont have the oiling galley that runs up the middle of the adjuster to the shaft, so they splash oil instead. Also if you run zero cold lash because your running chromoly push rods, then you have no splash oiling until the engine is up to temp and the lash opens up. Hence the bearing starves for oil.
Nothing wrong with splash oiling at all, many components of the engine are splash oiled, look at the cam, distributor drive, and wrist pins, all splash oiled.
I think the problem comes when things get set to tight and become starved for oil or expansion crom heat closes clearances and parts begin to seize. Again all heat/oil related, run it just a little loose and it will run years, makes for a little more noisy valve train but thats not a problem.

[FreeBug]

Pitting points to high stress, high pressures. Have you looked for any signs of valve float? Have you had a peek at the lifters?

[norris]

Another pic

[norris]

[vwracerdave]

With single valve springs I set the idle RPM at 800-850. With dual springs I set it at 950-1000 RPM. I personally feel it needs to be this high to get the proper oiling to the rockers.

CB knows what the problem is they just don't want to tell you.
_________________
2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK
Featured in Dec. 2001 HOT VW's Magazine page 63

Watch my racing video's http://www.youtube.com/user/okvwracer/videos

[norris]

[jpaull]

[jason]

Maybe they dont like your lash caps.

[Dan Ruddock]

I think if you don't see the tips black from flame heat treat like the CB 1.4's you might have a problem. I believe both 1.3 and 1.4 scats have the blackened tips.


Dan

[jpaull]

[jpaull]

[jfats808]