| Author |
Message |
Malcolm West (Ferrari_uk_tech)
Junior Member
Username: Ferrari_uk_tech
Post Number: 100
Registered: 7-2003
| | Posted on Wednesday, September 10, 2003 - 3:49 am: | |
Not only is it important to check the valve clearances, but equally important to check the condition of the cam lobes and tappet shims for any wear or case hardening problems - assuming the cam covers are off (they should be if you are having a belt service so as to verify the cam timing marks) checking the clearances would take no more than half an hour, replacing shims takes only a couple of minutes per shim so it's not that expensive in terms of labour it is probably more costly in terms of purchacing new shims. |
Bill Sebestyen (Bill308)
Member
Username: Bill308
Post Number: 528
Registered: 5-2001
| | Posted on Tuesday, September 09, 2003 - 8:01 pm: | |
Barry,
Before you turn your mechanic loose to set valve clearances ensure he has an impressive stock of shims available. Done properly, this process can be very time consuming. It's all a matter of shim availability and how good you want the clearances to be. I was bit anal on my 308 and got all clearances to near nominal values and recorded the clearances for each valve for future reference, including the measurement of the each shim thickness used for each valve. I now have a stock of about 60-shims, all pre measured, so the next time I do this it should go much quicker. I'll also have a good idea on how fast the clearances change. |
William Badurski (Billb)
Junior Member
Username: Billb
Post Number: 200
Registered: 6-2001
| | Posted on Tuesday, September 09, 2003 - 7:21 pm: | |
Valve clearance checks are important. The idea is to allow the valve to contact the seat long enough to transfer heat into the cylinder head, which of course is cooled. Too much clearance results in loss of performance and noise, while too little results in overheated valves and subsequent "burning" of the face. This is not a big job. |
Jeff Green (Carguy)
Member
Username: Carguy
Post Number: 503
Registered: 10-2002
| | Posted on Tuesday, September 09, 2003 - 4:06 pm: | |
Barry.....good points made by all so far. If the cam covers are already off, at least have him check the clearances. This is NOT that complicated and does not take hours to do. It would be good to at least have written documentation of what the clearances were. It does take some skill with feeler gages to get "correct" readings. If what you say about the super hard valve seats is correct, most likely no shim adjustments will be needed. From what you've said, it doesn't sound like the mechanic is too enthusiastic about doing it. If the cam covers are not off, and the car does not leak any oil anywhere, it's up to you. I would at least get them measured so I could sleep better at night. |
Mitch Alsup (Mitch_alsup)
Intermediate Member
Username: Mitch_alsup
Post Number: 1025
Registered: 4-2002
| | Posted on Tuesday, September 09, 2003 - 2:12 pm: | |
Getting the valve clearences checked and put right will:
A) make more power--trifflings
B) run smoother--as if a v12 can run smoother
C) run with less clattering in the engine bay
D) Will hold its tune better--wear out slower
E) it may even sound better!--intake resonances
Is it worth it? To me it would be, but I don't know about you, your asperations, and the love you have for this car, versus the money you have sitting in the bank..... |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 2097
Registered: 1-2001
| | Posted on Tuesday, September 09, 2003 - 1:12 pm: | |
1. Are you just doing tensioners and belts (i.e., the camcovers are not going to be removed)?
2. Any previous documented check/adjust done (like at some sort of 15K service)?
3. What's the recommendation in your 512TR OM? |
barry castelete (Bazzis)
New member
Username: Bazzis
Post Number: 25
Registered: 7-2002
| | Posted on Tuesday, September 09, 2003 - 12:17 pm: | |
Just having my 512TR cambelt service done,car has 30k miles. The mechanic wants to know whether I want my valve clearances checked? he tells me its a long job and quite expensive!but its up to me. Can anyone tell me what to do, I've been told that the valve seats on the 512TR were much harder than earlier Testarossas and dont require frequent checks, any advice would be very helpful, Many thanks, Barry Castle, UK. |