All: Reading previous posts, it seems like mileage, not time, is the determining factor for valve adjustment intervals. My father in law (who is mechanically knowledgeable but does not have experience with Ferraris) said it "sounds" like you need to adjust your valves when we were riding in my Dino. Is this something that a trained ear can hear? Or is it possible that he just doesn't recognize the valve noise of a 246GT. I believe the valves would have been adjusted when the motor was rebuilt 5+ years ago but I am checking to see if I can determine how many miles have clicked off. Here is the problem. My Dino is highly modified (I will post some stats and pics later) and I am not sure what camshafts are in the car. If they are not marked, they will have to be measured (which could be very expensive). My local Ferrari shop thinks it will cost around $2,600 to adjust the valves. Does this seem reasonable? I appreciate any help the group can provide on this topic. Joe
mileage is definitely the over-riding factor in valve shim clearance but badly adjusted shims do wear out cams very (very) quickly. Its difficult to assess if they need adjustment from sound alone, the mechanical noise from the cam area makes it impossible to identify. More likely to be loose chains which can be adjusted without removing the cam covers. Cost seems expensive to me, I take about 8hrs to do mine, can be done quicker if you don't stop for too many cups of tea!! Shims are now expensive if you need to replace, a full set can cost £100. I flip mine over at each service, but once you have done this once then they need to be thrown away next time. If you don't know the current status, ie if they have been used before, then replacement is a must.
I would adjust the chains first as mentioned by Tony. It is a 5 minutes job and must be done a few thousand miles after renovation anyway. I adjusted the chains in my dino this summer and noticed a significant reduction in engine noise and this was approximately 5000 km after engine overhaul . Best regards Peter
Good news. I found the latest engine rebuild (from 2 owners ago) for my Dino. While it was done back in 2011, it was only 1,700 miles ago. The valves should be just fine for a few years. I’m going to have the chains adjusted as well as the cold idle reset. Thanks for everyone’s help. Joe
I agree with this. And I had to change out my tensioner very early in the engine's life as well. The chains do appear to stretch.
You still may want to consider to check your valve clearance. I understand your engine (including heads?) has been rebuild 1,700 miles ago. In the first miles we discover the clearance to change relatively strong so the check is part of our standard "brake in service". Usualy the clearance shrinks on the Dino engines so this is nothing you could detect by noise.
Great. The entire group tells me that I have nothing to worry about and now you tell me I have something to worry about :-(
what I was suggesting is that you adjust the chains to see if that eliminates the noise you referred to, after that you can make a judgement on the valve shims. You cannot bypass sound maintenance intervals, shims are checked every 3000 miles under normal conditions/service intervals. If the noise is still there after you have adjusted the chains, then you need to investigate further.
Don't put me on the gallows. It is nothing to worry about, just something you need to check somewhere in the next few hundret miles. Also no rocket science in case you like to put your own hands on. Btw.: have oil and filter been changed since engine overhaul?
Yes, and the heads were re-torqued. It is difficult to know what to do. It is not an inexpensive endeavor. The manuals/books/most in the group say to adjust valves every 6,000+ miles with no limit on time.
It would be surprising to me if one would re-torque the heads but not check valve clearance while the head covers are off. Maybe the shop who did the job can confirm?
I think most questions are ansered there: https://www.ferrarichat.com/forum/threads/timing-chain-noise.286660/
Inspecting valvole clearance is 2-3 hrs total but you need neu valve cover gaskets. Bump engine to cam lobe, use feeler gauge, take measurement. No need to buy a full set that cost £100, at the most you will need a maximum of 12 and from your measurement you determine that size to buy. The simple bucket style is easy like Alfa so you can call the Alfa ricambi and ask for 33m diameter shims in your size. Especially check Cylinder #5, exhaust valvole center forward as the most heat