86 Testarossa Coupling on end of Cam

I am guessing then that they are drilling again. I saw the huge price increase and opted to instead to make the existing pieces solid. Only did it the one time. Was more work than expected so probably will not do again. It surprises me any are still out there. We were allowed to replace any we saw and Ferrari would pay. We did 100% of our customer cars. Same deal on the junk alternators in 348 and Mondial t. I guess other shops were not concerned enough to take care of their customers like that.

 

I think it would be easier for someone to make aluminum plugs that are a tight fit in the cam. They can be coated with a 518 type anaerobic sealant and put in behind the extension. The current price for the extensions is just absurd.

 

FYI….

Over 700usd

 

^__that was roughly the price I found too for the pre-drilled ones, but the ones *not* pre-drilled that I bought were closer to $175 IIRC.

 

I got mine drilled at a local machine shop for 20 dollars.

 

I let it burn itself out. You need to keep inner and outer indexed and the inner straight and centered. Kind of tricky. If you wanted to take it apart and build a bushing to take up the space occupied by the rubber then weld/solder/braze it all together better still but I was looking at a cost saving method, not a big project. Hence my comment about just plugging the cam behind the extension would be an easy, cost effective solution. .


By the way, the current US price for 133063 is currently just under $1000.

 

Interesting. I bought that same part number for approximately the same price from the same supplier last year and it was not drilled.

 

Hi,

just want to revive this somewhat older thread. I am in the process of a major and have the cams out. Funny enough I recognized that one cam was already equipped with 133063 but the other cam had 129121 (not even 126166). Obviously I had an oil leak in the distributor housing where 129121 was fitted. One reason was definitely a not properly sealing oil seal that was actually burned a bit and left oil out. So I am not certain if 129121 with that rubber seal failed. But as the cams are out I would like to act and stop the leaking or any future occurance. As Brian mentioned, I am also not willing to pay 1.000€/$ for that stupid 133063. Has anyone tried to "fix" the original 129121?

Also the question on how do I get the current extension separated from the cam?
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Just pop out that dowel pin with a punch and the part it just pressed into there. It wiggles out with some persuasion. I just used a pair of channel locks on my old one since it was already toast. However, you need the old one to get the proper hole drilled if the one you buy does not have a hole pre drilled.

 

And that is exactly where it leaks. It’s a two piece part.

 

The good news is that 133063 is down to ~$770US at MCP .

(F really got a little too tricky/risky on the original design -- never understood what "problem" that they were trying to solve, and, after 308 going thru the same design evolution in that area to prevent oil leaks, why they ever went back to a similar situation with a rubber component being relied on to seal thing up.)

 

Thanks guys! Seems easy to get that thing out. But there is no way I spend 1000$ for that little thing (700$ plus tax and shipping from US or UK brings me to 1000$).
I am actually thinking about the solution from Brian to block the cam. I don't get why that extension in hollow anyways...

 

Ridiculous... I got a quote from a German parts dealer for a USED 133063 of 750€... It' just a eff'in metal piece that has no special function.

 

During 308QV production Magnetti Marelli changed the plastic compound for the ignition rotors and we had a lot of problems with a break down of the electrical insulation properties allowing a direct short between the carbon contact and the end of the cam. It was a big issue for a while. Finally Ferrari got MM to spend the extra 2 cents per rotor to go back to the old plastic but in that period it cost Ferrari a bundle.

Some rocket scientist decided to avoid future problems by eliminating the metal clip that held the rotor to the cam and designed the screw on rotor for the TR and 3.2 motors. Well those used junk plastic too and on long high RPM dyno runs the torsional vibration of the cams caused the plastic to fracture and the rotors fell off. Further rocket science led them to decide the cure for that was to redesign the cam extensions with a rubber vibration damper and those went into production. Within just a few months it became obvious that was a bad fix because we had profuse oil leaks at the distributors. Ferrari tried a few fixes, none of which worked and finally threw up their hands and just made solid extensions and improved the plastic compound for the rotors. That process from start to finish took 3 or more years and cost Ferrari a fortune all because MM went to a cheap plastic on rotors.

The leaky distributors was one of the reasons the TRs earned the nickname in the dealers as "Liberian Tankers".

 

Hi Brian,

thanks for chiming in and giving some history on those stupid distributor assemblies! It's amazing that this design error is still a topic almost 40 years after being "produced".

This extension looks really simple and I am wondering how difficult it would be to reproduce? It probably does not need to be hollow and also it just needs the threads for the ignition rotors in the front. Just fabricate one off of steel and that's it?

The second option would be to bring back to live to old one with the plastic inserts and block the oil feed at the cam as Brian described it.

Here is how my distributor cap looked like... Obviously the owner before me already had that leak... I am still surprised that the rear bank got some sparks to run the engine smoothly.

 

It was actually one of the few times in memory Ferrari screwed something up and did not blame the mechanics as is their go to excuse.

All that really needs to be done is remove the extension, measure the I.D. of the cam and make an aluminum plug at near the ID. Clean the bore, put a little anerobic sealant on the plug and drive it in just far enough to leave room for the extension then reinstall it.

I am guessing that cap is from a 3.2 motor.

 

Yes, spot on - it's a 3.2 Mondi... For a TR some posts would be missing. :-D
But as parts are the same and this thread already existed I sneaked in TR territory... ;-)

Okay, convinced... I'll try that aluminum plug. Thanks for the advice. Any proceedings I will post here...

 

a testarossa with a 4 cylinder bank???

oh, have not read your next post before I was writing

 

Here are some pics of the base scenario... The aluminum plug for the camshaft should measure somewhat of 1cm. I'll post and update soom.
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I think putting a plug in the small diameter would be an exceedingly bad idea. If it manages ti migrate down the bore of the cam it will block oil to bearings. Put it in the larger diameter pressed up against the step.