Sjödin Motorsport / ÅBM Racing

Ok, now about the camshaft / camshafts problem!…

Five years ago I bought 2 Hemi camshafts for 2 different customers from the same company and one broke / took out the distributor gear on the cam after just a couple of rounds, I got a new one on warranty ASAP which I really appreciated because the manufacturer assumed it must have been something wrong with it because he have never seen anything like this before and he wanted to help out if he sent a bad camshaft to me, really good customer service if you ask me!!

He also did some extra checking on the batch of camshaft he sent out to see if he could find anything that was wrong, but all was good and I also got some extra information on stuff to check measure and so on, all was good!

Put the cam in the motor, fired it up and took out the mag to check the distributor drive gear and camshaft gear, all was good, made a pass and took out the mag again and checked the gears, still all good! Customer made one more pass and the second cam I got on warranty broke also!… Just after a couple of rounds in the exactly the same way as the one before, they did have cam number BK144 and BK146. Manufacturer did some real checking to try find the problem / reason to this, but did not find out anything after a lot of work and research, everything was ok and by the spec to fabricate the gear / camshaft and so the second time I was told / we must do something wrong or it’s something wrong with the block / distributor drive which my customer have been using for a lot of years with different camshafts in it without any problem.

So, after that I did a lot of research on my end with BAE, AJPE, Noonan, CN and no one had ever seen anything like this. Checked with multiple racers and of course no one have seen anything like this before!

After that I got kind of disappointed because the manufacturer got kind of cocky and treated me wrong, at least that was my feeling! So I did order a cam with the exactly same spec from Bullet Racing Cams instead, did put in the cam and distributor foot / drive and tried to break it in with a drill and did that back and forward for a couple hours with the new cam and distributor gear and the problem disappeared after that! Then we kind of forgot about this problem and after that my customer have changed cam a couple of times due to hurt lobes etc and I have bought him new camshafts from Bullet that have been working without any problems at all!. So the cam changes after have nothing to do with the cam itself but still the important thing, no problem with the gear on cam or to the distributor after using the Bullet camshafts.

Answer from the manufacturer with the 2 broken cams when I told him that I changed brand on cam and now it’s all good was like “ok, if you have found a cam that works that’s good for you” And that wasn’t an answer I was happy with.

Funny thing is that I still have the BK144 and BK146 camshaft here at my shop because I felt 5 years ago that I was not really done with this and really not satisfied with what happened with the manufacturer and his answers to the problem!…

Now to the problem we have today, the camshaft that I bought together with number BK144 have number BK145 and that one went into Jörgens motor…. On that I tried to check all the measurements I was given from the manufacturer when cam BK144 broke to make sure it was all good, and it was so we did put it back in again!

After that his new car got delayed and during that time he got sick and will never be able to drive his brand new car (you have more about this in an earlier post) so he asked me to drive it for him to see it go down a track before selling it. And I have totally forgot I sold the BK145 camshaft to him 5 years ago… Made 2 test hits on Friday and all worked good, until Saturday morning when we warmed up the motor. Started just fine ran for 30 seconds or so and then went silent, checked spark and we did not have any and then I realized that we didn’t have any oil pressure, took of the cap and turned the motor and the rotor did not move….. Now I already knew what the problem was… I did remember the earlier cams that I finally had forgotten about…. Pulled the mag and the cam was damaged in the exactly same way as the two others!….

This is a completely different motor and customer, and I think that this is kind of strange that I got cam number 144,145 and 146 that brakes in the exact same way in 2 different motors and this have never happened before or after when I ask the manufacturer.

Only thing that was good this time is that it happened on idle and I held the trans brake button so it did not take out any other parts around except that a piece of the cam gear got pressed into the block by the crankshaft when the parts fell down.

The biggest difference between the 145 and the rest is that 145 have been fired up many times and probably made 40 minutes on idle due to different reasons now because Jörgen cant drive the car and because it took a lot of time to figure out the fuel system problems before the Tierp race…. Number 144 and 146 only made “normal” warm ups (number 146 got some extra checking after warm up) and passes, so I really don’t think it’s a gear / tooth problem here either….

But we are doing some measuring and comparing between the parts / tooth’s that came from Jörgens camshaft and one older Bullet cam that we did install in the motor that we damaged cams in five years ago.

And with the new Bullet cam that we now installed in Jörgens motor.

The gears on the ones that breaks is way wider, less room in the bottom between the tooth’s, and they are also not machined as nice as the Bullet cams as you can see yourself.

Then if that makes a difference? Well I’m not the one to tell for sure because I do not know, I do just see the differences between the cams..

I of course sent an email to the one that made cam BK145 with pics and explained that the same thing happened again!…. But I did not get any answer so I sent pictures to Bullet and asked them what they think and what the reason for this is, and I got the answer below.

“ The gear issue on the camshaft is from improper heat treating of the core. The camshaft was hardened too long making the gear brittle. No other possibilities. That is was the problem is! “

So, I sent below to the manufacturer of the broken cams,

When I didn’t get any answer from you about my email I had to send the pictures to another manufacturer because I’m kind of tired and frustrated over this situation that now been going on for 5 years. And they told me it must be improper heat treating.

The answer I got was kind of disappointing I must say… Below is a short part of what he said,

“I’m glad you have a resolution. It is pretty amazing they are able to diagnose hardness with a picture. They must be pretty special. I’m sure it wouldn’t be hard for you to find someone local to verify hardness.  When you do find, in fact, that the heat treat is in spec, maybe your other source will eat some humble pie.

 

And I must say that the answer made me kind of angry for the first time because being cocky in this situation does not make me happier!…. So now I will for sure do all I can to find the real problem with the 3 camshafts, like I said I still have all three in my shop and I have already installed a new camshaft from Bullet in Jörgens motor, in less than three weeks from today we will know if he Bullet cam will survive or not.

I’m pretty sure it will and then I will continue to find the real reason and I’m not afraid to argue when I know I’m right and now when they start to treat me like they do nothing can stop me to find the real problem!

Next is to find out how the heat treating should be, I know how hard it should be on the surface! But how far in in the core is the next thing to find out!

I will let you know for sure!