Valve Guides and Older V12bs

What are valve guides? How hard are they to replace in older V12 Ferrari's. If the car has some light smoke, supposedly indicating worn valve guides, is there any harm to the engine other than moderate plug fouling?

The reason I ask is that there is a 330GTC on e-bay that appears to have this problem. I think I'm more curious than interested. Here is the link. http://cgi.ebay.com/ebaymotors/ws/eB...;category=6212

Hi Drew,

Valve Guides are inserts in the cylinder heads that the valves run in. In the case of the 330's they are bronze.

To replace the guides the heads must come off the engine. This can possibly be done with the engine in the car. One caveat to this though is if the heads have never been off the engine they will more than likely be stuck tighter than the gates of hell. To remove such heads requires a special puller plate and loads of work & patience. The plates are custom made, I have such a puller I had made many years ago, for just such problem heads. If the heads have been off within the last 5-10 yrs and anti-corrosion steps were taken then pulling is much more striaghtforward.

While the smoking "may be" valve guides, 35 years of dry starting & sitting may have taken their toll on the rings also, if the engine has never been done.

Additionally, the valve adjust screws, cams and rocker arm rollers and pins were subject to issues on the 330's.

In essence if none of the above have been repaired, serviced, replaced in the last 10 yrs or so, a Valve Job/Guide Job can add up to some hefty $$$$$$.

From the photos I saw the plug wires look older than Methusala. What about other service?

Regards, JRV

Drew,

a few more thoughts occured to me on the smoking.

The 330's are also well known to have Carb Throttle Shaft & Base Warpedge issues and I've seen a fair number of cars that had been bandaided by making them run rich to mask the intake air leaks. This rich running condition will also add to or create smoking issues.

Regards, JRV

Experience with 1972 C4 and valve guides

When I purchased it, it smoked when fired up, also smoked on deceleration. This situation progressively got worse in the 2000 miles I put on it. At that point it became embarrassing to drive.

I took the engine out, pulled the heads and found valves the wobbled in the guides and one valve that was slightly bent. JRV – I wondered what the guides were made of, I thought it was copper. My speedo indicated 40,000 miles and the guides were shot – seemed like a lot of ware for the mileage.

I did the valve job thing among others. The seats were serviceable. Concours in southern CA fabricated a set of stainless valves, silicon bronze guides and BMW style valve seals - $1700.00. The seat grinding and head machine work was done locally (Grass Valley CA.) and would run about $2000 now. What I got back was assembled heads with valve clearances set, cams at #1TDC position, ready to install on the engine.

The biggest surprise in doing the heads was the price variations of the head gaskets – wow! If you go this route, you really want to shop for gaskets – I tend to like GT Car Parts and Rutlands.

I now have 15,000 miles on the rebuild – no oil smoke, and the car out performs all the published specifications –

This is my first Ferrari, it has been just plan fun!

Aaron

Thanks, that's pretty much what I thought.

Another question? Why aren't bronze liners used in this application if the guide isn't that bad such that you can ream it out? Or does the head have to come off to install the liners and if you have done that you might as well replace the guide?

I'm not interested in this particular car but am still debating whether to buy a 330/365GTC or Daytona next year.

Hi Drew,

guides are to small for liners and they deform under heat and pressure as it is, because they are simply pressed into the heads. The fix is to remove heads and press out the old guides and replace with newer version Bronze Silicone Guides w/seals, and reem/hone to spec, complete the rest of the valve job and replace the heads.

Regards, JRV

>>To remove such heads requires a special puller plate and loads of work &amp; patience. The plates are custom made, I have such a puller I had made many years ago, for just such problem heads. <<

How does such a puller plate look like? I have no idea.

Regards Harry

Hi Harry,

I'll try to post a pic of the tool tonight.

Regards, JRV

Pics of JR's head puller.

This thing is MASSIVE! He asked me to take pictures and post this. He was at the time too busy messing with carbs on a Maserati Bora. Those things are sweeeet!

Anyway, without further ado...





Cheers

Hi Guys,

thanks Taek.

Anyone considering taking old V12 2 cam motors apart I reccomend "The Plate".

Yes it's massive...I strongly reccomend against cheap plates.

Regards, JRV