Cylinder heads, too much metal removed.

Shims and or multiple head gaskets...

That sort of machine shop misadventure is going to be pretty "expensive", no matter how one choses to interpret the double entendre...

I'm actually sort of stunned to hear somebody on this site say this "out loud" as a serious and or legitimate repair process of ANY wet liner block-let alone a Ferrari block...honestly...

 

Basically you have to true both surfaces and use something like this:

http://www.headgasket.com/gaskets.html

or pay quite a bit to have metal added by someone who REALLY know's what they're doing with Plasma.

 

Or Cold Spray... it doesn't have nearly the heat of plasma so the risk of damaging the substrate is quite possibly nonexistent.

http://www.supersonicspray.com/index.php

[ame]http://www.youtube.com/watch?v=rnZc8lJcd9s[/ame]
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A cylinder head warped on our early MB190 baby benz. One year of production on that head. Unobtainium.
There was/is a guy that advertises in Hemmings that can straighten out the head then machine it true. This was years ago so dont have the info. He may still be there. Worked great even after my local idiot machinist screwed it up "beyond specs".
Custom made copper head gasket to the proper thickness may be another option.
Or larger seating area on the valves.
More/better oil to the guides ?
Run a cooler thermostat ?
These are internal combustion engines. What works on a Chevy works on a Ferrari.
Not magical entities.
Blasphemy I know

 

Cool site, and in general terms, relatively staright forward and accurate-relatively...

Ferrari wet liner blocks with a specified, PREFERRED{see WS manual section}, protrusion of .09MM{range is .07-.11MM, in an era of unobtainium, asbestos based, crush material surrounding the fire rings...
as the materials moved into "green" non-asbestos materials...crushability became a far more precise affair...
I machine ALL blocks to specified m id point-this requires huge in crease in cost and effort...huge...but, it ALWAYS has worked for ME...admittedly, there is more to the story than thism and I do machining of these things for a living...so I can't afford to commit an error in judgement, or an omission of previously non discussed minutia....

Spray welding-as we call it-is not an appropriate sufaced finish when process completed-INMHO...there are those out there who disagree, NO PROBLEM...what I think they are really doing is welding while the heads are "loaded"...very slow, costly and accurate...final arbiter of success are the x-rays and sonic tests for density...consistency...

You can fix ANYTHING-SO LONG AS THE M ONEY IS AVAILABLE-THE TECHNOLOGY EXISTS TO FIX ANYTHING ON ANY CAR...

its ONLY about the money!
CIAO!

 

What would you do with a head that had been over milled but was original? Would you use an over sized gasket like the one I referenced or attempt "spray welding"?

Even though I have a set of NOS heads which I haven't fitted, one of my cars has one over milled head (It was like that when I bought it) and it's now using two head gaskets and working fine. I like that head because it's original and has some nice history and stamps.

Best

 

Call Denny at Nicksons Machine.
He has vacuum chambers, and plasma.
He is FAA certified, and works on aluminum aircraft motors.
He is currently rebuilding a 1964 330 motor.
(805) 925-2525



Edwardo

 

I read this thread, and I see that you are in Saudi Arabia, and that changes everything, I say that because I have NO idea what sort of local engineering, machining, and welding talent you have there.

Here in Southern California, we have a great automotive aftermarket industry, and we have many expert machinists, engineers, Ferrari mechanics, welders, etc.

If you cannot make the 2 head gasket idea work, then I think you are going to have to send the heads here to Calif. to get them fixed.

I suggest you contact Steve Tillac at Fast Cars Inc. in Redondo Beach and ask his opinion, they have a fabulous state of the art CNC machine shop and can probably fix anything, and he is a F-Chat sponsor.

I suspect the best thing to do is to have his shop refurbish the heads to spec, he can get it done. That's a tricky job for sure.

 

Thanks. I have sources as well but as it's worked fine for several years and many races so for the time being I'm going to leave it as it is.

My question for 335S is when the day comes to rebuild should I use a thicker head gasket or build it up with metal?

Best

 

Some years back we took a bead blast cabinet, silicone sealed it ait tight and installed a 2' x 2' welding lens in the window. Plumbed 2 bottles of Argon to the cabinet, placed a pizza oven new to the cabinet and pulled up a bar stool to sit on.

More than a few priceless Lampredi and Colombo heads saw complete surface build ups to rectify poorly thought out machine shop techniques... it's doable. Surely the metal spray technique has evolved to a point where this process would be less traumatic than welding but I have very limited experience with that technique. That said, there are a few 250 race cars running around to this day with completely welded head surfaces.... talk about a pucker up job! As long as a pair of gaskets is holding the pressures in check I find it hard to justify persuing radical repairs... dont fix what aint broken would be my thoughts.

 

Dave,

I would have liked to seen that done! Remember on a past post you talked about wise old mechanics with the "twitches" and "clumps of hair" missing? OK...I know how you got that way now...

 

Thanks.

 

I've done this kind of repair as well. The tricky part is keeping the cam bearings all in a straight line.

 

That would be the second most un-nerving welding job I have done in this field, the first I refuse to even talk about but it worked and is intact to this day. What the heck, I am just following the Masters of triage, the generation that refused to quit.

I watched the McClaren crew search the paddock area for a scrap of aluminum to weld over the hole in the side of a Renolds aluminum BBC out of a M8 at Road America. My USRRC Lotus 19 Harrison Special has a story that follows it of damage to the magnesium Colotti Gearbox being repaired with popsicle sticks and epoxy with the car tipped on its side, balancing on the outside of its wheels so the oil ran away from the hole. I have photo's of that being done and the next day it went on to win the Kent Grand Prix. I kinda figured if those guys could do that.... never say die.... we used the ultra fine sand from the camping area at RA to lap in valves that were bent and re straightened over a wood stump. Its all a matter of how far did you tow and where did you place on the grid for the next days race. Where there is a want, there is a way.

Re straightening the heads was the easy part. I had a 3 ft x 8" hard steel strap ground to the correct radius on one edge and clamped the head to a granite surface plate. Handed the whole affair to the heat treater and prayed. It is at this point where one finds the reasons Ferrari chose the valve seat material they did. Matched thermo expansion rates are an important factor that few consider. Surely by now the metal spray technology has advanced to where this lunacy is no longer needed.

Since that day I have done a few C Type Jaguar heads, one that a machine shop resurfaced .250" yet never considered what the poor cam had to do with that bore not corrected. Lets just say cylinders 1 and 6 were operating well into the diesel CR range.

Nothing is impossible when the value of a saved part is what it is on these important vintage cars. Justifiability is in the eyes of the owner, practicality is a highly debatable topic. I remember identifying the foam seal on the viewing glass of the blast cabinet not sealing well enough and damn near passing out due to Argon leaks in that area. Just when you thought you had made every stupid mistake possible.... "Wise" doesnt belong in the discussion Fatso.

 

Great stuff. More, please. If you should choose to write a book I will buy it.

 

+1

 

I imagine, too, that your double-head-gasket solution is in line with what the factory/any number of race teams would have done once upon a time. In a way, there's a pleasing authenticity to it....